Ronaldo Alves

Indoor allergen sensitization profile in allergic patients of the allergy clinic in the University Hospital in Uberlândia, Brazil

OBJECTIVE To evaluate allergens among patients with allergic respiratory disease attended at the Allergy Clinic of the University Hospital-Federal University of Uberlândia. METHODS A retrospective study was performed using medical records. Patients were included if their ISAAC questionnaires were correctly filled out and their skin prick tests were positive to at least one of the allergens from Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) and Alternaria alternata. RESULTS Two-hundred and twelve medical records fulfilled the inclusion criteria. Allergic rhinitis was the main clinical diagnosis (32%), followed by concomitant manifestation of asthma and rhinitis (29.7%), and asthma, rhinitis and atopic dermatitis (9.4%). Asthma alone was found only in 1.9% of patients. The total sensitization observed was 73.5%, of which 61.7%, 59.9%, 54.7%, 45.7%, 38.2%, 33.3%, 9.9% were sensitized to Der p, Der f, Blo t, Bla g, Can f, Fel d and Alternaria, respectively. No significant difference was found between allergic disease types and source of allergen sensitization. CONCLUSION The highest sensitization in allergic patients under study was to dust mites, especially Der p and Der f. It is noteworthy that the number of patients sensitized to cockroach extract was uncommonly high when compared to previous studies.OBJECTIVE: To evaluate allergens among patients with allergic respiratory disease attended at the Allergy Clinic of the University Hospital - Federal University of Uberlândia. METHODS: A retrospective study was performed using medical records. Patients were included if their ISAAC questionnaires were correctly filled out and their skin prick tests were positive to at least one of the allergens from Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) and Alternaria alternata. RESULTS: Two-hundred and twelve medical records fulfilled the inclusion criteria. Allergic rhinitis was the main clinical diagnosis (32%), followed by concomitant manifestation of asthma and rhinitis (29.7%), and asthma, rhinitis and atopic dermatitis (9.4%). Asthma alone was found only in 1.9% of patients. The total sensitization observed was 73.5%, of which 61.7%, 59.9%, 54.7%, 45.7%, 38.2%, 33.3%, 9.9% were sensitized to Der p, Der f, Blo t, Bla g, Can f, Fel d and Alternaria, respectively. No significant difference was found between allergic disease types and source of allergen sensitization. CONCLUSION: The highest sensitization in allergic patients under study was to dust mites, especially Der p and Der f. It is noteworthy that the number of patients sensitized to cockroach extract was uncommonly high when compared to previous studies.

Antibody and cytokine responses to house dust mite allergens and Toxoplasma gondii antigens in atopic and non-atopic Brazilian subjects

According to hygiene hypothesis, a lower exposure to infection is associated with increased prevalence of allergic diseases. This study aimed to investigate the association between atopy and Toxoplasma gondii (Tg) infection by analyzing the antibody and cytokine responses to house dust mite allergens and T. gondii antigens in Brazilian subjects. A total of 275 individuals were assessed and divided into atopics (n=129) and non-atopics (n=146) based on markers of allergy (positive skin prick test and ELISA-IgE to mite allergens) or Tg-seropositive (n=116) and Tg-seronegative (n=159) groups according to infection markers (positive ELISA-IgG to T. gondii). Tg-seropositive individuals presented lower allergenic sensitization (37%) to mite allergens than Tg-seronegative subjects (54%). A significant association was found between atopy and negative serology to T. gondii (OR: 2.0; 95% CI: 1.23-3.26; P<0.05). Proliferative responses and cytokine production after antigenic stimulation showed predominant synthesis of Th1-cytokines as IFN-gamma in Tg-seropositive patients, whether atopics or non-atopics. Conversely, Th2-cytokines as IL-5 prevailed in atopics compared to non-atopics, regardless the seropositivity to T. gondii. Levels of IL-10, IL-13, IL-17, and TGF-beta were not able to discriminate the groups. Hence, a negative association between atopy and infection by T. gondii was demonstrated for the first time in Brazilian subjects, focusing on the antibody and cytokine responses and indicating that the immunomodulation induced by the parasite may play a protective role in the development of allergic diseases.

Major histocompatibility complex (MHC) class II but not MHC class I molecules are required for efficient control of Strongyloides venezuelensis infection in mice

Strongyloides stercoralis is an intestinal nematode capable of chronic, persistent infection and hyperinfection of the host; this can lead to dissemination, mainly in immunosuppressive states, in which the infection can become severe and result in the death of the host. In this study, we investigated the immune response against Strongyloides venezuelensis infection in major histocompatibility complex (MHC) class I or class II deficient mice. We found that MHC II−/− animals were more susceptible to S. venezuelensis infection as a result of the presence of an elevated number of eggs in the faeces and a delay in the elimination of adult worms compared with wild‐type (WT) and MHC I−/− mice. Histopathological analysis revealed that MHC II−/− mice had a mild inflammatory infiltration in the small intestine with a reduction in tissue eosinophilia. These mice also presented a significantly lower frequency of eosinophils and mononuclear cells in the blood, together with reduced T helper type 2 (Th2) cytokines in small intestine homogenates and sera compared with WT and MHC I−/− animals. Additionally, levels of parasite‐specific immunoglobulin M (IgM), IgA, IgE, total IgG and IgG1 were also significantly reduced in the sera of MHC II−/− infected mice, while a non‐significant increase in the level of IgG2a was found in comparison to WT or MHC I−/− infected mice. Together, these data demonstrate that expression of MHC class II but not class I molecules is required to induce a predominantly Th2 response and to achieve efficient control of S. venezuelensis infection in mice.

Increased susceptibility to Strongyloides venezuelensis infection is related to the parasite load and absence of major histocompatibility complex (MHC) class II molecules.

In human and murine models strongyloidiasis induce a Th2 type response. In the current study we investigated the role of different loads of Strongyloides venezuelensis in the immune response raised against the parasite and the participation of the major histocompatibility complex (MHC) class II molecule in the disease outcome in face of the different parasite burden. The C57BL/6 wild type (WT) and MHC II(-/-) mice were individually inoculated by subcutaneous injection with 500 or 3000 S. venezuelensis L3. The MHC II(-/-) mice infected with 3000L3 were more susceptible to S. venezuelensis infection when compared with WT groups, in which the parasite was completely eliminated. The production of Th2 cytokines and specific IgG1 or IgE antibodies against parasite were significantly lowered in MHC II(-/-) infected mice with different larvae inoculums. The infection of MHC II(-/-) mice with S. venezuelensis induced slight inflammatory alterations in the small intestine, and these lesions were lower when compared with WT mice, irrespective of the parasite load utilized to infect animals. Finally, we concluded that MHC class II molecules are essential in the immune response against S. venezuelensis mainly when infection occurs with high parasite inoculum.

Responses of IgE, IgG1, and IgG4 to concanavalin A-binding Blomia tropicalis antigens in allergic patients

Blomia tropicalis (Bt) and Dermatophagoides pteronyssinus (Dp) are the prevalent house dust mites in tropical countries and are associated with allergic diseases. Glycosylated antigens are highly immunogenic and involved in different pathologies. We evaluated the presence of IgE, IgG1, and IgG4 to concanavalin A-binding antigens (Bt-Con-A) isolated from Bt-total extract in sera of allergic and non-allergic subjects. Bt-total and Bt-Con-A extracts were evaluated by SDS-PAGE and ELISA for reacting with IgE, IgG1, and IgG4 in sera of 121 patients with allergic rhinitis and 36 non-allergic individuals. All subjects were skin prick tested with Bt-total extract and inhibition tests were performed for IgE, IgG1, and IgG4 using both extracts (Bt-total and Bt-Con-A). Skin prick test showed that 58% of the patients were sensitized to Bt (Bt+), with 52% reactive to both mites (Bt and Dp) and 6% to Bt only. A broad spectrum of proteins (14-152 kDa) was visualized in Bt-total and components >27 kDa for the Bt-Con-A extract. ELISA showed a similar profile of IgE, IgG1 and IgG4 levels in response to Bt-total and Bt-Con-A extracts in different groups, although Bt+ patients showed a lower IgG4 reactivity to Bt-Con-A extract. Specific IgG1 levels were higher in Bt+ patients than in control subjects, and IgG4 levels showed no significant difference among groups. ELISA inhibition showed a partial IgE and total IgG1 and IgG4 cross-reactivity with Dp extract for Bt-total and Bt-Con-A extracts. We conclude that Con-A-binding components isolated from Bt constitute major allergens and are involved in both allergen sensitization (IgE response) and homeostasis maintenance (IgG1 and IgG4 responses).

Local cytokines and clinical symptoms in children with allergic rhinitis after different treatments.

Background Therapy for allergic rhinitis aims to control symptoms and improve the quality of life. The treatment of allergic rhinitis includes allergen avoidance, environmental controls, pharmacologic treatment, and specific immunotherapy. Objectives The aim of this study is to evaluate the clinical changes and the levels of interferon-γ (IFN-γ) and interleukin-5 (IL-5) in nasal lavage fluid from children with allergic rhinitis after different types of pharmacologic treatment (mometasone, montelukast, or desloratadine). Methods Twenty-four children aged from six to 12 years with moderate persistent allergic rhinitis were randomized into three groups receiving monotherapy treatment over four weeks: nasal corticosteroid (mometasone), leukotriene modifier (montelukast), or antihistamine (desloratadine). The perception of symptom improvement during the medication use was evaluated at the end of the treatment. Samples of nasal lavage fluid were collected before and after treatment for measuring IFN-γ and IL-5 cytokines by ELISA. Results All parents perceived an improvement in symptoms. Significant enhancement was seen in the mometasone group compared to those with montelukast (P = 0.01) and desloratadine (P = 0.02). No significant differences were found among the three groups in the levels of IL-5 and IFN-γ in nasal fluid at baseline or after treatment. Only the group treated with mometasone showed a slight but significant reduction in IL-5 levels after the treatment period as compared with levels before the treatment (P = 0.0469). Conclusion The group treated with mometasone showed better improvement of clinical symptoms and a slight reduction in IL-5 levels in the nasal fluid. This may indirectly reflect the relative immunomodulatory effects of the drugs tested.

Humoral and cellular immune responses to Blomia tropicalis and concanavalin A-binding fractions in atopic patients.

Department of Medicine, Center for Immunity, Inflammation and Regenerative Medicine, University ofVirginia, Charlottesville, VA, USACorrespondence to: E.A. Taketomi, Laboratorio de Alergia e Imunologia Clinica, ICBIM, UFU, Av. Para,1720, Bloco 4C, Campus Umuarama, 38400-902 Uberlândia, MG, BrasilFax: +55-34-3232-8620. E-mail: eat4y@yahoo.com.br

Spirometric parameters and levels of interferon gamma and IL-5 in induced sputum from patients with allergic rhinitis or asthma.

Background This study was designed to analyze spirometric parameters and cytokine (interferon [IFN] gamma and IL-5) levels in induced sputum from patients with asthma or allergic rhinitis (AR) and nonatopic subjects. Methods Thirty-three subjects aged 18–60 years were enrolled in the present study. Eight patients had asthma without AR symptoms, 16 had AR without asthma symptoms or history, and both groups had positive skin-prick test (SPT) to aeroallergens. The nine remaining subjects were healthy nonatopic subjects with negative SPT to aeroallergens. Spirometry was performed by evaluating the forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV 1 ), and forced expiratory flow between 25 and 75% (FEF 25–75 ) of FVC before and after bronchodilator use. Induced sputum samples were also collected for measuring cytokine (IFN-gamma and IL-5) levels by enzyme-linked immunosorbent assay. Results Significant pre- and postbronchodilator change was observed only for FEV 1 with higher variation values in asthmatic subjects compared with patients with AR (p < 0.05) and nonatopic subjects (p < 0.01). There was no significant difference in pre- and postbronchodilator spirometric parameters among the three groups, although asthmatic patients showed lower prebronchodilator FEF 25–75 values (p = 0.065). IL-5 levels were higher in induced sputum from patients with asthma and AR compared with nonatopic subjects (p = 0.020 and p = 0.032, respectively), but IFN-gamma levels showed no significant difference between the groups. Conclusion Spirometric measurements were not able to show any occurrence of bronchial constriction in patients with AR, but predominant IL-5 levels in induced sputum from these patients reinforce the role of Th2-type immune response in lower respiratory airways that could contribute to the concept of “one airway, one disease.”

Inducible nitric oxide synthase controls experimental Strongyloides infection

Infection with Strongyloides sp. induces a host immune response, predominantly the Th2 type, that is able to eliminate the parasite. However, little is known about the role of the nitric oxide (NO) mediator, induced by the enzyme nitric oxide synthase (NOS), in strongyloidiasis. Therefore, in this study, we investigated the immune response of mice genetically deficient in the enzyme inducible nitric oxide synthase (iNOS−/−), infected with Strongyloides venezuelensis. C57BL/6 wild‐type (WT) and iNOS−/− mice were individually inoculated by subcutaneous injection of 3000 S. venezuelensis L3 larvae. In the absence of iNOS, mice were more susceptible to the infection than WT animals, in which the parasite was completely eliminated. The overall production of cytokines and specific IgG, IgG1 or IgE antibodies against the parasite was significantly lowered in infected iNOS−/− mice. The expression of iNOS was observed in the intestine of WT hosts but mainly in the wall of the parasite, despite the presence of iNOS in mice. Altogether, we concluded that iNOS expression may play an important role in the control of S. venezuelensis infection.