Study on the association between interleukin-6 receptor Asp358Ala (rs2228145) single nucleotide polymorphism, with the severity of clinical symptoms in patients with COVID-19

Increasing of interleukin-6 (IL-6) in Covid-19 patients has been reported in various studies. Genetic variants of the IL-6 receptor are involved in the beginning and progression of severe infections, autoimmunity, and also inflammatory diseases. The aim of this study was to investigate the association between SNP (rs2228145) of IL-6 receptor with the severity of Covid-19 patients.

In the present cross-sectional and analytical study, 180 patients with Covid-19 entered voluntarily and were classified based on the severity of the disease in 4 groups: mild (90 patients, age 46.40 ± 15.8), moderate (45 patients, age 50.4 ±16.4), severe (25 patients, age 59.70 ±24) and critical (20 patients, age 15.30 ± 60.8). Peripheral blood samples were taken from patients and after DNA extraction, genotyping was performed by RFLP PCR and electrophoresis on 2% agarose gel. Data were analyzed using SPSS software and Chi-Square or ANOVA.

The mean age of patients in the outpatient group and the intubated inpatients were 46.40 ± 15.8 and 60.30 ± 15.8, respectively (P-value <0.001). Also, the frequency of diabetic patients in the outpatient group and intubated group were about 21% and 45%, respectively (P-value <0.05). A significant difference was observed in the CC genotype between outpatient and inpatient groups (P-value <0.01) as well as intubated patients (P-value <0.05).

The frequency of rs2228145 variants in Covid-19 patients with different severity is diverse and CC genotype can be a predictor of prognosis in admission to the ICU and intubation.