Dynamic Characteristics of Lymphocyte Subsets and Their Predictive Value for Disease Progression and Prognosis in Primary Infection and Unvaccinated COVID-19 Patients.

AIM

Our cohort study aimed to investigate the dynamic changes of lymphocyte subsets and their abilities to predict disease severity and prognosis in primary infection and unvaccinated COVID-19 patients.

METHODS

A total of 773 cases, including 718 primary infection and unvaccinated COVID-19 patients and 55 controls. COVID-19 patients were assigned to severe and nonsevere groups according to disease severity, as well as survival and death groups according to prognosis. Serum samples were collected to measure the numbers of total lymphocytes and lymphocyte subsets. The differences among different severity groups were analyzed. Spearman correlation was performed to assess associations between lymphocyte subsets and disease severity and prognosis. Meanwhile, receiver operating characteristic (ROC) curves were also analyzed to find optimal cutoff points.

RESULTS

At admission, the severe group demonstrated significantly lower total lymphocyte counts and percentages, CD3 and CD3CD4 T cell counts and percentages, CD3CD8 T cell counts, CD19 B cell counts and CD56 NK cell counts and percentages than the nonsevere group. Meanwhile, compared with the survival group, the death group also had lower total lymphocyte counts and percentages, CD3, CD3CD4 and CD3CD8 T cell counts. Additionally, differences in these parameters were also noticed within four weeks after admission. Furthermore, Spearman analysis reported that disease severity was negatively correlated with lymphocyte counts and percentages, CD3, CD3CD4 and CD3CD8 T cell counts, CD3 and CD3CD4 T cell percentages (=-0.166, -0.179, -0.173, -0.186, -0.127, -0.117, -0.149, respectively)(all <0.05). The prognosis of death was also negatively correlated with total lymphocyte counts and percentages, CD3, CD3CD4 and CD3CD8 T cell counts (=-0.125, -0.121, -0.123, -0.123, -0.091, respectively)(all <0.05).

CONCLUSION

In primary infection and unvaccinated COVID-19 patients total lymphocytes and T cell, B cell and NK cell subsets at COVID-19 onset play valuable roles in predicting disease severity and prognosis.

CLINICAL TRIAL REGISTRY

Chinese Clinical Trial Register ChiCTR2000034563.