Evaluation of renal function in leprosy: a study of 59 consecutive patients.
BACKGROUND
Renal abnormalities in leprosy have been largely described in medical literature, but there are few studies evaluating renal function in these patients.


METHODS
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.


RESULTS
Age and gender were similar between leprosy (MB or PB) and control groups. GFR <or= 80 ml/min/1.73 m(2) was observed in 50% of the leprosy patients. GFR and U/P(osm) in leprosy patients were significantly lower than in controls (P<0.001). Urinary acidification defect was found in 32% of PB and in 29% of MB patients and urinary concentrating ability was abnormal in 83% of PB and 85% of MB patients. Microalbuminuria was found in 4 patients (8.5%), leukocyturia was found in 13 (22%) and haematuria was present in 16 patients (27%). Plasma creatinine (P(cr)) >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 <or= 80 ml/min/1.73 m(2) in multivariate analysis.


CONCLUSIONS
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.
Oliveira
Rodrigo A
RA
Department of Internal Medicine, School of Medicine, Federal University of Ceará, Barbalha, CE, Brazil.
Silva
Geraldo B
GB
Souza
Clodoaldo J
CJ
Vieira
Eduardo F
EF
Mota
Rosa M S
RM
Martins
Alice Maria Costa
AM
Libório
Alexandre Braga
AB
Daher
Elizabeth F
EF
D000328:Adult; D001938:Brazil; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests; D007684:Kidney Tubules / Q000503:physiopathology*; D007918:Leprosy / Q000503:physiopathology*; D008297:Male