SUN-166 THROMBOTIC MICROANGIOPATHY IN KIDNEY DISEASE: SEVERAL ETIOLOGIES

Abstract

Thrombotic microangiopathy (TMA) in kidney disease is an histopathologic finding which is characterized by endothelial cell injury and microavascular thrombosis. It is a lesion associated with multiple etiologies. The presentation depends on the cause and typically includes the triad of hemolytic anemia, thrombocytopenia and acute kidney injury. In this paper, we propose to relate different etiologies of TMA noted on kidney biopsies and examine their clinical manifestations and laboratory data. We realized a retrospective descriptive monocentric study which took place at the internal medicine department in Charles Nicolle hospital in Tunisia. Over a period of 15 years (from January 2001 to January 2016). We collected the clinical and laboratory data in patients wich have had renal biopsies revealing histological TMA. We documented histological TMA in one hundred patients: 52 man and 48 women. The mean age of patients at the time of renal biopsy was 38,5+/-12,9 years (range 19-72). Seventy patients had high blood pressure. The diastolic blood pressure ranged from 50 to 130mmhg. Neurological examination was normal in 87 patients, 6 patients had systemized motor deficit and 7 patients had generalized seizures. Urine analysis showed: only 4 patients didn't have protenuria and 23 patients didn't have hematuria. Results of the laboratory investigations were as follows: hemoglobin was decreased in 75 patients. The mean hemoglobin concentration was 8,7+/-2,4g/dl (range15-4,2g/dl). The thrombocytes were decreased in only 30 patients. The mean thrombocyte concentration was 214.730+/-95.241/mm (range 19000-450000/mm). The level of serum lactate deshydrogenase was elevated in 38 patients. Coombs test was negative in 70 patients and red blood cell fragments were observed in 22 patients. Kidney injury was noted in 92 patients. Histological TMA was related to: malignant hypertension in 19 patients, an auto-immune disease in 20 cases, to oestroprogestatif medication in a patients, associated to a nephropathy in 47 case, post kidney transplantation in 9 cases, post stem cell transplantation in 1 cas, post partum in 2 cases and associated to multiple myelomain 1 case. In summary histological TMA can occur in a multiple range of diseases and the clinical manifestations can be extremely diverse. These findings leads to conclude to the necessity of a clear care pathway in thrombotic microangiopathies (TMA's) and the necessity to develop our knowledge about the mechanism and risk factor off all TMA'sincluding the role of the alternative complement pathway in secondaryTMA's.