Objective: To determine whether patients with rheumatoid arthritis (RA) have elevated Epstein-Barr virus (EBV) load in their peripheral blood mononuclear cells (PBMCs) and whether it is correlated with the HLA-DR genes they express, we developed an accurate EBV DNA quantitative assay using real-time polymerase chain reaction (PCR) with fluorescent probes.
Methods: We studied the EBV DNA load in the PBMCs of 84 patients with RA, 69 normal controls, and 22 patients with rheumatic conditions other than RA. A 214-bp segment from the long internal repeat of EBV was amplified from 500 ng of PBMC DNA (150,000 cells) and quantified by real-time PCR with fluorescent probes.
Results: We demonstrated that in patients with RA, the EBV DNA load in PBMCs is increased almost 10-fold compared with that in normal controls. The EBV load is stable over time and is not obviously influenced by disease-modifying antirheumatic drugs or HLA-DR.
Conclusion: Patients with RA have elevated EBV load in their peripheral blood.