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In vitro proliferative response to Mycobacterium leprae and PPD of T cell subsets, isolated by selective depletion procedure from peripheral blood using OKT4 or OKT8 monoclonal antibodies plus complement, was investigated in leprosy patients. Whole peripheral blood mononuclear cells (PBMC) developed a strong proliferative response to both M. leprae and PPD in most tuberculoid patients. This proliferation was confined to T cells, and concerned predominantly OKT4+ cells. Both antigens, however, induced a smaller, but significant proliferation of OKT8+ cells. In lepromatous patients, proliferative response of whole PBMC incubated with M. leprae was in most cases unsignificant, at variance with PPD-induced proliferation, which was not significantly lower than that of PBMC from tuberculoid patients. In a majority of M. leprae non-responders, neither OKT4+ nor OKT8+ enriched PBMC developed a proliferative response to M. leprae. Unexpectedly in four M. leprae unreactive patients, control treatment of PBMC with complement alone restored a strong proliferative response to M. leprae. Taken together, these results suggest that in vitro unresponsiveness to M. leprae results at least in some patients, from an active suppressor mechanism but that the effector phase of such suppression does not directly involve OKT8+ T cells. [ABSTRACT FROM AUTHOR]

I cell subsets and T cell functions were explored in 31 leprosy patients with the following methods: determination of the percentages of the different T cell subpopulations defined by monoclonal antibodies directed at total T cells, helper T cells and suppressor cytotoxic T cells: measurement of the in vitro proliferative responses to mitogens: study of the concanavalin A-induced suppressive activity, assessed on MLC: measurement of delayed-type hypersensitivity by skin testing. The confrontation between immunological lepromatous patients without type-2 reaction (erythema nodosum leprosum). (2) lepromatous patients without INL (erytherm nodosum leprosum). (2) lepromatous patients with recent IENL and (3) tuberculoid patients. Unexpectedly. groups 1 and 3. although differing strongly in their clinical status and their sensitivity to lepromin (absent in group 1 and strong in group 3), showed a similar immunological profile with a normal percentage of T cells and a normal distribution of T cells among the major T cell subset contrasting with a moderate decrease of proliferative responses to mitogens and impaired delayed-type hypersensitivity reactions. Concanavalin A-induced suppressive activity was type-2 reaction) strongly differed from both other groups. showing striking abnormalities other groups. showing striking abnormalities of the repartition oldie T cell subsets, with increased percentages of helper T cells and decreased percentages of suppressor T cells. and elevated proliferative responses to mitogens. Concanavalin A-induced suppressive activity was reduced in most patients of this group. It is suggested that this imbalance between I cell subsets contributes to the occurrence of ENL reactions in lepromatous patients. [ABSTRACT FROM AUTHOR]

In vitro proliferative response to Mycobacterium leprae and PPD to T cell subsets, isolated by selective depletion procedure from peripheral blood using OKT4 or OKT8 monoclonal antibodies plus complement, was investigated in leprosy patients. Whole peripheral blood mononuclear cells (PBMC) developed a strong proliferative response to both M. leprae and PPD in most tuberculoid patients. This proliferation was confined to T cells, and concerned predominantly OKT4+ cells. Both antigens, however, induced a smaller, but significant proliferation oF OKT8+ cells. In lepromatous patients, proliferative response of whole PBMC incubated with M. leprae was in most cases unsignificant, at variance with PPD-induced proliferation, which was not significantly lower than that of PBMC from tuberculoid patients. In a majority of M. leprae non-responders, neither OKT4+ nor OKT8+ enriched PBMC developed a proliferative response to M. leprae. Unexpectedly in four M. leprae unreactive patients, control treatment of PBMC with complement alone restored a strong proliferative response to M. leprae. Taken together, these results suggest that in vitro unresponsiveness to M. leprae results at least in some patients, from an active suppressor mechanism but that the effector phase of such suppression does not directly involve OKT8+ T cells.

Patients infected by the human immunodeficiency virus (HIV) represent a model in which endothelial proliferation and/or damage are of concern. We studied Von Willebrand factor (VWF) plasma values as a presumed marker of endothelial proliferation in patients with the lymphadenopathy syndrome (LAS) (n = 45), AIDS-related Kaposi's sarcoma (KS) (n = 23), and AIDS opportunistic infections (n = 9), in comparison with normal controls (n = 19) and classical KS (n = 12). VWF was increased in AIDS patients with KS (p less than 10(-6)), in AIDS patients without KS (p less than 10(-7)), and to a lesser extent in classical KS (p less than 10(-3)) and LAS (p less than 10(-2] patients. To evaluate the diffusion of the vascular proliferation in HIV-infected patients, we studied the number of vessels within the superficial dermis of clinically uninvolved skin by an indirect immunoperoxidase method. We used an antibody directed against VWF in skin biopsies from 20 LAS patients and 10 AIDS-related KS patients compared to 11 controls and 10 classical KS patients. An increase in the number of blood vessels in normal skin was found in LAS (p less than 10(-2)), classical KS (p less than 0.05), and AIDS-related KS (p less than 10(-2]. Statistical studies and comparisons between plasma and cutaneous values of VWF indicate that plasma VWF is a good marker of endothelial damage but a poor marker of vascular proliferation in HIV-infected patients.