Immunoreactivity in vitro to human testis in patients with lepromatous leprosy.

Patients with lepromatous leprosy and tuberculoid leprosy, together with normal aged matched controls, were tested for in vitro immunoreactivity against a panel of soluble extracts prepared from normal human tissues. The panel consisted of a soluble homogenate of human testis as well as two partially purified fractions of this extract, and control extracts from other human tissues. Immunoreactivity was assessed by extract induced peripheral blood lymphocyte (PBL) transformation, leucocyte migration inhibition (LMI) and leucocyte adherence inhibition (LAI). Although no difference in PBL transformation, LMI, or LAI was obtained between the groups with the control tissue extracts, significant reactivity was obtained for the patients with lepromatous leprosy in at least one of the in vitro tests, when one of the testis extracts was used (Mann-Whitney test). No such reactivity to the testis extracts was obtained in the patients with tuberculoid leprosy or the normal control subjects. Of the twenty-two patients studied with lepromatous leprosy, thirteen had clinical evidence of testicular disease and nine of these patients had raised PBL transformation and LAI reactivity to the testis extracts. This finding of immunoreactivity against testicular extracts in a significant number of patients with lepromatous leprosy by at least one of the vitro tests used, suggests that the associated in vivo testicular atrophy that occurs in these patients may have an auto-immune basis.