bluuebunny/crossref_metadata_2025 huggingface dataset:
MO016CD28 AS A MARKER OF T CELL IMMUNOSENESCENCE IN PATIENTS ON HEMODIALYSIS
Authors: Lioulios Georgios , Sampani Erasmia , Daikidou Dimitra Vasileia , Xochelli Aliki , Kasimatis Efstratios , Mitsoglou Zoi , Stangou Maria , Fylaktou Asimina , Papagianni Aikaterini
Published: May 2021

Background and Aims

Reduced expression of CD28 molecule on CD4+ and CD8+ cells is a potential marker of senescence and has also been described in end stage renal disease (ESRD). Aim of the present study was to evaluate changes of CD28 expression on CD4+ and CD8+ cells in ESRD patients, and to assess possible effects of ageing and HD.

Method

Flow cytometric analysis was performed in 96 patients [M/F 54/42 Age 56.6(18-81)yrs] on HD to evaluate the expression of CD28 antigen on CD4+ and CD8+ cells. Proportions and absolute numbers of CD4+CD28null and CD8+CD28null cells were estimated, and results were correlated to patients age and time on HD. Patients with malignant or systemic disease were excluded, as those with inadequate HD (KT/V<1,2), or recent (<3months) infection. Results were compared to those of 27 healthy controls, similar age, sex, and race.

Results

HD patients had significantly reduced lymphocyte count (p<0.001), percentage and total count of CD3+ cells (p=0.04, p<0.0001, respectively) and CD4+ cells (p=0.005, p<0.001, respectively). Percentage of CD4+CD28null and CD8+CD28null cells were both increased in patients compared to controls (p=0.009, p=0.01, respectively). However, although changes in CD8CD28null cells were evident early, even in <2yrs, similar changes in CD4CD28null cells, appeared only after ≥2yrs on HD, (p=0.004).

Age of the patients had significant correlation with CD8+CD28null cells (r=0.4, p=0.001). In the older groups (>40yrs) patients had significantly increased CD3+CD28null, CD4+CD28null and CD8+CD28null cells, compared to older controls (p=0.002, p=0.003, p=0.01, respectively).

Conclusion

CD28 expression is significantly reduced on CD4+ and CD8+ cells in HD patients. CD8+CD28null expression is significantly affected early, both by age and HD, while CD28 expression on CD4+ seems to be more stable, as CD4+CD28null cells increase in older patients, after long time on HD.
MO017THERAPEUTICAL POTENTIAL OF ENZYME REPLACEMENT: NEW INSIGHTS AND PERSPECTIVES IN HUMAN ENDOTHELIAL CELLS TREATED WITH CHLOROQUINE
Authors: Gregorio Paulo C , Cunha Regiane , Biagini Gilson , Bosquetti Bruna , Budag Julia , Ortiz Alberto , Sanchez-Nino Maria Dolores , Barreto Fellype , Stinghen Andréa E M
Published: May 2021

Background and Aims

COVID-19 is a pandemic with no end in sight. There is only one approved antiviral agent but global stocks are deemed insufficient. Despite in vitro antiviral activity, clinical trials of chloroquine and hydroxychloroquine were disappointing, and they may even impair outcomes. Chloroquine causes zebroid deposits reminiscent of Fabry disease (α-galactosidase A deficiency) and endothelial cells are key targets of COVID-19. The study aims to investigate in vitro the effect of enzyme replacement therapy (ERT) in chloroquine-induced endothelial dysfunction.

Method

We have explored the effect of chloroquine on cultured endothelial cells and its modulation by recombinant α-galactosidase A (agalsidase-β). Following dose-response studies, 0.5 μg/mL chloroquine was added to cultured human endothelial cells. Neutral red and Lysotracker were used to assess lysosomes. Cytotoxicity was evaluated by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) - MTT assay and cell stress by assessing reactive oxygen species (ROS) and nitric oxide (NO). In endothelial cells, chloroquine induced dose-dependent cytotoxicity at in vitro test concentrations for COVID-19 therapy.

Results

Chloroquine significantly induced the accumulation of acid organelles (P<0.05), increased ROS levels, and decreased NO production (P<0.05), in vitro. These adverse effects of chloroquine on endothelial cell biology were decreased by agalsidase-β (P<0.05).

Conclusion

Chloroquine-induced endothelial cell cytotoxicity and stress is attenuated by agalsidase-β treatment. This suggests that endothelial cell injury may contribute to the failure of chloroquine as therapy for COVID-19 and may be at least in part related to causing dysfunction of the lysosomal enzyme α-galactosidase A.
MO013SENESCENCE-LIKE CHANGES IN B CELL PHENOTYPE IN HEMODIALYSIS PATIENTS
Authors: Lioulios Georgios , Fylaktou Asimina , Xochelli Aliki , Sampani Erasmia , Tsouchnikas Ioannis , Giamalis Panagiotis , Daikidou Dimitra Vasileia , Mitsoglou Zoi , Papagianni Aikaterini , Stangou Maria
Published: May 2021

Background and Aims

End Stage Renal Disease (ESRD) is characterized by susceptibility to infections, high prevalence of cancer and cardiovascular disease and poor response to vaccination. All of the above are potential consequences to compromised immune function seen in ESRD and demonstrated by profound immune cells phenotype changes, resembling the natural course of senescence; therefore termed immunosenescence. Whereas alterations of T cells in ESRD have been largely studied, there are insufficient data regarding B cell immunity. In this study we evaluate the effects of hemodialysis (HD) on B cells, in terms of untimely expression of immunosenescent phenotype.

Method

B cells phenotype was analyzed by flow cytometry in 25 ESRD patients on HD (M/F 15/10, Mean Age 59±14.7yrs). Patients on HD with systemic diseases, malignancy or recent (<3 months) episode of infection were excluded. Subpopulations, including naïve (IgD+CD27-), IgM memory (IgD+CD27+), switched memory (IgD-CD27+) and late memory (IgD-CD27-) B cells were determined. Findings were compared to 12 healthy controls of similar age.

Results

In HD patients a severe B lymphopenia was observed; a decrease in B cells both percentage (6.5±2.7% vs 11.9±4.5%, p<0.0001) and absolute number [88(53) vs 229(271) cells/μl, p<0.0001]. Naïve and late memory B cells proportions were similar between patients and controls, however, absolute number was significantly lower in HD patients for both subsets [55(54)vs118(216) cells/μl, p=0.006, and 7(7) vs 21(24) cells/μl, respectively, p=0.001]. Switched memory B cells declined in HD both in terms of percentage [15.7(11.7)% vs 25.7(18.9)%, p:0.03] and absolute number [13(10) vs 59(64) cells/μl, p=0.00].

Conclusion

Chronic hemodialysis results in B cell phenotype alterations similar to normal aging. Switched memory B cells, the predictors of optimal antibody responses are significantly reduced, and this may act as an additional factor to relative immune deficiency of dialysis patients.
MO038SCARF EXPRESSION IN KIDNEY DISEASE
Authors: Carriazo Sol , Sanchez-Nino Maria Dolores , Perez Gomez Maria Vanessa , Castañeda-Infante Laura , Martin Catalina , Gonzalez-Martin Guillermo , Gomá Elena , Gonzalez-Rivera Marina , Ortiz Alberto
Published: May 2021

Background and Aims

Chronic kidney disease (CKD) is the most common risk factor for lethal COVID19 and the risk factor that most increases the risk of death of COVID19 patients. Additionally, acute kidney injury (AKI) is frequent in COVID19 and AKI increases the risk of death. However, the underlying cellular and molecular mechanisms of such increased risk are unclear. SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs) are required for and/or regulate (in a positive or negative manner) coronary cell entry and/or viral replication. We have now studied changes in the expression of genes encoding for SCARF in the context of acute and chronic kidney disease.

Method

Data mining of in-house (experimental models of AKI -folic acid nephropathy- and CKD -Unilateral ureteral obstruction- in mice) and publicly available databases (Nephroseq, published single cell transcriptomics studies) of kidney tissue transcriptomics as well as the Protein Atlas database.

Results

Out of 28 SCARF genes identified by Singh et al (Cell Reports 2020), 26 were represented in the experimental AKI database. Of them 7 (27%) were differentially expressed during AKI (FDR <0.05), 4 of them upregulated and 3 downregulated (Figure 1.A). Additionally, 27 were represented in the experimental CKD database. Of them 17 (63%) were differentially expressed during experimental CKD, 6 of them upregulated and 11 downregulated (Figure 1.B). Two genes were consistently upregulated (Ctsl and Ifitm3) and two consistently downregulated (Tmprss2 and Top3b) in both experimental AKI and CKD (Figure 1.A and B). They encode cathepsin L, interferon induced transmembrane protein 3, transmembrane serine protease 2, DNA topoisomerase III beta, respectively. Single cell transcriptomics databases localized Ctsl expression mainly to podocytes and tubular cells while protein atlas showed clear tubular staining. The main site of Ifitm3 was endothelium in both datasets and it was also localized to leukocytes by single cell transcriptomics. Tmprss2 was mainly localized to tubular cells in both datasets while Top3b was widely expressed in parenchymal renal cells, endothelium and leucocytes in single cell transcriptomics. Increased kidney expression of Ifitm3 and decreased expression of Tmprss2 and Top3b were confirmed in diverse CKD datasets in Nephroseq.

Conclusion

Both AKI and CKD are associated with differential expression of SCARF genes in kidney tissue, the impact of CKD appearing to be larger. Characterization of these changes and their functional impact in kidney tissue and beyond the kidneys may provide clues to the increased risk of severe or lethal COVID19 in kidney disease patients.

Kidney SCARF gene expression
MO039IDENTIFICATION OF A RECURRENT SYNONYMOUS GENETIC VARIANT IN NPHP3 LEADING TO NEPHRONOPHTHISIS AND CONGENITAL HEPATIC FIBROSIS
Authors: Olinger Eric , Al Alawi Intisar , Molinari Elisa , Ali Faqeih Eissa , Al Hamed Mohamed , Barroso-Gil Miguel , Wilson Ian , Research Consortium Genomics England , Sayer John
Published: May 2021

Background and Aims

Whole exome sequencing (WES) is becoming part of routine clinical and diagnostic practice and has been extensively applied in research studies as well as for diagnostic utility to detect various novel genes and variants. Filtering of variants and scoring variants in terms of pathogenicity still represents a major challenge and may explain why ∼50% of patients remain without diagnosis after initial assessment.

Method

In this study, we performed WES to determine the genetic cause of a hepato-renal ciliopathy syndrome in a genetically unsolved consanguineous family from Oman with 2 affected children. For variants filtering and annotation Qiagen Clinical Insight tool was used. Database searches for identical alleles in patients with similar phenotypes were performed using Genomics England, UK Biobank and a Saudi Arabian cohort. RNA studies were used to confirm a splicing defect. This research was made possible through access to the data and findings generated by the 100,000 Genomes Project and from UK Biobank, a major biomedical database.

Results

Initial bioinformatic analysis of WES data from 2 affected sibs excluded obvious pathogenic variants in known genes associated with primary ciliopathy syndromes with liver and kidney phenotypes. However, by manual curation of variants in candidate genes, a rare homozygous synonymous allele in NPHP3 was identified (c.2805C>T; p.(Gly935Gly)), mid-exon 20 and within a region of shared homozygosity on chromosome 3. Correct segregation was confirmed via Sanger sequencing in the parents and the 2 affected sibs. The variant was rare in gnomAD (2/251374 alleles) and was found heterozygously in just one individual within the UK Biobank cohort of 200,000 exomes. Using various in silico tools, the allele was shown to activate a cryptic splice donor site in the middle of exon 20. RT-PCR with sequencing of parental whole blood RNA confirmed alternative splicing leading to frameshift p.Gly935GlyfsTer47. The identical homozygous allele was identified in 2 additional unsolved families within the Genomics England 100,000 Genomes Project and in 1 Saudi Arabian family with similar hepato-renal phenotypes.

Conclusion

This study shows that automated filtering of WES data may exclude synonymous variants which are pathogenic, especially if they are mid-exon. Here we identified a recurrent synonymous NPHP3 variant leading to a splice defect as the cause of a hepato-renal ciliopathy phenotype in four families. In unsolved cases, rare synonymous alleles in candidate genes need to be reassessed for impact on RNA splicing and possible pathogenicity.
MO040REAL-WORLD USE OF TOLVAPTAN AND ITS IMPACT ON EGFR IN A NORTH EAST UK COHORT
Authors: Gkekas Eleftherios , Tang Tsz Yau Tiffany , Green Alan , Davidson Han , Fraser Rachel , Sayer John , Srivastava Shalabh
Published: May 2021

Background and Aims

Autosomal dominant polycystic kidney disease (ADPKD) is a cause of progressive chronic kidney failure (CKD) and end stage kidney disease (ESKD). Tolvaptan has been shown within clinical trials to slow down decline of kidney function in patients with ADPKD at risk of rapid progression. We performed a retrospective review of a cohort of ADPKD patients who had been established on tolvaptan therapy to determine its efficacy in a real- world clinic setting.

Method

Subjects who had a clinical diagnosis of ADPKD and who had been established on tolvaptan for a period of >18 months were reviewed retrospectively in terms of their eGFR. Subjects were between the ages of 18-65 years old and both males and females were included in this study. Other inclusion criteria involved a pre-treatment slope of <-2.5 ml/min/1.73m2 based on readings for a 3 year period, a pre-treatment eGFR of 30-90 ml/min/1.73m2 and ability to tolerate tolvaptan treatment and be maintained on treatment for at least12 months. We calculated based on eGFR slopes, predicted time to reach CKD stage 5 with and without tolvaptan therapy. Given this was a retrospective review, eGFR were estimated during clinic visits whilst on tolvaptan treatment, rather than after a drug washout period.

Results

The cohort of patients included 20 from Newcastle upon Tyne Hospitals and 2 from Sunderland Royal Infirmary. The mean rate of eGFR decline prior to treatment was -5.92 ml/min/1.73m2 per year for the cohort. Following tolvaptan treatment, the average decline in eGFR was reduced to -2.57 ml/min/1.73m2 per year. Therefore, tolvaptan lessened average eGFR decline within this cohort by 3.35 ml/min/1.73m2 per year, gaining 7 years and 9 months delay until CKD stage 5. The majority of patients (n=19) received full dose tolvaptan (90mg/30mg). At an individual level, 3 patients failed to respond at all to tolvaptan, with no improvement in decline of GFR and 2 others had a very mild improvement only (change in eGFR slope of <0.5 ml/min/1.73m2 per year). 6 patients had a dramatic improvement in eGFR slope (>5 ml/min/1.73m2 per year).

Conclusion

The real life use of tolvaptan seemed to give a dramatic improvement in eGFR slopes, much more than the previously reported clinical studies have shown. This may be in part due to patient selection and only including patients who tolerated therapy, a “tolvaptan clinic” effect where great personal care is given to these patients and to excellent compliance with medication. Reasons for both non-response and exaggerated response need to be evaluated carefully to determine how individualisation of tolvaptan therapy can be best used.
MO043HYPERURICEMIA IS RELATIVELY COMMON IN CHILDREN WITH HNF1B MUTATION, BUT ITS UTILITY AS A CLINICALLY USEFUL MARKER FOR PREDICTING THE MUTATION IS LIMITED
Authors: Kołbuc Marcin , Bieniaś Beata , Habbig Sandra , Kołek Mateusz , Szczepanska Maria , Kiliś-Pstrusińska Katarzyna , Wasilewska Anna , Adamczyk Piotr , Motyka Rafał , Tkaczyk Marcin , Sikora Przemysław , Beck Bodo B , Zaniew Marcin
Published: May 2021

Background and Aims

Hyperuricemia is recognized as an important feature of HNF1B nephropathy, and could serve as a good marker of the disease facilitating selection of patients for genetic testing. However, neither the casual relationship nor its predictive value have been proven yet. We thus decided to assess this in a cohort of children with renal malformations with (mut+) and without HNF1B mutations (mut-).

Method

We performed a retrospective analysis of clinical and genetic results of pediatric patients tested for HNF1B mutations, whose data were collected in a national registry. Hyperuricemia was assessed by using the newest, age- and gender-dependent reference values for serum uric acid (sUA) in children.

Results

A total of 108 children were included into the study comprising 43 mut+ patients, and 65 mut- subjects. Mean sUA was higher in mut+ than in mut- subjects (p = 0.006), and hyperuricemia was more prevalent in those with HNF1B mutations (42.5% vs. 15.4%, p = 0.002). Renal phenotype analysis revealed renal hyperechogenicity and multicystic dysplastic kidney disease were more frequent in mut+ patients, but no influence of any renal features/phenotypes on hyperuricemia was found. The two patient cohorts were different with regard to pancreatic anomaly (p < 0.001), glucose metabolism disorders (p = 0.003), hypomagnesemia (p < 0.001), and hyperparathyroidism (p < 0.001). In a multivariate linear stepwise regression model, eGFR, fractional excretion of uric acid, impairments in glucose metabolism and pancreatic anomaly were found to be independent predictive variables of sUA (R2=0.67, F=13.27, p < 0.001). Mutation was not identified as a determinant of sUA. After exclusion of patients with hyperglycemia and/or pancreatic malformations, the difference in hyperuricemia prevalence did not persist between mut+ and mut-. Potential of hyperuricemia for mutation prediction was tested in a model with hypomagnesemia and hyperparathyroidism, which showed an accuracy of 85% (sensitivity: 83%, specificity: 86%). Adding hyperuricemia to the model did not increase the accuracy (79%; sensitivity: 77%, specificity: 82%). Information gain, which informs selective potential of each parameter, was the lowest for hyperuricemia (0.34 compared with 0.99 and 0.63 for hyperparathyroidism and hypomagnesemia, respectively).

Conclusion

Hyperuricemia is relatively common in children with HNF1B mutation, however its direct association with this molecular defect remains still unproven. Its dependence on renal function and hyperglycemia diminishes the utility as a clinically useful marker for predicting HNF1B disease.
MO047STABLE EGFR IN PATIENTS WITH PRIMARY HYPEROXALURIA TYPE 1 TREATED WITH LUMASIRAN, REGARDLESS OF KIDNEY FUNCTION AT START OF TREATMENT
Authors: Hayes Wesley , Garrelfs Sander , Sas David , Lieske John , Ngo Taylor , Gansner John , McGregor Tracy , Frishberg Yaacov
Published: May 2021

Background and Aims

Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder characterized by hepatic oxalate overproduction. Excess oxalate is excreted by the kidneys, leading to recurrent kidney stones, nephrocalcinosis, and progressive kidney disease. Patients with PH1 generally experience a slow decline in kidney function over time that can be punctuated by abrupt worsening precipitated by infection, obstructing stones, or dehydration. Approximately half of patients with PH1 progress to kidney failure by early adulthood, and nearly all by 60 years of age. Lumasiran is an RNAi therapeutic indicated for the treatment of PH1 in all age groups. In clinical trials, treatment with lumasiran resulted in substantial reductions in urinary and plasma oxalate in pediatric and adult patients, with an acceptable safety profile. This analysis evaluates the change in kidney function of patients with PH1 with an eGFR of ≥30 mL/min/1.73m2 enrolled in clinical trials of lumasiran.

Method

We analyzed kidney function from 75 patients with PH1, age ≥12 months old, eGFR ≥30 mL/min/1.73m2, enrolled in 3 clinical trials of lumasiran (Phase 2 open-label extension, and Phase 3 ILLUMINATE-A and ILLUMINATE-B). In these trials, eGFR was calculated with the Modification of Diet in Renal Disease (MDRD) Study equation in adults or the bedside Schwartz equation in children. The effect of lumasiran on eGFR was assessed by baseline eGFR subgroup: ≥90, <90, 60 to <90, 45 to <60, and 30 to <45 mL/min/1.73m2.

Results

Of 75 patients available for analysis, 46 were treated with lumasiran from the start of the study through the Month 12 visit. eGFR remained stable in all eGFR subgroups. Patients with eGFR ≥90 mL/min/1.73m2 at baseline (N=16) demonstrated fluctuations in mean values by timepoint, with a mean change (95% CI) from baseline of -1 (-8, 6) mL/min/1.73m2 at Month 12. In patients with eGFR <90 mL/min/1.73m2 (N=30), no change in mean eGFR from baseline was observed at Month 12; the mean change (95% CI) was 0 (-3, 3). When evaluating subgroups with impaired kidney function, variations in the mean change were observed at Month 12 due to small sample sizes. For patients with eGFR 60 to <90 mL/min/1.73m2 (N=22), the mean change (95% CI) was -2 (-5, 1). For patients with eGFR 45 to <60 mL/min/1.73m2 (N=5), the mean change (95% CI) was 3 (-8, 14). For patients with eGFR 30 to <45 mL/min/1.73m2 (N=3), the mean change (95% CI) was 9 (7, 11).

Conclusion

Patients with PH1 had stable kidney function over time with lumasiran treatment, regardless of kidney function at baseline. Given the progressive kidney function decline that is characteristic of PH1, the eGFR stability observed during 12 months of treatment with lumasiran is encouraging. Kidney function will continue to be monitored for the duration of the lumasiran clinical trials.
MO051EFFECT OF TOLVAPTAN ON THE SUPPRESSION OF TOTAL KIDNEY VOLUME INCREASE IN PATIENTS WITH MODERATE-TO-SEVERE RENAL DYSFUNCTION IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE
Authors: Nomi Hiroki , Mori Daisuke , Tamai Shinjiro , Tokuchi Maho , Inoue Natsumi , Kawai Hideaki , Shimada Naoyuki , Haga Ryota , Nagatoya Katsuyuki , Yamauchi Atsushi
Published: May 2021

Background and Aims

Tolvaptan (TV) slows down the increase in total kidney volume (TKV) in patients with autosomal dominant polycystic kidney disease (ADPKD). The efficacy of TV in patients with moderate-to-severe renal dysfunction (RD) in ADPKD remains unknown.

Method

This was a single-centre retrospective study involving 27 patients with ADPKD who took TV and visited our hospital in the past six years. The participants were divided into two groups: the normal-to-mild RD (estimated glomerular filtration rate (eGFR) ≥ 45mL/min/1.73m2) group and the moderate-to-severe RD (eGFR < 45mL/min/1.73m2) group. Treatment effects were evaluated using ΔTKV, which was calculated as post-/pre-treatment annual TKV change. Continuous variables are presented using the median [interquartile range].

Results

The moderate-to-severe RD group comprised 11 patients. Baseline characteristics of the normal-to-mild vs. moderate-to-severe RD group were as follows: eGFR, 56 [50–69] vs. 29 [24–38] mL/min/1.73m2; age, 48 [39–55] vs. 49 [43–58] years; male gender, 57% vs. 36%; body mass index (BMI) , 26 [23–28] vs. 24 [22–27] kg/m2; TKV 1700 [1084–2574] vs. 1827 [1331–2424] mL; family history of ADPKD, 100% vs. 82%; history of cerebral aneurysm, 19% vs. 36%; hypertension, 81% vs. 82%; hyperuricemia, 13% vs. 27%; dyslipidaemia, 19% vs. 18%; diabetes, 6.1% vs. 9.1% and systolic blood pressure (sBP) on admission 138 [129–144] vs. 131 [128-137] mmHg. No significant differences were noted in all these parameters, except for renal function. The starting dose of TV was 60 mg/day in all cases (0.9 [0.7–1.0] vs. 0.9 [0.8–1.1] mg/kg; P = 0.35). Urine volume (7.5 [5.7–9.6] vs. 4.0 [3.3–4.7] L/day; P = 0.006) and urinary sodium excretion (163 [126–226] vs. 89 [81–120] mEq/day; P = 0.003) were higher in the normal-to-mild RD group. Between the groups, there were no differences in urine protein (0.12 [0.0–0.3] vs. 0.16 [0.08–0.29] g/day; P = 0.31) and ΔeGFR (98% [88–123] vs. 106% [102–112]; P = 0.45), which was calculated as post-/pre-treatment annual eGFR change. Although both groups experienced the therapeutic effects of TV, the efficacy was poorer in the moderate-to-severe RD group (ΔTKV, 82% [76–85] vs. 96% [86–97]; P = 0.001).

Conclusion

The efficacy of TV patients with moderate-to-severe RD in ADPKD might be modest.
MO062A RARE COMBINATION OF POLYCYTHEMIA VERA WITH A THROMBOPHILIA FACTOR V MUTATION IN A HEMODIALYSIS PATIENT :CASE REPORT
Authors: Ghabi Faten , Salma Toumi , Amouri Asma , Chaker Hanen , Agerbi Ikram , Damak Najla , Kammoun Khawla , Yaich Soumaya , Benhamida Mohamed
Published: May 2021

Introduction

Anemia is an almost constant complication in patients with end stage renal disease. In contrast, primary polycythemia is extremely rare, with only a few cases that have been reported in the literature. We report in this work a rare association of thrombophilia and acquired polycythemia in a chronic hemodialysis patient.

Observation

This is a 47-year-old man, non-smoking, hypertensive, with CKD in hemodialysis since 2015 secondary to undetermined nephropathy. The change in the patient's condition on hemodialysis was marked by the occurrence of repeated thrombosis of these arteriovenous fistulas(AVFs), including exploration that revealed a coagulation factor V mutation, hence his initiation of antivitamin K. The patient initially presented with severe anemia at the start of the extra renal purification , the average hemoglobin (Hb) level between 2015 and 2018 was 7.4 g / dl thus requiring the use of iron supplementation (IV iron) and stimulating agents erythropoiesis (ESA). In february 2019, erythropoietin requirements were reduced due to the increase in Hb levels and then stopped in April 2019. The Hb level continued to increase to reach 16.8 g / dl in february 2020 without receiving ESAs or iron supplements. From where an etiological investigation was initiated to search for the origin of this polycythemia going up to the genetic study for the JAK2V617F mutation which came back positive. Furthermore, gas scans, chest x-rays and abdominal ultrasounds are normal, hence polycythemia vera was retained in this patient. For fear of losing his AVF, the patient underwent intermittent phlebotomies during dialysis associated with the prescription of IEC and his Hb level rose to 14.5g / dl.

Conclusion

Primary erythrosis remains rare in dialysis, the pathophysiological mechanism of which remains poorly understood. Iterative phlebotomies remain the solution sometimes coupled with the prescription of IEC.
MO064ASSESSMENT OF KIDNEY SURVIVAL IN PATIENTS AFFECTED BY ADPKD
Authors: García Rabaneda Carmen , Morales García Ana Isabel , Bellido Díaz María Luz , Del Águila García María del Mar , Poyatos Andújar Antonio M , Martínez Atienza Margarita , Esteban de la Rosa Rafael Jose
Published: May 2021

Background and Aims

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary nephropathy that causes kidney failure and the need for renal replacement therapy (RRT). It has recently been established that there is a genotype-phenotype relationship for this disease, with differences in the age of access to TRS if the involvement occurs in the PKD1 or PKD2 gene and if the variant is truncating or not. Identifying patients at high risk for rapid progression has become increasingly important given the emergence of potential new treatments such as tolvaptan.

Method

Studies are carried out in 23 families affected in which a genetic study has previously been the variant identified. For the survival analysis, the Kaplan-Meier test was performed. Data are expressed in terms of mean ± SD, median and %.

Results

The data described in Table 1 show that there is huge variability of access to RRT according to the type of variant found in the family. We found families in which the age at which kidney failure occurred ranged from 48.03 (28.38-67.68) years to families in which RRT began with 78.04 (65.06-91.03).

We observed that those families that present a variant with a stop or frameshift codon suffer a loss of kidney function before those that present a missense variant. In the variants with a stop or frameshift codon, we observed that they ranged from 48.03 (28.38-67.68) for the variant c.7480G> T (p.Glu2494 *) to 73.75 (61.52-85, 98) in variant c.9616C> T p.Gln3203 *. In those missense variants, the age of access to RRT ranges from 62.17 (60.43-63.91) to 77.13 (71.56-82.71)

Conclusion

Advances in studies of the genes involved in ADPKD are expanding the identification of new variants and the knowledge about their involvement in the progression of the disease.

The correlation between genotype and kidney disease will provide a useful clinical prognosis for ADPKD and will allow us to establish current and future treatments.
MO036DAPAGLIFLOZIN RESCUES THE RENAL PHENOTYPE OF GLYCOGEN STORAGE DISEASE TYPE IB
Authors: D'Acierno Mariavittoria , Resaz Roberta , Siccardi Sabrina , Iervolino Anna , Sardella Donato , Capasso Giovambattista , Eva Alessandra , Trepiccione Francesco
Published: May 2021

Background and Aims

Glycogenosis I type b (GsdI-b) is a rare metabolic disease and immune disorder characterized by hepato-renal glycogen accumulation caused by a deficiency in the Glucose-6-phosphate transporter (G6PT). G6PT transports glucose-6-phosphate (G6P) from cytoplasm to endoplasmic reticulum (ER) where a G6Pase catalyses the hydrolysis of G6P in glucose and phosphate. G6PT deficiency lead to impaired glucose homeostasis, myeloid disfunction and long-term risk of hepatocellular adenomas. No causal therapy is so far available for GSDI-b patients besides a dietary approach to control glycemia and the use of Granulocyte Colony-Stimulating Factor (GCSF) to improve neutropenia. Over time, these supports increase the chronicity of GSDI-b with some complications. A mouse model recapitulating the GDSI-b has been recently generated by inducing G6PT suppression after tamoxifen injection. Here, we characterized the renal phenotype of TM-G6PT-/- mice model focusing on the molecular mechanisms that lead to renal dysfunction. Finally, we evaluated the efficiency of Dapagliflozin, a selective inhibitor of SGLT2, on kidney functions in terms of therapeutic effect.

Method

Machine learning approach to computer based evaluation of renal morphology was used to analyze the renal sections from TM-G6PT-/- treated with or without dapagliflozin.

Results: G6PT is expressed in all renal zones and a severe downregulation of G6PT mRNA expression in whole kidney of TM-G6PT-/- mice can be observed. TM-G6PT-/- mice show tubular vacuolization and overall cellular dysfunction of PT due to a high glycogen accumulation. TM-G6PT-/- mice manifest glycosuria, phosphaturia and polyuria associated with a down regulation of main transporters of PT cells. The urine concentrating defect is due to a primarily role of G6PT in CNT/CD cells confirmed by a downregulation of AQP2, main water channel along CD segments. This mouse model recapitulates the human GSD-Ib renal phenotype characterized by a disfunction of PT but also CNT/CD cells. In order to evaluate whether targeting the glucose metabolism would improve the renal phenotype of these mice we limited glucose flux across the apical membrane of PT cells, applying the SGLT2-inhibitor dapagliflozin to reduce new glycogen formation. After one month of treatment, Dapagliflozin prevents glycogen accumulation in TM-G6PT-/- mice and ameliorates the main dysregulated markers of PT function. This finding was paralleled by an improvement of the histological features of kidney morphology in dapagliflozin treated TM-G6PT-/- mice.

Conclusion

Our data provide evidence that treatment with dapagliflozin ameliorates intracellular glycogen storage and improves the renal functions in TM-G6PT-/- mice.
MO021ENHANCED MCP-1 RELEASE IN EARLY AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE
Authors: Janssens Peter , Decuypere Jean-Paul , De Rechter Stéphanie , Breysem Luc , Van Giel Dorien , Billen Jaak , Hindryckx An , De Catte Luc , Baldewijns Marcella , Claes Kathleen , Wissing Karl Martin , Devriendt Koenraad , Bammens Bert , Meyts Isabelle , Torres Vicente , Vennekens Rudi , Mekahli Djalila
Published: May 2021

Background and Aims

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in either the PKD1 or PKD2 gene. While kidney failure typically occurs in adulthood, the disease starts in utero. The best change of preserving renal function long term might be the use of agents with few side effects as early as possible. For this approach, both better early prognostic stratification and novel treatment options are needed. The pediatric phase of ADPKD, while kidney function is still normal and before significant tissue destruction has occurred could be the best stage both to identify and study prognostic biomarkers as well as to identify novel targets for early treatment. Copeptin (a surrogate for vasopressin), epidermal growth factor (EGF) ( a measure for functional tubular mass) and monocyte chemoattractant protein-1 (MCP-1) ( a chemoattractant for macrophages) are associated with severity and hold prognostic value in adults but remain unstudied in the early disease stage. Kidneys from adults with ADPKD exhibit macrophage infiltration, and a prominent role of MCP-1 secretion by tubular epithelial cells is suggested from rodent models.

Method

A monocentric cross-sectional study in a tertiary referral center was performed. All consenting genotyped ADPKD patients attending the outpatient pediatric ADPKD clinic of the university hospital of Leuven and age, sex and BMI matched healthy controls were included between June and October 2017. Plasma copeptin, urinary EGF and urinary MCP-1 were evaluated. MCP-1 was studied in mouse collecting duct cells, human proximal tubular cells and fetal kidney tissue.

Results

53 genotyped ADPKD patients and 53 controls were included. Mean (SD) age was 10.4 (5.9) vs 10.5 (6.1) years (P=0.543), and eGFR 122.7 (39.8) vs 114.5 (23.1) ml/min/1.73 m2 (P= 0.177) in patients vs controls respectively. Outcome parameters in table. Plasma copeptin and EGF secretion were comparable between both groups. Median (IQR) urinary MCP-1 (pg/mg creatinine) was significantly higher in ADPKD patients (185.4 (213.8)) compared to controls (154.7 (98.0)) (P= 0.010). Human proximal tubular cells with a heterozygous PKD1 mutation and mouse collecting duct cells with a PKD1 knockout exhibited increased MCP-1 secretion triggered by fetal bovine serum. Human fetal ADPKD kidneys displayed prominent MCP-1 immunoreactivity and M2 macrophage infiltration.

Conclusion

An increase in tubular MCP-1 secretion is an early event in ADPKD, long before kidney function decline and in children with few kidney cysts. MCP-1 is a promising early disease severity marker and a potential treatment target.
MO022EVALUATION OF THE EFFECT OF TOLVAPTAN ON OXIDATIVE STRESS IN PATIENTS WITH AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE (ADPKD)
Authors: Rigato Matteo , Bertoldi Giovanni , Ravarotto Verdiana , Carraro Gianni , Calò Lorenzo
Published: May 2021

Background and Aims

Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent monogenic kidney disease, with approximately 12.5 million affected people worldwide, and it is responsible for over 10% of patients with end-stage renal disease (ESRD) with an important impact on public health. It causes progressive renal failure and other extrarenal manifestations, including endothelial dysfunction and hypertension. These complications are both linked to reduced nitric oxide levels related to excessive Oxidative Stress (OxSt) that different studies confirm occurring in the early stages of ADPKD.

This study aims to evaluate ex vivo through a molecular biology approach the OxSt status of ADPKD patients under treatment with tolvaptan (Jinarc) and compare with both a group of untreated young ADPKD subjects with preserved renal function (eGFR> 80 mL/min/1.73m2) and a cohort of healthy subjects as controls.

Methods

In mononuclear cells of 9 ADPKD patients treated with tolvaptan, 9 untreated ADPKD patients with preserved renal function (eGFR> 80 mL/min/1.73m2) and 9 healthy subjects we evaluated the state of OxSt in terms of protein expression of p22phox, subunit of NADH/NADPH oxidase essential for the production of superoxide; protein expression of Heme oxygenase (HO)-1, protective from OxSt and anti-inflammatory and MYPT-1 phosphorylation, marker of Rho kinase activation, deeply involved in OxSt signaling for the induction of cardiovascular-renal remodeling;

Results

In patients with tolvaptan treated ADPKD, protein expression of p22phox and phosphorylation state of MYPT-1 were significantly reduced compared to untreated young ADPKD subjects with normal GFR (p=0.01 and p=0.03, respectively). Phosphorylation of MYPT-1 was significantly reduced in patients treated with tolvaptam vs untreated patients and also when compared to healthy controls (p=0.01 for both). HO-1 levels of treated ADPKD patients were significantly higher both vs untreated ADPKD patients with normal GFR (p=0.04) and vs healthy controls (p=0.01)

Conclusions

Tolvaptan is reported to reduce the rate of GFR deterioration of 1.20 mg/mL/year compared to placebo. Several animal studies have demonstrated the ability of tolvaptan to reduce OxSt and increase HO-1. Our study showed “ex vivo” in humans that in ADPKD patients tolvaptan reduces the OxSt state compared to untreated ADPKD with normal GFR and increases the antioxidant HO-1, in addition to reduce Rho kinase activation, further supporting its renoprotective effect also in terms of OxSt inhibition.

This study confirms for the first time in humans that tolvaptan is effective on the reduction of intracellular OxSt and may impair the biochemical/molecular mechanisms that contribute to the worsening of renal function, endothelial damage and hypertension.
MO023FLANK PAIN HAS A MAJOR NEGATIVE IMPACT ON HEALTH-RELATED QUALITY OF LIFE IN ADPKD: THE CYSTIC I STUDY
Authors: Winterbottom Jean , Simms Roslyn , Caroli Anna , Cornec-Le Gall Emilie , Demoulin Nathalie , Furlano Monica , Meijer Esther , Devuyst Olivier , Gansevoort Ronald , LeMeur Yannick , Perico Norberto , Torra Roser , Ong Albert
Published: May 2021

Background and Aims

ADPKD is the most common inherited kidney disease in man, a major cause of end-stage renal disease and is a significant medical and economic burden worldwide. However, the impact of this major disease on the quality of life of patients with preserved kidney function has not been systematically explored.

Method

The CYSTic I study was an observational, prospective study designed to study the natural history of ADPKD in adult patients with preserved kidney function (eGFR ≥30 ml/min/1.73m2). 465 patients were recruited from six expert centres across Europe (Belgium, France, Italy, Netherlands, Spain and UK) with baseline data recorded including HR-QoL (Health-Related Quality of Life) incorporating a Kidney Disease QOL short form questionnaire (KDQoL-SF v1.3), MRI for Total Kidney Volume (TKV) and DNA for genotyping. The cohort was stratified by baseline eGFR, Ht-TKV or genotype and correlated with HR-QOL scores. Bivariate and multivariate analyses were applied to examine the relationship between HRQoL and variables of interest. KDQoL-SF scores were calculated using an online tool provided by the Rand organisation.

Results

Mean age of the participants was 44 years, 54.6% were female with a mean eGFR of 77ml/min/1.73m2 and Ht-TKV of 849ml/m. 72.3% had PKD1 mutations. 32.5% of participants reported flank pain that was not significantly correlated with eGFR, Ht-TKV or genotype. Of all the variables examined, flank pain showed significant negative associations with the highest number of KDQoL-SF subscale scores assessed (12/20).

Conclusion

Our results indicate that flank pain is common, likely to be under-reported in routine care but has a major negative impact on patient-reported quality of life.
MO024THE ROLE AND MECHANISM OF DECOY RECEPTOR DCR2 IN EMBRYONIC KIDNEY DEVELOPMENT
Authors: Chen Jia , He Yani
Published: May 2021

Background and Aims

Decoy receptor 2 (DcR2), a transmembrane receptor of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), has been regarded as a hallmark of cell senescence. This study aimed to explore the role and the potential mechanism of DcR2 in the embryonic kidney development.

Method

The 12.5d, 16.5d, 20.5d embryonic kidney and mature renal tissue (8w) form WT and DcR2-KO mice were obtained. The ureteric buds, S-shaped bodies, renal vesicles were observed by periodic Acid-Schiff staining. The expression of DcR2 were detected by IHC. The co-expression of DcR2 and proximal tubular markers (AQP-1, villin), distal tubular markers (AQP-2), senescent markers (P16, LaminB1), proliferation markers (Ki-67, PCNA, Edu) were analyzed by confocal.

Results

In WT kidneys, DcR2 were specifically expressed in the tubules and the percentage of DcR2 expression were higher than mature renal tissue. In addition, the expression of tubular DcR2 were significantly decreased in DcR2-KO kidney than WT. The number of ureteric buds, S-shaped bodies, renal vesicles were decreased in DcR2-KO kidney than WT. And the cortex of DcR2-KO kidney were thinner and medullar were enlarger than WT. DcR2 were co-expressed with proximal tubular markers AQP-1 and villin, but not with distal tubular markers AQP-2. Furthermore, DcR2 were co-expressed with senescent markers P16 and LaminB1, but not with proliferation markers Ki-67, PCNA, Edu.

Conclusion

DcR2 is specifically expressed in proximal tubular cells in embryonic kidney, and DcR2 is involved in early renal development. The potential mechanism is related to cell senescence participating in tissue remodeling and inhibiting cell proliferation.
MO025TREATMENT WITH TOLVAPTAN IN ADPKD PATIENTS: RESULTS FROM AN OBSERVATIONAL, MULTICENTRIC STUDY
Authors: Galliani Marco , Vitaliano Elio , Chicca Silvana , Paone Antonio , Pistolesi Valentina , Morabito Santo , Di Lullo Luca , Floccari Fulvio , Marrocco Fulvio , Cioffi Massimiliano , Rifici Nunzio , Iacono Rossella , Feriozzi Sandro , Pasquarelli Cynthia , Morosetti Massimo , Bernabei Eleonora , Ferrazzano Maria Teresa , Orossi Antonella , Fini Riziero , Lai Silvia , Mazzaferro Sandro , Fulignati Pierluigi , Grandaliano Giuseppe
Published: May 2021

Background and Aims

In recent years, treatment of ADPKD (Autosomal Dominant Polycystic Kidney of the Adult) has been based on the antisecretive and antiproliferative effect of several drugs. Tolvaptan, a vasopressin receptor antagonist, has been shown to slow disease progression in the face of side effects such as aquaresis and liver damage. Currently, the drug's reimbursability is allowed in patients aged up to 55 years, CKD 2-4 (GFR ≥ 25 ml/min) with evidence of rapid disease progression.

Method

We report the experience with Tolvaptan in 62 patients with ADPKD who were recruited from 11 Nephrology Units in Lazio (Italy).

Baseline characteristics of patients are reported in Table 1.

Renal volume was evaluated by MRI (26 patients), CT scan (3 patients), or ultrasonography (28 patients).

Rapid progression’s criteria were the following: Mayo Clinic classification, PRO-PKD score and the annual loss of GFR. Mean duration of Tolvaptan’s treatment was 522 days (range 56-867).

The Tolvaptan dosage used at the beginning of therapy was 60 mg/day in 95% of patients; at the end of follow-up, 37% were still taking 60 mg/day, while 38.7% were taking 90 mg/day and 16.1% were taking 120 mg/day.

Results

Median diuresis was 5-6 liters over 24 hours. A mean reduction in GFR of 12.5% (which was maintained for the next 12 months) was observed after initiation of therapy as a likely effect of tubulo-glomerular feedback.

Monthly blood tests were performed to monitor side effects (hyper/hyponatremia, increased bilirubin and/or transaminases, etc.).

Therapy was withdrawn by 2 patients (3.2%) due to aquaresis, while it was discontinued in 3 patients (4.8%) according to clinicians’ decision due to hepatic damage (3-fold increase in transaminases and/or bilirubin normal values). No significant alteration in natremia was observed in any patient. An increase in CK was observed in one patient, leading to momentary discontinuation of therapy. One patient withdraw therapy because of CKD’s progression to stage 5 after 2 years of therapy.

Conclusion

Results of this observational study show that Tolvaptan therapy was well tolerated and the incidence of liver damage was superimposed on that described in the literature.

It will be necessary to continue clinical observation over the time and apply Tolvaptan’s therapy to a larger population in order to assess its effects on disease progression.
MO026CLINICAL AND MUTATIONAL SPECTRUM OF CHILDREN WITH AUTOSOMAL RECESSIVE AND AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE
Authors: Tutal Ozum , Gulhan Bora , Atayar Emine , Yuksel Selcuk , Ozcakar Z Birsin , Soylemezoglu Oguz , Saygili Seha , Inozu Mihriban , Baskin Esra , Duzova Ali , Hayran Mutlu , Topaloglu Rezan , Ozaltin Fatih
Published: May 2021

Background and Aims

Cystic kidney diseases are a heterogeneous group of chronic renal disease. Autosomal recessive polycystic kidney disease (ARPKD) is generally diagnosed in utero or at birth due to mutations in PKHD1 gene. Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease commonly associated with mutations in PKD1 or PKD2. In this study, we aimed to investigate clinical and genetic features of ARPKD and ADPKD in a group of Turkish patients.

Method

A total of 69 children with genetically confirmed ARPKD (10 females, 11 males) or ADPKD (28 females, 20 males) from seven pediatric nephrology centers were included in this study. Demographic features, family history, clinical and laboratory findings at presentation and during 12 months intervals were collected.

Results

For ARPKD patients, the median age at diagnosis was 10.5 (IQR; 0.75-58.5) months. Consanguinity between parents was present in 11 patients (52.4%). At the time of diagnosis, 14 (66.7%) patients had eGFR<90 ml/min/1.73 m2. Mean duration of follow-up was 4.1±3,7 years. At the last visit, median eGFR was 74 (IQR; 43-126) ml/min/1.73m2. A total of 6 patients (28,6%) underwent a renal replacement therapy (RRT), 3 of them died in infancy and 2 of them had renal transplantation during follow up. All patients had bi-allelic PKHD1 mutation.

For ADPKD patients, the mean age at diagnosis was 5.5±4.6 years. At the time of diagnosis 11 (22.9%) patients had eGFR<90 ml/min/1.73m2. Mean duration of follow-up was 2,7±2.3 years. At the last visit, median eGFR was 114 (IQR; 98-135) ml/min/1.73m2. Only one patient underwent a renal transplantation. A total of 42 patients (87.5%) had a heterozygous PKD1 mutation while 6 (12.5%) had a heterozygous PKD2 mutation. The rate of growth retardation, hypertension at diagnosis and progression to chronic kidney disease (CKD) were higher in patients with PKHD1 mutation than the patients with PKD1 or PKD2 mutation (p < 0.001, p < 0.001 and p = 0.001, respectively). In kidney survival analysis, mutation type, growth retardation at presentation, increased renal echogenity in ultrasonography were found as independent risk factors for progression to CKD.

Conclusion

Cystic kidney diseases are one of the most clinically and genetically heterogenous diseases. Differentiating them and establishing the predictors for CKD development is important to provide appropriate management including choosing appropriate donor in renal transplantation.