Among the 1,049 COPD participants studied (Table 1), the mean IgA level was 269.1 mg/dL (SD 150.9), with median of 240 mg/dL (25th percentile, 75th percentile 170, 340 mg/dL), comparable to levels reported in the general population.[12] One individual had deficient levels of IgA (<7mg/dL), and 25 participants (2.4%) had subnormal serum IgA levels ≤70 mg/dL. Here, CD79A is linked to chronic obstructive pulmonary disease.