CD79A and systemic lupus erythematosus: 56% axSpA, 4% controls (6); 69% axSpA, 45% PsA, 11% RA, 15% SLE, 0.8% controls (6); 85.1% axSpA, 7.8% controls (7); 47% axSpA, 4.7% controls (IgA) (8); 46.4% axSpA, 47.9% controls (IgG) (9)