The role of laboratory markers as predictors of severity in Covid 19 patients

Background: The pandemic due to novel coronavirus 19 has spread at a tremendous rate to more 
than 93 countries around the world. Many studies evaluated the role of laboratory markers in the 
diagnosis of the disease. However, their role in predicting non severe, severe, and post covid 19 cases 
is being explored. Aim of the study: To evaluate the role of laboratory markers in predicting the 
prognosis of covid 19 cases and in predicting the evolution of post covid 19 sequalae. Subjects and 
methods: This retrospective study included 650 Covid 19 patients; furtherly classified as 386 non 
severe patients; 200 severe patients, and 64 post covid patients. Complete blood count (CBC), Creactive protein (CRP), serum ferritin, D dimer, and Alanine Aminotransferase (ALT) were measured 
in all patients. Results: Higher CRP, ferritin, D dimer, ALT, total leucocytic count (TLC), absolute 
neutrophil and monocytic counts, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte 
ratio (PLR) were significantly found in severe covid 19 cases when compared to non severe and post 
covid recovered cases, together with lower absolute lymphocytic and eosinophil counts, hemoglobin 
(Hb), and lymphocyte to monocyte ratio (LMR). Moreover, post covid spontaneous recovery showed 
a decline in all laboratory markers together with a rise in lymphocytic and eosinophil counts, Hb 
level, platelet (PLT) count, and LMR upon convalescence. The multivariate regression analysis 
showed that ICU admission, dyspnea, low absolute lymphocyte count, high TLC, and high absolute 
monocyte counts are independent risk factors for the severity of covid 19. Conclusion: Laboratory 
markers are fast, simple, cost effective tools to stratify covid cases into non severe and severe and to 
predict the course of post covid cases. Hence, allowing the proper early intervention to each case.