The prognostic significance of T cell receptor β gene rearrangements and idiotype-reactive T cells in multiple myeloma

Abstract

Clonal T cell populations with idiotype specificity are present in the peripheral blood of a proportion of patients with multiple myeloma. We have identified the presence of both T cell sub-populations with a specificity for autologous immunoglobin fragments and T cell receptor β gene rearrangements in peripheral blood samples of patients with myeloma. T cell receptor β gene rearrangements were detected in 38 of 119 patient samples (32%) and were more common in progressive disease (70%), than at diagnosis (25%) or in stable disease (23%). The 38 patients who had T cell receptor β gene rearrangements detected at any time had a better overall survival (median not yet achieved) than the patients who never had rearrangements detected (median 45 months, n = 49;χ ² = 6.2, P < 0.01). All 12 patients with T cell receptor β gene rearrangements at diagnosis are still alive whereas the median survival for 28 patients with a germline configuration at diagnosis was 40 months (χ ² = 5.8, P > 0.01). The presence of T cell receptor β gene rearrangements even conferred a survival advantage during progressive disease (median survival 44 months vs 19 months;χ² = 8.7, P < 0.003). Two colour flow cytometry with biotinylated autologous immunoglobulin fragments demonstrated idiotype-reactive T cells in the peripheral blood of five out of 15 patients all of whom had T cell gene rearrangements. The remaining 10 patients had neither idiotype-reactive T cells nor a detectable T cell receptorβ gene rearrangement in concurrent samples. Thus in patients with myeloma there was a good correlation between the presence of T cell receptor β gene rearrangements and idiotype-reactive T cells. Patients with a rearranged T cell receptor β gene had a significantly better prognosis.