Association of IFNL2 (IL-28A) gene polymorphisms and human herpesvirus-7 detection in patients with chronic myeloid leukaemia

Objective: This study aimed to investigate the potential association between genetic polymorphisms in the IFNL2 (IL-28A) gene, detection of Human Herpesvirus-7 (HHV-7) DNA, and susceptibility to Chronic Myeloid Leukaemia (CML) in an Iraqi population. Methods: A case-control study was conducted involving 100 CML patients and 100 apparently healthy controls (AHC). Genomic DNA was extracted from peripheral blood. IFNL2 gene polymorphisms were analysed by PCR amplification of a 604 bp fragment followed by Sanger sequencing. HHV-7 DNA was detected using conventional PCR targeting a 458 bp fragment. Genotype and allele frequencies were compared using Chi-square and Fisher's exact tests. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age and sex. Results: The distribution of IFNL2 genotypes differed significantly between CML patients and controls (p<0.05). The CC (wild-type) genotype was less frequent in patients (44%) than in controls (72%), while the CT (heterozygous) genotype was more frequent in patients (34%) than in controls (12%). The CT genotype was associated with significantly increased odds of CML (adjusted OR: 3.86, 95% CI: 1.21-12.33, p=0.022). HHV-7 DNA was detected in 19% (19/100) of CML patients but in none of the controls (0/100), a statistically significant difference (p<0.001). Conclusion: The findings suggest a potential association between IFNL2 gene polymorphisms, HHV-7 infection, and CML susceptibility. The CT genotype and HHV-7 detection were significantly more prevalent in CML patients. These factors may represent host-viral interaction pathways relevant to CML pathogenesis, though further validation in larger cohorts is warranted.