Background. Post‑COVID syndrome (Long COVID) is a multisystem condition in which persistent inflammation, endothelial dysfunction, and dysregulation of the immune response play a significant role, particularly in patients with concomitant arterial hypertension.

Objective. To investigate the expression patterns of microRNAs (miR‑155 and miR‑28) and the distribution of gene polymorphisms AGT T174M, JAK2 V612P, IL6 −174G>C, and EDN1 Lys198Asn in patients with Long COVID depending on the presence of arterial hypertension.

Materials and Methods. A total of 174 individuals were examined: patients with Long COVID and arterial hypertension (n=50), patients with Long COVID without arterial hypertension (n=52), and a control group of healthy donors (n=72). MicroRNA expression was assessed by real‑time PCR, and genotyping was performed using allele‑specific PCR. Statistical analysis included nonparametric tests, correlation analysis, and ROC analysis.

Results. Patients with Long COVID and arterial hypertension demonstrated a significant decrease in miR‑155 and miR‑28 expression (p<0.001), associated with the presence of TM and MM genotypes of AGT T174M, as well as GG and GT genotypes of JAK2 V612P. IL6 and EDN1 polymorphisms did not exert a significant effect on microRNA levels. ROC analysis revealed high predictive value of ΔCt miR‑155 and miR‑28 for stratifying patients according to JAK2 genotype (AUC >0.95).

Conclusions. Comprehensive evaluation of microRNAs and genetic polymorphisms enables the identification of molecular markers associated with the severity of Long COVID in patients with arterial hypertension, opening prospects for personalized monitoring and prognosis.

Long COVID, microRNA, arterial hypertension, AGT, JAK2, genetic polymorphism.

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