Prick Test Reactivity Research Articles

Intestinal helminthic infection and allergic disorders among school children enrolled in mass deworming program, Sululta, Ethiopia

BackgroundIntestinal helminths have been proposed to have a protective role against allergic sensitization and atopic diseases. However, consistent data demonstrating this are lacking in Sub-Saharan countries. We aimed to assess the association between intestinal helminths and allergic disorders among school children enrolled in mass deworming program in Sululta, Ethiopia.MethodsA cross sectional study was conducted among 526 school children aged 5 to 14 years old from primary government schools in Sululta district, Ethiopia. An interviewer-led questionnaire administered to parents provided information on demographic and lifestyle variables. Questions on allergic disease symptoms were collected using the International Study of Asthma and Allergies in Children (ISAAC) questionnaire 6 months following deworming treatments. Atopy was defined as a positive skin prick test reaction to one or both dust mite (Dermatophagoides) and German cockroach (Blatella germanica) allergens. Fresh stool samples were collected, processed, and examined by direct wet mount, Kato-Katz technique, and formol-ether concentration technique. Multivariate logistic regressions were used to assess the association between allergic disorder and helminths infection.ResultsOf the total 526 school children, 58.2% were females. Overall, 24% (126/526) had allergic symptoms, 5.1% (27/526) had atopy, and 16.9% (89/526) had intestinal helminths. There was no association between helminthic infection and self-reported allergic symptoms (P = 0.317), but Ascaris lumbricoides infection was positively associated with atopy (AOR = 4.307, 95% CI 1.143–16.222, P = 0.031). Atopy was related to increased allergy symptoms (AOR = 2.787, 95% CI 1.253–6.197, P = 0.012), and family history of allergy was associated with increased childhood allergy (AOR = 2.753, 95% CI 1.565–4.841, P = 0.001). Deworming in the past 6 months showed a reduced odd of self-reported allergic symptoms (AOR = 0.581, 95% CI 0.366–0.954, P = 0.034).ConclusionWhile no significant association between self-reported allergy and helminths was found in this study, this may have been due to the low prevalence and intensity of helminthic infection in the sample. There was a positive association between Ascaris lumbricoides and atopy. To further examine the underlying mechanism behind this positive association, a longitudinal study is needed.

Impact of early life geohelminths on wheeze, asthma and atopy in Ecuadorian children at 8 years.

BackgroundEarly‐life exposures to geohelminths may protect against development of wheeze/asthma and atopy.ObjectiveTo study the effect of maternal geohelminths and infections in children during the first 5 years on atopy, wheeze/asthma and airways reactivity/inflammation at 8 years.MethodsBirth cohort of 2404 neonates followed to 8 years in rural Ecuador. Data on wheeze/asthma were collected by questionnaire and atopy by skin prick test (SPT) reactivity to 9 allergens. We measured airways reactivity to bronchodilator, fractional exhaled nitric oxide (FeNO) and nasal eosinophilia. Stool samples were examined for geohelminths by microscopy.Results1933 (80.4%) children were evaluated at 8 years. Geohelminths were detected in 45.8% of mothers and 45.5% of children to 5 years. Frequencies of outcomes at 8 years were as follows: wheeze (6.6%), asthma between 5 and 8 years (7.9%), SPT (14.7%), airways reactivity (10%) and elevated FeNO (10.3%) and nasal eosinophilia (9.2%). Any maternal geohelminth was associated with reduced SPT prevalence (OR 0.72). Childhood Trichuris trichiura infections during the first 5 years were associated with reduced wheeze (OR 0.57) but greater parasite burdens with Ascaris lumbricoides at 5 years were associated with increased wheeze (OR 2.83) and asthma (OR 2.60). Associations between maternal geohelminths and wheeze/asthma were modified by atopy. Parasite‐specific effects on wheeze/asthma and airways reactivity and inflammation were observed in non‐atopic children.ConclusionsOur data provide novel evidence for persistent effects of in utero geohelminth exposures on childhood atopy but highlight the complex nature of the relationship between geohelminths and the airways. Registered as an observational study (ISRCTN41239086).

Allergen skin test reactivity and asthma are inversely associated with ratios of IgG4/IgE and total IgE/allergen-specific IgE in Ugandan communities.

SummaryBackgroundSerum inhibition of allergen‐specific IgE has been associated with competing IgG4 and non‐specific polyclonal IgE. In allergen immunotherapy, beneficial responses have been associated with high IgG4/IgE ratios. Helminths potentiate antibody class switching to IgG4 and stimulate polyclonal IgE synthesis; therefore, we hypothesized a role for helminth‐associated IgG4 and total IgE in protection against atopic sensitization and clinical allergy (asthma) in tropical low‐income countries.MethodsAmong community residents of Ugandan rural Schistosoma mansoni (Sm)–endemic islands and a mainland urban setting with lower helminth exposure, and among urban asthmatic schoolchildren and non‐asthmatic controls, we measured total, Schistosoma adult worm antigen (SWA)–specific, Schistosoma egg antigen (SEA)–specific and allergen (house dust mite [HDM] and German cockroach)–specific IgE and IgG4 by ImmunoCAP® and/or ELISA. We assessed associations between these antibody profiles and current Sm infection, the rural‐urban environment, HDM and cockroach skin prick test (SPT) reactivity, and asthma.ResultsTotal IgE, total IgG4 and SWA‐, SEA‐ and allergen‐specific IgE and IgG4 levels were significantly higher in the rural, compared to the urban setting. In both community settings, both Sm infection and SPT reactivity were positively associated with allergen‐specific and total IgE responses. SPT reactivity was inversely associated with Schistosoma‐specific IgG4, allergen‐specific IgG4/IgE ratios and total IgE/allergen‐specific IgE ratios. Asthmatic schoolchildren, compared with non‐asthmatic controls, had significantly higher levels of total and allergen‐specific IgE, but lower ratios of allergen‐specific IgG4/IgE and total IgE/allergen‐specific IgE.Conclusions and clinical relevanceOur immuno‐epidemiological data support the hypothesis that the IgG4–IgE balance and the total IgE–allergen‐specific IgE balance are more important than absolute total, helminth‐ or allergen‐specific antibody levels in inhibition of allergies in the tropics.

Evaluation of skin prick test reactivity in children with allergic diseases: A cross sectional study

Allergic diseases are developed through complex interaction between exposure to environmental substances and genetic susceptibility. The prevalence of allergic diseases has increased during last decade globally. The present cross sectional study was designed to evaluate the skin prick test reactivity in children with allergic diseases. A total of 400 children between age group 1-12 years were recruited. The Skin prick tests (SPT) using 14 standardized allergen extracts were conducted in the volar surface of forearm. Majority children had asthma (52.5%), followed by atopic dermatitis (22.75%) and allergic rhinitis (15.75%). Food habits triggering allergic conditions in 76% children, environmental factors in 4.75% children, pets in 8.25% and indoor conditions in 11% children. Skin prick test was positive to egg (13.5%), milk (22%), wheat (9.75%), apple (4.5%), cereals (6.5%), cat (18%), dog (6%), blatella (9.5%), aspergillus fumigatus (9.5%), fungi (12.75%), Dermatophytes farina (24.75%), Dermatophytes pteromyssinus (23.75%), Blomia tropicalis (9.5%) and Bermuda grass (13.75%). Determination of allergen sensitization patterns in children with atopic disease is crucial for selecting proper preventive and therapeutic strategies which helps to improve quality of life of in children.

Improvement of clinical and immunological parameters after allergen-specific immunotherapy in atopic dermatitis.

Allergen immunotherapy (AIT) is considered a curative treatment in some atopic diseases, but in AD contradictory clinical results exist and the action of AIT has not been elucidated. In the literature, there is no evidence for parallel investigations of permeability barrier, cutaneous and blood immune responses after AIT in AD. The objective was to investigate immune parameters in the blood and skin and to detect clinical and barrier changes after AIT in AD. Mild-to-moderate AD patients (n=14) with concomitant allergic rhinitis to house dust mites were selected. All patients received topical treatment, while eight patients were randomly selected for adjuvant AIT also. At baseline and after 6months, clinical, barrier and immunological investigations (serum and skin tests) were performed. In selected patients, biopsies from atopy patch tests (APTs) were analysed by immunohistochemistry for AD-relevant immune cells and mediators. In the adjuvant AIT group, clinical parameters and barrier functions improved significantly. Blood immune parameters displayed no significant changes. Post-AIT APT became negative in all patients in the AIT group, but remained positive in the non-AIT group. Cutaneous dendritic cell and T-cell recruitment decreased significantly after allergen challenge in the AIT group, but no significant changes in skin or serum immunoglobulin E levels or prick test (SPT) reactivity were detected. Allergen immunotherapy is a beneficial adjuvant treatment for sensitized AD patients. AIT improves not only clinical symptoms, but also permeability barrier functions. The effect of AIT on sensitization should be detected by APT, not by SPT.

The relationship between malnutrition and TH 2 immune markers: a study in school-aged children of different socio-economic backgrounds in Makassar, Indonesia.

ObjectiveThe burden of underweight remains a major problem in Indonesia, and at the same time, the prevalence of overweight is increasing. Malnutrition is a major determinant of health and has been linked to allergic disorders in children. We examined the relationship between malnutrition and TH2 immune markers in school‐aged children in Makassar, Indonesia.MethodsA cross‐sectional study was performed in five schools where socio‐demographic characteristics were recorded. Children’s standardised z‐scores of body mass index (z‐BMI) and age‐standardised z‐scores of height (z‐HA) were assessed using WHO child growth standards. Skin prick test (SPT) reactivity was determined to house dust mite allergens. Helminth infection status, (growth) hormones including insulin‐like growth factor (IGF‐1) and TH2 immune markers were measured.ResultsIn total, 954 children were included of whom 21.6% were underweight and 14.8% overweight. After controlling for confounders, overweight was positively associated with leptin (GMR 3.55, 95% CI: 2.99–4.23) and IGF‐1 (GMR 1.45, 95% CI: 1.15–1.82), whereas underweight was negatively associated (respectively GMR 0.57, 95% CI: 0.49–0.66 and GMR 0.78, 95% CI: 0.63–0.97). Underweight was associated with a lower eosinophil count (GMR 0.79, 95% CI: 0.64–0.97) but not with total IgE levels or SPT reactivity. Overweight was positively associated with SPT reactivity (adjusted OR 2.68, 95% CI: 1.50–4.78) but no relationship was found with the other TH2 immune markers.ConclusionMalnutrition is prominent in school‐aged children in Makassar, with overweight associated with increased SPT reactivity. Therefore, interventions should focus on undernutrition, but also on overweight to prevent the increase of allergic disorders in Indonesia.

Sex- and Age-Dependent Changes in Polysensitization to Common Aeroallergens Over 20 Years.

IntroductionThe prevalence of airway allergies in Europe has increased from 23% to 31% in recent years. Polysensitization is associated with the development and severity of relevant allergies, particularly allergic asthma.ObjectiveWe investigated age- and sex-dependent monosensitization and polysensitization profiles as well as patterns of sensitization using skin prick test (SPT) reactivity to the most common aeroallergens.Patients and MethodsFrom 1998 to 2017, SPTs were retrospectively analyzed in 2886 symptomatic patients, referred to the University Medical Center Göttingen, located in central Germany. The major aeroallergen groups early flowering tree pollen, grass pollen, and house dust mites were evaluated in this study. Wheal diameters ≥2 mm were considered positive during the entire study period.ResultsPolysensitization to the most common aeroallergen groups increased significantly over 20 years. Boys and young men displayed the most remarkable rise in total sensitization rates in our study group over time.DiscussionOur patient-based study demonstrates a continuing increase in polysensitization rates over the last 20 years, with boys and young men being most frequently affected. Our data—without being a population-based study—suggest a scenario with climbing rates of allergic rhinitis and asthma.

Prevalence and risk factors for asthma, rhinitis, eczema, and atopy among preschool children in an Andean city.

Limited data are available on prevalence and associated risk factors for atopy and allergic diseases from high-altitude urban settings in Latin America. To estimate the prevalence of atopy, asthma, rhinitis, and eczema, and associations with relevant risk factors in preschool children in the Andean city of Cuenca. A cross-sectional study was undertaken using a representative sample of 535 children aged 3-5 years attending 30 nursery schools in the city of Cuenca, Ecuador. Data on allergic diseases and risk factors were collected by parental questionnaire. Atopy was measured by skin prick test (SPT) reactivity to a panel of relevant aeroallergens. Associations between risk factors and the prevalence of atopy and allergic diseases were estimated using multivariable logistic regression. Asthma symptoms were reported for 18% of children, rhinitis for 48%, and eczema for 28%, while SPT reactivity was present in 33%. Population fractions of asthma, rhinitis, and eczema attributable to SPT were 3.4%, 7.9%, and 2.9%, respectively. In multivariable models, an increased risk of asthma was observed among children with a maternal history of rhinitis (OR 1.85); rhinitis was significantly increased in children of high compared to low socioeconomic level (OR 2.09), among children with a maternal history of rhinitis (OR 2.29) or paternal history of eczema (OR 2.07), but reduced among children attending daycare (OR 0.64); eczema was associated with a paternal history of eczema (OR 3.73), and SPT was associated with having a dog inside the house (OR 1.67). A high prevalence of asthma, rhinitis, and eczema symptoms were observed among preschool children in a high-altitude Andean setting. Despite a high prevalence of atopy, only a small fraction of symptoms was associated with atopy. Parental history of allergic diseases was the most consistent risk factor for symptoms in preschool children.

Atopic Dermatitis: Identification and Management of Complicating Factors.

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease, associated with impaired skin barrier function and an atopic background. Various complicating factors, such as irritants, aeroallergens, food, microbial organisms, contact allergens, sweat, and scratching can induce the development of AD symptoms. Irritants, including soap/shampoo and clothes, can cause itching and eczematous lesions. In addition, young children with AD tend to become sensitized to eggs, milk, or peanuts, while older children and adults more often become sensitized to environmental allergens, such as house dust mites (HDM), animal dander, or pollen. Serum-specific IgE levels and skin prick test reactions to food tend to show high negative predictive values and low specificity and positive predictive values for diagnosing food allergy. On the other hand, AD adult patients tend to have severe skin symptoms and exhibit high HDM-specific IgE levels. Microbial organisms, e.g., Staphylococcus aureus and Malassezia furfur, might contribute to the pathogenetic mechanisms of AD. While sweat plays a major role in maintaining skin homeostasis, it can become an aggravating factor in patients with AD. Furthermore, scratching often exacerbates eczematous lesions. Several patient-specific complicating factors are seen in most cases. The identification and management of complicating factors are important for controlling AD.

The Effect of a Thixotropic Nasal Gel on Nasal Symptoms and Inflammatory Biomarkers in Seasonal Allergic Rhinitis

Background: Drug-free viscous nasal applications have been shown to reduce nasal symptoms in individuals with seasonal allergic rhinitis (SAR). Nascum®-Plus (NP), a commercially available thixotropic gel, has been designed to reduce dryness and soreness of the nasal mucosa and prevent the absorption of small particles. Objectives: The aim of this study was to assess the efficacy of single-dose NP in treating nasal symptoms and secretion during challenge in an allergen challenge chamber (ACC). Furthermore, the effect of this treatment on biomarkers and immune cells of the allergic cascade were measured. Methods: This open-label, cross-over, sequence-randomized, monocentric trial randomized 18 adults with SAR and a positive skin prick test reaction to Dactylis glomerata pollen to receive NP or no treatment during two 4-h ACC sessions 3 weeks apart. On Day 1, 9 subjects were challenged for 4 h with treatment, the other 9 without treatment, and vice versa on Day 22. Nasal lavage fluid and nasal filter eluate samples were obtained pre, 2, and 18 h post challenge in the ACC. Results: NP significantly reduced nasal symptoms, assessed by total nasal symptom score (p < 0.001), and minimized nasal secretion (p = 0.047), while no significant effect on biomarkers and immune cells in the nasal fluid was observed. The treatment was safe and well-tolerated. Conclusions: The physical barrier built by NP nasal gel can be safely applied in patients with allergic rhinitis. It reduces allergic nasal symptoms and secretion, but application of a single dose does not affect local inflammatory biomarkers.

The prevalence of IgE-dependent sensitizations to selected trophoallergens and airborne allergens in the population of children and adolescents of the north-eastern region of Poland.

IntroductionGood evidence has been provided over the last three to four decades that the prevalence of allergic diseases has been increasing in many developed countries worldwide. Recent data suggest that this increase may now be levelling off.AimRetrospective analysis of the prevalence of IgE-dependent sensitization and changes in selected environmental allergens in the population of children and adolescents in the north-eastern region of Poland in the years 1998–2012.Material and methodsSkin prick testing (SPT) with selected food allergens (trophoallergens) and airborne allergens was used to evaluate the sensitization process of patients recruited to the study in the years 1998–2012. A positive result of sensitization was defined when the patient had at least one positive skin prick test with the allergen studied. The skin prick tests were done after written consent had been obtained from the parents.ResultsThe retrospective study included children and adolescents aged up to 18 years with a suspicion of an allergic disease, referred to the regional tertiary medical centre for further diagnosis. A total of 6577 patients were studied, including 1556 (23.7%) in 1998, 1473 (22.4%) in 2003, 1690 (25.7%) in 2008, and 1858 (28.2%) in 2012. Sensitization to at least one allergen was observed in 39.0% of the examined children (regardless of the allergen type), of which 8.1% were sensitized to food allergens only, 23.9% to airborne allergens only, and 7.0% simultaneously to food and airborne allergens. During the 14-year study period, an increase was noted in the percentage of the sensitized children from 35.3% at baseline to 40.4% when the study was completed. The percentage of those sensitized to food allergens increased from 10.5% (1998) to 20.1% (2012). The percentage of children sensitized to airborne allergens remained unchanged at the level of 28.2% in 1998 and 27.2% in 2012.ConclusionsMeasurement of skin prick test reactivity to different allergens is a useful and commonly used method in epidemiological studies for the assessment of allergic sensitization and changes in selected populations. The obtained results confirmed the need for systematic epidemiological research into allergic sensitization and allergic diseases among children and adolescents in Poland.

Evaluation of Skin Prick-Test Reactions for Allergic Sensitization in Dogs With Clinical Symptoms Compatible With Atopic Dermatitis. A Pilot Study.

Skin prick-test is the first choice for the detection of type I hypersensitivity in human atopic dermatitis. Canine atopic dermatitis resembles several symptoms of the disease in the human counterpart. In canine atopic dermatitis, intradermal testing is the test of choice, and there are few reports on the use of skin prick test (SPT) in dogs. The purpose of this study was to evaluate SPT reactions in atopic dogs and a healthy control group to 11 environmental allergens. Eleven glycerinated allergens were applied on the left lateral thorax of nine atopic dogs and nine healthy dogs. The skin was pricked with a feather lancet and evaluated for the positive percutaneous reaction at 5, 10, 15, and 20 min after the application of the allergens. Data were analyzed by the Shapiro-Wilk test to test for normal distribution. Data that did not meet normality were analyzed by a one-sided Wilcoxon ranked sum test with a p-value of 0.05. Six out of 9 atopic dogs tested positive for at least one of the allergens tested. None of the dogs in the control group showed a positive reaction to the allergens included in the test. Blomia tropicalis, Dermatophagoides farine, and Dermatophagoides pteronyssinus exhibited the highest reaction rate among the group of atopic dogs. There was not a statistical difference in the histamine reaction (positive control) between both groups. In this set of dogs, the test exhibited a 100% specificity and a sensitivity of 66%. The use of skin prick-test in the detection of causative allergens of human atopic dermatitis has proved to be a sensitive and specific tool frequently used by human allergists. Due to the number of similarities in canine and human atopic dermatitis, this could be a valuable tool that needs intensive research in veterinary medicine. The published research so far correlates to the results obtained in this investigation. However, future studies evaluating the concordance between in vitro specific IgE antibody assays and SPT must be carried out simultaneously to validate the test.

Thermographic examination of prick test reactions with local anesthetic

In allergology, skin diagnostic tests are divided into epicutaneous, cutaneous and intracutaneous. The prick test is one of the cutaneous tests used most often for the diagnosis of hypersensitivity to local anesthetics. In the case of hypersensitivity to the examined anesthetic and reaction to the histamine-containing solution (positive control), inflammation appears with an increase in the local temperature. This warming can be detected objectively with a thermal camera and can be used in the diagnostic process. This study was used to examine the capabilities of the infrared thermography application, in the prick test of both men and women, by comparing temperature changes and the intensity of allergic inflammation in the positive and negative controls in addition with a negative reaction to an allergen. A group of 115 patients—55 male (52%) and 60 female (48%), are included. All are examined for hypersensitivity to Mepivastesin, together with the positive and negative control. Skin temperature changes of the skin were examined with FLIR A320 thermal camera and the FLIR Reporter Professional software 2013—application used to process the thermal camera images and data. The statistical analysis shows a marked temperature difference between men and women. Similarities in temperature values are detected between the negative reactions to dental anesthetic and the negative control. However, the latter substantially differs from the data obtained with the positive control. Results of the research indicate the possible applications of the thermography diagnostics in evaluation of the prick test results.

Skin Prick Test Reactivity to Common Aeroallergens among Allergic Rhinitis Patients in Jordan

The distribution and pattern of aeroallergens are significantly different between different countries and even in the different parts of the same country. The present study aims to evaluate the most common aeroallergens among allergic rhinitis patients in the city of Al-Karak, Jordan. A cross-sectional study was conducted at Department of Otorhinolaryngology, Mutah University, from March 2016-April 2018. Patients with a clinical diagnosis of allergic rhinitis were enrolled and Skin Prick Test (SPT) was performed using 11 common aeroallergens including, grass, weed, tree, mite, and mould in 140 patients. The results showed that the overall rate of sensitization to any allergen was 85.7%. It was shown that 69.3% of patients were poly-sensitized; while, 16.4% were sensitized to only one allergen. The majority of the common allergens were Olive tree pollen (51.4%), Dermatophagoides pteronyssinus (37.9%), respectively. Mould (Alternaria) was the least prevalent allergen (17.1%). The present study has shown the importance of Olive tree pollen which, is widely cultivated in Al-Karak, Jordan. The diagnosis of pollen allergen can be simplified by using a combination of a few common allergens.

Analysis of Allergen-Specific T Cell and IgE Reactivity to Different Preparations of Cow's Milk-Containing Food Extracts.

Background: cow’s milk allergy (CM) is among the most common food allergies in young children and is often outgrown by adulthood. Prior to developing a tolerance to CM, a majority of CM-allergic children may tolerate extensively-heated CM. This study aims to characterize the IgE- and T cell-reactivity to unheated CM and the progressively more heated CM-containing foods. Methods: CM-containing food extracts from muffin, baked cheese, custard and raw, pasteurized CM commercial extract were tested for skin prick test reactivity, IgE binding and T cell reactivity as assessed by IL-5 and IFNγ production. Results: the skin prick test (SPT) reactivity was significantly decreased to muffin extract compared to raw, pasteurized CM. Both IgE- and T-cell reactivity were readily detectable against food extracts from all forms of CM. Western blot analysis of IgE reactivity revealed variability between extracts that was protein-specific. T cell-reactivity was detected against all four extracts with no significant difference in IL-5 or IFNγ production between them. Conclusion: our data indicate that despite reduced clinical reactivity, extracts from heated CM-containing foods retain immunogenicity when tested in vitro, particularly at the T cell level.

Identification of Der f 23 as a new major allergen of Dermatophagoides farinae

House dust mites (HDM) are common allergen sources worldwide. At present, 32 of the 37 internationally recognized HDM allergen groups have been identified in Dermatophagoides farinae. The present study study describes the identification of the first known D. farinae Group 23 allergen (Der f 23). Recombinant Der f 23 protein (rDer f 23) was cloned, expressed and purified. The open reading frame of rDer f 23 was 525 base pairs and encoded a 174-amino acid protein (GenBank accession no., KU166910.1). ELISAs indicated that 72/129 HDM allergic serum samples (55.8%) had specific immunoglobulin E (sIgE) binding activity to rDer f 23. Additionally, 3/10 patients with HDM allergies (30%) exhibited positive skin prick test reactions to rDer f 23. IgE western blot analysis data suggested that only 4/11 HDM allergic sera had a positive sIgE binding result. Sequence homology analysis revealed an extra P2 region (Ser56-Thr117) in Der f 23 that was not present in the D. pteronyssinus homolog, which may affect sIgE binding. Der f 23ΔP2 demonstrated binding with HDM allergic sera, whereas the P2 peptide alone did not. The sIgE binding ability of Der f 23 ΔP2 (Der f 23 with a truncated P2 region) was more marked compared with that of Der f 23 in an IgE ELISA. These data indicate that P2 region in Der f 23 attenuates IgE binding ability. In conclusion, the results of the present study indicate that Der f 23 is a major HDM allergen with predominantly conformational sIgE binding epitopes. The allergenic identification of Der f 23 and its inclusion in World Health Organization/International Union of Immunological Societies database contributes to the theoretical basis underlying the diagnosis and treatment of HDM allergic diseases.

Role of Der p 1–specific B cells in immune tolerance during 2 years of house dust mite–specific immunotherapy

Long-term follow-up of allergen-specific B cells in terms of immunoglobulin isotype expression, plasmablast differentiation, and regulatory B (Breg) cell development during allergen-specific immunotherapy (AIT) has not been reported. Allergen-specific B-cell responses during 2years of house dust mite AIT were compared between responder and nonresponder patients. B cells specific for Der p 1 were detected by using the fluorochrome-labeled allergen method. The frequency of IgA-, IgG1- and IgG4-switched Der p 1-specific B cells, plasmablasts, and IL-10- and IL-1 receptor antagonist (IL-1RA)-producing Breg cells were investigated and correlated to clinical response to AIT. Sixteen of 25 patients completed the 2-year study. Eleven responder patients showed a successful response to AIT, as measured by a decrease in symptom-medication scores from 13.23±0.28 to 2.45±0.24 (P=.001) and a decrease in skin prick test reactivity to house dust mite from 7.0±1.3 to 2.7±0.5mm(P=.001). IgG4+ and IgA+ Der p 1-specific B cells showed a significant increase after AIT, with a significantly greater frequency in responders compared with nonresponders in the IgG4+ but not the IgA+ fraction. The frequency of plasmablasts and IL-10- and/or IL-1RA-producing Breg cells was greater among responders compared with nonresponders after 2years. The increased frequency of Der p 1-specific IgG4+ B cells, plasmablasts, and IL-10+ and dual-positive IL-10+IL-1RA+ Breg cells significantly correlated with improved clinical symptoms over the course of AIT. Allergen-specific B cells in patients responding to AIT are characterized by increased numbers of IgA- and IgG4-expressing Der p 1-specific B cells, plasmablasts, and IL-10+ and/or IL-1RA+ Breg cells.

Soil-transmitted helminth parasites and allergy: Observations from Ecuador.

SummaryThere is considerable interest as to potential protective effects of soil‐transmitted helminths (STH) against allergy and allergic diseases. Here, we discuss findings of studies done of the effects of STH parasites on atopy and allergic diseases in Ecuador. While cross‐sectional studies have consistently shown a reduced prevalence of allergen skin prick test (SPT) reactivity among infected schoolchildren, the removal of these infections by repeated deworming did not affect SPT prevalence over the short‐term (ie, 12 months) but may have increased SPT prevalence over the long‐term (ie, 15‐17 years). In the case of allergic symptoms, cross‐sectional studies have generally not shown associations with STH and intervention studies showed no impact on prevalence. However, a birth cohort suggested that early STH infections might reduce wheeze by 5 years. Allergic sensitization to Ascaris, however, explained a significant proportion of wheezing among rural schoolchildren. Studies of the effects of STH on immune and inflammatory responses indicated a potential role of STH in contributing to more robust regulation. The effects of STH on allergy are likely to be determined by history of exposure over the life‐course and by interactions with a wide variety of other infectious and non‐infectious factors.

Skin Prick Test Reactivity to Common Aeroallergens among Allergic Rhinitis Patients.

To identify the common aeroallergens causing allergy symptoms among the allergic rhinitis patients. Cross-sectional study. Department of Immunology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from January to July 2016. Patients with a clinical diagnosis of allergic rhinitis were enrolled. Skin Prick Test (SPT) was performed on these patients using 12 common aeroallergens along with positive (histamine hydrochloride, 10 mg/ml) and negative (glycerin saline) controls. Results were recorded after 15 minutes, considering a wheal diameter >3 mm as positive. Chi-square test was used to compare frequencies; and p-value of less than 0.05 was considered significant. Out of 130 patients, 78 (60%) were males and 52 (40%) were females. The rate of sensitization to any allergen was 90%. One hundred and two (78%) were poly-sensitized to more than two allergens and 20% were sensitized to more than six allergens. Most common outdoor and indoor allergens were Broussonetia papyrifera (50.7%) and Dermatophagoides farina (42.3%), respectively. Dog epithelia and aspergillus were the least prevalent allergens (13.8% each). This study highlighted an increased overall frequency of sensitization to any allergen and significance of tree and weed allergens; especially, Broussonetia papyrifera and Cannabis sativa. It also emphasized increased prevalence of skin reactivity to indoor allergen, Dermatophagoides farina in the city.

Sensitization to Common Aeroallergens in the Atopic Population of West Bengal, India: An Investigation by Skin Prick Test

Background: Aeroallergen sensitization is increasing worldwide. The optimal management of allergic disease requires the identification of the allergic sensitivities of the patient. Complete data of offending aeroallergens are scant from West Bengal, India. Hence, we employed a retrospective analysis of an atopic population of West Bengal to investigate the rate of sensitivity toward common aeroallergens including pollens, molds and house dust mites. Objectives: The aim of the present study was to evaluate the profile of skin prick test (SPT) reactivity of an atopic population of eastern India. Methods: The prevalence aeroallergen sensitization was investigated by SPT along with a questionnaire survey of patients who visited the Allergy and Asthma Research Center of West Bengal, India, from June 2016 to May 2018. Patients were categorized according to the demographic (age, gender) and clinical aspects. Statistical tests were applied to differentiate between age and gender of the sufferers. Results: 524 out of 605 patients exhibited a positive SPT response toward one or more aeroallergens tested. One-way ANOVA following Tukey’s post hoc test reveals the age group of 15–40 years was more sensitized than that of < 15 years and no male-female discrimination was found using the paired t test. House dust mites, namely Dermatophagoides pteronyssinus and Dermatophagoides farinae, elicited most significant SPT results (80.34 and 84.92%, respectively) followed by Cocos (73.28%) and Azaridacta (57.25%) pollen. The most sensitive mold was Alternaria alternata (26.9%). Allergic rhinitis, bronchial asthma and atopic dermatitis were recorded as the common symptoms. Other influencing factors were family history, nature and season/time of onset and house conditions. Conclusion: Following the increasing trend, house dust mite sensitization still held the dominance like in any other Indian population reported earlier. This study would pave the way to construct a standard and minimal SPT panel for the atopic patients of eastern India.