Cross-talk between inflammation and coagulation in severe COVID-19: Association of leptin and classical pro-inflammatory markers with coagulation disorders in a single-center observational cohort study

We performed a single-center observational cohort study on patients with COVID-19. We retrospectively analyzed 54 patients with confirmed SARS-CoV-2 infection, diagnosed as critically ill. Severely ill patients have a poor prognosis and it is a matter of great interest to identify these cases for an adequate management. Current findings revealed that altered levels of some blood markers might be linked with the degree of severity and mortality of patients with COVID-19. Our study aimed to assess the relationship between inflammation and coagulation in SARS-CoV-2 infection and to find out if pro-inflammatory markers are correlated with coagulation parameters in COVID-19. Pro-inflammatory markers included leptin and classical biomarkers. This paper highlights the results obtained. We found statistically significant associations between blood levels of various biomarkers including leptin, IL-6, ferritin, neutrophil-lymphocyte ratio, C-reactive protein, fibrinogen, erythrocyte sedimentation rate and lactate dehydrogenase and the presence of coagulopathy, as indicated by the Pearson Chi-Square and Likelihood Ratio tests. The relationships are not linear, as indicated by the nonsignificant Linear-by-Linear Association test. The correlations between some biomarkers such as leptin, IL-6, ferritin, neutrophil-lymphocyte ratio, C-reactive protein, fibrinogen, erythrocyte sedimentation rate and lactate dehydrogenase and coagulopathy are weak and not statistically significant and the correlation between IL-6 levels and coagulopathy is very weak and negative and not statistically significant. Different crosstabulations between serum leptin levels and D-dimers, Prothrombin time, Prothrombin activity, International-normalized-ratio and activated partial thromboplastin time have been performed including the analysis of a potentional correlation. There are statistically significant associations between serum leptin levels and coagulation parameters, including D-dimers, prothrombin time, prothrombin activity and activated partial thromboplastin time, as indicated by the Pearson Chi-Square test. There is also a statistically significant association between serum leptin levels and international-normalized ratio (INR) as indicated by the Pearson Chi-Square test. The Linear-by-Linear Association test indicates a significant linear relationship between Leptin levels and international-normalized ratio. Pearson R shows a moderate positive correlation, which is statistically significant.