HLA-DRB1 and rheumatoid arthritis: Indeed, 44/155 patients expressed HLA-DRB1*04:01 of whom 11 (25%) had rheumatoid nodules, 111/155 patients did not express HLA-DRB1*04:01 of whom 19 (17%) had rheumatoid nodules (Chi2, OR = 2.15 [0.91 – 5.25]; p = 0.081).