A Study to Evaluate the Ability of Lupron Depot to Enhance Immune Function Following Bone Marrow Transplantation

Inclusion Criteria: 1. Must be female between the ages of 18 - 50 or if female \> 50 years old have an estradiol concentration level \>= 30 pg/mL and follicle stimulating hormone level \< 40 mIU/mL, or male between the ages of 18-65 (inclusive). 2. Must have Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, or mantle cell lymphoma and be considered an appropriate candidate for hematopoietic stem cell transplant. 1. Multiple myeloma patients should have had a partial or complete response to chemotherapy. 2. Patients with Hodgkin's disease or non-Hodgkin's lymphoma who achieve a partial response to initial chemotherapy or first or second chemosensitive relapse, achieving a complete or partial response to salvage treatment. Patients in first remission with mantle cell lymphoma, or with intermediate or high grade lymphoma, presenting with high intermediate or high IPI (International Prognostic Index) scores are also eligible. 3. Must be seronegative for hepatitis C and HIV. 4. Must have received prior tetanus immunization 5. Must not have received prior KLH immunization. 6. Must have an ECOG performance status (PS) \<= 1 or Karnofsky PS \>= 70%. 7. Must have creatinine \<= 2.0 mg/dL; ejection fraction \> 45%; carbon monoxide diffusion in the lungs (DLCO) \> 50% of predicted; serum bilirubin \< 1.5 times the upper limit of normal unless Gilbert's syndrome, SGPT \< 3 times normal value. 8. Must be more than 3 weeks from any prior surgery (except for central line placement) and have fully recovered from the effects of surgery. 9. Must have an absolute neutrophil count (ANC) \>= 1,500 µL, platelet count \>= 100,000/µL and hemoglobin \>= 8.0 gm/dL within 21 days prior to randomization. 10. Must be able to return to the clinical site for follow-up visits. 11. Must be able to provide written consent. Exclusion Criteria: 1. Must not have an uncontrolled life-threatening infection (or active infectious process requiring intravenous \[IV\] systemic medical therapy within 1 week prior to study enrollment). 2. Must not have a diagnosed or suspected schistosomiasis infection. 3. Must not have previously received hematopoietic stem cell transplantation. 4. Must not require a tandem transplant. 5. Must not be female with a positive pregnancy test, pregnant, or lactating and breast feeding, or wish to become pregnant during the course of the study. Must agree to use barrier method of contraception. 6. Must not be receiving estrogen or testosterone replacement therapy,phytoestrogen, phyto-testosterone, or oral contraceptives (patients may enroll if oral contraceptives are ceased prior to study entry), or have been administered Depo Provera within 3 months of entering the study. 7. Must not have had prior mediastinal or sternal radiation. 8. Must not have received any investigational drug other than antibiotics within 3 weeks prior to study drug administration or are scheduled to receive an investigational drug during the course of this study. 9. Must not have unstable cardiac arrhythmias, uncontrolled congestive heart failure, history of myocardial infarction (MI) or ischemia, stroke, or embolic events within 6 months before study start. 10. Must not have medical or psychiatric conditions that, in the opinion of the investigator, would compromise the patient's ability to participate in the study. 11. Must not be receiving or plan to receive palifermin (KGF). 12. Must not have a allergy to shellfish. 13. Must not have previously taken a GnRH analog within 18 months. 14. Must not be a woman who has undergone bilateral oophorectomy, or man with orchiectomy.