Current concepts in immunoregulatory T-cell neoplasms.

Normal T cells play a crucial role in the regulation of humoral immune responses by acting as potentiators (helper cells) or inhibitors (suppressor cells) of the B-cell transition into immunoglobulin-secreting plasma cells. Certain patients with leukemias or lymphomas of T-cell origin may provide a resource for obtaining homogeneous populations of cells which act as either helper cells (eg, some but not all patients with Sézary's syndrome) or suppressor cells (eg, some patients with acute of subacute T-cell leukemia). The clinical and theoretic implications of such immunoregulatory cell neoplasms are discussed.