Antibody response to phenolic glycolipid I and Mycobacterium w antigens and its relation to bacterial load in M. leprae-infected mice and leprosy patients.
Twenty-six inbred BALB/cBy mice were infected with live Mycobacterium leprae by injecting 6 x 10(3) bacilli in the hind footpad. Bleeds were collected at monthly intervals. After 6 months, acid-fast bacilli (AFB) were harvested monthly from the footpad of mice. The sera were analysed in enzyme immunoassay for antibodies against phenolic glycolipid I (PGL-I) of M. leprae and antigens of Mycobacterium w (M. w); 21 out of 26 (80.7%) mice demonstrated the presence of antibodies against PGL-I and M. w . Anti-M. w antibodies appeared slightly earlier than did anti-PGL-I antibodies. The titre of anti-M. w antibodies was higher than that of anti-PGL-I antibodies. The mice giving a positive antibody response had more than 7 x 10(5) AFB/footpad. The coefficient of correlation (r) between the number of AFB and antibody titres at the time of harvest was 0.566 for PGL-I and 0.628 for M. w. The value of r for bacterial index and antibody titres in 188 leprosy patients was 0.510 for PGL-I and 0.418 for M. w; these values were statistically significant (P < 0.001). The decrease in bacterial index and antibody titres in treated lepromatous leprosy patients correlated with increase in the duration of chemotherapy. The measurement of anti-PGL-I antibodies of IgM class may serve as an adjunct to skin biopsy and skin-slit smear for serial monitoring of the bacterial load in the course of chemotherapy in leprosy control programmes.
Moudgil
K D
KD
Department of Biochemistry, All India Institute of Medical Sciences, New Delhi.
Gupta
S K
SK
Naraynan
P R
PR
Srivastava
L M
LM
Mishra
R S
RS
Talwar
G P
GP
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000942:Antigens, Bacterial; D016022:Case-Control Studies; D003429:Cross Reactions; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis; D007918:Leprosy / Q000276:immunology* / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009161:Mycobacterium / Q000276:immunology; D009166:Mycobacterium leprae / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006017:Glycolipids; D007075:Immunoglobulin M; C045169:phenolic glycolipid I, Mycobacterium leprae