Evaluation of the chest computed tomography and hemogram data in patients with COVID-19: the importance of thymus

Abstract

Background/aim: To investigate the relationship between imaging findings and peripheral blood cell counts of COVID-19 patients and the degree of thymus fat involution of these patients. Materials and methods: Computed tomography (CT) images of 87 patients with COVID-19 positive through RT-PCR testing were evaluated retrospectively by two radiologists. Ground glass densities and other signs of viral pneumonia were recorded, lung involvement was scored quantitatively. The patients thymus fat involution was graded on CT. Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratios (PLR), lymphocyte and platelet counts were calculated. Imaging findings and degrees of thymus fat involution were compared with laboratory data. Results: Quantitative scoring of lung involvement was calculated at mean 6.63 +/- 4.70 (1-23) for observer 1 and mean 6.55 +/- 4.65 (1-23) for observer 2 (K = 0.824-1.000). Statistical significance was determined between the increase in age and the increase in scores of lung findings (p = 0.003). Lymphocyte count (p = 0.0001) and PLR (p = 0.001) were significantly lower in patients with severe CT involvement. A statistically significantcorrelation was found between increased thymus fat component and presence of COVID-19 lung involvement in CT (r = 0.461). Conclusion: The severity of imaging findings for COVID-19 patients significantly correlates with the degree of fat involution in patients' thymus tissue.