IgM antibodies against phenolic glycolipid I from Mycobacterium leprae in leprosy sera: relationship to bacterial index and erythema nodosum leprosum.
Serum IgM antibodies against Mycobacterium leprae-derived phenolic glycolipid I (PG) were determined in 121 leprosy patients, in contacts and controls by an enzyme-linked immunosorbent assay technique. Anti-PG IgM levels correlated with disease classification, increasing from the tuberculoid towards the lepromatous pole of the disease spectrum. There was a linear correlation between serum IgM PG-antibody levels and bacillary index (BI), a measure of bacterial load. Elevated anti-PG IgM in bacillary negative patients was usually indicative of active disease, undetected by BI. We conclude that anti-PG IgM levels are valuable for monitoring the degree of disease activity. Serum anti-PG IgM levels were significantly lower in patients with erythema nodosum leprosum (ENL) as compared to those without ENL, suggesting that IgM PG-antibodies are also involved in the pathogenesis of ENL.
D000907:Antibodies, Bacterial / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D004893:Erythema Nodosum / Q000276:immunology* / Q000382:microbiology; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D007918:Leprosy / Q000276:immunology* / Q000382:microbiology; D009166:Mycobacterium leprae / Q000276:immunology*; D010636:Phenols / Q000276:immunology
D000907:Antibodies, Bacterial; D006017:Glycolipids; D007075:Immunoglobulin M; D010636:Phenols