bluuebunny/crossref_metadata_2025_split huggingface dataset:
A-057 Assessing Direct Renin Stability in EDTA Plasma Prior to Separation from Cells and Post-thaw
Authors: Troike K , Boyert N , Dee M , Colón-Franco J M 
Published: October 2024

Abstract

Background
Renin is an enzyme secreted by the kidneys responsible for blood pressure regulation through the renin-angiotensin-aldosterone axis. Direct renin measurements are frequently used to investigate underlying causes of hypertension, including primary aldosteronism (PA), which is screened for using an aldosterone:renin ratio (ARR). Appropriate handling of renin samples in the preanalytical phase is critical, as cryoactivation of prorenin can occur when samples are refrigerated or cooled for extended periods of time, falsely elevating results. Manufacturer instructions for renin handling are often poorly defined and there is currently no consensus as to best handling practices. Two variables that frequently lead to renin sample rejections in our laboratory are time to centrifugation after collection and time kept at room temperature (RT). The objective of this study was to evaluate the stability of direct renin under ambient and freeze-thaw conditions in an effort to reduce test cancellations due to improper handling.

Methods
Plasma samples collected from five volunteers with consent in K2EDTA tubes were used for renin stability studies. Baseline renin samples were kept at RT for two hours after collection, centrifuged, measured, and subsequently frozen for post-thaw studies. To assess stability before separation from cells, samples kept at RT for two and four hours prior to centrifugation were assayed in triplicate for direct renin. For post-thaw stability studies, plasma samples were split into two aliquots each and frozen at -20⁰C for at least 24 hours, but no longer than 30 days. After removal from -20⁰C, one set of aliquots was thawed on the benchtop at RT and the second set was thawed in an RT water bath for up to one hour. Samples were centrifuged and assayed for direct renin in triplicate at baseline and six hours post-thaw. Direct renin was measured using the LIAISON XL chemiluminescent immunoassay (Diasorin). Bias was assessed after each treatment. The total allowable error (TEa) was ±2 pg/mL or ±20%.

Results
Measured renin concentrations ranged from 6.8-29.7 pg/mL. The percent bias in direct renin concentrations when comparing samples stored for two-hour and four-hour timepoints before centrifugation was 2.0% on average. Post-thaw studies comparing renin concentrations at the baseline and six-hour timepoints revealed an average percent bias of 13.1% and 12.2% for RT and water bath thawing methods, respectively. All samples tested were within the TEa.

Conclusions
Direct renin is stable in lavender K2EDTA tubes at RT for up to four hours, prior to centrifugation and separation from cells. Renin concentrations remained stable after storage at -20⁰C and thawing at RT for up to six hours, regardless of thawing method. By expanding direct renin stability criteria, we hope to reduce the number of cancellations due to preanalytical handling errors and prevent redundant phlebotomy for patients.
A-061 Analytical Performance and R55G Mutant Detection Ability of an Improved Thyroid-Stimulating Hormone Assay, TSH3-Ultra II, on the ADVIA Centaur Immunoassay System and the Atellica IM Analyzer
Authors: Rhea-McManus J , Plumer A , Arrode-Bruses G , Dubravcic T 
Published: October 2024

Abstract

Background
Measurement of thyroid stimulating hormone (TSH) is a critical tool for the investigation of thyroid disorders. Previous studies have demonstrated that some immunoassays are unable to detect TSH from patients with the R55G mutation in the TSHβ subunit. This study evaluated the analytical performance of the ADVIA Centaur® and Atellica® IM TSH3-Ultra II (TSH3ULII) assay and its ability to detect the R55G TSH mutant.

Methods
Limit of quantitation (LoQ) and linearity were determined as described in CLSI EP17-A2 and EP06, respectively. Precision and method comparison (MC) studies were performed with three reagent lots according to CLSI EP05-A3 and CLSI EP09c using native and contrived human serum and plasma samples. For precision, one aliquot of each sample was tested in duplicate in two runs per day &gt;2 hours apart on each analyzer for ≥20 days. MC studies were performed by testing native human serum samples using ADVIA Centaur TSH3-UL assay (current TSH assay) and the newer ADVIA Centaur TSH3ULII assay. An additional MC was performed by testing native human serum samples with the TSH3ULII assay on both the ADVIA Centaur XP and the Atellica IM Analyzer. Samples from 61 patients with TSH results below the LoQ when using TSH3-UL were sequenced and confirmed to have the R55G mutant. Each of these samples was tested in duplicate using the ADVIA Centaur TSH3ULII assay.

Results
LoQ on both the ADVIA Centaur XP and the Atellica IM Analyzer was estimated to be 0.010 μIU/mL (mIU/L). Linearity was verified from 0.010 to 150.000 μIU/mL (mIU/L). ADVIA Centaur TSH3ULII repeatability %CVs ranged from 1.4 to 3.6% at 0.099 and 91.993 μIU/mL (mIU/L), and within-lab %CVs ranged from 2.3 to 6.2% at 4.908 and 91.993 μIU/mL, respectively. Atellica IM TSH3ULII repeatability %CVs ranged from 1.1 to 3.4% at 4.800 and 93.097 μIU/mL, and within-lab %CVs ranged from 2.2 to 4.6% at 0.103 and 93.097 μIU/mL, respectively. For the MC studies, slopes determined by the Passing-Bablock regression model were approximately 1 (0.96-0.97 range) across the sample interval tested. All TSH3ULII results from the 61 mutant patient samples were greater than LoQ, ranging from 0.864 to 23.443 μIU/mL (mIU/L).

Conclusions
Evaluation of the TSH3ULII assay using the ADVIA Centaur system demonstrated performance comparable to the commercially available TSH3-UL assay for LoQ, linearity, and precision, when using normal patient samples. TSH3ULII results on the Atellica IM Analyzer were comparable to the results obtained on the ADVIA Centaur XP. All 61 TSH mutant samples used in this study that had TSH values below the LoQ with the TSH3-UL assay, were detectable with the TSH3ULII assay. The data presented here demonstrate the ability of the TSH3ULII assay to detect the TSH in samples from patients with the R55G mutation.
A-062 Determination Neonatal 17-Hydroxyprogesterone Cutoff Levels for Congenital Adrenal Hyperplasia in Korea: 3 years' experience
Authors: Yoon Y , Park K 
Published: October 2024

Abstract

Background
Newborn screening for congenital adrenal hyperplasia (CAH) is a crucial practice with significant global adoption. While it offers substantial benefits, it also presents challenges due to high false positive rates, which can lead to mental strain for families and unnecessary hospital visits. Our research delved into the impact of birth weight (BW), gestational age (GA), and GA combined with sampling time on 17-hydroxyprogesterone (17-OHP) concentration. Specifically, we aimed to establish appropriate 17-OHP cutoff values for preterm, low birth weight weight (LBW), and sick newborns.

Methods
A total of 2,429 newborns born between October 2020 and January 2024 were screened for CAH. Samples were collected from neonates on a filter paper with a heel prick method. The 17-OHP concentration was measured by AutoDELFIA Neonatal 17-hydroxyprogesterone kit (PerkinElmer, Turku, Finland). This assay is a solid phase, time-resolved fluoroimmunoassay based on the competitive reaction between europium labeled 17-OHP and sample 17-OHP for a limited amount of binding sites on 17-OHP specific polyclonal antibodies. The 99.5 percentile was applied to the cutoff of 17-OHP for CAH.

Results
17-OHP concentrations in newborns with lower BW and GA were significantly higher than those in normal BW and term newborns. 17-OHP concentration showed a statistically significant negative correlation with BW (r = -0.512, p &lt; 0.001) and GA (r = -0.578, p &lt; 0.001). Not only the full-term subgroup, but also preterm subgroups had a same tendency of 17-OHP concentration decrease with increasing sampling time. Application of newly establishing 99.5 percentile cutoff criteria significantly reduced recall rates to 1.02%, 0.81%, and 1.45% according to each criterion of BW, GA, and GA with sampling time, respectively.

Conclusions
This research introduces novel 17-OHP cutoff values for preterm, low birth weight (LBW), and sick newborns in the context of congenital adrenal hyperplasia (CAH). We analyzed the distribution of these cutoff values, considering factors such as birth weight, gestational age, and the timing of sample collection. Notably, applying the newly established cutoff criteria led to a significant reduction in false positive rates. Our laboratory’s data can serve as a valuable reference for other institutions aiming to set appropriate cutoffs, thereby minimizing unnecessary follow-up tests and enhancing the efficiency of CAH screening. As we continue to accumulate additional data, further reserch in this field remains promising.
A-072 Growth hormone stimulation tests: experience of a large cohort from a Brazilian diagnostic medical center
Authors: Correa Wengerkievicz Lopes A , Munhoz M F , Schrank Y , Nakaguma M , Spina L D , Machado I F , Teles A C , Pieroni F B , Perozo A F , Cavalcante L L 
Published: October 2024

Abstract

Background
Growth hormone (GH) stimulation tests are used to diagnose short stature in children and to assess hypothalamic-pituitary axis in adults. The most frequently stimulation tests are: oral clonidine (CLO), insulin-induced hypoglycemia (ITT), glucagon (GLU) and exercise (EXE). Well-known side effects are hypotension, nausea and vomiting. The aim of this study was to evaluate side effects and intercurrences observed during the performance of GH stimulation tests and to identify their possible predisposing factors.

Methods
From April/2022 to May/2023, in a large private laboratory located in 8 different sites, 3,006 GH stimulation tests were performed, with 266 patients with two or more GH stimulation tests.

Results
Considering only patients aged &lt; 18 years (95% of the tests), the mean age was 10.3 ± 2.7 years (median 10.6 years), with 62.5% being male. GH stimulation test was distributed as follows: 64% CLO, 27.6% ITT, 7% GLU and 1.4% EXE. Patients with a history of asthma, allergies, seizure and heart disease were reported in 3%, 1.7%, 0.9% and 0.6%, respectively. More than 2 punctures for venous access were necessary in 9.3% of the cases, particularly in CLO test. The age of patients submitted to GLU was significantly lower compared to CLO and ITT (9.5 ± 3.3 years vs 10.3 ± 2.7 years and 10.6 ± 2.6 years, p &lt; 0.001). Side effects were noted in only 5.1% of the total tests (145/2,863 tests), most frequent in the GLU (50/197 tests, 25%) and none observed in the EXE. There was no correlation of reported side effects with age and weight. As expected, hypotension was more frequent in CLO (27%), not associated with the oral clonidine administered dose (0.1 or 0.150 mg/SC). Nausea and vomiting occurred in 23% of the GLU tests. Symptomatic hypoglycemia that needed glucose administration (oral or parenteral) occurred in 8% of the ITT. Cough was observed in 6 patients during CLO, with no previous history of asthma or allergies. There were no occurrences that hospital transfer was need.

Conclusions
GH stimulation tests are safe and rarely cause serious side effects, certainly due to the presence of a prepared team for promptly support.
A-082 Establishment of Infant Free T4 Reference Interval Through Indirect Methods
Authors: Wu Z , Bi C , Li E M , Schindler E I , Marcelli M I , Wong E C , Clarke N J 
Published: October 2024

Abstract

Background
Children require reference intervals distinct from adults and, based on their unique developing physiology, several intervals are often required to accurately reflect the distribution of expected results in a healthy pediatric population. The establishment of pediatric reference intervals has proven challenging. While consenting adults volunteer to contribute their biological material towards the development of a reference interval, well children usually do not have the occasion to get blood drawn and the smaller the child, the more significant the impact of phlebotomy. For these reasons, scientists have sought out other methods for determining pediatric reference intervals. As an alternative, indirect statistical methods may be applied to large data sets of laboratory test results to ascertain a reference interval. The Multi-Modal Decomposition (MMD) is an iterative indirect method that decomposes a mixture of multiple normal distributions into separate components using the expectation-maximization (EM) algorithm The objective of the current study, was to apply MMD to ascertain reference intervals for free T4 in infants.

Methods
The study population included infants ranging in age from 1 day to 60 days who had specimens submitted for free T4 testing involving equilibrium dialysis followed by LC-MS/MS in a commercial reference laboratory (Quest Diagnostics Nichols Institute, San Juan Capistrano, CA). MMD was performed on 25,271 de-identified free T4 results to establish the reference intervals that were validated by comparison against free T4 values obtained on 238 de-identified specimens submitted for acylcarnitine testing, the specimen were analyzed for TSH and only the in-range specimens were include for Free T4 reference interval analysis.

Results
MMD analysis demonstrated distinct reference intervals for the following ages: 0 to 6 days (1.8 - 6.1 ng/dL), 7 days to &lt;2 weeks (1 - 4.4 ng/dL), 2 to &lt;3 weeks (0.8 - 3.5 ng/dL), 3 to &lt;4 weeks (0.8 - 3 ng/dL), and 4 to &lt;8 weeks (0.7 - 2.8 ng/dL). The data did not support the use of separate intervals for male and female children.

Conclusions
MMD analysis demonstrated distinct reference intervals for the following ages: 0 to 6 days (1.8 - 6.1 ng/dL), 7 days to &lt;2 weeks (1 - 4.4 ng/dL), 2 to &lt;3 weeks (0.8 - 3.5 ng/dL), 3 to &lt;4 weeks (0.8 - 3 ng/dL), and 4 to &lt;8 weeks (0.7 - 2.8 ng/dL). The data did not support the use of separate intervals for male and female children.
A-083 Performance evaluation of Sentinel Diagnostics’ ACE assay on the Abbott Alinity c system and ARCHITECT c16000 System
Authors: Brambilla S , Assalini C , Frana E , Lucini R , Novati D 
Published: October 2024

Abstract

Background
The analytical performances of the Angiotensin Converting Enzyme (ACE) assay for quantitative determination of ACE activity in human serum and plasma have been evaluated on the Abbott Alinity c system and ARCHITECT c16000 System. ACE (dipeptidyl carboxypeptidase) is a glycoprotein peptidyldipeptide hydrolase that cleaves histidylleucine dipeptide from angiotensin I, a relatively inactive decapeptide. The latter is converted to the potent vasoconstrictor, angiotensin II. ACE also inactivates bradykinin. Elevated levels of ACE activity occur in serum of patients with active sarcoidosis, and occasionally in premature infants with respiratory distress syndrome, in adults with tuberculosis, Gaucher’s disease, leprosy, and in many other pathologic conditions involving lung and liver diseases.

Methods
ACE hydrolyses urylacryloylphenylalanine-glycylglycine (FAPGG) to furylacryloylphenylalanine (FAP) and glycylglycine. Hydrolysis of FAPGG results in a decrease in absorbance at 340 nm. The ACE activity in the sample is determined by comparing the sample reaction rate to that obtained with the Sentinel ACE calibrator. Performances evaluation have been done following the latest CLSI guidelines protocols available.

Results
Summary of the analytical performances for the tested assay is reported in table below.

Conclusions
Analytical performances of Sentinel Diagnostics’ ACE assay demonstrate that quantitative determination of ACE activity in human serum and plasma are suitable for the routine measurement of the analyte on Abbott Alinity c system and ARCHITECT c16000 System.
A-095 A New CO2 Assay with Concentrated Reagent Having Superior Onboard Stability on Mindray BS-2800M Analyzer
Authors: Wang J , Huang X , Jiang M , Dai J 
Published: October 2024

Abstract

Background
Measurement of total content of CO2 in serum or plasma can be used to assist in the diagnosis of various acid-base disorders. There are small amounts (about 0.04%) CO2 in the earth’s atmosphere, or more in an enclosed clinical laboratory space. The environmental CO2 could be dissolved into the CO2 reagent continuously, in particular at lowered temperature when it is opened and stored on the system, which leads an impact on CO2 assay performance. Presently, competitors mainly use additional inserts or with small opening of the reagent container to reduce the contact with air from reagent, to improve its onboard stability. Here, we designed a new CO2 assay by optimizing the reagent formulation with a new protection mechanism to reduce the amount of CO2 absorption to the reagent and improved its onboard stability. This study evaluated performances of the new CO2 assay on Mindray BS-2800M analyzer.

Methods
Mindray CO2 assay with concentrated reagent is based on PEPC (Phosphoenolpyruvate Carboxylase) enzymatic method. It is designed with an innovative mechanism of reagent formulations with a protective layer of chemical(s) on top of the reagent that prevents CO2 from entering the reagent and reduced its impact to its on-board stability. The onboard stability was conducted with a constant reagent consumption mode to simulate as it in clinical lab use. The onboard study used two levels of Quality Control materials and serum pools. According to CLSI protocols, the following assay performances were evaluated: onboard stability, precision, method comparison, linearity, and interference.

Results
On Mindray BS-2800M analyzer, Mindray CO2 assay demonstrated an excellent onboard stability. With uncapped reagent on the system, the stability is for 21 days without recalibration, with less than ± 5% deviation from day zero. In parallel onboard stability studies, with Roche CO2 reagent on Cobas c701 system, the relative deviation from day zero was found to be within ±10%; and other three manufacturers` results with deviation exceeded ±10% vs. day zero in 7 days. The linearity of Mindray CO2 assay was determined as from 2.0 to 50.0 mmol/L. Our CO2 assay correlated well with Roche CO2 on Cobas c701 (Mindray = 1.0032 * Roche - 0.0186, r≥0.99). The repeatability and with-lab CVs were ranged from 0.64% to 3.41%, respectively. There was no significant interference (&lt;±10%), at CO2 concentration of 15 mmol/L with bilirubin up to 60 mg/dL,hemolysate up to 800 mg/dL, Intralipid up to 1000 mg/dL, triglycerides up to 1000 mg/dL.

Conclusions
On Mindray BS-2800M analyzer, the new CO2 assay demonstrated a good ability against environmental CO2 inference in 21 days of onboard time. The new CO2 assay also shown good performances in precision, correlation (accuracy) and anti-interference from endogenous substances. Therefore, we conclude that the new Mindray CO2 assay is suitable for routine clinical laboratory use.
A-096 A New Direct Bilirubin (DBIL) Assay with Enhanced Performance in Anti-hemolysis Interference on Mindray BS-2800M Analyzer
Authors: Wang J , He H , Long K , Jiang M , Dai J 
Published: October 2024

Abstract

Background
Serum bilirubin could be used to assess liver functions. Due to clinical importance, it is highly desired to have an accurate bilirubin test. However, there are circumstances where error could occur in bilirubin test results. In particular, the hemolysis interference is one of the major problems that could mislead the direct bilirubin results because of their relatively high occurring frequencies in the clinical laboratories. To resolve this issue and improve the accuracy for the direct bilirubin, we developed a new reagent formulation for DBIL assay that minimizes hemolysis interference. In addition, this reagent also shown good performance characteristics on Mindray BS-2800M Clinical Chemistry analyzer.

Methods
The new DBIL assay is a vanadate-oxidation method that bilirubin is gradually transformed to biliverdin because of oxidizing agent vanadate, resulting in decreasing of absorbance at 450 nm. Two-level calibration is used for this assay. DBIL concentrations are obtained from the calibration line with signals from the patient samples in the assay. Following CLSI protocols, basic assay performances were evaluated: interference, precision, linearity, method comparison and low end detection (LOB, LOD, LOQ).

Results
Hemolysis interference was tested in parallel with DBIL reagents from different IVD companies, Roche, Wako and Chinese domestic main-player companies, A, B, and C. The results showed that the reagents of A and B companies were significantly suffered from hemolysis interference with maximum bias exceeded -30%. Although there are some effects on the anti-hemolysis with DBIL reagents of Wako and C company, the DBIL reagent of Mindray was the best with less than -8% of impact when hemolysate hemoglobin was up to 1000 mg/dL (H index). The Diazo DBIL assay from Roche shown issue with hemolysis interference. The interference to our new DBIL assay from lipid (up to 1000 mg/dL) and ascorbic acid (up to 30 mg/dL) were also with less than ±10% impact. The precision study was run according to EP05A3 with two commercial controls (∼ 10 and 30 µmol/L) and three serum sample pools (∼ 6.8,17.1 and 342 µmol/L). The CVs of repeatability were ranged from 0.54% to 0.58% for controls and 0.24% to 0.88% for serum pools, respectively. The within-lab precision was below 2.5%. The analytical linearity was determined as from 0.66 µmol/L to 439.66 µmol/L. For low-end detection, the LOB, LOD and LOQ were 0.5,1.0 and 1.7 µmol/L, respectively. In addition, the Mindray (y) correlated well with the DBIL assay of Wako (x) reagent on Mindray BS-2800M system (y): y =0.9847 x+0.1301 (r =0.9997, n =400, sample range: 1.08 - 430.00 μmol/L).

Conclusions
The new Mindray direct bilirubin assay shown a good anti-hemolysis interference performance on BS-2800M system and demonstrated good performances in other assay characteristics. It is therefore suitable for use in clinical laboratories.