A Case of Polymyositis Associated with Immunoglobulin A Nephropathy

ABSTRACT

Polymyositis (PM) is a chronic inflammatory disease that predominantly affects muscles. Systemic organ involvement, including the respiratory and gastrointestinal tracts, is frequently observed in PM, but renal involvement is rare. Herein, we report the case of a 56-year-old woman presenting with weight gain, edema, and generalized myalgia. Laboratory tests revealed elevated creatinine kinase level, hypoalbuminemia, and proteinuria. Histopathological examination of muscle biopsy revealed inflammatory myositis, and a renal biopsy confirmed immunoglobulin A (IgA) nephropathy. Based on the clinico-pathological results, the patient was diagnosed with PM with IgA nephropathy. This is a report of a rare occurrence of IgA nephropathy in a patient with PM presenting with chronic glomerulonephritis.