Fig. 1.

HLA DRB1 is associated with disease severity at the onset in DR4 + patients. (A) The six groups of patients positive or negative for HLA-DRB1* allele 01, 04 and 11 are divided in 3 classes, based on DAS at onset: DAS ≤ 2.4 (white), 2.4 < DAS < 3.7 (gray) and DAS ≥ 3.7 (black). (B) DR4 + patients (N = 27) were divided in two groups on the basis of the second DRB1* allele: all the DR4 + patients are shown individually on the basis of DAS at the onset and on the basis of the presence (black circles) or the absence (white circles) of DR4 or DR1 or DR11 as second allele. Each group is further subdivided, as described for panel A.