Sensitivity of ELISA anti-PGL-1 test with two derived synthetic antigens of PGL-1 of Mycobacterium leprae

Abstract

The diagnosis of leprosy is mainly clinical, but the identification of the main antigen of Mycobacterium leprae cell wall, phenolic glycolipid 1 (PGL-1), contributed to studies about humoral immunity in leprosy. This experimental study evaluated the sensitivity of ELISA anti-PGL-1 test using two semisynthetic glycolipids, disaccharide (ND-O-BSA) and trisaccharide (NT-P-BSA) as a potential tool for assisting the diagnosis of leprosy. The sensitivity/specificity to trisaccharide and disaccharide antigens was 97% and 98% and 83.3% respectively and 96.1% comparing patients with multibacillary leprosy (MB), consanguineous contacts (CCOS) and non-consanguineous (NCCOS). The trisaccharide antigen (NT-P-BSA) had a better development in the diagnosis with MB leprosy patients (p < 0.0001) compared to disaccharide antigen (ND-O-BSA), which was more suitable for the diagnosis of leprosy in paucibacillary patients - PB (PB x CCOS sensitivity = 80%). Besides that, the trisaccharide antigen was more suitable in the epidemiological surveillance CNCOS (X² = 12,979, p = 0.0003). In endemic regions, the use of two antigens in the serology of leprosy is helpful in analyzing serum-epidemiological aspects that are important to the diagnosis and monitoring of leprosy.