A review on aero-allergen induced allergy in India

Functional insights into PTGS2 rs689466 polymorphism associated to asthma in West Bengal, India

BACKGROUND

Asthma is characterized by bronchoconstriction and airway hyperresponsiveness. Interplay of environmental and genetic factors led to significant rise in asthma prevalence in India during past decades.

OBJECTIVE

This study investigated functional insights of prostaglandin-endoperoxide synthase 2 (PTGS2) rs689466 polymorphism among 155 pollen-induced patients and 155 controls in West Bengal population, India.

METHODS

Genotyping was performed using Polymerase chain reaction-Restriction fragment length polymorphism. Transcription Factors (TFs) for promoter region corresponding to the polymorphism location were searched by SNP2TFBS. DNA structures were docked with TFs in HDOCK. Protein-DNA interface was analysed by DNAproDB. Relative abundance of PTGS2 mRNA in controls and different polymorphic genotypes was obtained using Real time PCR. Protein expression was analyzed by western blot.

RESULTS

Genotype and allele frequencies differed significantly between study groups (P = 0.01 and 0.03 respectively). Frequency of GG and AG genotype was significantly higher in patients (P = 0.02 and 0.04 respectively). Significant differences in FEV1/FVC were obtained in different polymorphic genotypes of patients (P < 0.0001) whereas no difference was found in controls (P = 0.08). It was predicted PTGS2 expression decreased due to altered interactions between DNA and TFs in promoter region harbouring the polymorphism. PTGS2 mRNA expression was upregulated in patients bearing AA genotype whereas downregulated in patients with AG and GG genotypes. Protein expression was reduced in AG and GG carrying patients compared to patients bearing AA genotype.

CONCLUSION

This study is the first one to report association of PTGS2 rs689466 polymorphism in Indian population. This will help in gene-based therapy for improved asthma management in future.

Prevalence of aeroallergen sensitization in a polluted and industrialized area: a pilot study in South Africa's Vaal Triangle

This pioneering study evaluates the prevalence of aeroallergens reactivity among atopic populations living in the Vaal Triangle Airshed Priority Area (VTAPA), South Africa. A total of 138 volunteers (51 males and 87 females), of African, colored, white, and Asian ethnicity, and with a mean (range) age of 22 (18-56) years were participating in the study. The study was conducted on the North-West University (NWU) campus in Vanderbijlpark/VTAPA. The International Study of Asthma and Allergies in Childhood questionnaire was utilized for pre-screening to identify individuals with probable allergic dispositions. Subsequently, skin prick testing was conducted using commercial aeroallergen extracts for all confirmed participants with allergy symptoms. One hundred six participants were clinically diagnosed with pollen and fungal spore allergies. The highest allergy prevalence was attributed to Cynodon dactylon ((L.) Pers) (Bermuda grass) (41.5%), followed by Lolium perenne (L.) (ryegrass), grass mix, and Zea mays (L.) (maize) (31.1%), respectively. Moreover, among the tree allergens, Olea (L.) (olive tree) was the most prevalent allergen (20; 18.8%), followed by Platanus (L.) (plane tree) (18; 16.9%). Among the weeds, 16 (15.1%) participants were allergic to the weed mix (Artemisia (L.) (wormwood), Chenopodium (Link) (goosefoot), Salsola (L.) (saltwort), Plantago (L.) (plantain), and 11 (10.3%) to Ambrosia (L.) (ragweed)). Regarding the fungal spores, Alternaria (Fr.) (9; 8.5%) followed by Cladosporium (Link) (5; 4.7%) had the highest skin sensitivity. In this pilot study, our findings provide insights into the prevalence of allergic responses in the study population-underlining the strong impact of allergens of exotic plants-and contribute to the existing aerobiological data in South Africa.