Minimal-change nephrotic syndrome associated with mixed connective-tissue disease.

Sir, Mixed connective-tissue disease (MCTD) is a rheumato-logical disorder which has combined features of systemic lupus erythematosus, systemic sclerosis (SSc), polymyositisu dermatomyositis, and rheumatoid arthritis (RA) with anti-bodies to U 1 small nuclear ribonucleoprotein (U 1 snRNP). Although renal involvement was considered to be rare in the initial description w1x, several studies demonstrated that renal disease was found in 10±50% of patients with MCTD w2,3x. However, to our knowledge, nephrotic syndrome due to minimal-change glomerulopathy has not been reported in patients with MCTD. Here we would like to report a MCTD patient who developed minimal-change nephrotic syndrome (MCNS). Case. In November 1999, a previously healthy 31-year-old Japanese woman presented with fatigue, swollen ®ngers, and joint pain. Initial investigations showed: urinalysis, no proteinuria without haematuria; renal and liver function within the normal range; serum protein, 8.2 gudl; serum albumin, 4.2 gudl; blood cell count within the normal range; erythrocyte sedimentation rate, 13 mmuh; and C-reactive protein, 0.1 mgudl. Antinuclear and anti-U 1 snRNP anti-bodies were positive, and anti-dsDNA, anti-Sm, anti-Jo-1, and anti-Scl-70 antibodies were negative. The patient was diagnosed as having MCTD on the basis of Raynaud's phenomenon, swollen ®ngers, polyarthritis, sclerodactyly, muscle weakness, and positive anti-U 1 snRNP antibody. She was followed up in our outpatient clinic and was not given non-steroidal anti-in¯ammatory agents, steroids, or immunosuppressive drugs. In February 2000, 3 months after her initial presentation, the patient noticed persistent oedema on the lower extremities , and was found to have heavy proteinuria. She was admitted to the Nephrology Unit of the Osaka Rosai Hospital on 9 February 2000. The physical examination revealed swollen ®ngers and hands with typical scleroderma-tous skin changes, facial erythema, and pitting oedema on lower extremities. Her blood pressure was 90u60 mmHg, the pulse was 92 b.p.m., and temperature was 37.28C.