Table 3.

Genotype–phenotype association analyses

(a) Association with RF
Gene	SNP		Number of patients	Genotypes*			P **	OR	Alleles		P	OR
								(95% CI)				(95% CI)
IL‐10	rs1800872 G>T	RF‐positive	130	69	49	12	0·032	2·0	187	73	0·07	1·63
		RF‐negative	62	43	14	5		(1·06–3·8)	100	24		(0·97–2·74)
MIR146A	rs2910164 G>C	RF‐positive	130	80	42	8	0·05	0·55	202	58	0·05	0·63
		RF‐negative	62	29	27	6		(0·3–1·02)	85	39		(0·39–1·0)

(b) Association with ACPA
Gene	SNP		Number of patients	Genotypes*			P **	OR	Alleles		P	OR
								(95%CI)				(95% CI)
STAT‐4	rs7574865 G>T	ACPA‐positive	135	64	64	9	0·004	2·64	192	82	0·01	2·09
		ACPA‐negative	53	37	14	2		(1·34–5·18)	88	18		(1·18–3·69)

(c) Association with erosions presence
Gene	SNP		Number of patients	Genotypes*			P **	OR	Alleles		P	OR
								(95%CI)				(95% CI)
PSORS1C1	rs2233945 C>A	Erosions presence	69	51	16	2	0·042	0·44	118	20	0·06	0·52
		Erosions absence	45	25	18	2		(0·20–0·98)	68	22		(0·27–1·03)
PTPN2	rs2542151 T>G	Erosions presence	54	38	14	2	0·044	3·26	90	18	0·03	3·3
		Erosions absence	35	31	4	0		(1–10·77)	66	4		(1·07–10·21)

RF = rheumatoid factor; ACPA = anti‐citrullinated protein antibody; SNP = single nucleotide polymorphisms; OR = odds ratio; CI = confidence interval; STAT‐4 = signal transducer and activator of transcription 4; PSORS1C1 = psoriasis susceptibility 1 candidate 1; PTPN2 = protein tyrosine phosphatase, non‐receptor type 2; MIR146A = microRNA146a. Significant P‐values are reported in bold type. *wt = the homozygous genotype for the wild‐type allele; hz = the heterozygous genotype; var = the homozygous genotype for the variant allele. **Heterozygotes and variant homozygotes were considered together (1 df) in the comparisons between genotypes by χ² test.