Influence of Interferon Gamma Gene rs2430561 Variant on Complicated Course of Pneumonia in Patients with COVID-19

Background: Pneumonia is one of the most common complications of the course of COVID-19. Interferon-γ (IFN-γ) is an essential cytokine for lung defense against intracellular and extracellular pathogens. Since the rs2430561 variant of the IFNG gene, which encodes IFN-γ, affects the production of IFN-γ, it can potentially be associated with a severe course of COVID-19. Objective: The aim of our research was to determine the impact of the rs2430561 variant of the IFNG gene on the propensity of patients to develop and experience a severe course of COVID-19-related pneumonia. Methods: The study included 117 patients with a complicated course of COVID-19- associated pneumonia, who were hospitalized in the intensive care unit. All patients received a standard clinical and laboratory evaluation and course of treatment for COVID- 19. IFNG gene variants were determined by PCR method. For comparisons, we used clinical and laboratory indicators from the inpatients’ medical records, which reflected the course of the patient's disease, taking into account the rs2430561 variants of the IFNG gene. Results: In the group of patients, the following genotype frequencies were found: TT – 18.8%, TA – 52.1%, and AA – 29.1%. The results showed that AA genotype carriers had essentially higher SpO2/FiO2 ratio (p=0.043). High base excess rates were present in patients with the TT genotype (p=0.047). It was found that patients with the T allele (whether homozygous or heterozygous state) had significantly higher concentrations of such electrolytes as potassium and sodium (p=0.016 and p=0.004, respectively). Сonclusion: In patients with COVID-19, the rs2430561 variant of the IFNG gene is linked to a complicated course of pneumonia. Certainly, this finding requires further research.