Differential Expression of Rheumatoid Factor-Associated Cross- Reactive Idiotypes in Iranian Seropositive and Seronegative Patients with Rheumatoid Arthritis

Introduction: High levels of rheumatoid factors (RF) are detectable in serum of the majority of patients with rheumatoid arthritis (RA), but 5-10 % of patients remain seronegative (SN). Despite clinical and genetic similarities between these two subsets of RA, it has been proposed that they may be regarded as distinct clinical entities. Methods: In the present study a panel of monoclonal antibodies (mAb) recognizing RF-associated cross-reactive idiotypes (CRI) linked to the VH1 (G8), VH4 (LC1), VK3b (17-109) and a mA