The inflammasome in leprosy skin lesions: an immunohistochemical evaluation.

OBJECTIVE: Leprosy is a chronic infectious disease presenting with a spectrum of clinical manifestations that correspond to the type of immune response that develops in the host. Factors that may be involved in this process include inflammasomes, cytosolic proteins responsible for the activation of caspase 1, IL-1ß and IL-18 secretion, and induction of a type of death called pyroptosis. PATIENTS AND METHODS: We evaluated the expression of inflammasome markers (nucleotide-binding oligomerization domain-like receptor containing pyrin domain 1 [NLRP1], nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 [NLRP3], caspase 1, IL-1ß, and IL-18) by immunohistochemistry in 43 samples of skin lesions of leprosy patients from the groups indeterminate (I) leprosy (13 patients), tuberculoid (TT) leprosy (15 patients), and lepromatous leprosy (LL; 15 patients). RESULTS: The evaluated markers were most upregulated in LL lesions, followed by lesions of TT leprosy and I leprosy. Differences were statistically significant between the I leprosy and LL leprosy forms and between the I leprosy and TT leprosy forms. Positive and significant correlations were found between IL-18 and caspase 1 in LL (r=0.7516, P=0.0012) and TT leprosy (r=0.7366, P=0.0017). In I leprosy, correlations were detected between caspase 1 and IL-1ß (r=0.6412, P=0.0182), NLRP1 and IL-18 (r=0.5585, P=0.473), NLRP3 and IL-18 (r=0.6873, P=0.0094), and NLRP1 and NLRP3 (r=0.8040, P=0.0009). CONCLUSION: The expression of inflammasome markers in LL lesions indicates the ineffectiveness of this protein complex in controlling the infection. Caspase 1 may be involved in the pyroptotic cell death in the lepromatous form of the disease. Inflammasomes may act together in the initial phase of I leprosy; this phenomenon may influence the clinical outcome of the disease.

Langerin (CD207)-positive cells in leprosy: Possible implications for pathogenesis of the disease with special emphasis on dermal immunoreactivity.

Leprosy is a disease caused by Mycobacterium leprae, which is characterized by two distinct poles, the tuberculoid pole and the lepromatous pole, depending on the immune response to the bacillus. Langerin-positive cells are dendritic cells that appear to play an essential role in the development of the disease. These cells are specialized in the processing and presentation of antigens, exerting an important function in the activation of the immune system. To evaluate the expression of langerin-positive cells (CD207+) in skin lesion fragments of patients with a diagnosis of M. leprae infection and to associate the expression of these cells with the polar forms of the disease. Langerin-positive cells were detected in larger numbers in lesions of patients with the tuberculoid form compared to those with the lepromatous form. The presence of a larger number of these cells in patients with the tuberculoid form suggests an important participation of langerin-positive cells, capturing antigens and favoring an effective immune response to infection with M. leprae.

NFκB transcription factor (p65) immunohistochemistry in leprosy dermal microvasculature.

Leprosy caused by Mycobacterium leprae is characterized by a spectrum of clinical manifestations that are determined by the predominant immunological profile of the host. The recruitment of leukocytes to the sites of injury can influence the development of these profiles. Cell adhesion molecules such as ICAM-1, VCAM-1 and CD62E participate in this process and their expression is regulated by transcriptions factors such as NFκB. To correlate the expression of cell adhesion molecules and NFκB (p65) in leprosy lesions, 30 skin biopsies of patients with leprosy [16 with the tuberculoid (TT) or borderline tuberculoid (BT) forms and 14 with the lepromatous (LL) or borderline lepromatous (BL) forms] were analyzed by immunohistochemistry. A larger mean number of cells expressing VCAM-1 (BT/TT: 18.28 ± 1.4; BL/LL: 10.67 ± 1.2; p = 0.0002), ICAM-1 (BT/TT: 9.92 ± 1.1; BL/LL: 5.87 ± 1.0; p = 0.0084) and CD62E (BT/TT: 13.0 ± 1.5; BL/LL: 2.58 ± 0.3; p = 0.0001) were observed in BT and TT lesions. The mean number of cells expressing NFκB was similar in the two clinical forms (BT/TT: 2.21 ± 2.7; BL/LL: 2.35 ± 3.1;p = 0.9285). No significant correlation was observed between expression of the transcription factor and adhesion molecules analyzed. The synthesis of ICAM-1, VCAM-1 and CD62E depends on the activation of NFκB, which acts synergistically with other transcription factors. Adequate activation of intracellular signaling pathways results in the production of endothelial adhesion molecules, contributing to the recruitment of cells to the site of injury and thus eliciting an effective inflammatory response in the elimination of the bacillus.

Primary cutaneous follicle center lymphoma.

Cutaneous lymphomas are classified according to their cellular origin into T-cell lymphoma and B-cell lymphoma. The annual incidence rate is 0.3 per 100,000 population. We report a case of a 56-year-old male patient who presented with a two-month history of nodules of varying sizes, some ulcerated, on the face, abdomen, and upper limbs. Histopathological examination and immunohistochemical study confirmed the diagnosis of primary cutaneous centrofollicular lymphoma. Studies have shown an increased incidence of non-Hodgkin lymphomas in the last decade. We report an infrequent case that should be kept as a differential diagnosis of patients with nodules and cutaneous papules.

Response of iNOS and its relationship with IL-22 and STAT3 in macrophage activity in the polar forms of leprosy.

Leprosy is a chronic granulomatous infection that manifests as different clinical forms related to the immunological response. The aim of the study was to evaluated the response of IL-22, STAT3, CD68 and iNOS in leprosy skin lesions. The mean number IL-22 positive cells was 12.12±1.90cells/field in the TT form and 31.31±2.91cells/field in the LL form. STAT3 positive cells was 5.29±1.96 cells/field in the TT form, while this number was 11.13±3.48cells/field in the LL form. The mean number of CD68 positive cells was 25.18±6.21cells/field in the TT form and 62.81±8.13cells/field in the LL form. Quantitative analysis of iNOS revealed a significant difference, with the mean number of cells expressing the enzyme being 30.24±2.88cells/field in the TT form compared to 35.44±4.69cells/field in the LL form. Linear correlations in lesions of TT patients showed a moderate positive correlations between CD68 and iNOS, STAT3 and Inos, IL-22 and STAT3, and IL-22 and iNOS. Our results demonstrate that these factors can act synergistically to induce a microbicidal activity in the population of macrophages in the leprosy lesions.

Endothelium adhesion molecules ICAM-1, ICAM-2, VCAM-1 and VLA-4 expression in leprosy.

Leprosy triggers a complex relationship between the pathogen and host immune response. Endothelium plays an important role in this immune response by directly influencing cell migration to infected tissues. The objective of this work is to investigate the possible role of endothelium in M. leprae infection, correlating the characteristics of endothelial markers with the expression pattern of cytokines. Thirty-six skin biopsy samples were cut into 5-µm thick sections and stained with hematoxylin-eosin and Ziehl-Neelsen for morphological analysis and then submitted to immunohistochemical analysis using monoclonal antibodies against ICAM-1, ICAM-2, VCAM-1, and VLA-4. Immunostaining for ICAM-1 showed a significantly larger number of stained endothelial cells in the tuberculoid leprosy (9.92 ± 1.11 cells/mm2) when compared to lepromatous samples (5.87 ± 1.01 cells/mm2) and ICAM-2 revealed no significant difference in the number of endothelial cells expressing this marker between the tuberculoid (13.21 ± 1.27 cells/mm2) and lepromatous leprosy (14.3 ± 1.02 cells/mm2). VCAM-1-immunostained showed 18.28 ± 1.46/mm2 cells in tuberculoid leprosy and 10.67 ± 1.25 cells/mm2 in the lepromatous leprosy. VLA-4 exhibited 22.46 ± 1.38 cells/mm2 in the tuberculoid leprosy 16.04 ± 1.56 cells/mm2 in the lepromatous leprosy. Samples with characteristics of the tuberculoid leprosy exhibited a larger number of cells stained with ICAM-1, VCAM-1 and VLA-4, demonstrating the importance of these molecules in the migration and selection of cells that reach the inflamed tissue.

Th9 cytokines response and its possible implications in the immunopathogenesis of leprosy.

AIMS: Leprosy is an infectious-contagious disease whose clinical evolution depends on the interaction of the infectious agent with the immune response of the host, leading to a clinical spectrum that ranges from lepromatous leprosy (susceptibility, LL) to tuberculoid leprosy (resistance, TT). The immune response profile will depend on the pattern of cytokine production and on the activity of macrophages during infection. Classically, the clinical evolution of leprosy has been associated with Th1/Th2 cytokine profiles, but the role of new cytokine profiles such as T helper 9 (Th9) remains to be elucidated. METHODS: To evaluate the tissue expression profile of these cytokines, a cross-sectional study was conducted using a sample of 30 leprosy skin lesion biopsies obtained from patients with leprosy, 16 TT and 14 lepromatous LL. RESULTS: Immunohistochemical analysis revealed a significant difference in interleukin (IL)-9, IL-4 transforming growth factor (TGF)-ß and IL-10 levels between the two groups. IL-9 was more expressed in TT lesions compared with LL lesions. Higher expression of IL-4, IL-10 and TGF-ß was observed in LL compared with TT. IL-4, IL-10 and TGF-ß tended to be negatively correlated with the expression of IL-9, indicating a possible antagonistic activity in tissue. CONCLUSIONS: The results suggest that Th9 lymphocytes may be involved in the response to Mycobacterium leprae, positively or negatively regulating microbicidal activity of the local immune system in the disease.

In situ expression of M2 macrophage subpopulation in leprosy skin lesions.

The clinical manifestations of the leprosy depend on host immune response and the macrophages are the primary cells involved in this process. M1 and M2 cells exhibited distinct morphology, distinct surface marker profiles, as well as different cytokine and chemokine secretion. Macrophages express receptors such as CD163, CD68, CD206, and costimulatory molecules such as CD80 and CD86, and cytokines that trigger a suppressive or inflammatory response. Thirty-three untreated patients were selected, 17 patients had the tuberculoid leprosy (TT) and 16 had the lepromatous leprosy (LL). We performed immunohistochemistry to detect IL-13, IL-10, TGF-ß, FGF-ß, CD163, CD68, arginase 1. M2 macrophages showed significant differences between the groups studied with increase in the expression of costimulatory molecules (CD68 and CD163), arginase 1 and cytokines (IL-10, IL-13, TGF-ß and FGF-b) in the LL form. Response of M2 macrophages emerge as an alternative for a better understanding of the innate immunity in the polar forms of leprosy, highlighting the role of cytokines, arginase 1 and costimulatory molecules in the repair and suppressive responses in the lepromatous form of the disease.

Langerhans cells (CD1a and CD207), dermal dendrocytes (FXIIIa) and plasmacytoid dendritic cells (CD123) in skin lesions of leprosy patients.

The clinical course of infection with Mycobacterium leprae varies widely and depends on the pattern of the host immune response. Dendritic cells play an important role in the activation of the innate and adaptive immune system and seem to be essential for the development of the disease. To analyze the presence of epidermal dendritic cells (CD1a and CD207), plasmacytoid dendritic cells (CD123) and dermal dendrocytes (factor XIIIa) in lesion fragments of leprosy patients, skin samples from 30 patients were studied. These samples were submitted to immunohistochemistry against CD1a, CD207, FXIIIa, and CD123. The results showed a larger number of Langerhans cells, detected with the CD1a or CD207 marker, dermal dendrocytes and plasmacytoid dendritic cells in patients with the tuberculoid form. A positive correlation was observed between the Langerhans cell markers CD1a and CD207 in both the tuberculoid and lepromatous forms, and between Langerhans cells and dermal dendrocytes in samples with the tuberculoid form. The present results indicate the existence of a larger number of dendritic cells in patients at the resistant pole of the disease (tuberculoid) and suggest that the different dendritic cells studied play a role, favoring an efficient immune response against infection with M. leprae.

E-selectin and P-selectin expression in endothelium of leprosy skin lesions.

Leprosy is an infectious-contagious disease whose clinical evolution depends on the immune response pattern of the host. Adhesion molecules and leukocyte migration from blood to tissue are of the utmost importance for the recognition and elimination of infectious pathogens. Selectins are transmembrane glycoproteins that share a similar structural organization and can be divided into three types according to their site of expression. The biopsies were cut into 5µm thick sections and submitted to immunohistochemistry using antibodies against E-selectin and P-selectin. The number of E-selectin-positive cells was significantly higher in the tuberculoid form than in the lepromatous form. The immunostaining pattern of P-selectin differed from that of E-selectin. Analysis showed a larger number of endothelial cells expressing CD62P in the lepromatous form compared to the tuberculoid form. The presence of these adhesins in the endothelium contributing to or impairing the recruitment of immune cells to inflamed tissue and consequently influences the pattern of immune response and the clinical presentation of the disease.

Immunohistochemical analysis of the expression of cellular transcription NFκB (p65), AP-1 (c-Fos and c-Jun), and JAK/STAT in leprosy.

Leprosy is a disease whose clinical spectrum depends on the cytokine patterns produced during the early stages of the immune response. The main objective of this study was to describe the activation pattern of cellular transcription factors and to correlate these factors with the clinical forms of leprosy. Skin samples were obtained from 16 patients with the tuberculoid (TT) form and 14 with the lepromatous (LL) form. The histologic sections were immunostained with anti-c-Fos and anti-c-Jun monoclonal antibodies for investigation of AP-1, anti-NFκB p65 for the study of NFκB, and anti-JAK2, STAT1, STAT3, and STAT4 for investigation of the JAK/STAT pathway. Cells expressing STAT1 were more frequent in the TT form than in LL lesions (P = .0096), in agreement with the protective immunity provided by IFN-γ. STAT4 was also more highly expressed in the TT form than in the LL form (P = .0098). This transcription factor is essential for the development of a Th1 response because it is associated with interleukin-12. NFκB (p65) and STAT4 expression in the TT form showed a strong and significant correlation (r = 0.7556 and P = .0007). A moderate and significant correlation was observed between JAK2 and STAT4 in the TT form (r = 0.6637 and P = .0051), with these factors responding to interleukin-12 in Th1 profiles. The results suggest that STAT1, JAK2, and NFκB, together with STAT4, contribute to the development of cell-mediated immunity, which is able to contain the proliferation of Mycobacterium leprae.

Infectious diseases in paediatric pathology: experience from a developing country.

Infectious and parasitic diseases have always challenged man. Although many of them are typically seen in some areas of the world and can be adequately managed by just improving socioeconomic status and sanitary conditions, they are still quite prevalent and may sometimes be seen outside their original geographical areas. Human migration due to different reasons, tourism, blood transfusion and solid organ transplantation has created new concerns for health professionals all over the world. If not for diagnostic purposes, at least these tropical and infectious diseases should be largely known because their epidemiology, pathogenesis, host/parasite interaction, inflammatory and reparative responses are quite interesting and teach us about human biology. Curiosity is inherent to pathology practice and so we are compelled to look for things other than tumours or degenerative diseases. This review focuses on infectious and parasitic diseases found in a developing country and brings up-to-date information on diseases caused by viruses (dengue, yellow fever), bacteria (typhoid fever, leprosy), parasites (Chagas' disease, cutaneous and visceral leishmaniasis, amoebiasis, Capillaria hepatica, schistosomiasis, cysticercosis) and caused by fungi (paracoccidioidomycosis, cryptococcosis, histoplasmosis) that may be useful for pathologists when facing somewhat strange cases from developing countries.

Doença de Fabry: apresentação de um caso / Fabry disease: a case report

É relatado um caso de Doença de Fabry (Angioceratoma Corporal Diifuso Universal) em uma paciente que na segunda internação no Hospital da Santa Casa de Misericórdia do Pará, em 1995, aos 12 anos de idade, apresentava Encefalopatia Hipertensiva. No transcurso desta de de várias outras internações subsequentes, foram constatadas alterações renais, cardíacas (decorrentes da hipertensão arterial), vasculares de fundo de olho e cutâneas, prepoderando, entretanto, as manifestações renais. O diagnóstico de sua doença básica foi efeetuado por histopatologia de biópsia percutânea renal. Foi instituida a terapêutica com o uso de hipotensores, diuréticos e dieta. A recrudescência do quadro hipertensivo determinou as varias internações, a última em 13.08.1999. A paciente permanece em observação ambulatorial por uma eventual necessidade de transplante renal

Lesöes do ouvido interno experimentalmente produzidas pelo vírus mucambo / Inner ear lesions experimentaly induced by mucambo virus

O estudo histoplatológico de camundongos recém-nascidos experimentalmente inoculados com o vírus Mucambo (Amostra BeAn 10967), arbovírus isolado na Amazônia, revelou lesöes em estruturas do ouvido interno e do nervo acústico, além de encefalite. Aqui säo relatadas as lesöes das duas primeiras estruturas, baseadas na análise de 24 animais que permitiram cortes histopatológicos adequados para o estudo, constatando-se comprometimento do nervo acústico e de seus ramos cocleares e de gânglios espirais de Corti, como achados principais. Necrose celular, com lise citoplasmática e fragmentaçäo da cromatina nuclear (cariorexis), comprometendo celulas intersteciais, edema interstecial e congestäo capilar de intensidade variável, foram os achados mais evidentes em microscopia ótica, também afetando fibroconjuntivo do ouvido interno. Näo há referências semelhantes na literatura médica consultada