Low levels of antibodies against common viruses associate with anti-citrullinated protein antibody-positive rheumatoid arthritis; implications for disease aetiology

Table 2 Association between high levels of anti-viral antibodies and RA in subgroups of patients, divided based on the presence/absence of ACPA

Groups	Virus	Cases (%)	Controls (%)	OR (95% CI)^a
All RA	EBV low^b	805 (81)	525 (75)	1.0 ref
All RA	EBV high^c	185 (19)	175 (25)	0.7 (0.5–0.9)
ACPA- RA	EBV low	307 (79)	525 (75)	1.0 ref
ACPA- RA	EBV high	82 (21)	175 (25)	0.8 (0.6–1.1)
ACPA+ RA	EBV low	498 (83)	525 (75)	1.0 ref
ACPA+ RA	EBV high	103 (17)	175 (25)	0.6 (0.5–0.8)
All RA	B19 low	796 (80)	525 (75)	1.0 ref
All RA	B19 high	194 (20)	175 (25)	0.7 (0.6–0.9)
ACPA- RA	B19 low	296 (76)	525 (75)	1.0 ref
ACPA- RA	B19 high	93 (24)	175 (25)	0.9 (0.7–1.2)
ACPA+ RA	B19 low	500 (83)	525 (75)	1.0 ref
ACPA+ RA	B19 high	101 (17)	175 (25)	0.6 (0.5–0.8)
All RA	CMV low	753 (76)	524 (75)	1.0 ref
All RA	CMV high	234 (24)	175 (25)	0.9 (0.7–1.2)
ACPA- RA	CMV low	296 (76)	524 (75)	1.0 ref
ACPA- RA	CMV high	91 (24)	175 (25)	1.0 (0.8–1.3)
ACPA+ RA	CMV low	457 (76)	524 (75)	1.0 ref
ACPA+ RA	CMV high	143 (24)	175 (25)	0.9 (0.7–1.2)

RA rheumatoid arthritis, ACPA anti-citrullinated protein antibody, CI confidence interval, EBV Epstein-Barr virus, CMV cytomegalovirus, ref reference
^aOdds ratios (OR) were adjusted for age, gender and residential area. Significant ORs are shown in italics
^bLow indicates lower three quartiles of antibody titres (75% lowest)
^cHigh indicates highest quartile of antibody titres (25% highest)

ISSN: 1478-6362