[Immunogenetic studies in patients with IgM rheumatoid factor negative erosive chronic polyarthritis (c.p.)]

40 patients with erosive rheumatoid arthritis (RA), 20 of whom were IgM-negative and 20 IgM-positive, were studied prospectively with regard to their association with HLA-B-CREGs (B5-, B8-, B12-, B16-, B27-CREG). We found a highly significant association of IgM-negative RA patients and B5-CREG-antigens (Chi2 = 28.6; p less than 0.001).