Different cell death mechanisms are involved in leprosy pathogenesis.

Leprosy is a chronic granulomatous disease that remains a serious public health problem in developing countries. According to the Madrid classification, leprosy presents in four clinical forms: two immunologically unstable forms (indeterminate and borderline) and two stable polar forms (tuberculoid and lepromatous). In leprosy, the relationship of cell death to clinical disease outcome remains unclear. Therefore, we investigated the extent of autophagy and different cell death mechanisms-such as apoptosis, necroptosis, and pyroptosis-in cutaneous lesions of patients with leprosy, as well as the role of these mechanisms in clinical disease progression. This cross-sectional analytical study included 30 patients with a confirmed diagnosis of leprosy, with 10 patients in each of the following groups: lepromatous (LL), tuberculoid (TT), and indeterminate (II) leprosy groups. For histopathological analysis, skin samples were subjected to haematoxylin-eosin staining and immunostaining for apoptotic and necroptotic markers. The results indicated that FasL expression was much higher in the LL form than in the TT and II forms. Similar results (higher expression in the LL form than in the TT and II forms) were observed for caspase 8, RIP1, and RIP3 expressions. MLKL, BAX, and caspase 3 expression levels were highest in the LL form, especially in globular foamy macrophages. Beclin-1 expression was highest in the TT form but was low in LL and II forms. Caspase 1 expression was highest in the LL form, followed by that in the TT and II forms. In conclusion, our study elucidates the role of different cell death mechanisms in the pathophysiology of various forms of leprosy and suggests measures that may be used to control the host response to infection and disease progression.

Incomplete myelopathy and human T cell lymphotropic virus type-1 (HTLV-1).

This was a cross-sectional prospective study. We performed a multivariate statistical analysis of the neurological signs and symptoms of patients infected with human T cell lymphotropic virus type 1 (HTLV-1) in an attempt to separate them into distinct groups and identify clinical-neurological manifestations that could differentiate the various profiles. The study was performed in the city of Belém (state of Pará), located in the Amazon region of Brazil, from 2014 to 2016. We determined muscle strength and tone, reflexes, sensations, sphincter function, gait, and the Expanded Disability Status Scale score among individuals with HTLV-I. We then used exploratory statistical methods in an attempt to find different profiles and establish distinct groups. We analyzed 60 patients with HTLV-1. The filtering of the data, performed with mixed PCA, gave rise to a streamlined database with the most informative data and suggested the formation of three statistically distinct groups: asymptomatic carriers (AC), mono/oligosymptomatic (MOS), and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSPd), AC and MOS (p = 0.002), AC and HAM/TSPd (p < 0.001), and HAM/TSPd and MOS (p = 0.001). The subsequent cluster analysis confirmed the formation of three clusters. The classification and regression tree demonstrated that altered gait was the most important variable for the classification of an individual with HAM/TSPd and that, in the absence of this impairment, hyperreflexia characterized MOS. The present study was able to separate patients infected by HTLV-1 into three clinical groups (AC, HAM/TSPd, and MOS) and identify clinical manifestations that could differentiate the various patient groups.

Parvovirus B19 and in situ immune response in eczema and psoriasis skin lesions of patients from the Brazilian Amazon region.

Parvovirus B19 (PVB19) is a virus found in the skin that causes asymptomatic infections and can exist in the host for long periods to time. The virus induces a local inflammatory response and is associated with the development of arthritis and other autoimmunes diseases. Parvovirus B19 DNA was investigated by PCR in the skin of 20 patients with psoriasis and 20 patients with eczema. Additionally, immunohistochemistry was used to characterize the expression of cytokines in these lesions. The sociodemographic variables were similar in the two groups studied. Psoriasis vulgaris was the most common clinical type in men (50%) and women (80%) (p = 0.0106). Comorbidities were observed in most patients with psoriasis (75%), with an OR of 14 (p = 0.0068). Another important finding was the high prevalence (50%) of psychiatric disorders in patients with psoriasis (OR = 16, p = 0.0218). Only two patients (10%) with psoriasis were positive for PVB19. Comparison of cytokine expression showed the same cytokine profile in the two groups (p > 0.05). However, expression of TNF-α tended to be higher in psoriasis patients. There was no significant positivity for PVB19 in the two groups studied. Immunohistochemistry showed higher expression of TNF-α in psoriasis lesions compared to the eczema group.

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.

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.

Correlation between nerve growth factor and tissue expression of IL-17 in leprosy.

Leprosy is a serious public health problem in peripheral and developing countries. Leprosy is a chronic infectious-contagious disease caused by the intracellular, bacillus Mycobacterium leprae, which causes tissue damage and demyelination of peripheral nerves. Recent studies have demonstrated the participation of new subtype's cytokines profile in the inflammatory response of leprosy. Since nerve functions are affected by inflammatory response during the course of leprosy, changes in the production of NGF and its receptor (NGF R) may be directly associated with disability and sensory loss. Skin biopsies were collected and submitted to immunohistochemistry using specific antibodies to IL-17, NGF and NGF R. Quantitative analysis of NGF, NGFR and IL-17 immunostaining showed a significant difference between the clinical forms, with higher expression of NGF and NGFR in lepromatous leprosy and IL-17 in tuberculoid leprosy. The present study showed that IL-17, in addition to stimulating an inflammatory response, negatively regulates the action of NGF and NGF R in the polar forms of the disease.

Correlation between clinical symptoms and peripheral immune response in HAM/TSP.

HTLV-1 infects principally CD4+ T cells that are the main reservoirs of the virus in vivo, which play an important role in the immunological response. Most of the infected patients are asymptomatic. However, 2-3% of patients will develop HAM/TSP or Adult T lymphoma. HAM/TSP is a chronic inflammatory disease of the central nervous system, which is characterized by unremitting myelopathic symptoms. Studies have shown that cytokines levels alterations (IFN-γ and TNF-α) were associated with tissue injury in HAM/TSP. The aims of this study were to compare the gene expression of IFN-γ, IL-4 and IL-10 of asymptomatic and HAM/TSP HTLV-1 infected patients, and to correlate the gene expression with those of clinical symptoms. 28 subjects were included, 20 asymptomatic HTLV-1 and 8 with HAM/TSP. Spasticity was evaluated using the Modified Ashworth Scale and the degree of walking aid was classified on a progressive scale. The relative gene expression of IFN-γ, IL-4, and IL-10 was measured by Real-Time PCR. Results showed high gene expression of IFN-γ for all patients, but it was higher among HAM/TSP. A significant correlation was observed between IFN-γ gene expression and the degree of walking aid, and IFN-γ gene expression was higher among wheelchair users compared to non-wheelchair users. No association was found with IL-4 and IL-10. These findings indicate that HAM/TSP patients express higher amounts of IFN-γ than asymptomatic patients, and more importantly, the expression of this cytokine was strongly correlated with the need of walking aid.

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.

Human papillomavirus: prevalence and factors associated in women prisoners population from the Eastern Brazilian Amazon.

This study aimed to examine the prevalence of human papillomavirus (HPV) and the associated factors among female prisoners in Ananindeua City, State of Pará, Brazil. In 2010, 190 cervical samples were obtained, and Pap smear and polymerase chain reaction (GE Health Care™, Uppsala, Sweden) were performed. Additionally, a questionnaire was used. The prevalence of HPV was 10.5%, and the presence of cervical intraepithelial neoplasia grade I (n = 33, 17.5%; P < 0.1) was associated with HPV infection. The presence of low-grade squamous intraepithelial lesions was greater in women with HPV than in those without HPV infection, indicating that HPV infection is a risk factor for such injuries and that viral screening and prevention are extremely important in public health among female prisoners in Amazon.

Apoptotic activity and Treg cells in tissue lesions of patients with leprosy.

In order to understand the apoptotic response and the participation of Treg cells in the spectral clinical evolution of leprosy, this study evaluated the immunohistochemical expression of caspase-3 and FoxP3 in skin lesions of leprosy patients with the polar forms of the disease. Forty-nine patients with a confirmed diagnosis of the disease were selected, including 27 with the TT form and 22 with the LL form. Quantitative analysis of caspase-3 immunostaining showed a higher expression of this mediator in the LL form (3.409 ± 0.6517 cells/mm(2); p = 0.0001). Immunostaining for the transcription factor FoxP3 was higher in the LL form (3.891 ± 0.9294 cells/mm(2); p = 0.0001). A moderate correlation between the two markers was observed in the TT form (r = 0.5214; p = 0.005). It can be concluded that Treg cells and apoptosis play an effective role for the host defense response, inducing mechanisms involved in the activation of cascades that interfere with the control of the immune response and cell homeostasis.

Relationship between growth factors and its implication in the pathogenesis of leprosy.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae which affects the skin and peripheral nervous system. The immune response of the host determines the clinical course of the disease. The tuberculoid form is the result of high cell-mediated immunity characterized by a Th1 response, whereas the lepromatous form is characterized by low cell-mediated immunity and a Th2 humoral response. The neural damage established produces marked changes in the expression of growth factors such as nerve growth factor (NGF) and its receptors (NGF-R). The expression of NGF, associated with the expression of Th1 and Th2 cytokines, might be involved in the tissue damage caused by the bacillus. Therefore, the objective of this study was to correlate the immunoexpression patterns of NGF and NGF-R in the different clinical forms of leprosy, and to associate the findings with the in situ expression of TGF-ß and clinical classification of the disease. TGF-ß, NGF and NGF-R immunoexpression was analyzed by immunohistochemistry in paraffin-embedded material. Most patients were males with a mean age of 40.7 years. TGF-ß levels were significantly higher in the lepromatous forms. No significant difference in the immunoexpression of NGF or NGF-R was observed between the clinical forms, but expression tended to be higher at the lepromatous pole. There was a significant positive correlation between NGF and NGF-R in the different clinical forms of leprosy. A significant positive correlation was observed between NGF, NGF-R and TGF-ß. It can be concluded that, even existing evidence on the role of these molecules in the clinical spectrum of leprosy.

EGFR signaling downstream of EGF regulates migration, invasion, and MMP secretion of immortalized cells derived from human ameloblastoma.

Ameloblastoma is an odontogenic tumor characterized by local invasiveness and frequent recurrence. The surrounding stroma, composed of different cell types and extracellular matrix (ECM), may influence ameloblastoma invasive behavior. Furthermore, tumor and stromal cells secrete matrix metalloproteases (MMPs), which, in turn, can modulate the matrix and promote the release of ECM-bound growth factors. Among these growth factors, epidermal growth factor (EGF) and its receptor, EGFR, have already been shown to stimulate MMP synthesis, suggesting that an interdependent mechanism, involving MMP activity and growth factors release, may contribute to tumor invasiveness. The aim of this study was to evaluate the effects of the EGF/EGFR signaling pathway on migration, invasion, and MMP activity, in a primary cell line derived from human ameloblastoma. We established and characterized a primary cell line (AME-1) from a human ameloblastoma sample. This cell line was transduced with human papillomavirus type 16 (HPV16) E6/E7 oncogenes, generating the AME-HPV continuous cell line. EGF, MMP2, and MMP9 expression in ameloblastoma biopsies and in the AME-HPV cell line was analyzed by immunohistochemistry and immunofluorescence, respectively. Migratory activity of EGF-treated AME-HPV cells was investigated using monolayer wound assays and Transwell chambers. EGF-induced invasion was assessed in Boyden chambers coated with Matrigel. Conditioned medium from EGF-treated cells was subjected to zymography. EGFR expression in AME-HPV cells was silenced by small interfering RNA (siRNA), to verify the relationship between this receptor and MMP secretion. Ameloblastoma samples and AME-HPV cells expressed EGF, EGFR, MMP2, and MMP9. AME-HPV cells treated with EGF showed increased rates of migration and invasion, as well as enhanced MMP2 and MMP9 activity. EGFR knockdown decreased MMP2 and MMP9 levels in AME-HPV cells. EGFR signaling downstream of EGF probably regulates migration, invasion, and MMP secretion of ameloblastoma-derived cells.

Environmental impact and seroepidemiology of HTLV in two communities in the eastern Brazilian amazon.

The objective of this study was to detect antibodies for human T lymphotropic virus (HTLV) in subjects residing in two communities located in the eastern Brazilian Amazon and on the shores of the Tucuruí hydroelectric power plant. A total of 657 serum samples were analysed using an enzyme-linked immunosorbent assay with an anti-HTLV antibody (Symbiosis™, São Paulo, Brazil), demonstrating a virus prevalence of 4.7%. Most individuals with HTLV were aged over 30 years (P = 0.013), were unmarried (P = 0.019), resided in the area for more than 10 years (P = 0.001), had a low level of education (P = 0.015), and had a family income of up to $305 (100%). In contrast, there was no significant association between infection and sex, city of birth, haemotransfusion, or previous surgery. The prevalence observed in these communities suggests that the residents should be concerned about HTLV infection, and that some areas may become endemic for HTLV.

Immunohistochemical Characterization of M1, M2, and M4 Macrophages in Leprosy Skin Lesions.

Mycobacterium leprae is the etiological agent of leprosy. Macrophages (Mφs) are key players involved in the pathogenesis of leprosy. In this study, immunohistochemical analysis was performed to examine the phenotype of Mφ subpopulations, namely M1, M2, and M4, in the skin lesions of patients diagnosed with leprosy. Based on the database of treatment-naïve patients treated between 2015 and 2019 at the Department of Dermatology of the University of the State of Pará, Belém, routine clinical screening samples were identified. The monolabeling protocol was used for M1 macrophages (iNOS, IL-6, TNF-α) and M2 macrophages (IL-10, IL-13, CD163, Arginase 1, TGF-ß, FGFb), and the double-labeling protocol was used for M4 macrophages (IL-6, MMP7, MRP8, TNF-α e CD68). To confirm the M4 macrophage lineage, double labeling of the monoclonal antibodies CD68 and MRP8 was also performed. Our results demonstrated a statistically significant difference for the M1 phenotype among the Virchowian (VV) (4.5 ± 1.3, p < 0.0001), Borderline (1.6 ± 0.4, p < 0.0001), and tuberculoid (TT) (12.5 ± 1.8, p < 0.0001) clinical forms of leprosy. Additionally, the M2 phenotype showed a statistically significant difference among the VV (12.5 ± 2.3, p < 0.0001), Borderline (1.3 ± 0.2, p < 0.0001), and TT (3.2 ± 0.7, p < 0.0001) forms. For the M4 phenotype, a statistically significant difference was observed in the VV (9.8 ± 1.7, p < 0.0001), Borderline (1.2 ± 0.2, p < 0.0001), and TT (2.6 ± 0.7, p < 0.0001) forms. A significant correlation was observed between the VV M1 and M4 (r = 0.8712; p = 0.0000) and between the VV M2 × TT M1 (r = 0.834; p = 0.0002) phenotypes. The M1 Mφs constituted the predominant Mφ subpopulation in the TT and Borderline forms of leprosy, whereas the M2 Mφs showed increased immunoexpression and M4 was the predominant Mφ phenotype in VV leprosy. These results confirm the relationship of the Mφ profile with chronic pathological processes of the inflammatory response in leprosy.

Comparative Analysis of Human Hepatic Lesions in Dengue, Yellow Fever, and Chikungunya: Revisiting Histopathological Changes in the Light of Modern Knowledge of Cell Pathology.

Arboviruses, such as yellow fever virus (YFV), dengue virus (DENV), and chikungunya virus (CHIKV), present wide global dissemination and a pathogenic profile developed in infected individuals, from non-specific clinical conditions to severe forms, characterised by the promotion of significant lesions in different organs of the harbourer, culminating in multiple organ dysfunction. An analytical cross-sectional study was carried out via the histopathological analysis of 70 samples of liver patients, collected between 2000 and 2017, with confirmed laboratory diagnoses, who died due to infection and complications due to yellow fever (YF), dengue fever (DF), and chikungunya fever (CF), to characterise, quantify, and compare the patterns of histopathological alterations in the liver between the samples. Of the histopathological findings in the human liver samples, there was a significant difference between the control and infection groups, with a predominance of alterations in the midzonal area of the three cases analysed. Hepatic involvement in cases of YF showed a greater intensity of histopathological changes. Among the alterations evaluated, cell swelling, microvesicular steatosis, and apoptosis were classified according to the degree of tissue damage from severe to very severe. Pathological abnormalities associated with YFV, DENV, and CHIKV infections showed a predominance of changes in the midzonal area. We also noted that, among the arboviruses studied, liver involvement in cases of YFV infection was more intense.

Prevalence of viral hepatitis B and C in riverside communities of the Tucuruí Dam, Pará, Brazil.

Epidemiologically, the relevance of infection caused by hepatitis viruses is related mainly to their wide geographic distribution and the large number of infected individuals in all parts of the world. In this study, 668 residents from the islands around the Tucuruí Dam were selected. Blood samples were collected for investigation of serological markers (HBsAg, total anti-HBc, anti-HBS, and anti-HCV) by enzyme immunoassays. HCV-positive subjects were tested using RT-PCR and RFLP for the identification of viral genotypes. Among the 668 subjects studied, 1.9% were HBsAg positive, 28% were total anti-HBc positive, and 41.9% were anti-HBs positive. The anti-HBs marker alone (vaccine response) was detected in 25.7% of the volunteers. Anti-HCV antibody was detected in 2.2% of the subjects and genotype 1 was the predominant genotype (70%). The results indicate an intermediate level of HBV and HCV endemicity in the region studied, as well as low HBV vaccination coverage.

Decrease in naïve T cell production due to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) development.

Human T-lymphocytic virus 1 (HTLV-1) is mainly associated with adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Patients with HAM/TSP exhibit significant changes in their immune response, and HTLV-1 infection can interfere in cytokine production and perhaps in T cell production. The aims of this study were to evaluate thymic function in HAM/TSP patients and HTLV-1 healthy carriers (HCs) and correlate it to age and interleukin 7 (IL-7) gene expression. Thymic function in 21 HAM/TSP patients and 12 HCs was evaluated by quantifying T cell receptor rearrangement excision circle (TREC) particles and IL-7 gene expression, both measured by quantitative polymerase chain reaction. HAM/TSP patients presented lower TREC particle counts (p = 0.0112) and lower IL-7 expression (p = 0.0102) than HCs. Both TREC particles and IL-7 gene expression were separately analyzed in two age groups: ≤ 59 years and ≥60 years, The ≤59-year-old HAM/TSP patients had a lower TREC count compared with the ≤59-year-old HCs (p = 0.0476). In conclusion, HAM/TSP development could interfere with thymic function because the results showed TREC particle reduction in HAM/TSP patients in relation to HCs, and it could be associated with a concomitant reduction in IL-7 expression.

Computed tomography with 6-year follow-up demonstrates the evolution of HTLV-1 related lung injuries: A cohort study.

Previous observational studies have demonstrated the development of pulmonary impairments in human T-lymphotropic virus type 1 (HTLV-1) infected individuals. The main observed lesions due to chronic inflammation of viral infection in situ are bronchiectasis and lung-scarring injuries. This lung inflammation may be the causal agent of restrictive and obstructive lung diseases, primarily in tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP-HAM) patients. We conducted a prospective cohort study to compare spirometry and high-resolution computed tomography (HRCT) findings among 28 HTLV-1-carrier patients over the course of 6 years (2014-2019) (male/female: 7/21; mean age: 54.7 ± 9.5, range: 41-68 years). Chest HRCT exams revealed the development and evolution of lung lesions related to TSP-HAM: including centrilobular nodules, parenchymal bands, lung cysts, bronchiectasis, ground-glass opacity, mosaic attenuation, and pleural thickening. Spirometry exams showed maintenance of respiratory function, with few alterations in parameters suggestive of obstructive and restrictive disorders primarily in individuals with lung lesions and TSP-HAM. The findings of the present study indicate that pulmonary disease related to HTLV-1 is a progressive disease, with development of new lung lesions, mainly in individuals with TSP-HAM. To improve clinical management of these individuals, we recommend that individuals diagnosed with PET-MAH undergo pulmonary evaluation.

Immunohistochemical evaluation of macrophage activity and its relationship with apoptotic cell death in the polar forms of leprosy.

The objective of the present study was to investigate the correlation between macrophage activity and apoptosis in the polar forms of leprosy because the immunopathological phenomena involved in these forms are still poorly understood. For this purpose, 29 skin biopsy samples obtained from patients with the polar forms of leprosy were analyzed. Macrophage activity and apoptosis were evaluated by immunohistochemistry using lysozyme, CD68, iNOS and caspase 3 as markers. The nonparametric Mann-Whitney test and Spearman's linear correlation test were used for statistical analysis. The results suggest that the apoptosis rate is under the direct influence of macrophage activity in lesions of patients with the tuberculoid form. In contrast, in lepromatous lesions other factors seem to induce programmed cell death, possibly TGF-beta. Further studies are necessary to identify additional factors involved in the immunopathogenesis of leprosy.