HLA-DRB1 and arthritic joint disease: In our patients with PC and PCV-undifferentiated arthritis, HLA DRB1*01-B1*011 and C*06–C*07, haplotypes usually correlated with early arthritis [30,47] and were adequately represented with a predominance of HLADRB1*11 and HLAC*07 (Table S2).