We describe here a method, potentially suitable for field applications, for semi-quantitative detection of Mycobacterium leprae antigens in skin scrapings, which are taken normally for smear microscopy. Thirty acid-fast bacilli-negative paucibacillary (PB) leprosy patients comprised the main study group; eight acid-fast bacilli-positive multibacillary (MB) patients and five healthy laboratory workers served as controls. Samples in saline were spotted on nitrocellulose paper and probed with mycobacterium-specific polyclonal or M. leprae-specific mAbs against 12, 35 and 65kDa protein antigens, using a dot-ELISA format. Spot densities were read through a densitometer and also graded visually. The polyclonal antibody produced the best sensitivity, resulting in densitometric detection of mycobacterial antigen in 100% MB, 76% multiple-lesion PB and 62% single-lesion PB patients. None of the healthy volunteers showed antigen positivity. A correlation was noted between the densitometric and visual estimates of the antigen. Determination of antigen in the lesion and an apparently uninvolved area of skin in a subset of PB patients provided clues to the state of the underlying infection. Serological positivity of PB patients for M. leprae-specific antibodies against the 35kDa and phenolic glycolipid-I antigens was too low (<20%) for any diagnostic significance.
BT - Transactions of the Royal Society of Tropical Medicine and Hygiene C1 - http://www.ncbi.nlm.nih.gov/pubmed/17445850?dopt=Abstract DA - 2007 Jul DO - 10.1016/j.trstmh.2007.02.026 IS - 7 J2 - Trans. R. Soc. Trop. Med. Hyg. LA - eng N2 -We describe here a method, potentially suitable for field applications, for semi-quantitative detection of Mycobacterium leprae antigens in skin scrapings, which are taken normally for smear microscopy. Thirty acid-fast bacilli-negative paucibacillary (PB) leprosy patients comprised the main study group; eight acid-fast bacilli-positive multibacillary (MB) patients and five healthy laboratory workers served as controls. Samples in saline were spotted on nitrocellulose paper and probed with mycobacterium-specific polyclonal or M. leprae-specific mAbs against 12, 35 and 65kDa protein antigens, using a dot-ELISA format. Spot densities were read through a densitometer and also graded visually. The polyclonal antibody produced the best sensitivity, resulting in densitometric detection of mycobacterial antigen in 100% MB, 76% multiple-lesion PB and 62% single-lesion PB patients. None of the healthy volunteers showed antigen positivity. A correlation was noted between the densitometric and visual estimates of the antigen. Determination of antigen in the lesion and an apparently uninvolved area of skin in a subset of PB patients provided clues to the state of the underlying infection. Serological positivity of PB patients for M. leprae-specific antibodies against the 35kDa and phenolic glycolipid-I antigens was too low (<20%) for any diagnostic significance.
PY - 2007 SP - 699 EP - 706 T2 - Transactions of the Royal Society of Tropical Medicine and Hygiene TI - Semi-quantitative detection of Mycobacterium leprae antigens in skin scrapings: suitability as a laboratory aid for field diagnosis of leprosy. VL - 101 SN - 0035-9203 ER -