Leprosy as a model of subacute and chronic immunologic diseases

Immunological aspects of staphylococcal skin infection

Patients with staphylococcal infection of the skin were examined for immunological status. All cases examined in the present study had gamma-globulin levels within the normal range. The proliferative response of peripheral blood lymphocytes to staphylococcal antigen was significantly depressed in patients with furunculosis as compared with that in patients with common furuncle or in healthy controls. All patients with furunculosis showed higher titers of anti-Staphylococcus aureus antibody than did those with furuncle. The dissociation between cellular and humoral immunity in furunculosis seems to be explained in terms of immune deviation.

Malignant lymphoma in patients with rheumatic diseases other than Sjögren's syndrome: a clinicopathologic study of five cases and a review of the Japanese literature

We conducted clinicopathologic and immunohistochemical analysis of five patients with malignant lymphoma complicating rheumatic diseases other than Sjögren's syndrome, and reviewed 26 cases of similar lesions reported in the Japanese literature over a 17-year period. All five patients were women ranging in age from 31 to 74 years (mean 55 years). Two of them fulfilled the diagnostic criteria for systemic lupus erythematosus, two for dermatomyositis and one for progressive systemic sclerosis. The use of immunosuppressive drugs before the onset of malignant lymphoma was recorded in four patients. All the biopsied or resected specimens showed non-Hodgkin's lymphoma of B-cell phenotype. Three were nodal in origin (one diffuse mixed, one diffuse large cell and one immunoblastic) and two were extranodal (one low-grade B-cell lymphoma of mucosa-associated lymphoid tissue and one diffuse large cell). In three of four cases examined, Epstein-Barr virus-encoded small RNAs were identified in a small to large number of the lymphoma cells by in situ hybridization. Our study showed that the clinicopathological features of malignant lymphomas complicating rheumatic disease in Japan were similar to those in England and the USA. Furthermore, our findings suggested no evidence for a causative association between iatrogenic immunosuppression due to methotrexate therapy and the development of EBV-related lymphoid neoplasms.

Immunological monitoring of a patient with Guillain-Barré syndrome successfully treated with plasma exchange

A patient with Guillain-Barré syndrome was successfully treated by plasma exchange (without any other therapy), and the relationship between changes in his peripheral blood lymphocyte subpopulations and the clinical improvement induced by plasma-pheresis was studied. At the recovery, the most interesting findings were an increase in T suppressor lymphocytes, and in Fc receptor-bearing lymphocytes (above normal values), together with a decrease in B lymphocytes. In this patient, plasma exchange not only removed toxic humoral factors, but also restored a normal balance among peripheral lymphocytes.

Studies on the defect in cell-mediated immunity in lepromatous leprosy using HLA-D-identical siblings. Absence of circulating suppressor cells and evidence that the defect is in the T-lymphocyte, rather than the monocyte, population

Sixteen healthy siblings were identified as HLA-D-identical to 12 borderline lepromatous or polar lepromatous leprosy patients by the absence of a mixed lymphocyte reaction (MLR). The peripheral blood mononuclear cells (PBM) of the healthy siblings showed a lymphoproliferative response (delta cpm) to Mycobacterium leprae antigens which was about fivefold or more greater than that of the lepromatous patients. Lepromatous PBM, with or without mitomycin C treatment, were co-cultured with a constant number of normal PBM. In other experiments the two cell types were co-cultured in various proportions, with the total cell number kept constant. Neither approach revealed suppressor cells in lepromatous PBM capable of suppressing the lymphoproliferative response to M. leprae. On the contrary, we found that lepromatous PBM can respond to M. leprae antigens if the sensitized lymphocyte is provided by mitomycin-C treated normal PBM. Additionally, experiments in which isolated adherent cells and non-adherent cells of sibling pairs were recombined failed to reveal a defect in the M. leprae antigen-presenting function of lepromatous adherent cells. Since we found no evidence that sensitized cells are present in lepromatous PBM with their function unexpressed (due to a monocyte defect) or suppressed (due to suppressor cells), we conclude that lepromatous patients simply lack sufficient numbers of antigen-specific T lymphocytes to initiate a lymphoproliferative response to M. leprae antigens. The reason for their absence remains an important unanswered question.

Ultrastructural study of satellite lymph nodes in syphilitic rabbits

In an electron microscopy study of lymph nodes from syphilitic rabbits plasmablasts and plasma cells were unequivocally identified in germinal centres. Up to 20% of the plasma cells possessed unusual cytological features. Paracortical hypoplasia was shown to be associated with actively phagocytic histiocytes. These findings may reflect morphological correlates of the aberrant immune regulation which has been observed in infection with Treponema pallidum.

Absence of inhibitory effect of leprosy sera upon normal E rosetting

Inhibitory serum factors in certain infectious diseases (leprosy, tuberculosis, histoplasmosis) and malignant conditions (Hodgkin's disease, primary intracranial neoplasms) are said to be partially responsible for decreased cell-mediated immunity (CMI) and consequent anergy. The immunologic derangement in leprosy is not yet completely understood. In order to determine the effect of sera from patients with leprosy upon the rosetting capacity of normal T. lymphocytes, sera from untreated lepromatous (L) and tuberculoid (T) patients were studied. Control sera were obtained from normal volunteers and from patients with other dermatologic conditions (contact dermatitis and leg ulcer). The data indicated that test sera did not inhibit either spontaneous E rosette formation or active rosetting of normal lymphocytes.

Ultrastructural features of epithelioid cell granuloma induced by intradermal injection of xenogeneic nerve tissue

Epithelioid cell granulomas were induced in rabbits previously sensitised with human sensory peripheral nerve extract by skin testing with homogenate of sural nerve. Ultrastructurally some of the cells contained in their cytoplasm abundant and dilated rough endoplasmic reticulum filled with a moderately dense product while the cytoplasm of other cells contained numerous membrane-bound vesicles. These cells show all the ultrastructural characteristics of epithelioid cells found in human granulomatous disease and in human states of granulomatous hypersensitivity. Thus we have developed an animal model which supports the concept of granulomatous hypersensitivity as a distinct entity in humans to be differentiated from foreign body and delayed-type hypersensitivity reactions. The model may also prove important in elucidating the pathogenesis of granuloma formation in non-lepromatous leprosy and other granulomatous disease and in defining the nature of the products of epithelioid cells.