[Clinical characteristics and cytokine gene expression in patients with post-COVID-19 syndrome].

Background: Post-COVID-19 syndrome occurs 3 months after COVID-19 infection and lasts at least 2 months. There is insufficient information on the genes associated with immune system dysregulation.

Objective: To evaluate gene expression and its relationship with post-COVID-19 syndrome.

Material and methods: Cross-sectional, retrolective and analytical study which included 56 patients with post-COVID-19 syndrome. Clinical characteristics were recorded and serotonin IL-4, IL-1β, SOCS3, ILF13, and IFNL4 genes were analyzed with TRIzol® Reagent and PCR-RT techniques.

Results: The prevalence of post-COVID-19 syndrome was 82.1%, with no differences in relation to the severity of symptoms or comorbidities. The clinical characteristics related to the presence of the syndrome were female sex with an odds ratio (OR) of 4.25 (95% confidence interval [95% CI] 1.02-17.69), and drug consumption with an OR of 8.25 (95% CI 0.97-70.50). Protective factors for fatigue were serotonin expression with an OR of 0.238 (95% CI 0.060-0.949); for concentration problems, SOCS3 with an OR of 0.188 (95% CI 0.037-0.946), and for memory impairment the IFNL4 with an OR of 0.094 (95% CI 0.015-0.586).

Conclusions: The associated factors with post-COVID-19 syndrome were female sex, drug use, and gene dysregulation of serotonin, INFL4 and SOCS3.