Thymus dependent lymphocytes of peripheral blood in leprosy patients

Abstract

A study of the numbers of thymus derived lymphocytes by the rosette assay (T RFC) in patients with leprosy reveals that lower than normal numbers of T RFC are regularly seen in those patients with the active lepromatous form of this disease. Essentially normal numbers of T RFC were found in inactive lepromatous, borderline, and indeterminate types of leprosy. The lowest percentages and lowest absolute numbers of T RFC were encountered in patients with lepromatous leprosy resistant to chemotherapy. Patients with lepromatous leprosy complicated by erythema nodosum leprosum show numbers of T RFC that are more nearly normal than the numbers of T RFC in patients with uncomplicated lepromatous leprosy. These findings are discussed with respect to the pathogenesis of lepromatous leprosy and the T RFC deficiency demonstrated in this disease. The possibility that transient defects in T RFC numbers or function may predispose to lepromatous leprosy is proposed.