OBJECTIVETo analyze the clinical and pathological features of microscopic polyangiitis (MPA) to improve the diagnosis and treatment of the disease.

METHODSTwenty-five cases of MPA were retrospectively analyzed.

RESULTSThe onset symptoms of MPA, often nonspecific, included fever, muscle and joint pain, fatigue, loss of weight, etc, with varying degrees of proteinuria, hematuria and renal insufficiency. The pathological types revealed by renal biopsy were mainly focal segmental necrotizing glomerulonephritis or pauci-immune crescentic glomerulonephritis. Timely immunosuppressive therapy could improve the outcome.

CONCLUSIONThe early symptoms of MPA are often nonspecific to easily result in misdiagnosis. Examination of ANCA titers and timely renal biopsy are helpful to establish an early diagnosis. Immune suppression therapy and plasma exchange when necessary should be initiated after the establishment of the diagnosis. The disease activity and drug toxicity should be carefully monitored to improve the prognosis.