[Clinical features of polymyositis and dermatomyositis in four patients with renal involvement as mainly presentation.].

OBJECTIVE

To investigate the clinical features of polymyositis (PM) and dermatomyositis (DM) with renal involvement as mainly presentation.

METHODS

We analyzed clinical data retrospectively of 4 patients with PM/DM in our department who had renal involved and reviewed its clinical features and therapeutic approaches.

RESULTS

Four female patients (median age: 55 years) with PM/DM had renal involved from 2003 to 2008 were enrolled in this study. The clinical diagnosis was type 1 renal tubular acidosis for one patient and end stage renal disease (ESRD) for the reminding three patients. Two patients had renal biopsy which showed focal segmental glomerulosclerosis and minimal change disease. One patient had bladder carcinoma after 6 years of polymyositis and gradually progressed to ESRD.

CONCLUSIONS

Clear diagnosis of PM/DM should be made by physician combine clinical information, serum enzyme changes and electromyogram manifestation. Muscular biopsy is strongly recommended if condition permits. Due to potential opportunity of carcinoma coexisting with PM/DM, physician also should take thoroughly physical check-up to find or exclude potential systemic carcinomas. Renal involvement is rare in patients with PM/DM, mesangial proliferative glomerularnephritis is exclusively common in PM. Treatment with steroid or intravenous methylprednisolone and immunoglobulin are effective.