Suppressor response in lepromatous leprosy patients: role of Leu 2a cells.

The contribution of non-specific suppressor mechanisms to the overall immunoregulatory defect observed in lepromatous leprosy was evaluated. Con A-induced suppression was assayed using the standard two-stage test in 27 lepromatous leprosy patients, 19 of them during the quiescent stage (LL) and eight during erythema nodosum lepromatosum (ENL). Lymphocytes from normal individuals react in this assay, yielding higher suppression as the numbers of Con A-induced suppressor cells (Leu 2a+ cells) increase. In contrast, two patterns of response were observed in both LL and ENL patients: those giving lower suppression as the number of suppressor cells increased (LL-A and ENL-A) and those responding with the normal pattern (LL-B and ENL-B). The abnormal dose-response profile was not related to the disease stage, as both ENL and LL patients were included in groups with normal or atypical response. Reaction of the potential suppressor cells with anti-Leu 2a antibody abolished suppression in LL-B and normals, whereas Con A-induced suppression was unchanged or higher in ENL-A, ENL-B and LL-A, indicating that in these patients Leu 2a+ cells interfered with the generation of Con A-induced suppression. The contribution of spontaneous suppression was examined and it was shown that suppressor activity in the absence of Con A stimulus was higher in ENL (both ENL-A and ENL-B) and LL-A. Thus, it appears that the occurrence of high spontaneous suppressor activity, probably related to in vivo activation, is associated with a relative inability to generate de novo suppression after Con A stimulation in these patients.

ConA-induced suppressor cells in lepromatous leprosy patients during and after erythema nodosum leprosum.

ConA-induced suppressor activity in patients with lepromatous leprosy (LL) was studied. Patients were studied during and after erythema nodosum leprosum (ENL) reactions. The study included 16 patients with ENL, nine of whom returned once the ENL episode was over. Patients were compared to 12 normal controls. Suppressor activity was evaluated in vitro by cultivating peripheral blood lymphocytes (PBL) with an inducer of T suppressor cells, concanavalin A (ConA), and with two different mitogens, phytohemagglutinin (PHA) and ConA, in order to measure the inhibition of the proliferative responses in all cases. In contrast, in LL patients during ENL the ConA-induced suppressor response was markedly reduced. The reduction in suppressor responses was even more marked in the LL patients after the ENL episode. Reduced levels of suppressor activity in LL patients reveal a defect in central mechanisms of control in the immune response.

Serum factors affecting the cell migration inhibition response to lepromin.

Cell migration inhibition of white blood cells in the presence of total protein lepromin (TPL) was studied in ten lepromatous patients, six tuberculoid patients, and ten normal controls; adding normal, tuberculoid, lepromatous, or no serum to the culture medium. Using normal or no serum, lepromatous patients and skin negative controls gave negative reactions, while tuberculoid patients and skin positive controls gave positive cell migration inhibitions. The addition of lepromatous serum gave a very significant overall increase of migration indices in all groups of subjects, turning to negative the positive reactions of lepromatous patients and positive controls. On the contrary, the addition of tuberculoid serum gave a decrease of migration index in all groups of subjects, turning to positive the reactions in lepromatous patients. The significance of these circulating factors, able to enhance or inhibit cell migration inhibition responses in patients and controls, is discussed.

[Immunological examination of patients with undetermined leprosy]. / Exploracion inmunologica en pacientes con lepra indeterminada

The immunological competence of eleven patients with undetermined leprosy was compared with that of ten normal volunteers of the same age and sex distribution; these controls have not had previous contact with leprosy. The following parameters were studied in peripheral blood cells: 1) percentage of lymphocyte bearing surface immunoglobulins, as revealed by immunofluorescence; 2) percentage of lymphocyte bearing complement receptors, as studied by antibody and complement coated erithrocyte rosetting; 3) percentage of T cells, as revealed by spontaneous sheep erithrocyte rosettes; 4) blastogenic and mytogenic response of cultured lymphocytes to PHA and 5) cell migration inhibition test using lepromine (80 x 10(6) bacilli/ml) as antigen. Skin reactions to lepromine were also assayed. In the six lepromine-positive patients with undetermined leprosy, no major immunological alterations could be detected. On the contrary, the five lepromine-negative patients showed important alterations which could well be considered as precursors of lepromatous leprosy.

Exploracion inmunologica en pacientes con lepra indeterminada / [Immunological examination of patients with undetermined leprosy]

The immunological competence of eleven patients with undetermined leprosy was compared with that of ten normal volunteers of the same age and sex distribution; these controls have not had previous contact with leprosy. The following parameters were studied in peripheral blood cells: 1) percentage of lymphocyte bearing surface immunoglobulins, as revealed by immunofluorescence; 2) percentage of lymphocyte bearing complement receptors, as studied by antibody and complement coated erithrocyte rosetting; 3) percentage of T cells, as revealed by spontaneous sheep erithrocyte rosettes; 4) blastogenic and mytogenic response of cultured lymphocytes to PHA and 5) cell migration inhibition test using lepromine (80 x 10(6) bacilli/ml) as antigen. Skin reactions to lepromine were also assayed. In the six lepromine-positive patients with undetermined leprosy, no major immunological alterations could be detected. On the contrary, the five lepromine-negative patients showed important alterations which could well be considered as precursors of lepromatous leprosy.

Exploracion inmunologica en pacientes con lepra indeterminada / [Immunological examination of patients with undetermined leprosy]

The immunological competence of eleven patients with undetermined leprosy was compared with that of ten normal volunteers of the same age and sex distribution; these controls have not had previous contact with leprosy. The following parameters were studied in peripheral blood cells: 1) percentage of lymphocyte bearing surface immunoglobulins, as revealed by immunofluorescence; 2) percentage of lymphocyte bearing complement receptors, as studied by antibody and complement coated erithrocyte rosetting; 3) percentage of T cells, as revealed by spontaneous sheep erithrocyte rosettes; 4) blastogenic and mytogenic response of cultured lymphocytes to PHA and 5) cell migration inhibition test using lepromine (80 x 10(6) bacilli/ml) as antigen. Skin reactions to lepromine were also assayed. In the six lepromine-positive patients with undetermined leprosy, no major immunological alterations could be detected. On the contrary, the five lepromine-negative patients showed important alterations which could well be considered as precursors of lepromatous leprosy.