Relationship between blood routine characteristics and clinical classification in 129 COVID-19 patients

ObjectiveTo investigate the characteristics of blood routine in 129 patients with COVID-19, and analyze the correlation between blood routine parameter changes and clinical classification.

MethodsA total of 129 COVID-19 patients were recruited and their blood samples were collected at the beginning and the end of treatment.The neutrophil-to-lymphocyte ratio(NLR), platelet-to-lymphocyte ratio(PLR), lymphocyte-to-monocyte ratio(LMR) and C-reactive protein(CRP) were determined and used to calculate Δ NLR, Δ PLR, Δ LMR.The differences in these parameters were compared between the non-severe group (93 cases) and the severe group (36 cases).In addition, the relationship between the changes in blood routine test result and the prognosis of patients was determined.

ResultsThe average age of 129 patients was 46.9±17.4 years old, and the ratio of male to female was 1.2 ∶ 1.Thirty-five (35) cases (27.1%) had leucopenia (< 4×10⁹/L) and 59 cases (45.7%) had lymphopenia (< 1.1×10⁹/L).There were statistically significant differences in age, treatment days, blood routine indexes between these two groups.In all the patients, the differences between before and after treatment were statistically significant in the following: leukocyte number, neutrophil cell percentage, lymphocyte number, lymphocyte percentage, monocyte number, monocyte percentage.The differences in RBC, HGB, CRP, and NLR between the two groups before and after treatment were also statistically significant (P < 0.05).

ConclusionThe older COVID-19 patients have lower number of lymphocytes, higher NLR and PLR, lower LMR and higher CRP.They have a higher risk of progressing to severe disease.After treatment, there is an increase in the number of granulocytes, especially the number of lymphocytes, while a decrease in CRP and NLR.The change of lymphocyte count, NLR and CRP levels can predict the risk of severe COVID-19 and evaluate the therapeutic effect.