Mk. Ghosh et al., SUBPOPULATIONS OF T-LYMPHOCYTES IN THE PERIPHERAL-BLOOD, DERMAL LESIONS AND LYMPH-NODES OF POST KALA-AZAR DERMAL LEISHMANIASIS PATIENTS, Scandinavian journal of immunology, 41(1), 1995, pp. 11-17
Distribution of different subpopulations of T cells in the dermal lesi
ons, lymph nodes and peripheral blood of post kala-azar dermal leishma
niasis (PKADL) patients was studied by using appropriate phenotypic ma
rkers for CD2(+), CD4(+) and CD8(+) cells. Histopathological studies o
f skin lesions showed marginal to massive infiltration of mononuclear
cells depending upon the duration of illness and type of lesions. Thus
, while the hypopigmented patches were represented by small focal coll
ections of lymphocytes with scanty parasites in the dermis, these were
replaced at the nodular stage with massive granulomas consisting of l
ymphocytes, plasma cells and histiocytes with numerous amastigotes. Th
e involvement of CD4(+) and CD8(+) cell types in these lesions also sh
owed a gradual change from the appearance of a few cells of both the p
henotypes in early hypopigmented type to massive accumulation of cells
, primarily of CD8(+) phenotype, in the granuloma of nodular type. How
ever, the observed preponderance of CD8(+) cells at the lesion site of
chronic PKADL patients is in contrast to their peripheral blood CD4()/CD8(+) cell ratio (1.9:1) which remained within the normal limits. S
imilar studies of lymph nodes from PKADL patients with lymphadenopathy
revealed infiltration of the cortical areas by T cells which were mor
e of CD8(+) than CD4(+) phenotypes. All these results document the inv
olvement of CD8(+) cells in leishmanoid lesions. Thus, it is likely th
at these cells, in association with appropriate subpopulations of CD4(
+) cells, play a profound role in the evolution of dermal pathology in
PKADL.