Rheumatoid arthritis (RA) is considered a Th1-driven disease. Interleukin 4 (IL-4) binds to its receptor, promoting Th2 differentiation and limiting Th1 responses,but its role in the pathogenesis of RA is conflicting. Objective: To evaluate theoccurrence of interleukin-4 (IL-4) and interleukin-4 receptor alpha chain (IL-4Rα) gene polymorphisms in patients with RA and their possible contribution todisease severity. Methods: We analyzed 2 polymorphisms in each of the IL4 andIL-4Rα genes in patients with RA and in a control population, as well asmeasuring serum rheumatoid factor (RF) as a disease severity parameter. Results:The IL-4 –590 TT genotype (P<0.001) and the IL4 –590T allele (OR 2.84, 95%CI 1.0-8.77, p = 0.03) were significantly more frequent in patients with RA thanin controls, this is similar for IL-4 VNTR RP1⁄RP1 genotype (P<0.001) and theIL-4 RP1 allele (OR 2.91 CI 0.92-10.23, p = 0.04). Higher frequency of IL-4Rα+148 A/G genotypes (p = 0.02) in RA patients compared with controls was alsofound. Nevertheless, the more severe form of RA was observed in patientscarrying the IL-4 -590 T allele as compared with homozygous patients. The IL-4Rα +1902 A allele and IL-4Rα +148G allele were significantly associated withthe severe form of RA. Conclusion: The IL-4 -590 C/T, IL-4 VNTR in intron-3and IL-4Rα +148 A/G polymorphisms were associated with RA susceptibility inEgyptian population. IL-4Rα +148 A/G and IL-4Rα +1902 A/G polymorphismsmay be genetic risk factors for RA severity. (13) (PDF) Interleukin-4 (IL-4) and Interleukin-4 Receptor Alpha Chain (IL-4Rα) Gene Polymorphisms in Egyptian Rheumatic Arthritis Patients. Available from: https://www.researchgate.net/publication/321807959_Interleukin-4_IL-4_and_Interleukin-4_Receptor_Alpha_Chain_IL-4Ra_Gene_Polymorphisms_in_Egyptian_Rheumatic_Arthritis_Patients [accessed Aug 08 2024].