Although Mycobacterium leprae does not invade the renal parenchyma, there are many reports of “nephritis” in patients with leprosy. Glomerulonephritis has been observed in autopsy studies, but the relationship to leprosy has never been clearly established. 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 of erythema nodosum leprosum (ENL). Seven of 8 noninstitutionalized patients with active ENL also had urinary findings suggestive of glomerulonephritis. 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 throughout the body. These studies suggest that patients with lepromatous leprosy may experience glomerulonephritis as one manifestation of ENL, and are consistent with recent observations of immune complex deposition in the glomerular capillary walls of the kidneys of patients with leprosy.
Present address: Division of Infectious Diseases, San Francisco General Hospital, 1001 Potrero Avenue, San Francisco, California 94110.