We developed an immunopathological staining of
LAM-B antigen in
formalin-fixed
paraffin-embedded tissues, and compared it with, PGL-I immunostaining, Fite Faraco's
stain and
periodic acid carbol pararosaniline (PACPR)
stain. Out of the total 28
leprosy cases, 27 were positive to
LAM-B immunostaining while 23 were positive to PGL-I
stain. Fite's
stain was positive in 21 cases while PACPR
stain was positive in 24 cases. In
scrofuloderma,
LAM-B antigen was observed only in the
granuloma while no other positive findings were noted with other stains. Normal skin did not give any positive findings with any of the stains. Other
dermatoses showed no positive findings to any of the stains tested.
LAM-B staining was observed in the nerve even in the absence of bacilli in
leprosy tissues. Presence of
LAM-B in the cutaneous nerves is helpful in discriminating
leprosy from other mycobacterioses. Considering the high sensitivity of
LAM-B and the predilection of M. leprae for the nerves, we concluded that
LAM-B staining can be a useful new tool in the prompt diagnosis of
leprosy, especially in suspected or early cases.