Laboratory predictors of severe Coronavirus Disease 2019 and lung function in followed-up.

BACKGROUND: A pandemic caused by SARS-CoV-2 has infected more than 79 million people and killed exceeding 1.7 million people around the world by the end of 2020. METHOD: We obtained the clinical data of all diagnosed patients and lung function test of followed-up patients in Fuyang, Anhui province to investigate laboratory predictors of severe Coronavirus Disease 2019 (COVID-19) and the impairment of lung function. RESULTS: Of the 155 patients, 87 (56.13%) were males. The mean age was 41.95 (SD 15.34) years. Only 30 (19.35%) patients had the critical condition. Fever (84.52%) was the most common symptoms, and short of breath was more common in severe patients (p < 0.01). Lymphopenia was observed in most patients (74, 47.7%). It showed the elevation of CRP in 100 (64.5%) patients, the elevation of SAA or IL-6 in 104 (67.1%) patients. The calculated cut-off value of CRP was 19.35 mg/ml, the AUC was 0.777, sensitivity was 73.3%, specificity was 69.6%; SAA was 73.55 mg/L, 0.679, 83.3%, 56.8%, respectively; IL-6 was 18.85 pg/ml, 0.797, 83.3%, 64.8%; D-Dimer was 0.325 mg/L, 0.673, 66.7% and 68.8%. The combination of CRP, SAA, IL-6, and D-Dimer was 0.823 in AUC, 73.3% in sensitivity, and 78.4% in specificity. 12 (42.86%) followed-up patients had completely normal lung function indicators. CONCLUSION: Elevated CRP, SAA, IL-6 and D-Dimer can be predictors to severe COVID-19. The combination of these four indicators can improve the effectivity and specificity of assessing severe COVID-19. Most of the followed-up patients showed no abnormalities in lung function test. Abnormal lung function is mainly reflected in the diffusion function.