Associations of antibodies against citrullinated peptides with human leukocyte antigen-shared epitope and smoking prior to the development of rheumatoid arthritis

Table 1 Demographic data for individuals with samples at a median of 4.6 years (Q1 to Q3: 2.0 to 9.7) before the onset of symptoms of rheumatoid arthritis (RA) (pre-symptomatic individuals) at diagnosis and controls

	Pre-symptomatic individuals	RA	Controls ^a
	(n = 370)	(n = 203)	(n = 585)
Females (%)	81	77	71
Median age, years	49.9	56.5	50.3
(Q1-Q3) g	(30.6–58.8)	(48.7–63.7)	(40.2–60.1)
Ever-smoker (%)	230/348 (66.1)***	136/200 (68)***	254/552 (46.0)
HLA-DR SE^b, n (%)	240/366 (65.6) ***	129/204 (63.2) ***	229/585 (39.1)
anti-CCP2 abs^c, % (95% CI)	34.9 (30.2–39.9)***	74.5 (68.0–80.0)***^d	2.4 (1.4–4.0)
anti-CEP-1/Eno5-21 abs, % (95% CI)	28.9 (24.5–33.7)***	67.3 (60.5–73.5)***^e	6.1 (4.4–8.4)^f
anti-citC1359-369 abs, % (95% CI)	13.1 (10–17.1)***	32.2 (26.1–39.0)***^e	4.4 (3.0–6.4)^f
anti-Fibα563-583 abs, % (95% CI)	10.8 (8–14.4)***	34.2 (27.9–41.0)***^e	5.2 (3.6–7.4)^f
anti-Fibα580-600 abs, % (95% CI)	8.7 (6.2–12.1)	14.1 (9.9–19.7)***^e	6.1 (4.4–8.4)^f
anti-Fibß36-52 abs, % (95% CI)	29.7 (25.3–34.6)***	64.8 (58.0–71.1)***^e	6.6 (4.9–9.0)^f
anti-Fibß62-81a (72) abs, % (95% CI)	11.6 (8.7–15.3)***	14.6 (10.3–20.2)***^e	3.1 (2.0–5.0)^f
anti-Fibß62-81b (74) abs, % (95% CI)	15.9 (12.5–20.1)***	34.2 (27.9–41.0)***^e	1.7 (0.9–3.2)^f
anti-CCP-1/Fil307-324 abs, % (95% CI)	26.2 (22–30.9)***	46.2 (39.4–53.2)***^e	3.0 (1.8–4.7)^f
anti-Vim60-75 abs, % (95% CI)	13.0 (9.9–16.8)***	29.1 (23.3–35.8)***^e	5.4 (3.8–7.6)^f
anti-Vim2-17 abs, % (95% CI)	7.0 (4.8–10.2)*	11.1 (7.4–16.3)***^e	3.8 (2.5–5.8)^f

*P <0.05, ***P <0.001 pre-symptomatic individuals or RA patients, respectively compared with controls.
^aThe sensitivity and specificity calculations are based on ROC curves performed originally on the RA cases (n = 200/199) and controls (n = 1,307) [5]. ^bHLA-DR SE = shared epitope defined as 0101/0401/0404/0405/0408/. ^cabs = antibodies. ^davailable number of samples analysed = 200. ^en = 199. ^fn = 574. g (Q1-Q3)=first quartile to third quartile.

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