C-Reactive Protein and Lymphocyte are important indicators of severe coronavirus disease and poor prognosis in elderly patients

Abstract Objective：To explore the value of C-reactive protein (CRP) and lymphocyte (L) in the assessment of disease severity and prognosis of elderly COVID-19 patients.Methods: A total of 194 positive COVID-19 patients were collected from Tianyou Hospital and Puren Hospital, affiliated hospital of Wuhan University of Science and Technology. Their demographic characteristics were analyzed. The dynamic changes of CRP and L in peripheral blood were retrospectively studied.Results: (1) There were significant statistical differences in CRP, L in clinical typing and clinical outcome in patients over 60 years old compared with those under 60 years old. Survival analysis showed that the risk of death was greater in patients over 60 than in those under 60.（2）In 125 patients over 60 years old, the hospitalized patients with severe or critical types of disease had significantly higher CRP than those with moderate type (p<0.01). In the outcome of the elderly patients, the CRP of the patients with the outcomes of discharge, improvement, aggravation and death increased successively (p<0.01). According to the analysis of Logistic regression model, the increase of CRP constitutes a risk factor for death in elderly patients. (3) In the ROC curve analysis to distinguish the death outcome and non-death outcome of COVID-19 patients, the area under the curve (AUC) of CRP and L was 0.751 and 0.720 respectively. CRP and L had good diagnostic accuracy for the death outcome of patients. (4) Changes in CRP were correlated with changes in CT imaging and were consistent with changes in the course of the disease.Conclusions: (1) The cumulative survival rate of patients over 60 years old was lower than that of patients under 60 years old. With the increase of age, the CRP of patients showed an increasing trend, and the L of patients showed a characteristic lower than the normal reference interval. (2) CRP and L are important monitoring indicators of COVID-19 in elderly patients. Combined with CT examination and observation of their dynamic changes, CRP and L are of important clinical guiding value for the judgment of disease severity and the evaluation of prognosis.