Characteristics of blood cells in Omicron-associated Pneumonia patients with hematologic malignancies and the relationship between blood cells and the prognosis of Omicron-associated Pneumonia:a retrospective cohort study.

<bold>Background:</bold> It suggesting that lymphocyte and platelet are associated with the severity and prognosis of Omicron-associated Pneumonia[1,2,3]. Therefore, we aim to investigate the characteristics of blood cells in Omicron-associated Pneumonia patients with underlying hematologic malignancies, the trends after treatment, and whether the blood cells changes is correlated with prognosis. <bold>Methods:</bold> This retrospective cohort study analyzed 168 Omicron-associated Pneumonia patients (haematolymphoid malignancies [HM] group, n = 42; non-hematological malignancy(NHM) group, n =126). We use SPSS to Analyze the data. <bold>Results:</bold> The neutrophils was lower in the HM group than in the NHM group(OR=4.636,95%CI=1.606-13.387; P = 0.005),platelet was lower in the HM group than in the NHM group (OR=3.819,95%CI=1.681-8.677; P = 0.005)(Figure1). After treatment, there was an upward trend in platelet, lymphocyte, and neutrophil in all the patients. The increase in platelets and neutrophils was significantly different compared to pre-treatment（p<0.05), However, these increase had no significant difference between HM group and NHM group. The proportion of post-treatment neutrophil increase in died patients was lower than that in the survival patients(OR=3.583,95%CI= 1.024-12.544; P = 0.046).(Figure2) <bold>Conclusion:</bold> Patients with underlying hematological malignancies who have contracted Omicron-associated Pneumonia exhibit lower platelet, neutrophil. There was an overall upward trend in platelet, neutrophil and lymphocyte after treatment in Omicron-associated Pneumonia, and poor increases in neutrophil may indicate a worse prognosis.