Table 3 HLA-DRB1 phenotypes in PsA cases, UIA and controls (where data available)

HLA-DRB1	PsA cases			Controls n = 537	p value (PsA whole cohort compared with controls)	UIA n = 1621	p Value (UIA compared with controls)
HLA-DRB1	Whole cohort n = 465	Type I n = 342	Type II n = 120	Controls n = 537	p value (PsA whole cohort compared with controls)	UIA n = 1621	p Value (UIA compared with controls)
DRB1*02	118 (25)	81 (24)	36 (30)	145 (27)	0.57	342 (21)	0.006
DRB1*04	142 (31)	92 (27)	48 (40)	195 (36)	0.06	719 (44)	0.001
DRB1*07	188 (40)	159 (46)	29 (24)	129 (24)	3.09×10⁻⁸	344 (21)	0.21

PsA, psoriatic arthritis; UIA, early undifferentiated inflammatory arthritis; type I, patients with PsA with type I psoriasis; type II, patients with PsA with type II psoriasis.
Data shown in n (%) unless stated otherwise.