Table 3.

Association of antibodies with risk factors for RA^a

Risk factor	Smoking history			HLA−DRB1 SE positive	PD
	Never smoked	Former smoker	Current smoker
CCP‐2+ (n = 240)	37	43	21	81	37
CCP‐2− (n = 44)	45	48	7	49	23
P	–	–	0.076	<0.001b	0.085b
cFIBβ+ (n = 190)	35	39	25	79	41
cFIBβ− (n = 97)	42	51	7	69	24
P	–	–	0.001	0.061	0.005
cVIM+ (n = 92)	39	41	20	92	36
cVIM− (n = 195)	37	44	19	68	34
P	–	–	0.902	<0.001	0.802
CEP‐1+ (n = 95)	27	48	24	88	41
CEP‐1− (n = 192)	43	41	17	69	32
P	–	–	0.034	0.001	0.12
cTNC5+ (n = 145)	35	43	22	80	37
cTNC5− (n = 142)	40	44	16	71	33
P	–	–	0.412	0.085	0.539
cCK13‐1+ (n = 69)	42	35	23	72	38
cCK13‐1− (n = 218)	36	46	18	77	34
P	–	–	0.256	0.451	0.57

^aValues are the percent of patients. Except where indicated otherwise, chi‐square tests were used to compare frequency distributions of categorical variables. RA = rheumatoid arthritis; SE = shared epitope; PD = periodontitis; CCP‐2 = cyclic citrullinated peptide 2; cFIBβ = citrullinated fibrinogen β; cVIM = citrullinated vimentin; CEP‐1 = citrullinated α‐enolase peptide 1; cTNC5 = citrullinated tenascin‐C; cCK13‐1 = citrullinated cytokeratin 13–derived peptide 1.

^bBy Fisher's exact test.