Table 1 Odds ratios for the association of antibodies to citrullinated peptides, their uncitrullinated controls, rheumatoid factor (RF) and RgpB, with pre-RA (n = 103). Conditional logistic regression was used with matched controls are referent (n = 309). Cut-off for antibody positivity is the 98^th percentile of matched controls with the exception of anti-CCP2 and RF. RF; rheumatoid factor. CEP1, cFib and cVim; citrullinated peptides from α-enolase, fibrinogen and vimentin respectively. REP1, Fib and Vim are the arginine-containing control peptides. CPP3 and CPP5 are immunodominant peptides from PPAD, and RPP3 and RPP5 are the arginine-containing control peptides. RgpB; arginine gingipain

CCP2

10 (3)

24 (23)

9.94 (4.28–23.07)

<0.001

9.46 (3.89–23.00)

<0.001

RF

12 (4)

23 (22)

5.73 (2.79–11.76)

<0.001

5.84 (2.66–12.86)

<0.001

CEP1

6 (2)

15 (15)

7.11 (2.75–18.35)

<0.001

7.26 (2.53–20.82)

<0.001

REP1

6 (2)

2 (2)

0.77 (0.15–3.93)

0.748

1.17 (0.22–6.30)

0.853

cFIB

5 (2)

8 (18)

12.01 (4.06–35.55)

<0.001

10.44 (3.39–32.10)

<0.001

FIB

5 (2)

2 (2)

1.00 (0.19–5.19)

1.000

1.05 (0.20–0.57)

0.957

cVIM

3 (2)

5 (6)

2.84 (0.66–12.05)

0.157

4.84 (0.94–24.94)

0.059

VIM

5 (2)

4 (4)

2.00 (0.53–7.50)

0.304

2.47 (0.62–9.76)

0.199

CPP3

6 (2)

2 (2)

1.00 (0.20–4.95)

1.000

1.54 (0.28–8.31)

0.618

RPP3

5 (2)

5 (5)

2.88 (0.83–9.97)

0.095

3.76 (0.89–15.86)

0.071

CPP5

6 (2)

5 (5)

2.41 (0.73–7.91)

0.147

2.47 (0.71–8.54)

0.154

RPP5

5 (2)

2 (2)

1.20 (0.23–6.19)

0.827

1.78 (0.31–10.39)

0.521

RgpB

12 (4)

3 (3)

0.66 (0.17–2.62)

0.555

0.60 (0.15–2.46)

0.479

  1 (<1280)

123 (44)

51 (50)

ref

-

ref

-

  2 (≥1280)

75 (27)

29 (28)

0.93 (0.54–1.60)

0.787

0.98 (0.55–1.77)

0.957

  3 (≥2560)

68 (24)

20 (19)

0.74 (0.39–1.38)

0.341

0.85 (0.44–1.68)

0.647

  4 (≥5120)

12 (4)

3 (3)

0.59 (0.14–2.45)

0.472

0.57 (0.13–2.44)

0.449