Clinical features of kidney involvement in microscopic microscopic polyangiitis

Aim. To evaluate clinical features and outcomes of renal involvement in patients with microscopic polyangiitis (MPA). Materials and methods: We enrolled 99 patients with MPA, diagnosed in accordance with the algorithm of the European Medicines Evaluation Agency (EMEA) and the Chapel Hill consensus conference definition (2012). Serum creatinine (sCr), estimated glomerular filtration rate (eGFR), hematuria and proteinuria were estimated. Frequency of rapidly progressive renal failure (a twofold increase in the sCr level in ≤3 months) was regarded as the clinical equivalent of rapidly progressive glomerulonephritis (RPGN). Results and discussion. Renal involvement was present in 92 (92.9%) patients. RPGN developed in 51 (55,4%) patients. The most common features of kidney involvement were hematuria and subnephrotic proteinuria. Arterial hypertension was revealed in 32 (34.7%) patients and was associated with RPGN (p