Association of the HLA-DRB1*0701 allele with perinuclear anti-neutrophil cytoplasmatic antibodies in Mexican patients with severe ulcerative colitis

Table 1 Gene frequencies (g.f.) of HLA-DR alleles in patients with UC and healthy controls

HLA	p-ANCA +	p-ANCA –	Healthy controls
	N= 96	N=84	N=198
	n g.f.	n g.f.	n g.f.
DR7	21 0.21812	4 0.047	22 0.111
DR2	16 0.166	13 0.154	14 0.090
DR4	14 0.145	17 0.202	47 0.237
DR1	13 0.135	12 0.142	10 0.050
DR8	10 0.104	11 0.130	33 0.165
DR5	8 0.083	11 0.130	20 0.100
DR6	6 0.062	9 0.107	21 0.109
DR3	5 0.052	5 0.059	11 0.055
DR10	3 0.031	2 0.023	1 0.005

N = Number of chromosomes n= number of alleles.

¹p-ANCA positive vs negative: pC = 0.02, OR = 5.2, CI 95%: 1.06-37.82.

²p-ANCA positive vs controls: pC = 0.04, OR = 2.9, CI 95%: 1.01-20.56.

Table 2 Clinical features of UC patients with positive and negative p-ANCA

Clinical	p-ANCA	p-ANCA	P value
feature	+	-
	n=48	n=42
Age at diagnosis (yr)	31 ± 8	33 ± 7	0.34
Gender (F/M)	23/25	22/20	0.62
Disease duration (yr)	7.4 ± 6.3	6.8 ± 6.2	0.45
Clinical relapses	2 ± 1	3 ± 2	0.25
Medical Treatment
5-ASA	90%	85%	0.75
Corticosteroids	44%	45%	0.90
Azatioprine or 6-MP	24%	22%	0.82
Extensive colitis	29	27	0.47
Distal colitis	19	15
Colectomy	7	7	0.94
No Colectomy	41	35
EIMs present	21	25	0.67
EIMs absent	27	17
Disease activity
Absent	19	21	0.82
Mild	9	10	0.71
Moderate	5	6	0.65
Severe	15	5	0.000008

^aOR = 11; CI 95%:4.0-34.0.n = Number of patients.