Activated idiotype-reactive cells in suppressor/cytotoxic subpopulations of monoclonal gammopathies: correlation with diagnosis and disease status.

The phenotypic pattern of peripheral blood T (PBT) lymphocytes was correlated with diagnosis and clinical status in 63 patients with monoclonal gammopathies (MGs). The numbers of lymphocytes expressing activation and CD11 determinants were significantly increased in suppressor/cytotoxic and helper/inducer subpopulations of patients with multiple myeloma (MM) and MG of undetermined significance (MGUS). The number of activated suppressor/cytotoxic cells was closely correlated with diagnosis and disease status. These cells were significantly higher in MM at diagnosis (160 +/- 88) than MGUS patients (61 +/- 79; P less than .01). Their number decreased to MGUS levels in MM in stable remission (58 +/- 53), but not in MM with tumor progression (172 +/- 102; P less than .001). In individual patients, part of these cells specifically adhered to dishes precoated with the related M-protein. No monoclonal T-beta gene rearrangement was detected in PBT and cytotoxic/suppressor subpopulations from two patients with a large proportion of activated cells.