Analysis of serum cytokine and protective vitamin D levels in severe cases of COVID‐19
Nihayet Bayraktar, Hamdiye Turan, Mehmet Bayraktar, Ali Öztürk, Hamza Erdoğdu
Abstract
In this study, we investigated the role and relationship between the cytokine profile and protective vitamin D by measuring their serum levels in COVID-19 intensive care unit patients with severe illnesses. A total of 74 patients were included in our study. Patients were divided into two groups. Patients in the COVID-19 group (n = 31) and individuals without a history of serious illness or infection were used as the control group (n = 43). The serum concentrations of interleukin-1 (IL-1), IL-6, IL-10, IL-21, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assays. Levels of serum vitamin D were detected with Liquid chromatography-mass spectrometry methodologies. TNF-α, IL-1, IL-6, IL-10, IL-21, and vitamin D levels were measured in all patients. The serum cytokine levels in the COVID-19 patient group were significantly higher (151.59 ± 56.50, 140.37 ± 64.32, 249.02 ± 62.84, 129.04 ± 31.64, and 123.58 ± 24.49, respectively) than control groups. Serum vitamin D was also significantly low (6.82 ± 3.29) in patients in the COVID-19 group than the controls (21.96 ± 5.39). Regarding the correlation of vitamin D with cytokine levels, it was significantly variable. Our study shows that COVID-19 patients are associated with lower serum vitamin D and higher pro-inflammatory cytokines associated with increased virus presence. Our data provide more evidence of the anti-inflammatory effect of vitamin D on COVID-19 patients and the protective effects of vitamin D on risk were demonstrated.