HLA-B and rheumatoid arthritis: As patients with the HLA-B*44 allele were more likely to have a 20-fold increase in anti-CCP levels compared to the rest of the RA cohort (other HLA-B* alleles), we further investigated whether there was an overall correlation between the HLA-B*44 allele and increased anti-CCP levels by simple linear regression (Fig 2, Table 4).