IL-6 and IL-17 as potential links between pre-existing hypertension and long-term COVID sequelae in patients undergoing hemodialysis: a multicenter cross-sectional study.

Long COVID, characterized by persistent symptoms following acute infection, poses a significant health challenge, particularly for patients with pre-existing chronic conditions such as hypertension. We hypothesized that an increase in the production of interleukins (IL)-6 and IL-17 could serve as a potential mechanism linking pre-existing uncontrolled blood pressure (BP) to the occurrence of long-term COVID sequelae in patients undergoing hemodialysis (HD). This cross-sectional study examined serum IL-6 and IL-17 levels in 80 patients undergoing HD, considering preinfection BP, the presence of long-term COVID sequelae, and the time interval after acute COVID-19 infection, which was either 5 or 10 months. Controlled BP was defined as a 3-month average pre-dialysis BP < 140/90 mmHg and post-dialysis < 130/80 mmHg. The findings suggest that the prevalence of long-term COVID sequelae was significantly higher in patients with uncontrolled BP than in the BP-controlled group. Both IL-6 and IL-17 concentrations were also significantly higher in patients with uncontrolled BP compared with the BP-controlled group. The patients with long-term COVID sequelae had higher IL-6 and IL-17 values than the fully recovered patients at both time points, but their concentrations decreased significantly over time. Further research and prospective studies are warranted to validate these findings.