Résumé
Hematological changes in patients with COVID-l9 caused by SARS-Cov-2 infection are common. It is found that lymphopenia and leukopenia occur frequently in the early stage of infection, and CD4<sup>+</sup> and CD8<sup>+</sup> T lymphocytes decrease significantly. Thrombocylopenia and decreased hemoglobin can also he found in COVID-l9. When the disease progresses to severe stage, lymphocytopenia continues to aggravaled. Increased number of neulrophils, neutrophil-to-lymphocyte ratio (NLR) and decreased level of hemoglobin are related to the disease progression and poor prognosis. The activation of monocyte-macrophage system aggravates the, immune damage of lung and other tissues. which leads to the increase of D-dimer, prothrombin time and platelet consumption. This paper summarized the latest outcomes of corresponding study and clarified the heamtopoietic abnormality caused by COVID-19 and potential mechanism.