Is there an ethnic difference in the prevalence of lupus cystitis? A report of six cases.

Lupus cystitis was rare but frequently resulted in obstructive uropathy and had a strong association with gastrointestinal (GI) symptoms. We treated six patients with systemic lupus erythematosus (SLE) and obstructive uropathy from January 1996 to December 2001 in a university hospital. Evidence of cystitis was obtained from cystoscopic biopsy or the presence of thickened bladder wall in image study. Similar to other reports, five patients had GI manifestations such as abdominal pain, nausea/vomiting, diarrhoea or ileus. In addition, mesenteric lymphadenopathy or pancreatitis was noted in three patients. Two patients had been treated for idiopathic thrombocytopenic purpura (ITP), four and 20 years ago, respectively. All six patients had antibodies to double-stranded DNA (dsDNA). Five patients each had antibodies to cardiolipin (IgG aCL) or SSA. The high prevalence of anti-SSA had also been reported in Chinese lupus patients with intestinal pseudo-obstruction, a clinical manifestation frequently associated with bilateral ureterohydronephrosis. Two patients died of intractable infection after the surgical procedures for persistent ureterohydronephrosis and both patients had antibodies to ribosomal P proteins. Lupus cystitis might not be so rare in Chinese patients with SLE. The diagnosis should be kept in mind when lupus patients have urinary and/or GI symptoms.