CD4 and alkaline phosphatase measurement: During immune cell-type infiltration analysis, the results indicated that with the progression of AP, peripheral blood DCs, monocytes, macrophages, and neutrophils showed an increasing tendency, and B cells, CD4 T cells, CD8 T cells, Treg cells, T helper (Th) cells, Th1 cells, Th2 cells, and Tfh cells showed a decreasing tendency (Figure 4A).