This study found that the use of prophylactic antibiotics in those with selective IgA deficiency and COPD was associated with a significant decrease in exacerbations.[6] Notably, the comprehensive biomarker analysis from both COPDGene and SPIROMICS analyzing all biomarkers (n = 90) on the multiplex platform did not find an association of serum IgA with exacerbation risk;[10] however IgA concentrations were modeled continuously and linearly. The gene discussed is CD79A; the disease is selective IgA deficiency disease.