Abstract
OBJECTIVE: To investigate whether oligoclonal T cell populations occur in peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE). METHODS: RNA was extracted from the lymphocytes isolated from whole peripheral blood of five female patients fulfilling ARA criteria for SLE and two healthy female controls, and synthesised into cDNA. CDR3 length spectratyping was performed using a polymerase chain reaction (PCR) run to saturation followed by a primer extension with a radioactively labelled primer. The resulting samples, one for each of the 23 V beta families, were then run on a polyacrylamide sequencing gel to examine the T cell receptor beta chain repertoire at the level of VDJ length heterogeneity. RESULTS: The two healthy female controls showed faint oligoclonal bands in only two and three V beta families respectively. Three of the patients showed a similar degree of oligoclonality to the controls, while the other two, who had active disease as shown by SLAM scores of 17 and 19 and in one case low C4 and raised C3dg levels, showed marked oligoclonality of their T cell beta chain repertoire affecting more than 17 of the 23 V beta families analysed. CONCLUSIONS: Using the technique of CDR3 length spectratyping, restriction of T cell receptor beta chain usage by peripheral blood T cells in patients with SLE has been demonstrated for the first time.