#6849 CLINICOPATHOLOGIC CHARACTERISTICS IN RENAL THROMBOTIC MICROANGIOPATHY

Abstract Background and Aims Thrombotic microangiopathy (TMA) is a life-threatening condition that can be caused on the background of various mechanisms, converging to severe endotheliopathy often affects kidneys. Morphologic features TMA kidney biopsy have not been systematically studied. We studied diagnostic prognostic role in patients with TMA, either linked coexisting (i.e., secondary TMA) or complement-mediated [C-]TMA). Method Patients an enzymatic activity ADAMTS13 >10% were recruited from Limburg Renal Registry. C-TMA was defined as massive ex vivo C5b9 formation endothelium and/or rare variants complement genes [1]; presence normal regulation. Kidney tissue sections for chronicity; also, C3d staining performed. Results diagnosed 35 39 patients, respectively. The diagnosis based 52 (70%) out 74 systemic hemolysis, is, microangiopathic hemolytic anemia (MAHA) thrombocytopenia, lacking. activity, such as, glomerular thrombosis mesangiolysis, associated MAHA (p = 0.116) thrombocytopenia 0.380). however, C-TMA, lower age higher serum creatinine. did differentiate TMA. A Mayo Clinic Chronicity Score (MCCS) ≥4 increased partial- 0.023) complete renal remission rate 0.030), decreased end-stage disease 0.050). Conclusions Only small proportion initially present suggesting essential histologic examination prevent underdiagnosing. Glomerular mesangiolysis however there no differentiating An MCCS indicates worse outcome