Exploring the Impact of IL-33 Gene Polymorphism (rs1929992) on Susceptibility to Chronic Spontaneous Urticaria and Its Association with Serum Interleukin-33 Levels

Abstract

Urticaria is a debilitating skin condition affecting up to 20% of the global population, characterized by erythematous, maculopapular lesions and significant quality of life impairment. This study focused on the role of interleukin 33 (IL-33) and its polymorphisms, particularly SNP rs1929992, in chronic spontaneous urticaria (CSU). Using demographic, clinical, and laboratory data from CSU patients and controls, we estimated allele and genotype frequencies, Hardy-Weinberg equilibrium condition, and serum IL-33 levels, using unconditional binomial logistic regression for association analysis. Results revealed that CSU patients had significantly higher frequencies of the minor allele of IL-33 rs1929992 compared to controls (31.25% vs. 17.35%, p = 0.024), and carriers of the GA genotype exhibited increased odds of CSU (adjusted OR = 2.208, p ≤ 0.001). Additionally, serum IL-33 levels were markedly elevated in CSU patients, particularly those with the GA genotype. The findings suggest that the IL-33 SNP is associated with an increased susceptibility to CSU, emphasizing its potential as a diagnostic and therapeutic biomarker. This study underscores the genetic and immunological underpinnings of CSU, paving the way for personalized treatment approaches.

Keywords: CSU; IL-33; SNP rs1929992; autoimmune; chronic urticaria; cytokine; genetic polymorphisms; personalized medicine; susceptibility.

Figure 1

Distribution of IL-33 values in patients carrying GG and GA genotypes of IL-33 rs1929992 gene polymorphism split by group (CSU group is represented in gray while non-CSU group is represented in yellow). Dot plot shows individual IL-33 levels and box-and-whisker plot shows distribution of data based on median and IQR in studied groups.

Figure 2

Enzymatic digestion of the 529 bp fragment for IL-33- rs1929992 identification. Lane 1—pBR HaeIII digest DNA molecular marker V; lanes 2, 4, 5, 10–13—homozygous GG genotype: fragment of 529 bp; lanes 3, 6, 8, 14–18—heterozygous AG genotype: fragments of 529,398 and 131 bp; lanes 7, 9, 19 and 20—homozygous AA genotype: fragment of 398 and 131 bp.