SARS-CoV-2 Seroprevalence in Healthcare Workers before the Vaccination in Poland: Evolution from the First to the Second Pandemic Outbreak.

Healthcare workers (HCWs) are on the frontline, struggling with the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To describe recent or past infections, the serological assays enabled the assessment of the immune response developed in coronavirus disease (COVID-19) in the period when testing was hardly available. In this study, we investigated SARS-CoV-2 seroprevalence in HCWs in a Polish teaching hospital and the Regional Occupational Medicine Center after both the first and the second waves. ELISA-based tests for anti-SARS-CoV-2 IgA and IgG were used to determine immune response to SARS-CoV-2 in volunteer HCWs who worked in those institutions in May 2020 (208 participants aged 47.1 ± 12.5, 88% women) and in December 2020 (179 participants aged 45.2 ± 12.4, 86% woman). Risk factors for seropositivity were also assessed using a questionnaire filled out by all participants. We reported a significant increase in seroprevalence after the second wave (22.9%) compared with the first outbreak (2.4%) (OR 12.1; 95%CI 4.6-31.3; p < 0.0001). An association between IgG seroprevalence and severity of infections was noted. Furthermore, we demonstrated that amongst medical personnel, nurses exhibited a proportionally higher SARS-CoV-2 seroprevalence. Moreover, given the high seroprevalence in non-clinical group of HCWs, we suggest that community transmission can play a superior role to workplace exposure.

Diagnostic strategies for SARS-CoV-2 infection / Diagnostyka zakazen SARS-CoV-2.

COVID-19 pandemic highlighted the importance of laboratory diagnostics to reduce the spread of SARSCoV-2 and to treat patients with severe coronaviral disease. The situation required a rapid development of molecular and serological tests to enable mass screening, testing of high-risk groups, and establishing epidemiological data. Knowledge of diagnostic methods is continuously evolving, so it is crucial to understand the nature of the tests and to be able to interpret their results. This review discusses the current literature on diagnostic methods, prognostic markers, diagnostic recommendations, choice of the appropriate test, type of biological material, and interpretation of results depending on test sensitivity and disease duration. Also, the percentage of positive results in the selected countries at two distant time points of the epidemic was analyzed. Further development of diagnostic techniques and incorporation of new technologies can provide more accurate and faster tools for control the epidemic.

Fetuin-A (AHSG) and its usefulness in clinical practice. Review of the literature.

BACKGROUND: Fetuin-A, also called Alpha 2-Heremans Schmid Glycoprotein, is a multifunctional plasma agent what has been proven in animal and human studies. It plays a role as a physiological inhibitor of insulin receptor tyrosine kinase associated with insulin resistance and a negative acute phase reactant. It also regulates bone remodeling and calcium metabolism being an important inhibitor of calcium salt precipitation and vascular calcifications. METHODS: PubMed database was searched for articles from 2002 up to December 2014 to identify the role of fetuin-A in the pathogenesis of selected internal diseases. RESULTS: Due to secretion of fetuin-A mainly by the liver, it may be a marker of liver function and predictor of mortality in patients with cirrhosis and hepatocellular cancer. The associations between high fetuin-A and metabolic syndrome as well as its hepatic manifestation- nonalcoholic fatty liver disease and atherogenic lipid profile have been well proven. However, fetuin-A relation with BMI is not so clear. Contrary to few reports, many authors suggest that fetuin-A may be an independent risk factor for type 2 diabetes and marker of diabetic complications. Close associations of high and low fetuin-A concentrations with cardiovascular diseases and mortality risk have been reported which is explained by differences in analyzed populations, stages of atherosclerosis and calcifications, coexistence of type 2 diabetes or kidney dysfunction and different main pathways of fetuin-A actions in various diseases. CONCLUSIONS: Fetuin-A has a diagnostic potential as a biomarker for liver dysfunction, cardiovascular diseases and disorders associated with metabolic syndrome.