Evaluation of the relationship between cockroach sensitivity and house-dust-mite sensitivity in Turkish asthmatic patients

In Silico Comparative Exploration of Allergens of Periplaneta americana, Blattella germanica and Phoenix dactylifera for the Diagnosis of Patients Suffering from IgE-Mediated Allergic Respiratory Diseases

The burden of allergic illnesses is continuously rising, and patient diagnosis is a significant problem because of how intricately hereditary and environmental variables interact. The past three to four decades have seen an outbreak of allergies in high-income countries. According to reports on the illness, asthma affects around 300 million individuals worldwide. Identifying clinically important allergens for the accurate classification of IgE-mediated allergy respiratory disease diagnosis would be beneficial for implementing standardized allergen-associated therapy. Therefore, the current study includes an in silico analysis to identify potential IgE-mediated allergens in date palms and cockroaches. Such an immunoinformatic approach aids the prioritization of allergens with probable involvement in IgE-mediated allergic respiratory diseases. Immunoglobulin E (IgE) was used for molecular dynamic simulations, antigen-antibody docking analyses, epitope identifications, and characterizations. The potential of these allergens (Per a7, Per a 1.0102, and Bla g 1.0101) in IgE-mediated allergic respiratory diseases was explored through the evaluation of physicochemical characteristics, interaction observations, docking, and molecular dynamics simulations for drug and vaccine development.

Concordance of skin test reactivity between indoor inhalant allergens among children with allergic respiratory disease

Background

In vitro studies have demonstrated cross-reactivity among indoor allergen proteins in children with allergic respiratory diseases. However, there are only few studies evaluating in vivo response. A skin prick test (SPT) with commercial indoor solutions is widely used in clinical practice. We aimed to evaluate SPT agreement in children with allergic respiratory disease between pairs of common indoor allergens.

Methods

We reviewed SPT results of children 2 to 18 years old, diagnosed with respiratory allergic disease. Results from house dust mite (Dermatophagoides farinae, Dermatophagoides pteronyssinus), cockroach (Periplaneta americana, Blatella germanica), cat and dog were collected. Sensitization was defined as ≥ 3 mm in wheal diameter. Kappa coefficient (κ) was used to analyze sensitization concordance for each allergen pair.

Results

The charts of 300 children, 187 (62.33%) males, were reviewed. Mean age was 7.43 ± 3.29 years with 183 (61%), 140 (46.67%), 45 (15%), 30 (10%) sensitizations to house dust mite (HDM), cockroach, cat and dog, respectively. Sensitization concordance between HDM and cockroach was moderate: κ = 0.53 (95% CI: 0.42–0.64). Moderate agreement occurred between dog and cat: κ = 0.41 (95%CI: 0.30–0.52). HDM-sensitized children showed poor concordance with both cat κ = 0.17 (95%CI: 0.09–0.24) and dog κ = 0.09 (95%CI: 0.03–0.14). There was also poor concordance between cockroach-sensitized children to cat κ = 0.19 (95%CI; 0.11–0.28) and dog κ = 0.11 (95%CI; 0.04–0.18).

Conclusion

We demonstrated moderate agreement of SPT response between HDM and cockroach as well as dog and cat. This may be due to cross-reactivity. Component-resolved diagnosis should be considered in children with co-sensitization of these allergen pairs.

Cockroach exposure and its allergy sensitization in asthma patients

Asthma is a heterogeneous disease with distinct phenotypes. Serum tIgE, SSIgE and SPT are the methods of evaluating allergen sensitization. The present study evaluates the exposure and sensitization to cockroach (Periplaneta americana) antigens in asthma patients in a metropolitan city of India. The study enrolled 200 consecutive bronchial asthma patients, diagnosed as per GINA guidelines. As per history of exposure to cockroaches, the patients are divided in two groups as exposed and non-exposed asthmatic. All the enrolled subjects underwent SPT against common aeroallergens including cockroach, spirometry and estimation of tIgE level and SSIgE against cockroach. Out of 200 asthma patients, a total of 114 (57%) asthmatic were found SPT positive against one of the common aeroallergens, of which 68 (34%) showed SPT sensitivity against cockroach. A total of 103 (51.5%) patients were found exposed to cockroaches. In the cockroach exposed group, the mean serum tIgE was found significantly higher than the non-exposed group (569.31±224.64 vs 479.29±237 IU/ml; p=0.007). The mean SSIgE against cockroach in exposed groups was found not significant than non-expose group (4.87±11.19 vs 4.11±8.39 KUA/L; p=0.589). The mean tIgE was also not significant in atopic compared to non-atopic asthmatic (553.25±218.12 IU/ml vs 489.1±251.16 IU/ml; p=0.056). The mean SSIgE against cockroach was 5.66±10.45 KUA/L for atopic and 2.96±8.98 KUA/L for non-atopic (p=0.054). The airway obstruction was almost the same in both groups.  Asthmatic patients who were exposed to cockroach and atopic had high tIgE, SSIgE levels and SPT positivity against cockroach antigen compared to non-exposed patients.

Evaluation of Sensitivity Toward Storage Mites and House Dust Mites Among Nasobronchial Allergic Patients of Kolkata, India

House dust mites (HDMs) are the major constituents of house dust (HD). HD and HDM sensitization is well documented worldwide. Storage mite (SM) sensitization is presently lacking from India. The present study evaluated the sensitization of both HDM and SM among 372 allergic rhinitis patients reported to the Allergy and Asthma Research Center of Kolkata metropolitan, India. HD samples were collected from the patients' home and analyzed for the major constituent mites. HD and six constituent mites Dermatophagoides pteronyssinus (DP), Dermatophagoides farina Hughes (Acari: Pyroglyphidae) (DF), Blomia tropicalis (BT), Acarus siro Linnaeus (Acari: Acaridae) (AS), Lepidoglyphus destructor (LD), and Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) (TP) are tested for the allergenic potential through Skin Prick Test (SPT). Three SMs, namely AS, LD, and TP, were newly included in the mite SPT extract for the first time in Kolkata. In total, 330 patients showed significant positive SPT toward any one allergen tested. HD was the major elicitor exhibiting 92.42% response. Individuals of age group 15-40 were the worst sufferers. DF showed the highest sensitization (87.87%) among the dust mites. The SMs also contributed significantly to prove their sensitizing potential. SPT rates for AS, LD, and TP were 33, 25, and 18%, respectively. SPT grades and total Immunoglobulin E (IgE) were positively correlated for each of the allergens. Most of the patients were multi-sensitized (95%) and represented markedly high total IgE levels (>500 IU/ml). Three SMs proved to be significant allergens for the studied population. The sensitization toward these SMs is first time reported from India and can be recommended for inclusion of routine SPT for better outcome in the future.

Pattern of Allergen Sensitivity among Patients with Bronchial Asthma and/or Allergic Rhinosinusitis in a Tertiary Care Centre of Southern India

INTRODUCTION

The distribution of aeroallergens varies among various geographical areas of India and the knowledge of allergen sensitivity pattern in this part of Southern Indian (Karnataka) is limited. This data can provide clinically useful information and better understanding of common allergies prevalent in this area.

AIM

To study the pattern of allergen sensitivity among patients with bronchial asthma and/or allergic rhinosinusitis.

MATERIALS AND METHODS

In this retrospective study, patients diagnosed with bronchial asthma and/or allergic rhinitis who underwent skin prick testing, were included in the study. Patients who had taken drugs that could affect the test results, within one week prior to testing were excluded. Also, patients on long-acting oral antihistamines within four weeks of testing and pregnant women were excluded. A total of 64 antigens were used which included eight types of pollens, eight types of dusts, six types of fungi, eight types of insects, two types of danders, wool and 31 types of food items. Skin prick testing was done as per standard protocol.

RESULTS

Out of 2219 patients, 1193 (53.8%) were males and 1026 (46.2%) were females. The mean age of the subjects was 41.47 (±14) years. There were 740 (33.3%) patients diagnosed with bronchial asthma, 357 (16.1%) allergic rhinitis and 1122 (50.6%) had both bronchial asthma and allergic rhinitis. Overall the highest percentage of skin-prick test positivity was found among insect allergens (24.45%) followed by dust (24.21%), grass and tree pollen (20.57%), fungus (13.92%) and food allergens (9.28%), in that order. Among the individual allergens, the highest percentage of skin-prick test positivity was present in rice grain dust allergen (33.30%) and the least common was chicken allergen (4.40%).

CONCLUSION

Among the allergen groups, insects and dusts elicited the highest percentage of skin-prick test positive results. Whereas, among all the individual allergens rice grain dust elicited highest percentage of positives.

Sensitisation to Blattella germanica among adults with asthma in Yaounde, Cameroon: a cross-sectional study

Background

German cockroach or Blattella germanica is commonly found in homes across the inter-tropical region. The contribution of sensitisation to Blattella germanica in people with asthma in sub-Saharan Africa has not received attention. The aim of this study was to assess the prevalence and investigate the predicting factors of sensitisation to Blattella germanica in patients with asthma in Yaounde, Cameroon.

Methods

This was a cross-sectional study conducted between January 2012 and June 2013. All patients (aged 15 years and above) with asthma, receiving care at the Yaounde Jamot Hospital and the CEDIMER medical practice during the study period and who had received a prick skin testing for perennial aeroallergens were included in the study.

Results

The final sample comprised 184 patients including 123 (66.8%) women. The median age (25th-75th percentiles) was 38 (24–54) years. Prick skin test for Blattella germanica was positive in 47 (25.5%) patients. Sensitisation to Blattella germanica was associated with a sensitisation to mite in 41 (87.2%) patients, a sensitisation to Alternaria in 18 (38.3%) patients, and a sensitisation to cat or dog dander in 7 (14.9%) patients. Independent predicting factors of a sensitisation to Blattella germanica were the sensitisation to Blomia tropicalis [adjusted odd ratio (95% confidence interval) 4.10 (1.67-10.04), p = 0.002] and sensitisation to Alternaria [3.67 (1.53-7.46), p = 0.003].

Conclusions

Sensitisation to Blattella germanica is present in about a quarter of adult patients with asthma in Yaounde. Sensitisation to Alternaria and Blomia tropicalis appears to be a powerful predicting factor of sensitisation to Blattella germanica in this setting.

Minimum prick test panel for adult patients with asthma and rhinitis in Ankara, Turkey

OBJECTIVE

Determination of the number and type of allergens needed to be tested in epidemiological studies is important in order to identify most of the sensitized subjects with a cost-effective approach. This study aimed to investigate the minimum skin prick test panel for the identification of at least 95% of the sensitized subjects with symptoms of asthma and/or allergic rhinitis (AR) in Ankara, Turkey.

METHODS

Skin prick test results of 7492 patients who were referred to our outpatient clinic with clinical symptoms of asthma and/or AR between 1991 and 2005 were evaluated retrospectively. Seven allergens were tested in all and 13 allergens in 4202 patients. The allergen group needed for detection of 95% of the sensitized subjects was determined for both the 7 and 13 allergen panels. The study protocol was approved by the local ethics committee of Hacettepe University.

RESULTS

The atopy prevalences in the whole study population and in 4202 patients tested with the 13 allergen panel were calculated as 32.2% and 42.6%, respectively. Three allergens (Phleum pratense, Dermatophagoides pteronyssinus and Artemisia vulgaris) within the 7 allergen panel were adequate for the identification of at least 95% of the sensitized subjects. Olea europae was added to the previous three allergens when the 13 allergen panel was applied.

CONCLUSION

Three to four allergens are sufficient for identification at least 95% of sensitized subjects with asthma and/or AR in Ankara, Turkey.

Effect of area of residence on patterns of aeroallergen sensitization in atopic patients

BACKGROUND

An association with sensitization to inhaled allergens and allergic rhinitis and asthma has been established. A recent study concluded that the disparity in allergen sensitization might primarily be caused by environmental factors rather than genetic differences. The primary objective was to identify potential differences in sensitization among subjects with the same ethnicity in South India who reside in different environments.

METHODS

Five hundred forty-six patients presenting to a tertiary allergy center with allergic rhinitis and or asthma underwent evaluation using a structured questionnaire, skin-prick testing to common aeroallergens, and spirometry and were categorized according to area of residence.

RESULTS

The most common allergens causing sensitization were house-dust mite (range, 65-70%), trees (range, 52-56%), and cockroaches (range, 39-53%). There was lower risk of sensitization to cockroach allergens for subjects <21 years old living in suburban (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.12-0.81) and rural environments (OR, 0.33; 95% CI, 0.11-0.96) compared with subjects <21 years old living in urban areas. There was higher risk of sensitization to fungi in subjects <21 years old living in suburban areas (OR, 1.51; 95% CI, 0.60-3.77) and rural environments (OR, 2.71; 95% CI, 0.98-7.48) compared with subjects <21 years old living in urban environments.

CONCLUSION

Sensitization patterns are similar in different areas of residence except in younger subjects. Sensitization to fungi was higher in younger subjects from the rural area and cockroach sensitization were higher in younger subjects from urban areas. Sensitization is an important precursor of clinical allergic disease and further studies to unravel the complex gene-environment interactions of aeroallergen sensitization in different environments are needed.