Effect of Vitamin D Concentration on Course of COVID-19.

BACKGROUND The course of COVID-19 disease is associated with immune deregulation and excessive release of pro-inflammatory cytokines. Vitamin D has an immunomodulatory effect. We aimed to assess the possible correlation between the incidence and severity of SARS-CoV-2 infection and serum vitamin D concentration. MATERIAL AND METHODS A total of 505 successive patients admitted to a COVID-19-dedicated hospital were included in the retrospective analysis. Serum 25-hydroxyvitamin D (25-OHD) levels and SARS-CoV-2 RT-PCR throat swab test results were determined for each patient. The course of COVID-19 was assessed on the basis of the serum Vitamin Modified Early Warning Score (MEWS), which includes respiratory rate, systolic blood pressure, heart rate, temperature, and state of consciousness), as well as number of days spent in the intensive care unit (ICU) and need for oxygen therapy. RESULTS There was no difference in 25-OHD concentration between COVID-19-confirmed and negative results of the PCR tests. No correlation was found between serum 25-OHD in the COVID(+) group and the need for and time spend in the ICU, as well as the MEWS score. Multivariate analyses showed a positive correlation between need for oxygen therapy and lower 25-OHD concentration, as well as older age (P<0.001) and similar positive correlation between need for ventilation therapy with lower 25-OHD concentration, as well as older age (P=0.005). CONCLUSIONS Our findings do not support a potential link between vitamin D concentrations and the incidence of COVID-19, but low vitamin D serum level in COVID-19 patients might worsen the course of the disease and increase the need for oxygen supplementation or ventilation therapy.

Dynamics of humoral response to coronavirus antigens among employees of a designated COVID­19 hospital: an observational study.

INTRODUCTION: During the COVID­19 pandemic studies on workplace safety of hospital staff taking care of patients with this disease are a high priority. We decided to analyze the results of opportunistic screening for anti-SARS­CoV-2 antibodies among employees of a designated COVID-19 center. OBJECTIVES: The aim of the study was to investigate whether potential exposition to SARS­CoV-2 antigens is reflected in the results of serological studies. PATIENTS AND METHODS: Every employee who performed at least a single test between April 21 and July 20, 2020 was included in the study. The tests assessed the levels of immunoglobulin (Ig) G and IgM+IgA. Employees working in direct contact with COVID­19 patients and those participating in aerosol­generating procedures were identified. RESULTS: The results of 2455 tests taken by 1572 employees were analyzed. A total of 357 participants (22.7%) had at least 1 positive or equivocal result during the study period. Linear mixed models revealed gradual increases in mean levels of both IgG and IgM+IgA antibodies among employees with all negative results. The rate of change was higher among persons who had direct contact with COVID­19 patients and the highest rate of change was observed among individuals participating in aerosol­generating procedures. CONCLUSIONS: We detected developing humoral immune response to a new set of coronavirus antigens among the study group. It is possible that employees of designated COVID­19 centers are regularly exposed to noninfectious doses of SARS­CoV-2 or its antigens.