This Phase 2 study will be conducted in patients with Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, or mantle cell lymphoma undergoing high-dose chemotherapy and autologous stem cell transplantation. Patients will be randomized to receive either LAD 11.25 mg 3 Month treatment or placebo and all patients will be vaccinated with KLH 6 months posttransplant. Patients will be evaluated to determine if the rate of immunologic recovery in the LAD group is enhanced compared with the placebo group.