Clinical and diagnostic value of the combination of lymphocyte count and creatine kinase in the detection of coronavirus 2019.

Du, Yanqing; Wang, Xiang; Qin, Zhonghua; Zhang, Lixia

The present study aimed to investigate the diagnostic efficiency of the absolute number of lymphocytes (LYM) and creatine kinase (CK) levels in the diagnosis of coronavirus disease 2019 (COVID-19). For this, the clinical data from 84 patients with COVID-19 admitted to Tianjin Haihe Hospital (Tianjin, China) between January and February 2020 were collected. The patients were divided into the following groups: The common COVID-19 group (n=61) and severe COVID-19 group (n=23). In addition, 30 healthy subjects were included as a control group. The results demonstrated that the percentage of neutrophils (NEU%) was significantly increased, while the absolute number of white blood cells, LYM and the percentage of lymphocytes (LYM%) were significantly decreased in patients with COVID-19. Furthermore, in the severe group, the absolute number of red blood cells in female patients, the NEU%, the neutrophil-to-lymphocyte ratio (NLR) and the serum levels of interleukin-6 and C-reactive protein (CRP) were markedly elevated, while those of LYM and LYM% were significantly decreased (all P<0.05). In addition, in the receiver operating characteristics curve analysis for the combination of LYM + CK, the area under the curve values were 0.96 and 1.00, with a sensitivity of 95.08 and 100%, specificity of 86.67 and 100% and cut-off values of 0.42 and 0.50 for the common and severe COVID-19 group, respectively. The results indicated that the diagnostic efficiency of LYM + CK was higher than that of each single factor. Finally, a moderate correlation of lactate dehydrogenase with CRP and NLR (r=0.492 and 0.433, respectively; both P<0.05) was obtained. Overall, the results of the present study indicated that the values of LYM and CK were associated with the progression of COVID-19, suggesting that the combination of both factors may be of clinical diagnostic value for COVID-19.