IL-8 polymorphisms (-251T/A, -1633T/C) and their effects on COVID-19 clinical outcomes: An observational study.

BACKGROUND

COVID-19 presents with a wide spectrum of clinical outcomes, ranging from asymptomatic infection to critical illness. The cytokine storm is a hallmark of severe COVID-19 and is associated with elevated levels of pro-inflammatory cytokines, often observed in severe cases. Genetic polymorphisms in the IL-8 gene may influence individual responses to SARS-CoV-2 infection and the severity of the disease.

METHODS

A case-control study was conducted involving 200 COVID-19 patients and 201 healthy controls. Two IL-8 gene polymorphisms, -251T/A and +1633T/C, were genotyped using the PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) technique.

RESULTS

The IL-8 -251TA genotype and -251A allele were significantly associated with COVID-19 patients (P = 0.02, OR = 2.31; P = 0.03, OR = 1.38). The AT haplotype (-251A/+1633C) showed a non-significant trend toward increased risk for COVID-19 (P = 0.11, OR = 2.24). The IL-8 +1633 TT genotype was associated with impaired platelet counts among COVID-19 patients (P = 0.05, OR = 2.42). The IL-8 -251TA genotype was significantly associated with all stages of COVID-19 severity-critical (P = 0.05, OR = 8.15), severe (P = 0.002, OR = 2.74), moderate (P = 0.008, OR = 2.16), and mild (P = 0.01, OR = 2.89). In contrast, the IL-8 -251AA genotype was significantly associated with the critical stage (P = 0.04, OR = 2.53). A marginally significant association was observed between the IL-8 +1633CT genotype and the severe stage of COVID-19 (P = 0.07, OR = 2.13). Additionally, a borderline significant association was noted between elevated serum creatinine levels and the IL-8 -251AA genotype (P = 0.07, OR = 2.45).

CONCLUSION

The IL-8 -251T/A polymorphism may serve as a potential risk factor for severe disease progression; the +1633 TT genotype may be linked to thrombocytopenia and poor clinical outcomes; and the -251AA genotype may be associated with elevated serum creatinine levels and an increased risk of renal dysfunction.