Effect of leprosy sera and foetal calf serum (FCS) on the T cell number of peripheral blood of leprosy patients.

Study was conducted in 24 cases of various types of leprosy and 10 healthy controls to find out the effect of various sera on the T cell count of peripheral blood lymphocytes by sheep erythrocyte rosetting method. The percentage of T lymphocytes in lepromatous and tuberculoid cases were significantly lower compared to that in normal healthy controls. All sera except FCS had a stimulatory effect on the number of T cells. The cells incubated for 24 hours in FCS did not show any stimulatory effect on the number of T cells, however, these FCS incubated cells showed a significant elevation in the number of T cells when further incubated in sera either from leprosy cases or from healthy subjects.