Cytotoxic T lymphocyte associated antigen-4 gene polymorphisms confer susceptibility to primary biliary cirrhosis and autoimmune hepatitis in Chinese population

Table 1 CTLA-4 exon 1 + 49 polymorphism in patients with AIH, PBC and controls

	Control (% )	AIH (%)	P	PBC (%)	P
Genotype frequencies			0.4		0.006
A/A	23 (14.4)	6 (9.7 )		6 (7.8)
A/G	93 (58.1)	34 (54.8)		34 (44.2)
G/G	44 (27.5)	22 (35.5)		37 (48.0)
Allele frequencies(1)			0.22		0.0046
A	139 (43.4)	46 (37.1)		46 (29.9)
G	181 (56.6)	78 (62.9)		108 (70.1)
Phenotype frequencies(2)			0.32		0.035
A positive	116 (72.5)	40 (64.5)		40 (51.9)
G positive	137 (85.6)	56 (90.3)		71 (92.2)

¹Odds ratio for G allele (AIH) = 1.3, 95%CI = 0.85-1.99; Odds ratio for G allele (PBC) = 1, 95%CI = 1.20-2.72, ²Odds ratio for G phenotype (AIH) = 1.27, 95%CI = 0.79-2.05; Odds ratio for G phenotype (PBC) = 1.65, 95%CI = 1.03-2.63.

Table 2 CTLA-4 promoter –318 polymorphism in patients with AIH, PBC and controls

	Control (% )	AIH (%)	P	PBC (%)	P
Genotype frequencies			0.10		0.55
C/C	122 (76.3)	54 (87.1)		3 (81.8)
C/T	30 (18.8)	8 (12.9)		12 (15.6)
T/T	8 (5.0)	0 (0)		2 (2.6)
Allele(1)			0.02		0.23
C	274 (85.6)	116 (93.6)		138 (89.6)
T	46 (14.4)	8 (6.5)		16 (10.4)
Phenotype frequencies(2)			0.11		0.39
C positive	152 (95.0)	62 (100)		75 (97.4)
T positive	38 (23.8)	8 (12.9)		14 (18.2)

¹Odds ratio for C allele (AIH) = 0.41, 95%CI = 0.19-0.90; Odds ratio for C allele (PBC) = 0.69, 95%CI = 0.38-1.26, ²Odds ratio for C phenotype (AIH) = 0.52, 95%CI = 0.23-1.17; Odds ratio for C phenotype (PBC) = 0.75, 95%CI = 0.38-1.46.

Table 3 CTLA-4 exon 1- promoter genotypes in patients with AIH, PBC and controls

	Control	AIH(1)	PBC(2)
AA-CC	12 (7.5)	4 (6.5)	4 (5.2)
AA-CT	7 (4.4)	2 (3.2)	1 (1.3)
AA-TT	4 (2.5)	0 (0)	1 (1.3)
AG-CC	70 (43.8)	30 (48.4)	30 (39.0)
AG-CT	19 (11.9)	4 (6.5)	3 (3.9)
AG-TT	4 (2.5)	0 (0)	1 (1.3)
GG-CC	36 (22.5)	20 (32.3)	29 (37.7)
GG-CT	8 (5.0)	2 (3.2)	8 (10.4)
Total	160 (100)	62 (100)	77 (100)

¹AIH vs controls: χ² = 6.82, P = 0.45; ²PBC vs controls: χ² = 13.02, P = 0.07.