Case Report: In Situ and Systemic Immune Response to Mucosal Leishmaniasis in an HIV-Infected Patient

In situ and systemic evaluations of the immune responses of HIV-infected patients to mucosal leishmaniasis have been poorly described. We describe a recently diagnosed HIV-infected patient with mucosal leishmaniasis who was characterized by a CD4 count of 85 cells/mm3 and nasal septum destruction resulting from pruritic and ulcerated nasal mucosa with crust formation and progression over 2 years. In situ and systemic immune evaluations of T cell activation, memory, and exhaustion were conducted using cytofluorometric assays, and sequencing of the Leishmania species was performed. The immune profile of HIV-infected patient with mucosal leishmaniasis shows a mixed Th1/Th2 pattern and an activated and exhausted status.

Contribution to the study of inflammasome and programmed cell death in paracoccidioidomycosis oral lesions

BACKGROUND

Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America, with a high incidence in Brazil, Colombia and Venezuela, and constitutes a serious public health problem, a frequent cause of morbidity and disability for work. Some mechanisms of cell death are described as important tools in infectious processes. When apoptosis is blocked, RIPK (Receptor-interacting protein kinase) 3 dependent, a caspase-independent form of cell death, can limit the replication and spread of pathogens. Some molecules that mediate necroptosis include RIPK3 and have been extensively studied due to their signalling mechanism and pathological function. RIPK3 activates NLRP1 and NLRP3-mediated inflammasome formation. Caspase-1 has an important role in processing the cytokines ILβ and IL18 to their active form. Such molecules are part of the inflammasome characterization, whose caspase-1-dependent activation promotes the death of pyroptotic cells and the secretion of proinflammatory cytokines. Knowledge about the mechanisms of pathogen-mediated cell death can be useful for understanding of the pathogenesis of infections and inflammatory conditions.

OBJECTIVE

The objective of this work was to identify the mechanisms of programmed cell death and inflammasome components in human oral mucosal lesions of paracoccidioidomycosis through immunohistochemical methods and identification of RIPK-3, IL1β, IL18, NLRP-1 and caspase-1. Thirty specimens were included, and a histopathological analysis of the lesions was performed using haematoxylin-eosin staining.

RESULTS

Our results on in situ expression of inflammasome elements and programmed cell death showed increased expression of IL-1β, NLRP-1, caspase-1 and RIPK-3. We suggest that inflammasome complex participate in the immunopathogenesis in paracoccidioidomycosis oral lesions in an interplay with RIPK3.

Plasmacytoid Dendritic Cells, the Expression of the Stimulator of Interferon Genes Protein (STING) and a Possible Role of Th17 Immune Response in Cervical Lesions Mediated by Human Papillomavirus

Human papillomavirus (HPV) is a virus with a DNA structure that specifically targets squamous epithelial cells. In individuals with a healthy immune system, HPV infection is typically resolved naturally, leading to spontaneous regression. However, when the viral genetic material integrates into the host DNA, it can disrupt the immune response and eventually give rise to neoplastic manifestations. Remarkably, HPV infection appears to activate a protein called Stimulator of Interferon genes (STING), which contributes to the infiltration of Treg Foxp3 + cells. This cellular response acts as a predisposing factor in patients with HPV, potentially exacerbating the progression of the infection. The STING is versatile in different circumstances and can play a role in the immune response as an anti-tumour therapeutic target in HPV-related carcinogenesis. The function of Th17 cells is ambiguous, depending on the microenvironment in the tumour. In this study, 46 biopsies of the uterine cervix of human immunodeficiency virus (HIV) positive patients were divided into three groups: I-cervicitis (10); II-low-grade intraepithelial neoplasia (26); III-moderate or severe intraepithelial neoplasia (10) and it was performed an immunohistochemical technique with the specific antibodies to HPV, CD123, STING and IL17. Immunostained cells were quantified and statistically analysed. Antigens of HPV were detected in the cervical intraepithelial neoplasia (CIN) groups and were absent in cervicitis group. The expression of CD123 was positive in 10.87% of the casuistic, with no statistical difference among groups. STING was present in the three groups. Group 1 presented an area fraction that varied from 3 to 20%, group 2 presented a variation of 3-23% and group 3 presented an area fraction between 4 and 12%. Cells expressing IL17 were present in three groups, more frequent in cervicitis. Considering that the casuistic is composed of women carrying HIV, this infectious agent could influence the numerical similarities of the cells studied among three groups, even in the absence of HPV.

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.

Experimental Yellow Fever in Squirrel Monkey: Characterization of Liver In Situ Immune Response

Non-human primates contribute to the spread of yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas, such as Brazil. This study aims to investigate virological, histopathological and immunohistochemical findings in livers of squirrel monkeys (Saimiri spp.) infected with the YFV. Viremia occurred 1-30 days post infection (dpi) and the virus showed a predilection for the middle zone (Z2). The livers were jaundiced with subcapsular and hemorrhagic multifocal petechiae. Apoptosis, lytic and coagulative necrosis, steatosis and cellular edema were also observed. The immune response was characterized by the expression of S100, CD11b, CD57, CD4 and CD20; endothelial markers; stress and cell death; pro and anti-inflammatory cytokines, as well as Treg (IL-35) and IL-17 throughout the experimental period. Lesions during the severe phase of the disease were associated with excessive production of apoptotic pro-inflammatory cytokines, such as IFN-γ and TNF-α, released by inflammatory response cells (CD4+ and CD8+ T lymphocytes) and associated with high expression of molecules of adhesion in the inflammatory foci observed in Z2. Immunostaining of the local endothelium in vascular cells and the bile duct was intense, suggesting a fundamental role in liver damage and in the pathogenesis of the disease.

Skin fibrosis associated with keloid, scleroderma and Jorge Lobo's disease (lacaziosis): An immuno-histochemical study

Fibrosis is a common pathophysiological response of many tissues and organs subjected to chronic injury. Despite the diverse aetiology of keloid, lacaziosis and localized scleroderma, the process of fibrosis is present in the pathogenesis of all of these three entities beyond other individual clinical and histological distinct characteristics. Fibrosis was studied in 20 samples each of these three chronic cutaneous inflammatory diseases. An immunohistochemical study was carried out to explore the presence of α-smooth muscle actin (α-SMA) and vimentin cytoskeleton antigens, CD31, CD34, Ki67, p16; CD105, CD163, CD206 and FOXP3 antigens; and the central fibrotic cytokine TGF-β. Higher expression of vimentin in comparison to α-SMA in all three lesion types was found. CD31- and CD34-positive blood vessel endothelial cells were observed throughout the reticular dermis. Ki67 expression was low and almost absent in scleroderma. p16-positive levels were higher than ki67 and observed in reticular dermis of keloidal collagen in keloids, in collagen bundles in scleroderma and in the external layers of the granulomas in lacaziosis. The presence of α-actin positive cells and rarely CD34 positive cells, observed primarily in keloids, may be related to higher p16 antigen expression, a measure of cell senescence. Low FOXP3 expression was observed in all lesion types. CD105-positive cells were mainly found in perivascular tissue in close contact with the adventitia in keloids and scleroderma, while, in lacaziosis, these cells were chiefly observed in conjunction with collagen deposition in the external granuloma layer. We did not find high involvement of CD163 or CD206-positive cells in the fibrotic process. TGF-β was notable only in keloid and lacaziosis lesions. In conclusion, we have suggested vimentin to be the main myofibroblast general marker of the fibrotic process in all three studied diseases, while endothelial-to-mesenchymal transition (EndoMT) and mesenchymal stem cells (MSCs) and M2 macrophages may not play an important role.

Inflammasome and Inflammatory Programmed Cell Death in Chromoblastomycosis

Chromoblastomycosis (CBM) is a chronic, progressive fungal disease of the skin and subcutaneous tissue caused by a group of dematiaceous fungi. Verrucous lesions present parasite-rich granulomas and predominance of a Th2 patterns of cytokines. The inflammasome constitutes a macromolecular protein complex that play a role in the activation of caspase 1 that cleaves pro-IL1β and pro-IL18, essential mediators of inflammation, and also activates pyroptosis. We intended to explore the presence and a possible role of inflammasome elements in cutaneous human lesions in CBM, considering the expression of IL1β, IL18, caspase 1, NLRP1, and also RIPK3, a key downstream component of necroptosis signaling. 35 skin biopsies of cutaneous lesions of verrucous form of CBM and 10 biopsies from normal skin were selected. The diagnosis was based on histological and clinical analysis. An immunohistochemical protocol was performed. The histopathological analysis evidenced epidermis with hyperkeratosis, irregular acanthosis, and micro abscesses. The dermis presented suppurative granulomas and inflammatory infiltrate composed by giant cells, macrophages, epithelioid cells, lymphocytes, and some eosinophils. Positive cells were distributed in the inflammatory infiltrate, with an increased number of cells expressing caspase 1, IL1β and IL18. Cells expressing RIPK3 and NLRP1 were less frequent. The intense presence of caspase 1, IL1β and IL18, allied to NLRP1 expression, suggest that inflammasome and pyroptosis could play a role in the immune response against fungal agents of CBM. Our results, allied to data from literature, could suggest that inflammasome-mediated response and pyroptosis could be a target to be explored to decrease CBM lesions.

SOCIODEMOGRAPHIC CHARACTERISTICS RELATED TO KNOWING THE BENEFITS OF BREASTFEEDING

OBJECTIVE

To describe the characteristics of women according to the reported number of benefits of breastfeeding and to verify its association with the duration of this practice until the sixth month of the child's life.

METHODS

This was a qualitative and prospective observational study performed with postpartum mothers in two stages (n=78, and after six months n=62). Generalized linear models were used to identify the profile of the mothers as well as to determine the factors associated with the duration of breastfeeding until the sixth month of the child's life.

RESULTS

The profile of women who reported fewer benefits (≤3) was: younger age (p=0.008), with lower schooling (p<0.001), single (p=0.02), unemployed (p=0.04) and who attended prenatal care at the public health service (p=0.01). The analysis of the interaction of these factors indicated that women who had only completed elementary school and who attended prenatal care at the public health service (p<0.001) or privately (p=0.01) reported fewer benefits. Factors such as: level of education, marital status, previous education/training about breastfeeding, place of prenatal care and the reported number of benefits were not associated with the duration of breastfeeding until the sixth month of the child's life.

CONCLUSIONS

The lowest number of breastfeeding benefits was reported by women with elementary education and who undewent prenatal care in the public health system or privately. The number of reported benefits was not associated with the duration of this practice until the age of sixth months of the child.

Differential expression analysis and profiling of hepatic miRNA and isomiRNA in dengue hemorrhagic fever

Dengue virus causes dengue hemorrhagic fever (DHF) and has been associated to fatal cases worldwide. The liver is one of the most important target tissues in severe cases, due to its intense viral replication and metabolic role. microRNAs role during infection is crucial to understand the regulatory mechanisms of DENV infection and can help in diagnostic and anti-viral therapies development. We sequenced the miRNome of six fatal cases and compared to five controls, to characterize the human microRNAs expression profile in the liver tissue during DHF. Eight microRNAs were differentially expressed, including miR-126-5p, a regulatory molecule of endothelial cells, miR-122-5p, a liver specific homeostasis regulator, and miR-146a-5p, an interferon-regulator. Enrichment analysis with predicted target genes of microRNAs revealed regulatory pathways of apoptosis, involving MAPK, RAS, CDK and FAS. Immune response pathways were related to NF- kB, CC and CX families, IL and TLR. This is the first description of the human microRNA and isomicroRNA profile in liver tissues from DHF cases. The results demonstrated the association of miR-126-5p, miR-122-5p and miR-146a-5p with DHF liver pathogenesis, involving endothelial repair and vascular permeability regulation, control of homeostasis and expression of inflammatory cytokines.

Livedoid vasculopathy in 75 Brazilian patients in a single-center institution: Clinical, histopathological and therapy evaluation

This study presents a single center experience with livedoid vasculopathy (LV). A rare disease that can lead to severe quality of life impairment. Characterize clinical data of LV patients at the Dermatology Division at the University of São Paulo. A retrospective and transversal study was conducted, from 1 January 2005 to 31 December 2019. About 75 patients diagnosed as LV and confirmed by skin biopsy were included. Epidemiology, clinical appearance, histopathology data, and treatment history were observed. There were 78.66% Caucasian women, with a mean age of 39.9 years. Frequent cutaneous manifestations were ulcers, atrophic blanche-like scars, hyperpigmentation, purpuras, telangiectasias, and livedo racemosa. Pain, pruritus, and hypoesthesia were the main symptoms. After treatment, almost 40% of cases relapsed during spring and summer months. About 66% of cases had thrombophilia factors associated, such as high levels of lipoprotein(a). Frequent treatments included acetylsalicylic acid, pentoxifylline, and diosmin with hesperidin. Not being a prospective study. This research provides useful data on Latin American LV patients, indicating multifactorial conditions involved in LV pathogenesis. An extensive work-up including autoimmune laboratory tests, thrombophilia factors, and other conditions associated with venous stasis should be part of LV investigation and controlled to improve treatment response.

Correlation between clinical outcome and tissue inflammatory response in kidney transplant recipients with cryptococcosis

Cryptococcosis is the second most common invasive fungal infection reported in renal transplant recipients. Tissue granulomatous inflammation is necessary to contain Cryptococcus infection. This study aims to analyze the granuloma patterns and in situ expression of regulatory T (Treg) immune response in tissue samples from 12 renal transplant recipients with cryptococcosis. Fungal isolates were molecularly identified as Cryptococcus neoformans species complex. A detailed characterization of granulomas in tissue samples from 12 kidney transplant recipients with cryptococcosis was described by checking six lung and six skin biopsies by conventional histology and for immunohistochemical detection of CD4 and Treg markers: forkhead box P3 (FoxP3), interleukin (IL)-10 and transforming-growth factor (TGF)-β. Granulomas were classified as compact, loose or mixed. Patients with mixed (n = 4) and compact (n = 3) granulomatous inflammation patterns were associated with a better prognosis and presented a higher number of CD4+FoxP3+T cells compared to the group of patients with loose granulomas. In counterpart, three out of five patients with loose granulomas died with cryptococcosis. We suggest that Treg may have a protective role in the tissue response to Cryptococcus infection given its association with compact and mixed granulomas in patients with better clinical outcomes.

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.

What the physicians should know about mast cells, dendritic cells, urticaria, and omalizumab during COVID-19 or asymptomatic infections due to SARS-CoV-2?

Coronavirus disease (COVID-19) pandemic presents several dermatological manifestations described in the present indexed literature, with around 700 cases reported until May 2020, some described as urticaria or urticarial rashes. Urticaria is constituted by evanescent erythematous-edematous lesions (wheals and flare), which does not persist in the same site for more than 24 to 48 hours and appears in other topographic localization, resolving without residual hyper pigmentation. During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, some cytokines are synthesized, including Interferon (IFN) type I, TNF-α, and chemokines which may induce mast cells (MCs) and basophils degranulation by mechanisms similar to the autoinflammatory monogenic or polygenic diseases. In this article, we discuss the spectrum of the urticaria and urticarial-like lesions in the COVID-19's era, besides other aspects related to innate and adaptative immune response to viral infections, interactions between dermal dendritic cells and MCs, and degranulation of MCs by different stimuli. Plasmacytoid dendritic cells share, in allergic patients, expression of the high-affinity IgE receptors on cell membranes and demonstrated a low pattern of type I IFN secretion in viral infections. We discuss the previous descriptions of the effects of omalizumab, a monoclonal antibody directed to IgE and high-affinity IgE receptors, to improve the IFN responses and enhance their antiviral effects.

Tissue Damage in Human Cutaneous Leishmaniasis: Correlations Between Inflammatory Cells and Molecule Expression

Cutaneous leishmaniasis (CL) is caused by the bite of the infected sand fly, which inoculates parasites of Leishmania spp and triggers an immune response. An exacerbated cutaneous inflammatory response is crucial for controlling parasite burden but can also promote tissue damage. This study aimed to characterize the populations of natural killer (NK), CD57⁺, CD4⁺, and CD8⁺ T cells, CD20⁺ B cells, as well as CD68⁺ macrophages, in biopsies of ulcerated CL lesions, and quantify the production of perforin⁺, grazyme B⁺, interleukin 1 beta (IL-1β⁺) and Tumor Necrosis Factor (TNF-α⁺ cells). We then correlated these parameters with necrosis, inflammation and the number of amastigotes. CD4⁺ T cells were positively correlated to the extent of inflammation, B cells and IL-1β⁺ were associated with the extent of necrosis, CD68⁺ macrophages and perforin were correlated with the number of amastigotes, and CD57⁺ NK cells was correlated to CD68⁺ macrophages and amastigotes. In sum, the finding suggests that the production of cytotoxic granules and cytokines by inflammatory cells contributes to tissue damage in CL lesions.

Lessons from dermatology about inflammatory responses in Covid-19

The SARS‐Cov‐2 is a single‐stranded RNA virus composed of 16 non‐structural proteins (NSP 1‐16) with specific roles in the replication of coronaviruses. NSP3 has the property to block host innate immune response and to promote cytokine expression. NSP5 can inhibit interferon (IFN) signalling and NSP16 prevents MAD5 recognition, depressing the innate immunity. Dendritic cells, monocytes, and macrophages are the first cell lineage against viruses' infections. The IFN type I is the danger signal for the human body during this clinical setting. Protective immune responses to viral infection are initiated by innate immune sensors that survey extracellular and intracellular space for foreign nucleic acids. In Covid‐19 the pathogenesis is not yet fully understood, but viral and host factors seem to play a key role. Important points in severe Covid‐19 are characterized by an upregulated innate immune response, hypercoagulopathy state, pulmonary tissue damage, neurological and/or gastrointestinal tract involvement, and fatal outcome in severe cases of macrophage activation syndrome, which produce a ‘cytokine storm’. These systemic conditions share polymorphous cutaneous lesions where innate immune system is involved in the histopathological findings with acute respiratory distress syndrome, hypercoagulability, hyperferritinemia, increased serum levels of D‐dimer, lactic dehydrogenase, reactive‐C‐protein and serum A amyloid. It is described that several polymorphous cutaneous lesions similar to erythema pernio, urticarial rashes, diffuse or disseminated erythema, livedo racemosa, blue toe syndrome, retiform purpura, vesicles lesions, and purpuric exanthema or exanthema with clinical aspects of symmetrical drug‐related intertriginous and flexural exanthema. This review describes the complexity of Covid‐19, its pathophysiological and clinical aspects.

Paracoccidioidomycosis: characterization of subpopulations of macrophages and cytokines in human mucosal lesions

Mucosal lesions of paracoccidioidomycosis (PCM) are frequently described and clinically important. Macrophages are classified as M1 or M2. M1 are proinflammatory and M2 are related to chronicity. Dectin-1 recognizes β-glucan and plays an important role against fungal cells. The objective was to verify the presence of M1, M2, and dectin-1 and a possible correlation with Th1/Th2 cytokines in mucosal PCM lesions. In sum, 33 biopsies of oral PCM were submitted to histological and immunohistochemistry analysis, and positive cells were quantified. Eleven biopsies were characterized by compact granulomas (G1), 12 with loose granulomas (G2), and 10 with both kind of granulomas (G3). pSTAT-1 was equally increased in the three groups. G1 was characterized by an increased number of CD163+ macrophages. G2 presented similar number of arginase 1, iNOS, and CD163 expressing cells. G3 presented an increased number of cells expressing arginase 1 and CD163 over iNOS. G1 and G3 presented high number of cells expressing interferon (IFN)-γ; interleukin (IL) 5 was increased in G2 and G3; the expression of IL10 was similar among the three groups, and the expression of tumor necrosis factor (TNF)-α was higher in G3. G1 correlates to Th1 cytokines and pSTAT-1 and G2 correlates to Th2 cytokines. G3 presents both kinds of cytokines. We could not associate the expression of arginase-1, CD163, iNOS, and dectin-1 with the pattern of cytokines or kind of granuloma.

M2-Polarized Macrophages Determine Human Cutaneous Lesions in Lacaziosis

Lacaziosis is a cutaneous chronic mycosis caused by Lacazia loboi. Macrophages are important cells in the host immune response in fungal infections. The macrophage population exhibits strong plasticity that varies according to the stimuli in the microenvironment of lesions M1 profile promotes a Th1 pattern of cytokines and a microbicidal function and M2 is related to Th2 cytokines and immunomodulatory response. We investigated the population of M1 and M2 polarized macrophages in human cutaneous lesions. A total of 27 biopsies from human lesions were submitted to an immunohistochemistry protocol using antibodies to detect M1 and M2 macrophages (Arginase-1, CD163, iNOS, RBP-J and cMAF). We could observe high number of cells expressing Arginase1, CD163 and c-MAF that correspond to elements of the M2 profile of macrophage, over iNOS and RBP-J (elements of the M1 profile). The results suggest a predominant phenotype of M2 macrophages, which have an immunomodulatory role and probably contributing to chronicity of Lacaziosis.

Mononuclear Phagocyte Activation Is Associated With the Immunopathology of Psoriasis

Psoriasis is a chronic, inflammatory disease affecting the skin and joints. The pathogenesis of this disease is associated with genetic, environmental and immunological factors, especially unbalanced T cell activation and improper keratinocyte differentiation. Psoriatic lesion infiltrate is composed of monocytes and T cells, and most studies have focused on the participation of T cells in the pathogenesis of this disease. Here we investigated the contribution of mononuclear phagocytes in the immunopathology observed in psoriatic patients. Significant increases in the levels of TNF, IL-1β, CXCL9, as well as the soluble forms of CD14 and CD163, were observed within the lesions of psoriatic patients compared to skin biopsies obtained from healthy individuals. Moreover, we found an association between the levels of CCL2, a monocyte attractant chemokine, and disease severity. In conclusion, our findings suggest a potential role for mononuclear phagocytes in the pathogenesis of psoriasis.

Upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in renal tissue in severe dengue in humans: Effects on endothelial activation/dysfunction

INTRODUCTION

Dengue is an important mosquito-borne disease in tropical and subtropical regions. Adhesion molecules have not been systematically characterized in the renal tissue of patients with severe dengue (SD). The objective of this study was to detect viral antigens in samples from patients that evolved with SD, correlating with the expression of ICAM-1, VCAM-1, VE-cadherin, and E-selectin to contribute to a better understanding of the pathophysiology of SD.

METHODS

Kidney specimens from patients with SD were selected according to clinical and laboratorial data and submitted to histological and immunohistochemistry analysis. A semiquantitative evaluation was performed considering positive immunostaining in 20 glomeruli.

RESULTS

Viral antigens were mainly detected in distal tubules. The intense immunostaining of VCAM-1 and ICAM-1 was observed. The expression of E-selectin was discrete, and VE-cadherin expression varied from mild to moderate. VCAM-1 was slightly intense in the glomerular capsule; the expression of ICAM-1 was diffuse. E-selectin was diffuse, and VE-cadherin varied from mild to moderate. The most frequent histological findings were glomerular congestion, mild glomerulitis, acute renal injury, and glomerular atrophy.

CONCLUSIONS

The results appear to demonstrate an imbalance between vascular endothelial permeability regulating events in renal lesions in SD. The increase in the expression of ICAM-1 and VCAM-1 is an in-situ indicator of higher permeability with a consequent influx of cells favoring the inflammation of the endothelium. These molecules are important in the pathophysiology of the disease and provide the possibility of developing new markers for the evaluation, clinical follow-up, and therapeutic response of patients with SD.

In situ immune response in human dermatophytosis: possible role of Langerhans cells (CD1a+) as a risk factor for dermatophyte infection

Dermatophytosis is a cutaneous mycosis caused by a plethora of keratinophilic fungi, but Trichophyton rubrum is the most common etiological agent. Despite its high prevalence worldwide, little is known about the host defense mechanisms in this infection, particularly the in situ immune response. Using an immunohistochemistry approach, we investigated the density of CD1a+, factor XIIIa+ and CD68+ cells in the skin of dermatophytosis patients. Langerhans cells (CD1a+ cells) were significantly decreased in the epidermis of patients, both in affected and unaffected areas. In the dermis, however, no differences in the density of macrophages (CD68+ cells) and dermal dendrocytes (factor XIIIa+ cells) were observed. These results suggest that the decreased number of Langerhans cells may be a risk factor for development of dermatophytosis.

Severe Leptospirosis Features in the Spleen Indicate Cellular Immunosuppression Similar to That Found in Septic Shock

Objectives: To compare microscopic and immunologic features in the spleens of patients who died of pulmonary hemorrhage and shock caused by leptospirosis (11 cases) or Gram-positive/-negative bacterial septic shock (10 cases) to those from control spleens (12 cases from splenectomy).

Methodology: Histological features in the red pulp and white pulp were analyzed using archived samples by a semi quantitative score. Immunohistochemistry was used for the recognition of immune cell markers, cytokines, caspase-3 and Leptospira antigens.

Results: The control group differed significantly from the leptospirosis and septic shock patients which demonstrate strong similarities: diffuse congestion in the red pulp with a moderate to intense infiltration of plasma cells and polymorphonuclear cells; follicles with marked atrophy; high density of CD20⁺ cells; low density of NK, TCD4⁺ and active caspase-3 positive cells and strong expression of IL-10; leptospirosis patients had higher S100 and TNF-α positive cells in the spleen than the other groups.

Conclusion: The results suggest that an immunosuppressive state develops at the terminal stage of severe leptospirosis with pulmonary hemorrhage and shock similar to that of patients with septic shock, with diffuse endothelial activation in the spleen, splenitis, and signs of disturbance in the innate and adaptive immunity in the spleen. The presence of leptospiral antigens in 73% of the spleens of the leptospirosis patients suggests the etiological agent contributes directly to the pathogenesis of the lesions. Our results support therapeutic approaches involving antibiotic and immunomodulatory treatments for leptospirosis patients and suggest that leptospirosis patients, which are usually young men with no co-morbidities, form a good group for studying sepsis and septic shock.

Paradoxical effects of vitamin C in Chagas disease

Trypanosoma cruzi infection stimulates inflammatory mediators which cause oxidative stress, and the use of antioxidants can minimize the sequelae of Chagas disease. In order to evaluate the efficacy of vitamin C in minimizing oxidative damage in Chagas disease, we orally administered ascorbic acid to Swiss mice infected with 5.0 × 10⁴ trypomastigote forms of T. cruzi QM2 strain. These animals were treated for 60 days to investigate the acute phase and 180 days for the chronic phase. During the acute phase, the animals in the infected and treated groups demonstrated lower parasitemia and inflammatory processes were seen in more mice in these groups, probably due to the higher concentration of nitric oxide, which led to the formation of peroxynitrite. The decrease in reduced glutathione concentration in this group showed a circulating oxidant state, and this antioxidant was used to regenerate vitamin C. During the chronic phase, the animals in the infected and treated group showed a decrease in ferric reducing ability of plasma and uric acid concentrations as well as mobilization of bilirubin (which had higher plasma concentration), demonstrating cooperation between endogenous non-enzymatic antioxidants to combat increased oxidative stress. However, lower ferrous oxidation in xylenol orange concentrations was found in the infected and treated group, suggesting that vitamin C provided biological protection by clearing the peroxynitrite, attenuating the chronic inflammatory process in the tissues and favoring greater survival in these animals. Complex interactions were observed between the antioxidant systems of the host and parasite, with paradoxical actions of vitamin C.

Post-Radiation Angiosarcoma of the Breast: A Clinical Case

After conservative treatment of breast carcinoma (quadran-tectomy and axillary dissection, plus radiotherapy), the growth of an angiosarcoma in the irradiated skin is a very rare event. We report a case, developed in the breast skin 62 months after the irradiation, and discuss the therapeutic possibilities and the role of follow-up in these patients.

Esophageal mucosa in HIV infection: A"deeper" look at this little spoken organ

BACKGROUND AND AIM

Although the esophagus is a common site of opportunistic infection in AIDS patients, little is known about the impact of HIV as well as opportunistic infection in the esophageal mucosa. Our aim is to analyze the esophageal immune profile in HIV+ patients with different immunological status with and without the opportunistic Candida infection.

METHODS

Immunohistochemistry to CD4⁺ and CD8⁺ T-cells, γ-interferon, transforming growth factor-β, interleukin (IL)-4, IL-6, IL-13, and IL-17 was performed in esophageal samples of 40 chronically HIV+ patients under highly active antiretroviral therapy (16 with Candida esophagitis, 12 virologically non-supressed with blood CD4 count < 500, and 12 virologically suppressed with blood CD4 count > 500; the latter two groups without esophageal candidiasis). The controls were 12 HIV-negative healthy individuals.

RESULTS

Esophageal CD4⁺ T-cell expression in HIV+ patients did not differ from the control group (P = 0.50). Mucosal CD8⁺ T-cell expression was significantly increased in HIV+ patients (P = 0.0018). Candida esophagitis and virologically non-supressed HIV+ patients with CD4 < 500 showed an increased expression of IL-17 and IL-6 with fewer expressions of γ-interferon, more attenuated in the latter group. Transforming growth factor-β was increased only in virologically suppressed HIV+ patients with CD4 > 500. IL-4 and IL-13 were similar to the control group.

CONCLUSION

In contrast to CD8⁺ T-cell expression, esophageal CD4⁺ T-cell expression does not reflect the HIV+ patient's immunological status. T-helper 17 (Th17) response seems to play a role in the esophageal mucosa of virologically non-supressed HIV+ patients with blood CD4 < 500. Candida esophagitis showed a Th1/Th17 response but seems to be dominantly regulated by the Th17 pathway.

The Digital Heart Manual: A pilot study of an innovative cardiac rehabilitation programme developed for and with users

OBJECTIVE

Patients are seeking greater choice and flexibility in how they engage with self-management programmes. While digital innovations offer opportunities to deliver supportive interventions to patients undergoing cardiac rehabilitation little is known about how accessible, useful and acceptable they are for this group. This project developed a digital version of a leading evidenced cardiac rehabilitation programme, the Heart Manual (HM). The prototype was developed and evaluated iteratively in collaboration with end users.

METHODS

Using a mixed methods design 28 participants provided feedback using semi-structured questionnaires and telephone interviews.

RESULTS

Rich data revealed the perceived user-friendliness of the HM digital format and its effectiveness at communicating the programme's key messages. It flagged areas requiring development, such as more flexible and intuitive navigation pathways. These suggestions informed the refinement of the resource.

CONCLUSION

This evaluation offers support for the new Digital Heart Manual and confirms the value of employing a user-centred approach when developing and improving online interventions. The system is now in use and recommendations from the evaluation are being translated into quality improvements.

PRACTICE IMPLICATIONS

The Digital Heart Manual is user friendly and accessible to patients and health professionals, regardless of age, presenting a suitable alternative to the paper version.

Langerhans Cells Express IL-17A in the Epidermis of Chromoblastomycosis Lesions

Chromoblastomycosis (CBM) is a chronic fungal infection that affects skin and subcutaneous tissue, and little is known about the immunological aspects of such lesions. We have previously described the high expression of IL-17 in this group. Understanding the innate immune response of patients with CBM would improve the knowledge of its immunopathogenesis and contribute to the most appropriate therapies. Nineteen biopsies of verrucous form were obtained from patients with clinical and histopathological diagnosis of CBM, without treatment. This was done with a double immunostaining with conventional immunohistochemistry and immunofluorescence technique as well as confocal microscopy to detect Langerin and IL-17 expression. All of the specimens that were analyzed showed expression of Langerin in the epidermis - the same as the control group. However, only the CBM group presented cells expressing CD207 in the dermis. Interestingly, the coexpression of IL-17 and Langerin was visualized along the epidermis and dermis in 100% of the lesion group. We demonstrated for the first time in situ coexpression of IL-17 and Langerin (CD207) in epidermal cells of patients with CBM and speculated on their role as IL-17-producing cells or whether they could be a new subpopulation of dendritic cells distinct from Langerhans cells.

The cytotoxic T cells may contribute to the in situ immune response in Jorge Lobo's Disease human lesions

Jorge Lobo's Disease (JLD) is a cutaneous chronic granulomatous disease caused by the pathogenic fungus Lacazia loboi. It is characterized by a granulomatous reaction with multinucleated giant cells and high number of fungal cells. In order to contribute to the comprehension of immune mechanisms in JLD human lesions, we studied the cytotoxic immune response, focusing on TCD8+ and NK cells, and granzyme B. Forty skin biopsies of lower limbs were selected and an immunohistochemistry protocol was developed to detect CD8+ T cells, NK cells and Granzyme B. In order to compare the cellular populations, we also performed a protocol to visualize TCD4+ cells. Immunolabeled cells were quantified in nine randomized fields in the dermis. Lesions were characterized by inflammatory infiltrate of macrophages, lymphocytes, epithelioid and multinucleated giant cells with intense number of fungal forms. There was a prevalence of CD8 over CD4 cells, followed by NK cells. Our results suggest that in JLD the cytotoxic immune response could represent another important mechanism to control Lacazia loboi infection. We may suggest that, although CD4+ T cells are essential for host defense in JLD, CD8+ T cells could play a role in the elimination of the fungus.

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)-β 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-β was observed in LL compared with TT. IL-4, IL-10 and TGF-β 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.

Development of Type 2, But Not Type 1, Leprosy Reactions is Associated with a Severe Reduction of Circulating and In situ Regulatory T-Cells

Leprosy is frequently complicated by the appearance of reactions that are difficult to treat and are the main cause of sequelae. We speculated that disturbances in regulatory T-cells (Tregs) could play a role in leprosy reactions. We determined the frequency of circulating Tregs in patients with type 1 reaction (T1R) and type 2 reaction (T2R). The in situ frequency of Tregs and interleukin (IL)-17, IL-6, and transforming growth factor beta (TGF)-β-expressing cells was also determined. T2R patients showed markedly lower number of circulating and in situ Tregs than T1R patients and controls. This decrease was paralleled by increased in situ IL-17 expression but decreased TGF-β expression. Biopsies from T1R and T2R patients before the reaction episodes showed similar number of forkhead box protein P3+ (FoxP3+) and IL-17+ cells. However, in biopsies taken during the reaction, T2R patients showed a decrease in Tregs and increase in IL-17+ cells, whereas T1R patients showed the opposite: Tregs increased but IL-17+ cells decreased. We also found decreased expansion of Tregs upon in vitro stimulation with Mycobacterium leprae and a trend for lower expression of FoxP3 and the immunosuppressive molecule cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in T2R Tregs. Our results provide some evidence to the hypothesis that, in T2R, downmodulation of Tregs may favor the development of T-helper-17 responses that characterize this reaction.

Paracoccidioides brasiliensis interacts with dermal dendritic cells and keratinocytes in human skin and oral mucosa lesions

Paracoccidioidomycosis (PCM) is a systemic disease caused by the fungus Paracoccidioides brasiliensis and Paracoccidioides lutzii. In PCM the skin and oral mucosa are often affected. Dendritic cells and keratinocytes of the integument play a role in innate and adaptive immune response against pathogens, due to their function as antigen presenting cells. Aiming to verify the interaction of P. brasiliensis with these cell populations, we studied 52 skin and 47 oral mucosa samples taken from patients with proven diagnosis of PCM. The biopsies were subjected to immunohistochemical and/or immunofluorescence staining with anti-factor XIIIa (marker of dermal dendrocytes), anti-CD207 (marker of mature Langerhans cells), anti-pan cytokeratins (AE1-AE3) and anti-P. brasiliensis antibodies. Analyses with confocal laser microscopy were also performed for better visualization of the interaction between keratinocytes and the fungi. In sum, 42% of oral mucosa samples displayed yeast forms in Factor XIIIa dermal dendrocytes cytoplasm. Langerhans cells in skin and oral mucosa samples did not show yeast cells in their cytoplasm. In sum, 54% of skin and 60% of mucosal samples displayed yeast cells in the cytoplasm of keratinocytes. The parasitism of keratinocytes may represent a possible mechanism of evasion of the fungus to local immune mechanisms. Factor XIIIa dendrocytes and keratinocytes may be acting as antigen-presenting cells to fulfill the probably impaired function of Langerhans cells in skin and oral mucosa of human PCM.

Th17 and regulatory T cells contribute to the in situ immune response in skin lesions of Jorge Lobo's disease

Jorge Lobo's disease (JLD) is a chronic granulomatous mycosis described in various Latin American countries. The main objective of the present study was to investigate the possible role of Th17 and Foxp3+ Treg cells in the pathogenesis of Jorge Lobo's disease. Human skin biopsies were submitted to an immunohistochemistry protocol to detect Foxp3, interleukin (IL)-1beta, CD25, IL-6, IL-17, and IL-23. The epidermis presented acanthosis, hyperkeratosis, and frequent presence of fungi. The dermis presented inflammatory infiltrate comprising macrophages, lymphocytes, epithelioid and multinucleated cells, and an intense number of fungi. Foxp3+ Treg cells and IL-17+ cells were visualized in lymphocytes in the inflammatory infiltrate. IL-1, IL-2R (CD25), IL-6, and IL-23 were visualized in the dermis, intermingled with fungal cells, permeating or participating of the granuloma. Following IL-17, the most prominent cytokine was IL-6. IL-23 and cells expressing CD25 were present in fewer number. The comparative analysis between IL-17 and Foxp3 demonstrated a statistically significant increased number of IL-17+ cells. Th17 cells play a role in the immune response of JLD. IL-1beta and IL-6 added to the previously described increased number of TGF-beta would stimulate such pattern of response. Th17 cells could be present as an effort to modulate the local immune response; however, high levels of a Th17 profile could overcome the role of Treg cells. The unbalance between Treg/Th17 cells seems to corroborate with the less effective immune response against the fungus.

Jorge Lobo's disease: immunohistochemical characterization of dendritic cells in cutaneous lesions

BACKGROUND

Jorge Lobo's disease (JLD) is a cutaneous chronic mycosis caused by Lacazia loboi. We studied Factor XIIIa + dermal dendrocytes (FXIIIa + DD), Langerhans cells (LC) through the expression of langerin and the expression of S100 protein.

METHODS

A total of 41 biopsies and 10 normal skins (control) were developed with a polymer-based immunohistochemical method.

RESULTS

Lesions presented infiltrate comprising macrophages, some asteroid corpuscles, lymphocytes, multinucleated giant cells and a large number of fungi. LCs presented short dendrites and were scarcely distributed. Dermal langerin + cells were detected in nine JLD lesions. FXIIIa + DD were hypertrophic, visualized in the inflammatory infiltrate of JLD lesions. Cells S100+ were present in JLD and control group with a similar number of cells. A total of 14 specimens did not express FXIIIa, and this considerable number probably contributed to the statistical similarity with the control group.

CONCLUSIONS

The results indicate that LCs are present in the immune response against Lacazia loboi. Some dermal langerin + cells could be another subset of dendritic cells. Our data indicate changes of LCs in JLD cutaneous lesions and present, for the first time, results that show langerin + cells in the dermis and corroborate previous observations on the participation of FXIIIa + DD in the in situ immune response in JLD.

Analysis of microvasculature phenotype and endothelial activation markers in skin lesions of lacaziosis (Lobomycosis)

Jorge Lobo's disease is a rare mycosis characterized by chronic inflammation, which causes skin lesions in the absence of visceral dissemination. The disease occurs mainly in hot and humid climates and most cases have been registered in the Brazilian Amazon region. This study investigated possible microvascular alterations in skin lesions caused by infection with Lacazia loboi which may interfere with the clinical progression of the disease. Immunohistochemistry was used to evaluate the density of blood and lymphatic vessels, as well as expression of the cell adhesion molecules ICAM-1, VCAM-1 and E-selectin. The results showed a reduced number of blood (62.66 ± 20.30 vessels/mm(2)) and lymphatic vessels (3.55 ± 5.84 vessels/mm(2)) in Jorge Lobo's disease when compared to control skin (169.66 ± 66.38 blood vessels/mm(2) and 8 ± 2.17 lymphatic vessels/mm(2)). There were a larger number of vessels expressing ICAM-1 (27.58 ± 15.32 vessels/mm(2)) and VCAM-1 (7.55 ± 6.2 vessels/mm(2)). No difference was observed in the expression of E-selectin (4.66 ± 11 vessels/mm(2)). Taken together, the results indicate changes in the local microvasculature which may interfere with the development of an efficient cell-mediated immune response and may explain restriction of the fungus to the site of injury.

Plasmacytoid dendritic cells in cutaneous lesions of patients with chromoblastomycosis, lacaziosis, and paracoccidioidomycosis: a comparative analysis

Plasmacytoid dendritic cells (pDCs) are characterized by expression of CD123 and BDCA-2 (Blood Dendritic Cell Antigen 2) (CD303) molecules, which are important in innate and adaptive immunity. Chromoblastomycosis (CBM), lacaziosis or Jorge Lobo's disease (JLD), and paracoccidioidomycosis (PCM), are noteworthy in Latin America due to the large number of reported cases. The severity of lesions is mainly determined by the host's immune status and in situ responses. The dendritic cells studied in these fungal diseases are of myeloid origin, such as Langerhans cells and dermal dendrocytes; to our knowledge, there are no data for pDCs. Forty-three biopsies from patients with CBM, 42 from those with JLD and 46 diagnosed with PCM, were evaluated by immunohistochemistry. Plasmacytoid cells immunostained with anti-CD123 and anti-CD303 were detected in 16 cases of CBM; in those stained with anti-CD123, 24 specimens were obtained from PCM. We did not detect the presence of pDCs in any specimen using either antibody in JLD. We believe that, albeit a secondary immune response in PCM and CBM, pDCs could act as a secondary source of important cytokines. The BDCA-2 (CD303) is a c-type lectin receptor involved in cell adhesion, capture, and processing of antigens. Through the expression of the c-lectin receptor, there could be an interaction with fungi, similar to other receptors of this type, namely, CD207 in PCM and CD205 and CD209 in other fungal infections. In JLD, the absence of expression of CD123 and CD303 seems to indicate that pDCs are not involved in the immune response.

Immunity and immune response, pathology and pathologic changes: progress and challenges in the immunopathology of yellow fever

Yellow fever is a viral hemorrhagic fever, which affects people living in Africa and South America and is caused by the yellow fever virus, the prototype species in the Flavivirus genus (Flaviviridae family). Yellow fever virus infection can produce a wide spectrum of symptoms, ranging from asymptomatic infection or oligosymptomatic illness to severe disease with a high fatality rate. In this review, we focus in the mechanisms associated with the physiopathology of yellow fever in humans and animal models. It has been demonstrated that several factors play a role in the pathological outcome of the severe form of the disease including direct viral cytopathic effect, necrosis and apoptosis of hepatocyte cells in the midzone, and a minimal inflammatory response as well as low-flow hypoxia and cytokine overproduction. New information has filled several gaps in the understanding of yellow fever pathogenesis and helped comprehend the course of illness. Finally, we discuss prospects for an immune therapy in the light of new immunologic, viral, and pathologic tools.

Ultrastructure of vascular permeability in urticaria

BACKGROUND

Few studies have addressed the ultrastructure of vascular permeability in urticaria.

OBJECTIVES

To describe the types of endothelial cell organelles involved in vascular permeability in drug-induced acute urticaria (DIAU).

METHODS

Seven patients with DIAU were enrolled in the study. Biopsies of urticarial lesions and apparently normal skin were performed. The 14 collected fragmentswere processed with immunogold electron microscopy using single stains for tryptase and factor XIIIa (FXIIIa) and double immunogold labeling for both tryptase and FXIIIa.

RESULTS

Some sections demonstrated mast cells in the degranulation process, in both anaphylactic and piecemeal degranulation. After double immunogold staining, 10 nm (FXIIIa) and 15 nm (tryptase) gold particles wereboth present, covering the granules in the mast cells, indicating that both tryptase and FXIIIa were localized within the granules of these cells. Interestingly, we found strong evidence of the presence of caveolae and vesico-vacuolar organelles (VVOs) in the endothelial cells of the biopsies. In addition to these findings, we were able to demonstrate the presence of tryptase and FXIIIa in the endothelial celIs, in urticarial lesions and in apparently normal skin.

CONCLUSIONS

VVOs are present in the endothelial cells of post-capillary venules in DIAU. This is the first report on the expression of FXIIIa and tryptase in the cytoplasm of endothelial cells in urticaria.

Adult Langerhans cell histiocytosis presenting as metachronous colonic polyps

Langerhans cell histiocytosis (LCH) is a rare disease characterized by proliferation of Langerhans-type cells that express CD1a, Langerin (CD207) and S100 protein. Birbeck granules are a hallmark by ultrastructural examination. LCH presents with a wide clinical spectrum, ranging from solitary lesions of a single site (usually bone or skin) to multiple or disseminated multisystemic lesions, which can lead to severe organ dysfunction. Most cases occur in children. Gastrointestinal tract involvement is rare and has been associated with systemic illness and poor prognosis especially in children under the age of 2 years. Adult gastrointestinal LCH is very rare. We report a case of a previously healthy, nonsmoking 48-year-old male who was referred for routine screening colonoscopy. Two sessile, smooth, firm and yellowish LCH polyps measuring 0.2 cm and 0.3 cm were detected in the sigmoid colon. Fifteen months later a second colonoscopy found two histologically confirmed hyperplastic polyps at the sigmoid colon. No other LCH lesions were seen. A third colonoscopy after 28 months of follow-up found a submucosal 0.5 cm infiltrated and ulcerated LCH polyp in the cecum, close to the ostium of the appendix. The patient had been asymptomatic for all this period. Imaging investigation for systemic or multiorgan disease did not find any sign of extracolonic involvement. On histology all lesions showed typical LCH features and immunohistochemical analysis showed strong and diffuse staining for CD1a and CD207. This case illustrates two distinct clinicopathologic features not previously reported in this particular clinical setting: metachronous colonic involvement and positivity for CD207.

Retinal involvement of Paracoccioidomycosis: A Case Report

Purpose: to describe the clinicopathologic features and treatment of a rare case of systemic paracoccidioidomycosis with choroidal and retinal involvement. Design: retrospective interventional case report. Participant: A 36-year-old young man with visual impairment in left eye with anterior uveitis and presence of whitish perimacular choroidal nodule, multiple underlying whitish spots and mid-periphery exudative retinal detachment. A primary extensive work-up for systemic infectious, autoimmune, neoplasic or inflammatory conditions was performed and high-resolution computer tomography scan demonstrated asymmetric parietal thickening of the trachea and bilateral diffuse multiple lobular opacities. Pulmonary bronchoscopy/biopsy of larynx, trachea and bronchial tube were also performed. Histopathological evaluation showed characteristic of Paracoccidioidomycosis. Intervention: Patient was treated with oral sulphadiazine (1.5 g/day). Main Outcome Measures: Anterior uveitis, retinal examination, histopathological evaluation and primary clinical outcome were observed during systemic treatment. Results: After 3 months of irregular treatment, choroidal lesions decreased in size forming atrophic scars and fibrotic spots; however visual acuity did not show any improvement. Conclusion: We report a rare case of systemic paracoccidioidomycosis with choroidal and retinal involvement treated with oral sulphadiazine.

Immunoelectron microscopy study of superficial skin nerves in drug-induced acute urticaria

BACKGROUND

Few studies have evaluated the ultrastructure of the superficial skin nerves in urticaria.

OBJECTIVE

The objective of this study was to describe findings in superficial skin nerves in cases of drug-induced acute urticaria.

METHODS

Seven patients with drug-induced acute urticaria were included in the study. Skin biopsies were obtained from the urticarial lesion and from the apparently normal skin. The 14 fragments collected were processed for immunogold electron microscopy using single stains for antitryptase and anti-FXIIIa antibodies, as well as double immunogold labeling for both.

RESULTS

Some sections showed mast cells in the process of degranulation. Following double immunogold staining, 10 nm (FXIIIa) and 15 nm (Tryptase) gold particles were found together throughout the granules in mast cells, indicating that tryptase and FXIIIa are located inside each one of the granules of these cells. Interestingly, we found strong evidence of the presence of tryptase and factor XIIIa in the superficial skin nerves of these patients, both in cases of urticarial lesions (wheals) and in the apparently normal skin.

CONCLUSIONS

Tryptase and FXIIIa are present in the superficial nerves of the skin in drug-induced acute urticaria. This is the first report of tryptase and FXIIIa expression in the superficial skin nerves of patients with urticaria. Tryptase may be participating in neural activation in these patients, while FXIIIa may be present in the nerves to guarantee the functional integrity of structures.

Increased expression of regulatory T cells and down-regulatory molecules in lepromatous leprosy

T regulatory cells (Tregs) play an important role in the mechanism of host's failure to control pathogen dissemination in severe forms of different chronic granulomatous diseases, but their role in leprosy has not yet been elucidated; 28 newly diagnosed patients (16 patients with lepromatous leprosy and 12 patients with tuberculoid leprosy) and 6 healthy Mycobacterium leprae-exposed individuals (contacts) were studied. Tregs were quantified by flow cytometry (CD4+ CD25+ Foxp3+) in peripheral blood mononuclear cells stimulated in vitro with a M. leprae antigenic preparation and phytohemagglutinin as well as in skin lesions by immunohistochemistry. The lymphoproliferative (LPR), interleukin-10 (IL-10), and interferon-γ (IFN-γ) responses of the in vitro-stimulated peripheral blood mononuclear cells and the in situ expression of IL-10, transforming growth factor-β (TGF-β), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) were also determined. We show that M. leprae antigens induced significantly lower LPR but significantly higher Treg numbers in lepromatous than tuberculoid patients and contacts. Mitogen-induced LPR and Treg frequencies were not significantly different among the three groups. Tregs were also more frequent in situ in lepromatous patients, and this finding was paralleled by increased expression of the antiinflammatory molecules IL-10 and CTLA-4 but not TGF-β. In lepromatous patients, Tregs were intermingled with vacuolized hystiocyte infiltrates all over the lesion, whereas in tuberculoid patients, Tregs were rare. Our results suggest that Tregs are present in increased numbers, and they may have a pathogenic role in leprosy patients harboring uncontrolled bacillary multiplication but not in those individuals capable of limiting M. leprae growth.