Clinical trial NCT05991245: French National Cohort MATRIX "Renal and Systemic Thrombotic Microangiopathy"
Official title: French National Cohort MATRIX "Renal and Systemic Thrombotic Microangiopathy"
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Thrombotic Microangiopathy
Acute Kidney Injury
Hemolytic Uremic Syndrome
Nephrology
Kidney Diseases
Keywords: Thrombotic microangiopathy
Acute kidney injury
Hemolytic uremic syndrome
Kidney histology
Complement
Lead sponsor: University Hospital, Tours
Sponsor class: OTHER
First posted: 2023-08-14
Enrollment: 1000
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The population corresponds to French adult nephrology patients with renal and/or systemic thrombotic microangiopathy, for whom renal biopsy data are available. It is not extendable to renal transplant patients.

Brief summary: Thrombotic microangiopathies (TMAs) are a diverse, rare but serious group of diseases. Progress has been made regarding the epidemiology of TMA (Bayer CJASN 2019). It has been shown that secondary TMAs account for 95% of cases, whereas primary TMAs (atypical hemolytic syndromes (HUS) and thrombotic thrombocytopenic purpura (TTP)) account for only about 5%.

However, in many cases, the pathophysiology, optimal management and prognosis of TMA remains unclear and it has been shown that patients with TMA may have renal-limited TMA or renal and hematological TMA (ie. With (mechanical anemia, thrombocytopenia, elevated LDH, decreased haptoglobin, schistocytes). In most studies, kidney biopsies are not performed and the diagnostic workup is uncomplete.

As this is a rare disease, only a multicenter approach (\>20 centers) over a long period of time (\>10 years), with adequate diagnostic workup including kidney biopsies can help us to answer these questions (investigators in the present are usually members of the CNR-MAT (a network of the TMA centers in France).

Detailed description: Thrombotic microangiopathies (TMAs) are a diverse, rare but serious group of diseases. Their epidemiology has recently been elucidated thanks to work published by our team. It has been shown that secondary TMAs account for 95% of cases, whereas primary TMAs (atypical hemolytic syndromes (HUS) and thrombotic thrombocytopenic purpura (TTP)) account for only about 5%.

However, many epidemiologic problems remain. First, many but not all patients with TMA as classically defined (mechanical anemia, thrombocytopenia, elevated LDH, decreased haptoglobin, schizocytes) have impaired renal function. If a renal biopsy is performed (which is not always the case, as TMA is a risk factor for bleeding after renal biopsy), the renal lesions do not always show "renal-limited" TMA. We also do not know which of the causes of systemic TMA are associated with renal TMA and which are not.

Conversely, in patients with renal biopsy, we can find stigmata of renal-limited TMA in the absence of systemic TMA. Why do some patients have systemic TMA but not renal TMA and others have renal TMA but not systemic TMA? Most studies are based on a few small clinical cases and the literature reviews that report them.

The vital, renal, and cardiovascular prognosis of patients with TMA obviously depends on the cause, the clinical presentation of the patients, and their management. However, the renal, systemic, and vital outcomes of renal-only vs. systemic-only vs. systemic and renal TMA, regardless of the cause and severity of TMA, are currently unknown.

As this is a rare disease, only a multicenter approach (\>20 centers) over a long period of time (\>10 years), including highly recruited university and general hospitals, with experienced and motivated investigators, can help us to answer these currently unanswered questions (these investigators usually belong to the competence centers of the national reference center).

Eligibility criteria: Inclusion Criteria:

1. Adult patients 18 years of age or older
2. Who have undergone renal biopsy of the native kidney for impaired renal function between 2009 and July 2022.
3. Presence of classically defined systemic MAT (most of the following parameters: elevated LDH, decreased haptoglobin, schizocytes, thrombocytopenia and anemia) AND/OR presence of arteriolar or glomerular renal MAT as indicated by the pathologist (including endothelial turgor, mesangiolysis, double contours, presence of thrombi, fibrinoid necrosis of the arterial wall).

Exclusion Criteria:

1. Kidney transplantation

Primary outcomes:
measure: Presence of isolated renal, hematological or renal associated with hematological features ot thrombotic microangiopathies
timeFrame: 1/ Baseline, ie date of kidney biopsy
Secondary outcomes:
measure: Assess correlations between specific anatomopathological lesions and thrombotic microangiopathies phenotypes
timeFrame: 1/ Baseline, ie date of kidney biopsy
measure: Assess correlations between cause of thrombotic microangiopathies and clinical phenotypes
timeFrame: 1/ Baseline, ie date of kidney biopsy
measure: Define the biological profile (standard biology and alternative complement pathway analyses including genetic data) of these thrombotic microangiopathies.
timeFrame: 1/ Up to 2 weeks after baseline date ; 2/ Date of last follow-up, an average of 2 years
measure: Define the renal, cardiovascular and vital prognosis of these patients
timeFrame: 1/ Hospital discharge date, an average of 2 weeks ; 2/ Date of last follow-up, an average of 2 years
measure: Define treatments for these patients
timeFrame: 1/ Hospital discharge date, an average of 2 weeks
Other outcomes:
Locations:
city: Tours
country: France
facility: Department of Nephrology, University Hospital of Tours
Study officials:
affiliation: CHRU TOURS, Nephrology
name: Jean-Michel Halimi, MD, PhD
role: STUDY_DIRECTOR
affiliation: CHRU TOURS, Nephrology
name: Valentin Maisons, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Goodship TH, Cook HT, Fakhouri F, Fervenza FC, Fremeaux-Bacchi V, Kavanagh D, Nester CM, Noris M, Pickering MC, Rodriguez de Cordoba S, Roumenina LT, Sethi S, Smith RJ; Conference Participants. Atypical hemolytic uremic syndrome and C3 glomerulopathy: conclusions from a "Kidney Disease: Improving Global Outcomes" (KDIGO) Controversies Conference. Kidney Int. 2017 Mar;91(3):539-551. doi: 10.1016/j.kint.2016.10.005. Epub 2016 Dec 16.
citation: Bayer G, von Tokarski F, Thoreau B, Bauvois A, Barbet C, Cloarec S, Merieau E, Lachot S, Garot D, Bernard L, Gyan E, Perrotin F, Pouplard C, Maillot F, Gatault P, Sautenet B, Rusch E, Buchler M, Vigneau C, Fakhouri F, Halimi JM. Etiology and Outcomes of Thrombotic Microangiopathies. Clin J Am Soc Nephrol. 2019 Apr 5;14(4):557-566. doi: 10.2215/CJN.11470918. Epub 2019 Mar 12.
citation: Genest DS, Patriquin CJ, Licht C, John R, Reich HN. Renal Thrombotic Microangiopathy: A Review. Am J Kidney Dis. 2023 May;81(5):591-605. doi: 10.1053/j.ajkd.2022.10.014. Epub 2022 Dec 10.