Sensitivity of a Rapid Mix Test with Combined Synthetic Antigens Derived from Mycobacterium Leprae PGL-1 for Diagnosis and Surveillance of Leprosy

Abstract

Introduction: In the Americas, Brazil contributes 91.63% of the total cases and the state of Pará still has high endemia for leprosy. Objective: To analyze the performance of a rapid test for the diagnosis and epidemiological surveillance of leprosy in endemic areas. Methods: The sample consisted of 70 MB multibacillary leprosy (MB) patients, 63 paucibacillary (PB) patients, and 80 intradomiciliary consanguineous contacts (ICSCO) of patients. A rapid test with a 15-minute reading was applied using two prototypes: prototype 1, double test with trisaccharide antigen (NT-P-BSA) at 1a. line (83.2 ng/test) and disaccharide antigen (ND-O-BSA) at 2a. (83.2 ng/test), both with a flow of 0.08 μL/mm with a 10 μC membrane, anti-IgM conjugate with a flow of 0.040 μL/mm and a Tris-Triton and prototype 2 runner buffer with MIX antigen (trisaccharide + disaccharide) in the same concentrations and conditions of prototype 1. Results: The comparison of the MIX test positivity rate and the disaccharide or trisaccharide doublet test across all samples was statistically significant, demonstrating that the MIX test had higher seropositivity rates compared to the ND-O-BSA or NT-P-BSA. It was demonstrated that the MIX test showed a good performance, with 25.39% of the PB patients negative for the disaccharide and trisaccharide duplet test, but positive for MIX. Conclusions: These data suggest the potential for further optimizing the performance by adding other synthetic antigens to the MIX antigens.

BCG Vaccination Status, Age, and Gender as Risk Factors for Leprosy in Endemic Areas in the Brazilian Amazon

“…The group of patients was composed of individuals with a clinical diagnosis of leprosy, undergoing treatment from three months to five months, who at the time of diagnosis were classified according to the Ministry of Health of Brazil into paucibacillary (PB) or multibacillary (MB) [ 2 , 8 ]. The contact group consisted of individuals who lived with leprosy patients and did not have clinical symptoms of leprosy.…”

HSP60 mimetic peptides from Mycobacterium leprae as new antigens for immunodiagnosis of Leprosy

“…The complementary immunological tests available for leprosy, which include the use of natural Mycobacterium leprae antigens, have represented an important tool in the diagnosis of the disease, as PGL-1 (Leturiondo et al 2019 ), recombinant proteins (Reece et al 2006 ; Silvestre et al 2018 ), or fused proteins (Silva et al 2017 ; Silvestre et al 2020 ) have been used in ELISA (enzyme-linked immunosorbent assay) and lateral flow tests (Bührer-Sékula et al 2007 ).…”