CD4+ AND CD8+ T-CELL EXPANSIONS USING SELECTED TCR-V AND TCR-J GENE SEGMENTS AT THE ONSET OF GIANT-CELL ARTERITIS

Objective. To investigate T cell receptor (TCR) V-alpha/V-beta (and in selected cases, J(beta)) usage in CD4+ and CD8+ peripheral blood lymphocytes of patients with giant cell arteritis (GCA), before and after treatment, as well as to analyze the HLA types of these patients. Methods. Flow cytometry, with 10 anti-TCR V-specific monoclonal antibodies (MAb), was used. To analyze J(beta) usage by cell populations expressing certain V-beta, we used the polymerase chain reaction (PCR) technique, with V-beta- and C-beta-specific primers, Southern blotting of PCR products, and subsequent hybridization with radiolabeled J(beta)-specific probes. HLA typing was performed using the microlymphocytotoxicity technique. Results. Seven of the 9 GCA patients had increased anti-TCR V MAb reactivities (interpreted as T cell expansions), which in many cases, correlated with clinical signs of disease. A strict preference for particular J(beta) segments was found in 3 of 3 expanded CD4+ T cell populations. Conclusion. T lymphocytes expressing specific antigen receptors are implicated in the pathogenesis of GCA.