Detection of Hyperreactive T Cells in Multiple Myeloma by Multivalent Cross-Linking

Cellular immunity was investigated in 43 patients with multiple myeloma (MM) by assessing ,HTdR uptake induced by monocyte-dependent [CD3 monoclonal antibodies (MoAbs), phytohemagglutinin (PHA)] and monocyte-independent (CD2 MoAbs, ionomycin + phorbolester) stimulations. The former were evaluated in peripheral blood mononuclear cells (PBMNC) and purified T cells; the latter were evaluated in purified T-cell preparations only. MM showed significantly lower PBMNC responses t o PHA (P < .OOl), soluble OKT3 (CD3) (P = .Ol), and immobilized OKT3 MoAbs (P = .01). On purification of T cells, MM responses were still defective to soluble T11, + T11, (CD2) MoAbs (P = .004), phorbol myristate acetate (PMA) plus ionomycin (P < .001), but significantly higher to plastic-immobilized OKT3 (P = .004). In some MM, 'HTdR uptake, interleukin-2 (IL-2) receptor (CD25) expression, and IL-2 production were as high on stimulation with plastic-immobilized OKT3 as that observed in normal subjects under optimal conditions (ie, plastic-immobilized OKT3