Coagulation Dysfunction and Hematological Changes in 633 Patients with COVID-19

Background: A previously unknown beta-coronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. The virus was named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the international committee for the classification of viruses (ICTV). The disease caused by this virus was named as coronavirus disease 2019 (COVID-19). In addition to pulmonary manifestations, hematological changes such as lymphocytopenia, thrombocytopenia, and coagulation dysfunction can also be found in COVID-19 patients, and the mechanism is still unclear.

Case data and methods: A total of 633 COVID-19 patients from Wuhan hospital of China were retrospectively analyzed. Clinical case data of all patients were collected, including gender, age, chronic underlying diseases, outcome, and blood laboratory test results. The hematological features of COVID-19 patients and the factors affecting their outcome were analyzed.

Results: Of 633 patients with COVID-19，the median age was 62 years (interquartile range, IQR, 51.0-70.0) and 330 (52%) were men. Lymphocytopenia (lymphocyte count, 1.0 ×10⁹ / L [IQR, 0.7-1.4]) occurred in 317/607 patients (52%), thrombocytopenia (platelet count <100 × 10⁹/ L) occurred in 14/62 death patients (23%), prolonged prothrombin time (13.8 seconds [IQR, 13.1-15.1]) in 289/486 patients (59%), increased D-Dimer level (0.7 mg/L[IQR，0.2-2.9]) in 230/411 patients (57%) and increased C-reactive protein levels (10.7 mg/L [IQR, 2.2-49.7]) in 217/426 patients (51%) . Compared with the survival patients, death patients have higher white blood cell count (11.7 × 10⁹/L [IQR, 8.4 to 15.6]), neutrophil count (10.8 × 10⁹/L [IQR, 7.8 to 13.9]), neutrophil count/lymphocyte count (20.5 [IQR, 12.4-34.2]), activated partial thromboplastin time (36.8 seconds [IQR, 31.3-42.3]), prothrombin time (17.1 seconds [IQR, 14.7 to 19.7]), D-Dimer level (4.6 mg/L [IQR, 1.0 to 7.8]), C-reactive protein level (111.8 mg/L (IQR, 53.1 to 196.6), and low lymphocyte count (0.5 × 10⁹/L [IQR, 0.3 to 0.7]). The results of logistic multivariate regression analysis showed that age, neutrophil count, prothrombin time, and C-reactive protein were risk factors for patients with COVID-19.

Conclusion: Hematological changes are common in patients with COVID-19. The early stage of the disease is mainly characterized by lymphocytopenia, thrombocytopenia, and the late stage may be characterized by more severe lymphocytopenia, even neutrophils elevation, elevated C-reactive protein, and severe coagulation disorder. The pathogenesis may be mediated by a direct viral infection and/or indirect immunopathology.