Association of IL4 (Rs2243250) Gene Variant and Mycoplasma Pneumoniae Infection with Asthma Susceptibility in an Iraqi Population

Sarah Kassab Shandaway Al-Zamali; Shahad Saad Mohammed; Safa Hasan Radhi; Sara Aqeel Hassan; Ghufran Abd Omran Abdulridha

doi:10.33594/000000778

Association of IL4 (Rs2243250) Gene Variant and Mycoplasma Pneumoniae Infection with Asthma Susceptibility in an Iraqi Population

Cell Physiol Biochem. 2025 May 19;59(3):347-357. doi: 10.33594/000000778.

Authors

Sarah Kassab Shandaway Al-Zamali¹, Shahad Saad Mohammed², Safa Hasan Radhi³, Sara Aqeel Hassan⁴, Ghufran Abd Omran Abdulridha⁵

Affiliations

¹ Department of Medical Microbiology, Hammurabi College of Medicine, University of Babylon, Hillah, Babylon, Iraq, ham114.sarah.kassab@uobabylon.edu.iq.
² Technical Institute of Babylon, Al-Furat Al-Awsat Technical University (ATU), Iraq.
³ Biology Department, College of Science, Al-Qasim Green University, Babylon, Iraq.
⁴ Department of Medical Microbiology, Hammurabi College of Medicine, University of Babylon, Hillah, Babylon, Iraq.
⁵ Department of Clinical Chemistry, Faculty of Medicine Hammurabi, University of Babylon, Babylon, Iraq.

PMID: 40420775
DOI: 10.33594/000000778

Abstract

Background/aims: Asthma is a multifactorial disease influenced by both genetic and environmental factors. This study aimed to investigate the association between the IL4 gene polymorphism (rs2243250) and asthma susceptibility, along with serum IL-4 levels. Additionally, it explored Mycoplasma pneumoniae infection as a potential risk factor for asthma.

Methods: A total of 118 individuals were enrolled, including 60 asthma patients and 58 healthy controls. Genotyping for IL4 rs2243250 was performed using allele-specific PCR (AS-PCR). Previous Mycoplasma pneumoniae infection was assessed serologically, and serum IL-4 levels were measured using ELISA.

Results: No significant differences were observed between groups in terms of age, sex, or residence. Smoking (OR: 7.85, P = 0.001) and family history of asthma (OR: 5.33, P = 0.004) were identified as significant risk factors. Mycoplasma pneumoniae infection was significantly more prevalent in asthma patients (41.7%) than in controls, with a strong association with asthma risk (OR: 8.75, P < 0.0001). Genotype frequencies of rs2243250 differed significantly: CC (36.7% vs. 68.9%), CT (41.7% vs. 24.2%), and TT (21.6% vs. 6.9%) in patients versus controls, respectively. The T allele was more frequent among patients (42.5%) than controls (18.97%), increasing asthma risk (OR: 3.16, P = 0.0001). Both CT (OR: 3.25) and TT (OR: 5.91) genotypes were strongly associated with asthma. Moreover, individuals with the TT genotype had significantly higher serum IL-4 levels (P < 0.001).

Conclusion: The IL4 rs2243250 polymorphism is associated with increased asthma susceptibility and elevated serum IL-4 levels in the Iraqi population. Mycoplasma pneumoniae infection also appears to be a significant contributing factor. Larger-scale studies are warranted to confirm these findings and further explore the role of this infection in asthma pathogenesis.

Keywords: Interleukin-4 ; Rs2243250 ; Single Nucleotide Polymorphism ; Asthma ; Mycoplasma pneumoniae.

MeSH terms

Adult
Alleles
Asthma* / complications
Asthma* / epidemiology
Asthma* / genetics
Case-Control Studies
Female
Gene Frequency
Genetic Predisposition to Disease*
Genotype
Humans
Interleukin-4* / blood
Interleukin-4* / genetics
Iraq / epidemiology
Male
Middle Aged
Mycoplasma pneumoniae
Pneumonia, Mycoplasma* / complications
Pneumonia, Mycoplasma* / genetics
Polymorphism, Single Nucleotide*
Risk Factors

Substances

Interleukin-4
IL4 protein, human