Renal involvement in leprosy: retrospective analysis of 461 cases in Brazil

Renal lesions in leprosy have been extensively described, including amyloidosis, glomerulonephritis, nephrosclerosis, tubulointerstitial nephritis and granulomas.

A retrospective study was designed to detect renal function abnormalities in 461 leprosy patients, without any co-morbidity, seen in a university hospital in northeast Brazil. The laboratory test results concerning renal function were examined in the patients' medical records.

The mean age was 39 +/- 18 years and 217 (47%) were male. The mean duration of disease was 21 +/- 38 months. Levels of creatinine above 1.4 mg/dL had been detected in 40 patients (8.6%). The levels of creatinine and urea were higher in lepromatous leprosy patients. Proteinuria, hematuria and hemoglobinuria were significantly more frequent in this presentation of leprosy. Nephrotic levels of proteinuria (>3.5 mg/dL) were found in three (2.1%) of 138 lepromatous leprosy patients. A positive association was found between duration of disease and high levels of creatinine in the general sample and in the lepromatous leprosy patients. There was no association between time of treatment and high levels of creatinine.

Renal involvement in leprosy seems to be related to the quantity of bacilli present in the body. It is important to evaluate the renal function in all leprosy patients in order to detect any abnormality and prevent renal failure, which is still a potential cause of death in this disease.