Detection of Phenolic Glycolipid I of Mycobacterium leprae in Sera from Leprosy Patients before and after Start of Multidrug Therapy

Abstract

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.

Unveiling healthy carriers and subclinical infections among household contacts of leprosy patients who play potential roles in the disease chain of transmission

“…The result of each test alone has special clinical significance. The anti-PGL-I serology was strongly correlated with the MB OC and associated CFs of leprosy, indicating a possible active infection, as shown elsewhere (Cho et al 2001, Martinez et al 2011. However, the presence of M. leprae DNA in nasal swabs has been used as an epidemiological tool to understand the role of both patients and contacts in the complex transmission chain (Hatta et al 1995, Beyene et al 2003, Patrocínio et al 2005, Job et al 2008.…”

Expression of the capsid protein of Chikungunya virus in a baculovirus for serodiagnosis of Chikungunya disease

“…Enzyme-linked immunosorbent assays (ELISA) were performed to confirm the reactivity of recombinant CHIKV capsid protein to anti-CHIKV IgM antibodies as described before (Cho et al, 2001;Thein et al, 1992). Ninety-six-well enzyme immunoassay (EIA) plates (Costar, Cambridge, MA, USA) were coated with serial dilutions of recombinant CHIKV capsid protein (1, 2, 4 and 8 g/ml) in polycarbonate buffer (pH 9.2) overnight at 4 • C. Plates were then washed and blocked with PBS (pH 7.4) containing 1% BSA for 1 h at 37 • C. Sera samples were diluted in PBS containing 1% BSA (1:100) and were then added to the wells and incubated for 1 h at 37 • C. The bound antibodies were detected with HRP-conjugated mouse anti-human IgM antibody (1:3000 dilution, Standard Diagnostics, Yongin, Korea).…”

Hanseníase: considerações sobre o desenvolvimento e contribuição (institucional) de instrumento diagnóstico para vigilância epidemiológica

“…O estudo de Douglas et al 21 demonstrou um risco 30 vezes maior de o contato positivo ao PGL-I vir a adoecer de hanseníase, comparado ao negativo. Esses estudos sugerem que a infecção subclínica é mais comum que a manifestação da doença clínica 21,22 .…”