Browsing by Subject "Sarcoidosis"

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    A human in vitro granuloma model for the investigation of multinucleated giant cell and granuloma formation
    (Murcia : F. Hernández, 2001) Seitzer, U.; Haas, H.; Gerdes, J.
    A method for the in vitro generation of granulomas and its use in the analysis of the human granulomatous response is summarized. As a target for the cellular response L3 larvae of Nippostrongylus brasiliensis are coincubated with human mononuclear blood cells, and within seven to fourteen days the development of blood monocytes to mature macrophages and to epithelioid cells and multinucleated giant cells (MGC) as typical constituents of granulomas clustered around the nematode is observed. The following review describes the uses and applications of this model for phenotyping, functional, formation and modulating studies of granulomas and MGCs, taking into account its unique features compared to other in vitro models. With respect to MGC formation, procedures are described and examples are given which allow the phenotyping of these cells using immunofluorescence and immunohistological techniques. In addition, the potential of this model for illuminating functional aspects of MGC is described applying an isolation protocol for MGC and a subsequent reverse-transcriptase polymerase chain reaction method for the analysis of single cells. Moreover, the significance and relevance of using this granuloma model is discussed in the follow up analysis of in vivo findings of interleukin-6 expression in MGC of granulomas of patients with sarcoidosis. These in vivo results implicated a role for interleukin-6 in granuloma and MGC development. The in vitro granuloma model was used to investigate potential modulatory effects of this cytokine by analysing the cell numbers and the number of MGC per in vitro granuloma, the size of the MGC formed, the fusion index and the morphology of the in vitro granuloma. The results demonstrated significant modulatory effects of interleukin-6 on the cell number per in vitro granuloma and on the morphology of the cells involved. Conceivably, elevated interleukin-6 levels may modulate granuloma formation with respect to the number of cells involved and in influencing distinct cell populations involved in granuloma formation.
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    Immunolocalization of cell-wall-deficient f orms of Mycobacterium tuberculosis com plex in sarcoidosis and in sinus histiocytosis of lymph nodes draining carcinoma
    (Murcia : F. Hernández, 1996) Alavi, H.A.; Moscovic, E.A.
    In sarcoidosis, pleomorphic chromogens (PCs) occur as multivariate pigmented elements within sinusoids of lymph nodes (sinusoidal phase) and as tiny «round bodiesm detectable in granulomas (generalized phase). The sinusoidal phase occurs in other conditions as well and characteristically contains yeastlike bodies also known as H-W bodies. To elucidate the antigenic profile of al1 variant forms, 28 cases of sarcoidosis (series A) and 14 cases of malignancy associated sinus histiocytosis (series B) were studied immunohistochemically with panels of various antibodies, including antimycobacterial MAbs specific for M. tuberculosis complex (TB68, TB71), for M. leprae (MMP-1-3C3) and for cross-reactive mycobacterial antigens (F24-2-3 and F116-5, the latter recognizing superoxide dismutase). Results for series A indicate that: 1) PCs are cell-walldeficient (CWD) mycobacterial forms belonging to M. tuberculosis complex (over 95%); 2) both phases are antigenically identical parts of the L-cycle; 3) «round bodies» of the «infective» phase have an endolysosomal evolution; 4) uncommon vacuolated forms represent a labile spheroplast stage; 5) the yeastlike bodies are specialized sinusoidal large bodies of unknown function. Results for series B show that in roughly two thirds of cases the pigmented forms are also CWD mycobacteria, have the same immunophenotype as sarcoid PCs in 35.7% of cases, have a much higher incidence of labile vacuolated forms and, finally, that malignancy associated «pseudosarcoid» granulomas do not differ antigenically from genuine sarcoid granulomas. Unlike conventional mycobacteria, PCs do not express cytoskeletal proteins consistently. Their general reactivity for HBcAg raises the possibility of phage interactions being responsible for the L-cycle since it may reflect shared epitopes between unrelated virus entities.
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    Leukocyte immunophenotypes in bronchoalveolar lavage fluid and peripheral blood of paracoccidioidomycosis, sarcoidosis and silicosis
    (Murcia : F. Hernández, 1991) Tapia, F.J.; Goihman-Yahr, M.; Cáceres-Dittmar, G.; Altieri, E.; Gross, Ana; Isturiz, G.; Rosquete, R.; Viloria, N.; Ávila-Millán, E.; Carrasquero, M.; Borges, N.S.; Fernández, B.P.de; Rothenberg, A.; Albornoz, M.B.de; Pereira, J.; Gómez, M.H.de; San Martín, B.; Román, A.de; Bretaña, A.
    Leukocyte subsets in bronchoalveolar lavage (BAL) fluid and peripheral blood of patients with paraccoccidioidomycosis, sarcoidosis and silicosis were characterized using monoclonal antibodies and an immunoperoxidase technique. In paraccocidioidomycosis, the number of T-helperl inducer CD4-positive lymphocytes was lower in peripheral blood than in BAL fluid. Additional analysis showed that the expression of HLA-DR was very similar in alveolar macrophages, lung and blood T-cells. In sarcoidosis and silicosis there were higher proportions of T-helperlinducer cells in peripheral blood than in BAL fluid. The alterations in the T-helperlinduceriT-suppressorl cytotoxic CD4lCD8 ratio in sarcoidosis and silicosis were more appreciable in peripheral blood than in BAL fluid, contrasting with the results in paracoccidioidomycosis. The expression of HLA-DR by alveolar macrophages in sarcoidosis was the highest of al1 the diseases studied. No statistically significant differences were observed between chronic multifocal and chronic unifocal paracoccidioidomycosis disease, stage 11 and stage 111 sarcoidosis, and chronic and accelerated silicosis. The three granulomatous diseases analyzed had a few alveolar macrophages expressing the CD4 molecule on their surface. These findings and the technique of analyzing both peripheral blood and BAL leukocyte subsets may help to understand the pathogenesis of interstitial lung diseases.
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    Micronodular thymic epithelial tumors with lymphoid hyperplasia and mimicking lesions
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Thomas de Montpréville, Vincent; Chalabreysse, Lara; Hofman, Véronique; de Muret, Anne; Sizaret, Damien; Dubois, Romain; Piton, Nicolas; Mansuet Lupo, Audrey; Molina, Thierry J
    Micronodular arrangement of epithelial cells and lymphoid B-cell hyperplasia with follicles are both peculiar histological features in thymic tissue. Such features may especially occur in thymic epithelial tumors. The most common form is called micronodular thymoma with lymphoid stroma. We have recently described some characteristics of thymic micronodular carcinoma with lymphoid hyperplasia, highlighting how this carcinomatous counterpart should not be misdiagnosed as a thymoma. In this review, we discuss these two entities but also other mimics, which may occur in the anterior mediastinum. These mimics include various types of cellular micronodules and lymphoid backgrounds encompassing a wide range of mediastinal lesions. Non-neoplastic lesions, such as thymic nodular epithelial hyperplasia, thymic lymphoid hyperplasia, or sarcoidosis, as well as tumors of very varying aggressiveness, such as micronodular thymic epithelial tumors, low-grade lymphoma, seminoma, or lympho-epithelial carcinoma, are discussed. We show how these lesions may be misleading and we describe how a correct diagnostic may be obtained in current practice.