In patients who did not survive COVID-19, the number of antibody-synthesizing lymphocytes (AS-LYMP parameter of the Sysmex XN series hematology analyzer) was significantly lower upon hospital admission compared to survivors, indicating impaired humoral immune response of B-cells as a cause of fatal outcome in COVID-19 infected patients. Thus, a decrease in AS-LYMP level appears to be an important indicator of severity and an independent predictor of mortality in critically ill COVID-19 infected patients.
Source: Rolla R. et al. Reduced activity of B lymphocytes, recognised by Sysmex XN‐2000™haematology analyser, predicts mortality in patients with coronavirus disease 2019 //International Journal of Laboratory Hematology. – 2020.
