Table 1.

Phenotype frequencies in HLA-B antigens in patients with AS and control groups, stratified by HLA-B27 positivity.

	CONT B27-negative, N = 462		AS, N = 367		CONT B27-positive, N = 549		AS B27-positive, N = 318		AS B27-negative, N = 49
HLA-B allele	n	%	n	%	n	%	n	%	n	%
B*27:02	0	0.00	22	5.99	19	3.46	22	6.92	0	0.00
B*27:04	0	0.00	1	0.27	0	0.00	1	0.31	0	0.00
B*27:05	0	0.00	293	79.84	531	96.72	293	92.14	0	0.00
B*27:08	0	0.00	2	0.54	0	0.00	2	0.63	0	0.00
B*07:02 ^a	87	18.83	35	9.54	53	9.65	27	8.49	8	16.33
B*08:01	71	15.37	36	9.81	44	8.01	30	9.43	6	12.24
B*13:02	7	1.52	7	1.91	10	1.82	5	1.57	2	4.08
B*14	55	11.90	29	7.90	46	8.38	23	7.23	6	12.24
B*18:01	62	13.42	21	5.72	34	6.19	18	5.66	3	6.12
B*38:01 ^f	21	4.55	18	4.90	12	2.19	8	2.52	10	20.41
B*39	5	1.08	5	1.36	10	1.82	4	1.26	2	4.08
B*40:01 ^e	19	4.11	17	4.63	1	0.18	13	4.09	4	8.16
B*40:02	7	1.52	4	1.09	4	0.73	2	0.63	2	4.08
B*44 ^c	139	30.09	53	14.44	69	12.57	40	12.58	13	26.53
B*47	4	0.87	4	1.09	3	0.55	4	1.26	0	0.00
B*51:01 ^d	78	16.88	32	8.72	40	7.29	21	6.60	11	22.45
B*52	11	2.38	5	1.36	6	1.09	5	1.57	0	0.00
B*57:01 ^b	36	7.79	10	2.72	27	4.92	8	2.52	1	2.04
All other alleles	298	64.50	139	37.87	185	33.70	108	33.96	29	59.18

AS versus CONT:
↵a 9.5% vs 18.8%, P_BONF < 0.01, OR 0.45, 95% CI 0.30–0.70.
↵b 2.7% vs 7.8%, P_c < 0.005, OR 0.33, 95% CI 0.16–0.68.
↵c 14.4% vs 30.1%, P_BONF < 10⁻⁵, OR 0.39, 95% CI 0.28–0.56.
↵d 8.7% vs 16.9%, P_BONF < 0.05, OR 0.47, 95% CI 0.30–0.73. AS B27-positive vs CONT B27-positive:
↵e 4.1% vs 0.2%, P_BONF < 0.001, OR 23.36, 95% CI 3.04–179.42. AS B27-neg versus CONT:
↵f 20.4% vs 4.6%, P_BONF < 0.01, OR 5.38, 95% CI 2.37–12.24. AS: ankylosing spondylitis; P_BONF: P value using Bonferroni correction; P_c: 2-tailed Fisher’s exact test; CONT: controls.