SUBPOPULATIONS OF T-LYMPHOCYTES IN THE PERIPHERAL-BLOOD AND LYMPH-NODES OF INDIAN KALA-AZAR PATIENTS

Distribution of T cells in the peripheral blood and lymph nodes of Ind ian kala-azar (KA) patients was studied by using appropriate phenotypi c markers for CD2(+), CD4(+) and CD8(+) cells. Significant reduction i n the CD2(+), CD4(+) cell numbers as well as CD4(+)/CD8(+) cell ratio was noted in the peripheral blood of active KA cases. Such alteration in the T cell population appeared to be a manifestation of the disease process as it showed a tendency to return close to normalcy several m onths after successful chemotherapy. Histopathological studies of KA p atients with lymphadenopathy demonstrated gradual destruction of lymph node follicular architecture which correlated well with the severity and duration of illness. Massive infiltration of CD2(+) cells in the c ortical region of lymph node was evident. The observed preponderance o f CD4(+) cells over CD8(+) ones in these infiltrates was in sharp cont rast to the distribution pattern of these cells in the periphery. Sign ificance of these findings is discussed in relation to the current con cepts on the immunology of leishmaniasis and related diseases.