Performance of recombinant ESAT-6 antigen (ML0049) for detection of leprosy patients.
OBJECTIVE
The study was aimed to evaluate the Mycobacterium leprae recombinant early secreted antigenic target-6 (rESAT-6) for its serological performance in leprosy patients.


RESULTS
Employing enzyme-linked immunosorbent assay (ELISA), serum samples were tested for prevalence of immunoglobulin G antibodies against M. leprae rESAT-6. The results revealed that the sensitivity of the assay for smear-positive leprosy patients was 82.4% (14 of 17) while for smear-negative patients it was 19.4% (six of 31). Interestingly, the performance of ESAT-6-based assay was statistically comparable with anti-phenolic glycolipid-I antibody-detecting ELISA, a most widely studied serological assay in leprosy. Regarding specificity, none of the 48 controls was positive indicating that antibody response to ESAT-6 was highly specific. Moreover, a high concordance between bacterial index and anti-ESAT-6 antibody-detecting assay was noted.


CONCLUSIONS
Recombinant ESAT-6 seems to be a potential serological reagent for detection of M. leprae infection.


CONCLUSIONS
ESAT-6 serology may have utility for (i) early diagnosis, particularly, of highly infectious form (multibacillary, MB) of leprosy, (ii) monitoring the response in smear-positive leprosy patients during the course of the chemotherapy, (iii) classification of leprosy patients into MB and paucibacillary groups for treatment purpose. Hence, further research on these lines is warranted.
Parkash
O
O
National JALMA Institute for Leprosy and other Mycobacterial Diseases, TajGanj, Agra, India. om1234@gmail.com
Pandey
R
R
Kumar
A
A
Kumar
A
A
D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007918:Leprosy / Q000175:diagnosis* / Q000382:microbiology; D009166:Mycobacterium leprae / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; C525005:ESAT-6 antigen, Mycobacterium leprae; D011994:Recombinant Proteins