An analysis of circulating T lymphocytes among asthmatic children with different sensitized patterns / 中国免疫学杂志

Objective:To investigate the difference in circulating T lymphocyte subsets among asthmatic children with different sensitized patterns.Methods:A total of 374 asthmatic children were enrolled in present study,and the sensitized patters were identified using skin prick testing.The numbers of circulating T cells (CD3+,CD19+),CD4+T cells (CD3+,CD4+),CD8+ T cells (CD3 + CD8 +),Tregs(CD4+ CD25+ FOXP3+),Th1 (CD4+IFN-γ+T),Th2 (CD4+ IL-4+ T)and Th17 cells(CD4+ IL-17+ T)in peripheral blood were measured by flow cytometry.Results:According to positive skin responses detected by SPT,patients with asthma were divided into three groups:un-sensitized asthma group,mono-sensitive asthma group and poly-sensitized asthma group.Compared with healthy controls,there were significant variations in CD4+ T cells and CD8+ T cells and CD4/CD8 ratio,Th1 cells and Th2 cells and Th1/Th2 ratio,Tregs,Th17 cells,Tregs/Th17 ratio (all P ＜ 0.05).A further pairwise comparison indicated that the statistically significant difference in Tregs,Th17 cells and Tregs/Th17 were found among un-sensitized asthma group,mono-sensitive asthma group and poly-sensitized asthma group(all P＜0.05).According to the type of allergens detected by SPT,the asthmatic patients were divided into the dust mite group,mould group,animal dander group,pollen group and other groups.Compared with healthy controls,there were significant variations in CD4+ T cells and CD8+ T cells and CD4/CD8 ratio,Th1 cells and Th2 cells and Th1/Th2 ratio,Tregs,Th17 cells,Tregs/Th17 ratio(all P＜0.05).Similarly,a pairwise comparison indicated that the numbers of Th1 cells,T h2 cells,Th2 cells,Th1/Th2 ratios,Tregs,Th17 cells and Tregs/Th17 ratios were found significant among these 5 groups(all P＜0.05).Conclusion:The finding highlights the importance of paying attention to the differences in the distribution of T lymphocyte subgroups among asthmatic patients with different sensitization patterns.

Aeroallergen Sensitization in Childhood Asthmatics in Northern India.

Objective: To determine the prevalence of sensitization to common aeroallergens in asthmatic children and study the differences in characteristics of atopics and non atopics. Design: Analysis of data from a prospective cohort study. Setting: Pediatric Chest Clinic of tertiary care center in Northern India Patients: Asthmatic children from 5-18 year of age. Main outcome measures: Prevalence of sensitization to common aeroallergens. Results: Skin prick testing (SPT) was performed on 180 children above 5 years of age, with a mean (SD) age of 111.4 (34.2) months. 100 children (55.6%) were sensitized to at least one aeroallergen, suggesting atopy; 68 (37.8%) were sensitized to more than one allergen. 36.7% children were sensitized to housefly antigen; 31.1% to rice grain dust, 18.3% to cockroach, and 7.8% to house dust mite antigens. Atopic children had significantly higher median FENO during follow up than nonatopic children (17.5 ppb vs 13 ppb, P=0.002). There was a positive correlation between age and the number of allergens that an individual was sensitized to (r= 0.21; P=0.0049). Conclusions: More than half of asthmatic children in our cohort had sensitization to one or more aeroallergens suggesting atopy; sensitization was most commonly seen to housefly antigen and rice grain dust. Atopic children had significantly higher FENO measurements during follow up as compared to non-atopic children.

Correlation of atopy and FeNO in allergic rhinitis an Indian study.

Background. Fractional exhaled nitric oxide (FeNO) is a non-invasive marker of airway inflammation. Limited published data are available on the effect of atopy on FeNO in allergic rhinitis. Objectives. To investigate the relationship between atopy and FeNO in patients with allergic rhinitis. Methods. Patients with allergic rhinitis were assessed for atopy and exhaled breath analysis of nitric oxide. Atopy was assessed by skin prick testing (SPT) against 58 common aero-allergens; a wheal size of 3mm or more as compared to buffer saline was considered positive. Patients were labelled to be atopic if they had at least one positive SPT result. The measurement of FeNO level was done by using NIOX chemiluminescence analyser. Results. Forty-nine participants (26 males) aged between 8-50 years were studied and 31 of them were found to be atopic. The average value of FeNO in the subjects studied (n=49) was 26.0±22.7 parts per billion (ppb) with significantly higher values being observed in atopic group as compared to non-atopic group (34.2±24.3 versus 11.9±9.0 ppb; p<0 .05). Conclusion. As FeNO is a marker of lower airway inflammation, significantly higher FeNO levels in atopic allergic rhinitis patients suggest that it may be a predictor for onset of asthma in these patients.

Utility of penicillin allergy testing in patients presenting with a history of penicillin allergy

BACKGROUND: Current statistics show that approximately 10% of patients claim to be allergic to penicillin yet only 10% of these have demonstrable allergy. The most appropriate and cost-effective antibiotics are sometimes withheld on the basis of patient history of drug allergy. OBJECTIVE: Investigation of IgE hypersensitivity and delayed hypersensitivity in patients with a history of penicillin allergy to a teaching hospital allergy clinic. METHODS: Patients underwent skin prick and intradermal testing (IDT) with major and minor penicillin determinants. Those with negative skin tests were administered a three-day oral challenge. Demographic and clinical details about the reactions were noted. RESULTS: One hundred twenty eight patients underwent testing, of these, one hundred and ten had self-reported histories of penicillin allergy and eighteen were referred because of other antibiotic allergies. Seventeen patients with self-reported penicillin allergy had either positive skin tests or oral challenge results, corresponding to 15% of patients having proven allergy. None reacted on skin prick testing, four reacted to IDT, thirteen reacted to oral challenge (five immediate and eight delayed). Analysis of clinical histories showed that patients with a well-defined history of allergy and a history of anaphylaxis were more likely to have a positive test compared to patients with vague histories. Skin testing proved to be less sensitive than oral challenge. CONCLUSION: A minority of patients presenting with a history of penicillin allergy have evidence of immune-mediated hypersensitivity (17/110, 15%) in this study. Of these, eight out of seventeen (47%) had delayed reactions, demonstrating the usefulness and discriminating power of objective testing, which must include three-day oral challenge. Discriminating factors for immune-mediated allergy from patient history were a clear description of the original reaction and a history of anaphylaxis. Negative allergy testing enables the use of penicillin as first-line treatment when necessary and this can significantly reduce costs of antibiotics.

Prevalence and clinical characteristics of adult-onset atopic dermatitis with positive skin prick testing to mites.

Background The clinical role of house dust mite (HDM) in atopic dermatitis (AD) is still controversial. Objective The aim of the study is to assess the prevalence, clinical relevance and characteristics of adult-onset AD patients with positive skin prick tests (SPT) to mites. Methods The case record forms of adult-onset AD patients who underwent SPT at the Skin Allergy Clinic, Siriraj Hospital were reviewed. Results Forty-one of 62 patients (66.1%) had positive SPT to mites. The frequency of intrinsic AD among adult-onset AD was 4.8% (3/62). SPT to HDM tended to be positive in patients who had personal or family history of atopy, positive SPT to several specific antigens or who presented with elevated serum IgE, chelitis, recurrent conjunctivitis and perifollicular accentuation, respectively. Conclusion The prevalence of adult-onset AD patients with mite sensitivity was high. There were some notable features that tended to be present in mite sensitive adult-onset AD patients.

In-vivo allergenic potency of Siriraj Mite Allergen Vaccine (SMAV) comparing with standardized vaccine in mite-sensitive patients.

Background: The prevalence of allergic diseases, particularly asthma and allergic rhinitis, has increased tremendously in Thailand and worldwide. House dust mite (HDM) is the major IgE sensitizer among allergic children and adults. We have developed local standardized mite allergen extracts, Siriraj Mite Allergen Vaccine (SMAV) from Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) from our source materials which were highly purified (99%). Objective: To compare in-vivo allergenic potency of both SMAV Dp and Df with commercial standardized mite allergen vaccine by using skin prick testing in mite-sensitive individuals. Methods: This was a double-blind, randomized, self controlled study comparing SMAV and commercial standardized mite allergen vaccine (Dp and Df) by using skin prick testing in mite-sensitive adult volunteers, 18 – 60 years of age. Results: The study was performed in 54 adult volunteers (19 males, mean age 26.6 + 5.5 years old) who had positive skin test to commercial Dp and Df. Seventeen of them had no allergic disease. The most common allergic disease among the volunteers was allergic rhinitis (21/37). Mean wheal diameter of SMAV Dp and commercial Dp at the concentration of 10,000 and 5, 000 AU/ml were equivalent but at the concentration of 2,500 AU/ml was inequivalent. Mean wheal diameter of SMAV Dp was significantly larger than commercial Dp at concentration of 2,500 AU/ml (p < 0.05). Mean wheal diameter of SMAV Df and commercial Df at all 3 concentrations were equivalent. There was no systemic side effect in all subjects. Conclusion: The study demonstrated that in mite-sensitive adults, SPT using SMAV Dp (10,000 AU) and Df (10,000 AU) had equivalent allergenic potency to the commercial comparator without any systemic side effect.