It is time to review concepts on renal involvement in leprosy: pre- and post-treatment evaluation of 189 patients.

BACKGROUND: Functional and morphological renal lesions have been widely described in leprosy for decades. Nevertheless few studies have assessed renal function pre- and during treatment after the advent of multidrug therapy (MDT). METHODS: This is a prospective study involving 189 consecutive patients, with all forms of leprosy (Ridley-Jopling scale). Laboratory (serum urea and creatinine, estimated GFR, urinalysis, microalbuminuria, urinary RBP) and clinical features of renal disease were evaluated previously and after onset (3 and 8 months later) of MDT. RESULTS: One hundred and eighty-nine patients (M 1.8: F 1; mean age 44 ± 16 years) were included just after diagnosis of leprosy and before the introduction of MDT. Mean time until manifestation of symptoms and/or signs of leprosy was 29 ± 56 months (25 days-480 months). Microhematuria and microalbuminuria were detected in 7.5% and 9.6% of the cases, respectively. Elevated serum creatinine was detected in 34% pre-MDT; this was statistically more frequent in males, hypertensive and frequent users of non-steroidal anti-inflammatory drugs (NSAID), as well as in patients with erythema nodosum lepromatosum, 45.5% by the time of diagnosis, 18% after 3 months and 9% after 8 months of MDT (p = 0.039). CONCLUSIONS: Our results suggest that functional renal lesions in leprosy are currently mild and predominantly of glomerular origin, in opposition to the severe involvement described in the past. This improved outcome of renal disease secondary to leprosy is possibly due to the advent of MDT and effective treatment of episodes of reaction, leading to shorter periods of active infectious disease.

Renal manifestations of leprosy: glomerulonephritis, a complication of erythema nodosum leprosum

Although Mycobacterium leprae does not invade the reanl parenchyma, there are many reports of nephritis in patients leprosy. Glomerulonephritis has been observed in autopsy studies, but the relationship to leprosy has never been clearly estabilished. In the present study, we found urinary abnormalities consistent with glomerulonephritis in 11 of 636 leprosarium inhabitants; there was a strong correlation with a history aof erythema nodosum leprosum (ENL). Seven of 8 noninstitutionalizes patients with active ENL aldo had urinary findings suggestive of glomerunephritis. In 2 patients with ENL, 1 of whom had alterations of serum complement suggestive of complement consumption, renal biopsies revealed proliferative glomerulonephritis. ENL has been considered to reflect, in part, the deposition of circulating immune complexes throught the body. These studies suggest that patients with lepromatous leprosy may expreience glomerulonephritis as one manifestation of ENL, and are consistent with recent observations of immne complex deposition in the glomerular capillary walls of the kidneys of patients with leprosy.