Detection of phenolic glycolipid I of Mycobacterium leprae in sera from leprosy patients before and after start of multidrug therapy

• Published in: Clinical and diagnostic laboratory immunology Vol. 8; no. 1; pp. 138 - 142
• Main Authors: Cho, S N, Cellona, R V, Villahermosa, L G, Fajardo, Jr, T T, Balagon, M V, Abalos, R M, Tan, E V, Walsh, G P, Kim, J D, Brennan, P J
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.01.2001
• Subjects: Antigens, Bacterial - blood; Enzyme-Linked Immunosorbent Assay - methods; Glycolipids - blood; Humans; Leprostatic Agents - therapeutic use; Leprosy - blood; Leprosy - drug therapy; Leprosy - immunology; Leprosy - microbiology; Microbial Immunology; Mycobacterium leprae; Mycobacterium leprae - immunology; phenolic glycolipid I; Prospective Studies
• ISSN: 1071-412X; 1098-6588
• DOI: 10.1128/CDLI.8.1.138-142.2001

A total of 100 untreated new leprosy patients were recruited prospectively and examined for the presence of phenolic glycolipid I (PGL-I) antigen in their serum specimens by dot enzyme-linked immunosorbent assay (ELISA) using rabbit anti-PGL-I antiserum. The presence of circulating PGL-I antigen was closely related to the bacterial indices (BI) of the patients. The PGL-I antigen was detectable in 27 (93.1%) of 29 patients with a BI of 4.0 or above and in 15 (68.2%) of 22 patients with a BI of 3.0 to 3.9. However, none of the 37 patients with a BI of less than 1.9 had detectable PGL-I antigen by the methods used in this study. The level of PGL-I in serum declined rapidly by about 90% 1 month after the start of multidrug therapy. This study showed clearly that anti-PGL-I IgM antibodies and circulating PGL-I antigen levels reflect the bacterial loads in untreated leprosy patients. The serological parameters based on the PGL-I antigen may therefore be useful in the assessment of leprosy patients at the time of diagnosis and possibly in monitoring patients following chemotherapy.