Serological measures of Epstein-Barr virus (EBV) reactivation may identify individuals at high risk of transitioning to clinical systemic lupus erythematosus (SLE). That is the conclusion of a study published this month in the Annals of the Rheumatic Diseases.
For the study, SLE patient relatives (n=436) who did not have SLE at baseline were recontacted after 6.3 (±3.9) years and evaluated for interim transitioning to SLE. Fifty-six (13%) transitioned to SLE prior to the follow-up visit. At the baseline and follow-up visits, antibodies against viral antigens were measured and single nucleotide polymorphisms (SNPs) in EBV-associated host genes (IL10, CR2, TNFAIP3 and CD40). Generalised estimating equations were used to test associations between viral antibody levels and transitioning to SLE.
Mean baseline viral capsid antigen (VCA) IgG (4.879 vs 3.866; P=.0003) and early antigen (EA) IgG (1.192 vs 0.7774; P=.0236) levels were higher in transitioned compared with autoantibody negative non-transitioned relatives.
Increased VCA IgG and EA IgG were associated with transitioning to SLE (odds ratio [OR], 1.28; 95% CI, 1.07-1.53; P=.007 and OR, 1.43; 95% CI, 1.06-1.93; P=.02, respectively). The negative predictive value for EA IgG positivity in SLE relatives was 89.33 per cent and is possibly better than the currently available measures for assessing risk of transitioning in SLE relatives, the authors said.
Significant interactions were observed between CD40 variant rs48100485 and VCA IgG levels and IL10 variant rs3024493 and VCA IgA levels in transitioning to SLE.
The authors concluded that increased serological reactivation of EBV prior to SLE classification is associated with transitioning to SLE in genetically susceptible individuals.