Activity of systemic lupus erythematosus in end-stage renal disease patients: study in a Brazilian cohort

BACKGROUND: Dialysis has been associated with lupus remission. We studied the prevalence of systemic lupus erythematosus (SLE) as a cause of end-stage renal disease (ESRD) in the metropolitan area of Rio de Janeiro and assessed disease activity in SLE patients on dialysis. METHODS: Of 3,535 ESRD patients, 63 had SLE (1.8%). Fifty-seven entered the study (54 females, 3 males, 38 +/- 10 years). Hemodialysis consisted of 3 sessions per week of about 4 h duration, blood flow of about 400 ml/min, bicarbonate dialysate ([Ca(2+)] = 2.5-3.5 mEq/l) at 500 ml/min and cellulose acetate or polysulfone dialyzers. Activity was initially defined as: non-renal (nr) SLE disease activity index (SLEDAI) of >0; use of at least 20 mg/day of prednisone; and/or any dose of another activity-controlling drug. Fifty-seven ESRD patients without SLE were used as controls. RESULTS: Eighteen SLE patients were under drug treatment; of the remaining, 30 had an nrSLEDAI of >0 totaling 48 patients (84%) initially labeled as active. An apparent activity was also present in 21 controls (37%). Of those, 19 had an nrSLEDAI of <4. With a cutoff of >or=4, figures in each group would be 49 and 4%. Under this criterion, age was the only significant predictor of flare in our SLE ESRD population in a multivariate logistic regression model. Activity remained high in patients who were on dialysis for >5 years (7/18, 39%). CONCLUSION: SLE accounted for 1.8% of our ESRD patients. Application of SLEDAI to dialysis patients may require consideration of confounding factors related to the ESRD state. Even with a score of >or=4 as a cutoff, SLE activity in dialysis patients was high (49%) and long-lasting. Age was the major determinant of flare.