Table 3.

Association of EBV Serologies by Titer Cut-offs with Risk of RA

Anti-EBV Titer	Pre-RA Cases	Matched Controls	Univariable Odds Ratio1 (95% CI)	Multivariable Odds Ratio2 (95% CI)
Anti-EBNA1
<1: 80	56	61	1.0 ref.	1.0 ref.
>=1: 80	31	26	1. 29 (0.69, 2.44)	1.29 (0.66, 2.47)
Anti-EBNA2
<1: 80	66	68	1.0 ref.	1.0 ref.
>=1: 80	21	19	1.13 (0.57, 2.27)	1.28 (0.62, 2.64)
Anti-EBNA1: Anti-EBNA2 ratio
≤ 1.0	19	18	1.0 (ref.)	1.0 (ref.)
> 1.0	68	69	0.92 (0.41, 2.08)	0.86 (0.37, 1.97)
Anti-VCA
<1: 5120	72	70	1.0 ref.	1.0 ref.
>= 1: 5120	15	17	0.82 (0.34, 1.97)	0.60 (0.23, 1.57)
Anti-EA Diffuse
<1:20	80	84	1.0 ref.	1.0 ref.
>= 1:20	7	3	3.00 (0.61,14.86)	3.25 (0.64, 16.51)
Anti-EA Complex
< 1:20	71	68	1.0 ref.	1.0 ref.
>=1: 20	16	19	0.80 (0.37, 1.71)	0.88 (0.39, 1.99)
Anti-CMV
Negative	22	34	1.0 ref.	1.0 ref.
Positive	65	53	1.86 (0.97, 3.56)	1.77 (0.89, 3.54)

EBNA: Epstein Barr nuclear antigen, VCA: viral capsid antigen, EA: early antigen, CMV: cytomegalovirus; CI: confidence interval

¹Univariable conditional logistic regression, conditioned on matching factors

²Multivariable conditional logistic regression, conditioned on matching factors, and adjusting for packyears of smoking and alcohol intake.