Prevalence of discordant immunologic and virologic responses in patients with AIDS under antiretroviral therapy in a specialized care center in Brazil

Some patients under antiretroviral therapy (ART) do not reach immune recovery when the viral load becomes undetectable. This is called discordant immunologic and virologic responses. Its prevalence varies between 8% and 24%. This study describes its prevalence and the characteristics of the affected subjects in the outpatient clinic of a Brazilian specialized-care center. Of 934 patients on ART, 536 had undetectable viral loads. Prevalence was 51/536 or 9% (95% confidence interval: 6.6% to 11.4%). Median age at the beginning of ART was 37 years (interquartile range - IQR: 31 to 45). Male gender and mixed race predominated (76.5% and 47.1% respectively). AIDS-defining illnesses were absent at the beginning of ART in 60.8%. Fifty-one percent were taking protease inhibitors, 43.2% Efavirenz and 5.8% both. Median time on ART was 36 months (IQR: 17-81 months). Irregular treatment was recorded for 21.6%. ART had been modified for 63% prior to the study, and 15.7% had used monotherapy or double therapy. Median CD4 count was 255 cells/mm³ (IQR: 200-284). Median viral load before ART was 4.7 log10 copies/mL (IQR: 4.5-5.2). Discordant responders were not different from AIDS patients in general, but there was a high frequency of multiple schedules of treatment.

TOLL-LIKE RECEPTORS (TLR) 2 AND 4 EXPRESSION OF KERATINOCYTES FROM PATIENTS WITH LOCALIZED AND DISSEMINATED DERMATOPHYTOSIS

There are few studies on the role of innate immune response in dermatophytosis. An investigation was conducted to define the involvement of Toll-Like Receptors (TLRs) 2 and 4 in localized (LD) and disseminated (DD) dermatophytosis due to T. rubrum. Fifteen newly diagnosed patients, eight patients with LD and seven with DD, defined by involvement of at least three body segments were used in this study. Controls comprised twenty skin samples from healthy individuals undergoing plastic surgery. TLR2 and TLR4 were quantified in skin lesions by immunohistochemistry. A reduced expression of TLR4 in the lower and upper epidermis of both LD and DD patients was found compared to controls; TLR2 expression was preserved in the upper and lower epidermis of all three groups. As TLR4 signaling induces the production of inflammatory cytokines and neutrophils recruitment, its reduced expression likely contributed to the lack of resolution of the infection and the consequent chronic nature of the dermatophytosis. As TLR2 expression acts to limit the inflammatory process and preserves the epidermal structure, its preserved expression may also contribute to the persistent infection and limited inflammation that are characteristic of dermatophytic infections.

Hand, Foot, and Mouth Syndrome in an Immunocompetent Adult: a Case Report

BACKGROUND: Hand, foot, and mouth syndrome (HFMS) is a common acute illness. It is characterized by mild clinical symptoms including fever, blisters, and sores in the mouth and on the palms and soles following a 3- to 7-day incubation period. This syndrome is rarely seen in adults. CASE PRESENTATION: A 35-year-old male Caucasian patient had a history of multiple episodes of acute pharyngitis, hypertension, hypercholesterolemia, and occasional abdominal pain. He presented with polyarthralgia in the knees and hands and odynophagia, followed by fever, oral mucosal aphthous lesions, and vesicles on the palms and soles. Three weeks after presentation, he was admitted to the emergency room with acute myocarditis. The in-hospital evaluation revealed positive serology for coxsackie A9 (1:160), positive anti-transglutaminase and anti-gliadin antibodies, normal immunoglobulins, and human immunodeficiency virus negativity. CONCLUSION: We herein describe a case of HFMS that was associated with coxsackie A9 infection complicated by acute myocarditis. Although an association between celiac disease and HFMS has not been described, this patient's immunologic disruption could have favored the development of infection and ultimately HFMS.

Regulatory Cells, Cytokine Pattern and Clinical Risk Factors for Asthma in Infants and Young Children with Recurrent Wheeze

Several risk factors for asthma have been identified in infants and young children with recurrent wheeze. However, published literature has reported contradictory findings regarding the underlying immunological mechanisms. OBJECTIVES: This study was designed to assess and compare the immunological status during the first 2 years in steroid-naive young children with >or= three episodes of physician-confirmed wheeze (n=50), with and without clinical risk factors for developing subsequent asthma (i.e. parental asthma or a personal history of eczema and/or two of the following: wheezing without colds, a personal history of allergic rhinitis and peripheral blood eosinophilia >4%), with age-matched healthy controls (n=30). METHODS: Peripheral blood CD4(+)CD25(+) and CD4(+)CD25(high) T cells and their cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), GITR and Foxp3 expression were analysed by flow cytometry. Cytokine (IFN-gamma, TGF-beta and IL-10), CTLA-4 and Foxp3 mRNA expression were evaluated (real-time PCR) after peripheral blood mononuclear cell stimulation with phorbol 12-myristate 13-acetate (PMA) (24 h) and house dust mite (HDM) extracts (7th day). RESULTS: Flow cytometry results showed a significant reduction in the absolute number of CD4(+)CD25(high) and the absolute and percentage numbers of CD4(+)CD25(+)CTLA-4(+) in wheezy children compared with healthy controls. Wheezy children at a high risk of developing asthma had a significantly lower absolute number of CD4(+)CD25(+) (P=0.01) and CD4(+)CD25(high) (P=0.04), compared with those at a low risk. After PMA stimulation, CTLA-4 (P=0.03) and Foxp3 (P=0.02) expression was diminished in wheezy children compared with the healthy children. After HDM stimulation, CTLA-4 (P=0.03) and IFN-gamma (P=0.04) expression was diminished in wheezy children compared with healthy children. High-risk children had lower expression of IFN-gamma (P=0.03) compared with low-risk and healthy children and lower expression of CTLA-4 (P=0.01) compared with healthy children. CONCLUSIONS: Although our findings suggest that some immunological parameters are impaired in children with recurrent wheeze, particularly with a high risk for asthma, further studies are needed in order to assess their potential as surrogate predictor factors for asthma in early life.

Phylogeography, conservation genetics and parasitology of chimpanzees (Pan troglodytes versus) in Guinea-Bissau, West Africa

Tese de doutoramento em Antropologia, especialidade em Antropologia Biológica e Etnoecologia

T cell Maturation and Regulatory T Cell Differentiation:From the Thymus to the Periphery

Immunological tolerance, that is, the failure to mount an immune response to an otherwise immunogenic molecule, is one of the fundamental questions in immunology. The fact that lymphocytes express antigen receptors that are generated randomly and have the potential to recognize any conceivable antigen, adds another puzzle to the physiology of immunological tolerance. The other side of the coin, the general absence of immune responses to self antigens, is ensured by a tight regulation and several selection steps during T and B cell differentiation. One of these processes is the differentiation of regulatory T cells (Treg). While developing in the thymus, T cell clones bearing receptors with high affinity/avidity to antigens present at the time of differentiation may be eliminated by apoptosis or, alternatively, express Foxp3 and become Treg. Treg are key players in the regulation of immunological tolerance since humans and mice with complete loss of function variants of this gene develop fatal autoimmune conditions early in life.(...)