CD79A and rheumatoid arthritis: An aggregate pattern was more frequent among RA patients (aggregate in RA: 76.9% vs. aggregate in other patients: 23.1%, P = 0.04) and was associated with the positivity for ACPA (ACPA positivity: aggregate 61.5% vs. diffuse 14.3%, P = 0.004), for IgM RF (IgM RF positivity: aggregate 46.2% vs. diffuse 10.7%, P = 0.02) and for IgA RF (IgA RF positivity: aggregate 30.8% vs. diffuse 3.6%, P = 0.02).