#2580 Renal thrombotic microangiopathies: etiological spectrum and prognostic factors

Abstract Background and Aims Renal thrombotic microangiopathy (TMA) is a histopathological lesion that can arise in multiple pathological conditions. This study aimed to assess the clinical, biological, histological, prognostic, and therapeutic aspects of patients diagnosed with renal TMA while identifying distinguishing features across different etiological contexts. Method We conducted a retrospective descriptive and analytical study (2010–2024), reviewing cases of patients over the age of 16 years old who had biopsy-confirmed TMA on renal biopsy. Results A total of 160 cases of renal TMA were analyzed. The mean patient age at the time of the renal biopsy was 44.2 ± 15.3 years. Hypertension was the most common presentation, affecting 133 patients (83%). Laboratory findings revealed acute kidney injury in all patients at the time of renal biopsy. The majority of patients (n = 128) exhibited biological markers of TMA (80%): hemolytic anemia in 151 cases (94.3%), thrombocytopenia in 142 cases (88.7%). Renal histopathological examination identified arteriolar involvement in all cases and glomerular TMA in 48 patients (30%). The primary underlying conditions associated with TMA included lupus nephritis (54 cases), non-lupus glomerulopathies (53 cases), malignant HTN (36 cases), and post kidney transplantation (14 cases). Threes cases were attributed to atypical hemolytic uremic syndrome (1.8%). Disease progression to stage 5 chronic kidney disease (CKD) was observed in 145 patients (90%). Age <20 years (P = 0.003), Male sex (P = 0.04), thrombocytopenia at initial presentation (P = 0.03) were identified as independent risk factors for progression to stage 5 CKD in patients with non-lupus glomerulopathy. Conclusion The overall prognosis remains poor, especially in terms of renal function. There is no particular histological parameter that is indicative of an irreversible decline in renal function.