[A case of lupus cystitis in a 74-year-old woman].

The patient was a 74-year-old woman. As the history of the present illness, Raynaud's phenomenon appeared in 1998, antinuclear antibody positivity was detected in 2002, and she visited our department for the first time. Leukopenia and positivity for anti-DNA and anti-RNP antibodies were present, but active lesions were not, and thus, course observation was selected. Pollakiuria and a sensation of residual urine appeared in February 2005, diarrhea and nausea developed in November, and she was admitted to our hospital. Abdominal CT detected bilateral hydronephrosis, marked hydroureter, and hypertrophy of the urinary bladder wall, cystoscopy detected trabeculation, and features of interstitial cystitis were noted on biopsy. Edematous colon mucosa was noted on lower endoscopy, submucosal inflammatory cell infiltration on biopsy, and IgG deposition in the small vascular wall on immunostaining. Systemic lupus erythematosus (SLE) that developed as lupus cystitis was diagnosed. The clinical findings were improved by 50 mg of prednisolone. Although she developed lupus cystitis at an elderly age of 74 years, IgG deposition in the small vascular wall was detected by immunostaining of the intestinal mucosa. It is a valuable case proved that causative disease of a digestive tract symptom was enterocolitis through an immune complex as autoimmune reaction by SLE immunohistologically. There are 46 cases of lupus cystitis in Japan by 2007 since Kato reported lupus cystitis in 1985. We summarize clinical features of 46 cases and discuss difference with this case.