Serological Diagnosis of Leprosy in Patients in Vietnam by Enzyme-Linked Immunosorbent Assay with Mycobacterium leprae -Derived Major Membrane Protein II

Abstract

A serological diagnostic test using phenolic glycolipid-I (PGL-I) developed in the 1980s is commercially available, but the method is still inefficient in detecting all forms of leprosy. Therefore, more-specific and -reliable serological methods have been sought. We have characterized major membrane protein II (MMP-II) as a candidate protein for a new serological antigen. In this study, we evaluated the effectiveness of the enzyme-linked immunosorbent assay (ELISA) using the MMP-II antigen (MMP-II ELISA) for detecting antibodies in leprosy patients and patients' contacts in the mid-region of Vietnam and compared to the results to those for the PGL-I method (PGL-I ELISA). The results showed that 85% of multibacillary patients and 48% of paucibacillary patients were positive by MMP-II ELISA. Comparison between the serological tests showed that positivity rates for leprosy patients were higher with MMP-II ELISA than with PGL-I ELISA. Household contacts (HHCs) showed low positivity rates, but medical staff members showed comparatively high positivity rates, with MMP-II ELISA. Furthermore, monitoring of results for leprosy patients and HHCs showed that MMP-II is a better index marker than PGL-I. Overall, the epidemiological study conducted in Vietnam suggests that serological testing with MMP-II would be beneficial in detecting leprosy.

Insight toward Early Diagnosis of Leprosy through Analysis of the Developing Antibody Responses of Mycobacterium leprae -Infected Armadillos

“…Having demonstrated the ability of a protein antigen (LID-1) to indicate progressive M. leprae infection in armadillos, we expanded our analyses to examine several other proteins that are recognized during the immune responses of leprosy patients (8,9,16,21). We first assessed the ability of each antigen to distinguish sera from an armadillo infected with a high dose of M. leprae from sera obtained from an uninfected armadillo.…”

Identification of serological biomarkers of infection, disease progression and treatment efficacy for leprosy

“…The titres of IgG antibodies to protein antigens generally correlate with the bacterial load and strong responses in MB patients can rival anti-PGL-I responses. The best protein candidates to assess the IgG response include ML0405, ML2331, ML2055 (Reece et al 2006, Duthie et al 2007), ML2028 (Launois et al 1994) and ML2038 , Kai et al 2008. A bioinformatics analysis predicted ML0405 to be one of the most promiscuous M. leprae proteins studied to date and to contain T cell epitopes predicted to be recognised by 50 out of 51 human leukocyte antigen-DR alleles along with seven potential T cell epitopes and 39 potential B cell epitopes, whereas ML2331 contained 24 potential B cell epitopes (Sampaio et al 2011).…”