Identification of the main allergen sensitizers in an Iran asthmatic population by molecular diagnosis

Abstract

BackgroundThere has been a significant growth in the prevalence of allergy, mainly associated to IgE-mediated disorders such as asthma and rhinitis. The identification of atopy in asthmatic patients through the measurement of specific IgE can help to identify risk factors that cause asthmatic symptoms in patients. The development and use of individualized allergen-based tests by the Component Resolved Diagnosis has been a crucial advance in the accurate diagnosis and control of allergic patients. The objective of this work was to assess the usefulness of molecular diagnosis to identify environmental allergens as possible factors influencing the development and manifestation of asthma in a group of asthmatic patients from Iran.MethodsStudied population: 202 adult asthmatic patients treated at the Loghman Hakim Hospital and Pasteur Institute of Teheran (Iran) from 2011 to 2012. Specific IgE determined by the ImmunoCAP system were used to both evaluate the patients’ atopic condition and the molecules involved in the allergic sensitization. SDS-PAGE IgE-immunoblotting associated with mass spectrometry was carried out to study the cockroach IgE-binding sensitizing proteins.ResultsForty-five percent of all patients could be considered atopic individuals. Eighty-two percent of atopic patients were sensitized to pollen allergens. The Salsola kali (Sal k 1) and the Phleum pratense (rPhl p 1 and/or rPhl p 5) major allergens were the most common sensitizers among pollens (71% and 18%, respectively). Thirty-five percent of the atopic population was sensitized to cockroach. Four different allergens, including a previously unknown alpha-amylase, were identified in the cockroach extract. No significant associations could be demonstrated between the severity of asthma and the specific IgE levels in the atopic population. Statistical analysis identified the Sal k 1 as the main protein allergen influencing the development and expression of asthma in the studied population.ConclusionsPollen and cockroach were the most relevant allergen sources in the asthmatic population. The Salsola kali major allergen was the main cause for sensitization in the atopic patients suffering asthma. Using the Component Resolved Diagnosis, it was possible to identify a new Blattella germanica cockroach allergen (Blattella alpha amylase 53 kDa) that could sensitize a relevant percentage of this population.

A WAO — ARIA — GA2LEN consensus document on molecular-based allergy diagnosis (PAMD@): Update 2020

“…139 In Iran, IgE in 202 adult asthmatic patients was directed against the grass pollen allergens Phl p 1 and 5, but even more to Salsola kali (Sal k 1), which is an important pollen source in this area. 140 However, the authors did not find a correlation between IgE levels and asthma symptoms.…”

Sensitization and Geographical Distribution of Main Aeroallergens in Iran

“…34 Animal Dander Exposure to animal dander rapidly induces respiratory symptoms in individuals who are sensitive to cat or dog dander or any kind of bird feather. Farrokhi et al 5 and Khazaei, 26 found that the prevalence of feather allergies was 78.5%, and 70% in Bushehr, Sistan and Baluchistan, respectively. The lower prevalence of allergies to feathers than to cat dander may be due to genetic factors or to a lower exposure to birds than to cats in the Iranian populations.…”

Review of Sensitization to prevalent allergens in Iran and their geographical distribution

“…There are approximately 100,000 pollen allergens; however, only anemophilous plants (which produce large quantities of tiny pollen grains that become airborne for days with a density higher than 25 grains per cubic meter of air), can initiate an allergy [23]. The prevalence of allergies to pollen grains has increased in past years, rising up to 86.7% of the allergic patients in different cities, depending on phytogeography, humidity, air pollution and temperature conditions [24][25][26][27][28][29]. According to local studies, there are three main sources of pollen allergens in Iran.…”