In terms of theoretical bone marrow-derived serum-type IgA level (calculated by subtracting sIgA from total IgA), the viral infection group exhibited higher levels (25.0–149.9 mg/dL (median = 70 mg/dL)) than the bacterial infection group (11.0–130.0 mg/dL (median = 28.0 mg/dL), p < 0.05) and non-infection group (16.0–78.0 mg/dL (median = 50.0 mg/dL), p < 0.05) (Figure 1c and Table 1). Here, CD79A is linked to bacterial infectious disease.