Peripheral Blood Immune Profiling of Patients

Peripheral blood samples were collected by PUMCH laboratories at enrollment with EDTA anticoagulant for measurement of lymphocyte counts and immunological biomarkers, as described previously (Li D. et al., 2020 (link)). Peripheral blood mononuclear cells were separated, stained with fluorescent monoclonal antibodies, and underwent flow cytometric analysis (3-color EPICSXL flow cytometer; Beckman Coulter, Brea, CA, United States) to detect T cells (CD3⁺), CD4⁺ T cells (CD4⁺CD3⁺ and CD28⁺CD4⁺), CD8⁺ T cells (CD8⁺CD3⁺, CD28⁺CD8⁺), B cells (CD19⁺), and natural killer cells (CD3^–CD16⁺CD56⁺). (Supplementary Figure 1) Rate nephelometry (Array 360; Beckman Coulter) was used to measure serum levels of IgA, G, and M. Inflammatory markers were also recorded, including interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α.