Lacaziosis: immunohistochemical evaluation of elements of the humoral response in cutaneous lesions.

Lacaziosis is a cutaneous mycosis caused by the fungus Lacazia loboi, described in different countries of Latin America and prevalent in the Amazon region. The ineffective immune response against the agent seems to be related to a Th2 pattern of cytokines. There are few reports exploring elements of the humoral response in these lesions. Our aim was to investigate some elements focusing on B cells, plasma cells and local expression of IgG and IgM antibodies. Forty skin biopsies of lower limbs were selected. The diagnosis of lacaziosis was based on direct mycological examination and histological analysis. The visualization of fungal cells was improved by using Gridley's staining. An immunohistochemical protocol was performed to detect the expression of B cells, plasma cells, IgG and IgM. A double staining was performed to explore the presence of yeasts in the cytoplasm of keratinocytes, using an anti-AE1 AE3 antibody over Gridley's staining. The inflammatory infiltrate consisted of macrophages, multinucleated giant cells, lymphocytes, and fibrosis. Fungal cells were frequent in the stratum corneum and in both, the dermis and, in 50% of the specimens, also in the epidermis. Cells expressing IgG were more abundant when compared to cells expressing IgM. B cells and the presence of IgG might indicate that the humoral response promotes a Th2 immune response resulting in an anti-inflammatory phenotype. Our results lead us to suggest a possible role of B cells and immunoglobulins in the mechanisms of lacaziosis pathogenesis.

Non Hodgkin T cell lymphoma: an atypical clinical presentation.

Cytotoxic lymphomas comprise a spectrum of peripheral T-cell lymphomas that can have a initial or late cutaneous presentation. We describe a 46-year-old man from Cape Verde, with a dermatosis involving his face and trunk, consisting of monomorphic papules with a smooth surface and both motor and sensory polyneuropathy.The hypothesis of leprosy was supported by the clinical and initial hystopathological findings and the patient was referred to our hospital with suspected Hansen's disease. In the new skin and lymph node biopsies a lymphocyte population was identified whose immunohystochemistry study allowed the diagnosis of T-cell lymphoma with expression of cytotoxic markers. The patient was started on chemotherapy with initial remission of the skin lesions but, subsequently, progression of systemic disease.

Non Hodgkin T cell lymphoma: an atypical clinical presentation / Linfoma não Hodgkin de células T citotóxico: uma apresentação clínica atípica

Cytotoxic lymphomas comprise a spectrum of peripheral T-cell lymphomas that can have a initial or late cutaneous presentation. We describe a 46-year-old man from Cape Verde, with a dermatosis involving his face and trunk, consisting of monomorphic papules with a smooth surface and both motor and sensory polyneuropathy.The hypothesis of leprosy was supported by the clinical and initial hystopathological findings and the patient was referred to our hospital with suspected Hansen's disease. In the new skin and lymph node biopsies a lymphocyte population was identified whose immunohystochemistry study allowed the diagnosis of T-cell lymphoma with expression of cytotoxic markers. The patient was started on chemotherapy with initial remission of the skin lesions but, subsequently, progression of systemic disease.

Os linfomas citotóxicos compreendem um espectro de linfomas de células T periféricos e linfomas Natural Killer que podem ter expressão cutânea primária ou secundária. Descrevemos o caso de um homem com 46 anos de idade, natural de Cabo Verde,com dermatose envolvendo a face e tronco constituída por pápulas monomorfas superfície lisa e polineuropatia sensitivo motora.A hipótese de Hanseníase foi colocada suportada por achados histopatológicos sugestivos sendo o doente referenciado à consulta de Doença de Hansen do nosso hospital. Em biopsia de pele e de gânglio identificou-se proliferação linfocitária cujo estudo imunohistoquímico permitiu o diagnóstico de linfoma T com expressão de marcadores citotóxicos. Iniciou quimioterapia verificando-se inicialmente remissão parcial das lesões cutâneas mas posteriormente a progressão da doença sistémica.

Mycobacterium leprae induces insulin-like growth factor and promotes survival of Schwann cells upon serum withdrawal.

Peripheral nerve lesions are considered the most relevant symptoms of leprosy, a chronic infectious disease caused by Mycobacterium leprae. The strategies employed by M. leprae to infect and multiply inside Schwann cells (SCs), however, remain poorly understood. In this study, it is shown that treatment of SCs with M. leprae significantly decreased cell death induced by serum deprivation. Not displayed by Mycobacterium smegmatis or Mycobacterium bovis BCG, the M. leprae survival effect was both dose dependent and specific. The conditioned medium (CM) of M. leprae-treated cultures was seen to mimic the protective effect of the bacteria, suggesting that soluble factors secreted by SCs in response to M. leprae were involved in cell survival. Indeed, by quantitative RT-PCR and dot blot/ELISA, it was demonstrated that M. leprae induced the expression and secretion of the SC survival factor insulin-like growth factor-I. Finally, the involvement of this hormone in M. leprae-induced SC survival was confirmed in experiments with neutralizing antibodies. Taken together, the results of this study delineate an important strategy for the successful colonization of M. leprae in the nerve based on the survival maintenance of the host cell through induction of IGF-I production.

Cyclooxygenase 2 expression in vessels and nerves in reversal reaction leprosy.

Tissue expression of cyclooxygenase (COX)2, an inducible enzyme synthesizing eicosanoids in inflammation, was studied in reversal reaction (RR) leprosy in comparison with nonreactionary leprosy. COX2 was consistently expressed in cells of the mononuclear-macrophage lineage across the leprosy spectrum. Only in RR, the following two additional sites showed COX2 expression in the dermis and subcutis: 1) microvessels and 2) nerve bundles and isolated nerve fibers. The same sites also express vascular endothelial growth factor (VEGF). This is in keeping with experimental models relating VEGF to COX2 expression, with VEGF enhancing prostaglandin production through COX2 stimulation and prostaglandin synthase expression. We postulate that selective COX2 inhibitors, which are currently used in several inflammatory conditions, could be considered for RR treatment to reduce acute symptoms caused by tissue edema and possibly prevent long-term nerve damage, the main complication of RR.

Short report: Cyclooxygenase 2 expression in vessels and nerves in reversal reaction leprosy

Tissue expression of cyclooxygenase (COX)2, an inducible enzyme synthesizing eicosanoids in inflammation, was studied in reversal reaction (RR) leprosy in comparison with nonreactionary leprosy. COX2 was consistently expressed in cells of the mononuclear-macrophage lineage across the leprosy spectrum. Only in RR, the following two additional sites showed COX2 expression in the dermis and subcutis: 1) microvessels and 2) nerve bundles and isolated nerve fibers. The same sites also express vascular endothelial growth factor (VEGF). This is in keeping with experimental models relating VEGF to COX2 expression, with VEGF enhancing prostaglandin production through COX2 stimulation and prostaglandin synthase expression. We postulate that selective COX2 inhibitors, which are currently used in several inflammatory conditions, could be considered for RR treatment to reduce acute symptoms caused by tissue edema and possibly prevent long-term nerve damage, the main complication of RR.

[The comparative cultural-biochemical and immunochemical identification of laboratory strains of cultured mycobacteria from leprous patient lesions and from soil]. / Sranitel'naia kul'tural'no-biokhimicheskaia i immunokhimicheskaia identifikatsiia laboratornykh shtammov kul'tiviruemykh mikobakterii iz leproznykh porazhenii bol'nykh i pochvy.

The paper presents the results of studied of cultural biochemical and immunochemical properties of the cultured mycobacteria isolated from patients with leprous lesions of (M.01, M.011) and the soil (M. lufu) in compared to other well-known mycobacteria and between them. M.01, M.011, and M. lufu differ from other representatives of the genus Mycobacterium, but they are close to each other in their cultural biochemical and immunochemical properties, antigenic composition, and protein spectra. The findings are an additional characteristic of the biological properties of M.01, M.011, and M. lufu.

Symposium on the immunodiagnosis of rheumatic and related diseases, Part II. Rheumatoid factors.

Human rheumatoid factors are antibodies of IgG, IgA, or IgM class that show reactions with antigenic determinants present on other immunoglobulin molecules. The most commonly measured rheumatoid factor relates to the 19S IgM type, which reacts by agglutination of latex particles coated with 7S IgG and is often measured in the standard latex fixation test. Approximately 65 to 70 per cent of patients with rheumatoid arthritis show positive serologic tests for rheumatoid factor; however, a number of other chronic disease conditions are also associated with positive rheumatoid factor reactions, including infective endocarditis, sarcoidosis, leprosy, and other hyperglobulinemic conditions. Although extensive serologic and immunochemical studies have identified a number of specific antigenic structural sites on immunoglobulin molecules that react with rheumatoid factors, recent studies have shown that a certain proportion of such antibodies may show cross-reactivity with DNA-histone complexes as well. It is still not entirely clear how rheumatoid factors fit into the pathogenesis of rheumatoid arthritis itself.

Immunologic identification of M. leprae. Immunofluorescence and complement fixation.

A markedly improved immunofluorescent technic employing FITC conjugated IgG antibody prepared from lepromatous serum is described as a means of specific identification of M. leprae. An additional immunologic identification method for M. leprae is presented as a micro-complement fixation technic employing antigen rather than antibody dilution. Studies with these technics suggest that M. leprae specific antigen is probably a surface antigen and has as part of its mosaic a lecithin-phospholipid component. It is not unlikely that it is a protein-glyco-phospholipid with a polysaccharide component. These technics employed with nodular extract (NE) from lepromas, with 15 strains of mycobacteria, with M. leprae from human tissue as well as from previously reported in vitro culture, strongly reinforce the allegation that M. leprae is readily cultivated in vitro in the hyaluronic acid based medium LA-3, previously reported.

Estudos imunoquimicos na hanseniase. III: Pesquisa de alto-anticorpos sericos. Tentativa de associacao com a reacao de Rubino / Imunoquímicos studies in leprosy. III. Research of séricos auto-antibodies. Attempt of association with the reaction of Rubino

Pesquisou-se, em soros de pacientes de hanseníase, classificados em Rubino positivos e negativos, a presença de auto-anticorpos (anti-tireoglobulina) foram detectados apenas no grupo virchoviano Rubino positivo, com positividade de 43 por cento. O fator reumatóide foi detectado nos dois grupos virchovianos, em 30 por cento e 17 por cento, respectivamente, nos grupos virchovianos Rubino positivo e Rubino negativo, sem que, contudo, a diferença fosse significante.