RENAL THROMBOTIC MICROANGIOPATHY IN SYSTEMIC LUPUS-ERYTHEMATOSUS - CLINICAL CORRELATIONS AND LONG-TERM RENAL SURVIVAL

Background. Renal (TMA) is an uncommon vascular complication of system ic lupus erythematosus (SLE). Its clinical symptoms and impact on rena l survival remain unclear. Methods. Eight patients aged 25 +/- 6 years with biopsy-proven renal TMA and at least four ARA criteria for the d iagnosis of SLE were retrospectively studied over a 7-year period. Res ults. All patients presented with renal failure (creatinine 3.3 +/- 2. 1 mg/dl), six had proteinuria (2.5 +/- 1.3 g/day) with microscopic hae maturia in four cases. Six patients had hypertension, which was severe in five cases. Renal histology disclosed arterial and/or arteriolar t hrombosis with parietal thickening without angeitis (8 patients), glom erular microthrombi (3 patients), and vascular fibrin deposits (5/6 pa tients). In two cases, vascular lesions were associated with a mesangi al or a proliferative glomerulonephritis. Thrombocytopenia was present in four patients with haemolytic microangiopathic anaemia in one case . Lupus anticoagulant (LA) was detected in five of eight patients, who also had anticardiolipin antibodies (3/7 patients) and/or were positi ve for VDRL (3/6 patients). Four patients with LA experienced arterial thrombosis and/or repeated spontaneous abortions. Treatment consisted of corticosteroids (8 patients), cytotoxic drugs (4 patients), plasma exchanges and/or intravenous immunoglobulins (4 patients) and antipla telet and/or anticoagulant therapy (3 patients). Two patients recovere d normal renal function and five had persistent renal insufficiency. O ne patient started haemodialysis on admission and died of sepsis 2 mon ths later. Conclusions. TMA may be the sole renal complication in SLE and is not usually associated with haemolytic microangiopathic anaemia . In our series renal survival was influenced by the extent and severi ty of vascular lesions. Despite a frequent association with antiphosph olipid antibodies, pathophysiological mechanisms of renal TMA in SLE r emain unknown. Renal histology is mandatory for the diagnosis and the prognostic evaluation of renal vasculopathy in SLE.