Evaluation of renal function in leprosy: a study of 59 consecutive patients

Renal abnormalities in leprosy have been largely described in medical literature, but there are few studies evaluating renal function in these patients.

This is a cross-sectional study in 59 consecutive paucibacillary (PB) and multibacillary (MB) leprosy patients. Glomerular filtration rate (GFR) was estimated by simplified-MDRD formula. Microalbuminuria was determined by 24 h urine collection. Urinary acidification capacity was measured after water deprivation and acid-loading with CaCl(2). Urinary concentration capacity was evaluated after desmopressin acetate administration, using the urinary to plasma osmolality (U/P(osm)) ratio. All parameters except microalbuminuria were measured in a control group of 18 healthy volunteers.

Age and gender were similar between leprosy (MB or PB) and control groups. GFR 1.2 mg/dl was observed in 17.9% of MB patients and in none of the controls (P=0.020). A negative correlation was observed between GFR and time of treatment (r= -0.339; P=0.002). Age and time of treatment were independent risk factors for GFR

Asymptomatic GFR changes and renal tubular dysfunction, including urine concentration defect and impaired acidifying mechanisms, can be caused by leprosy on specific treatment and without any reaction episodes.