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In the use of autologous PBPC transplantation in patients with multiple myeloma, contamination of PBPC with myeloma cells is commonly observed. Enrichment for CD34+ cells has been employed as a method of reducing this contamination. In this study the reduction of myeloma cells in PBPC was accomplished by the positive selection of CD34+ cells using immunomagnetic bead separation (Isolex 300 system). PBPC were mobilized from 18 patients using cyclophosphamide (4.5 g/m2) and G-CSF (10 μg/kg/day). A median of two leukaphereses and one selection was performed per patient. The median number of mononuclear cells processed was 3.50 × 1010 with a recovery of 1.11 × 108 cells after selection. The median recovery of CD34+ cells was 48% (range 17–78) and purity was 90% (29–99). The median log depletion of CD19+ cells was 3.0. IgH rearrangement, assessed by PCR, was undetectable in 13 of 24 evaluable CD34+ enriched products. Patients received 200 mg/m2 of melphalan followed by the infusion of a median of 2.91 × 106/kg CD34+ cells (1.00–16.30). The median time to absolute neutrophil count >0.5 × 109/l was 11 days, and sustained platelet recovery of >20 × 109/l was 14 days. We conclude that immunomagnetic-based enrichment of CD34+ cells results in a marked reduction in myeloma cells without affecting engraftment kinetics. [ABSTRACT FROM AUTHOR]

Between October 1991 and May 1994, 42 patients were treated with cyclophosphamide, thiotepa, and total body irradiation followed by an allogeneic transplantation of marrow depleted of T cells with soybean agglutinin and E-rosetting. Patients included in this study had acute myelogenous leukemia (13), chronic myelogenous leukemia (12), acute lymphocytic leukemia (nine), Hodgkin's disease or non-Hodgkin's lymphoma (four), multiple myeloma (three), or myelodysplastic syndrome (one). The mean age was 34 (range 8 to 51 years). Nineteen patients had a matched sibling donor and 18 received marrow from 6/6 matched unrelated donors while five received transplants from unrelated donors disparate at one DR locus (5/6 match). Time to granulocyte engraftment (AGC > or = 500/mm3) occurred at a mean of 16.5 days for related and 11.4 days for unrelated transplant recipients, and was related to the increased use of G-CSF in the unrelated population. There was no correlation with number of mononuclear cells, T cells, or CD34-positive cells infused, the rate of engraftment or the incidence of transplant complications. Multivariate analysis determined that G-CSF administration and a diagnosis other than ALL were the only factors associated with a faster rate of engraftment. Patients receiving unrelated donor transplants, those with ALL, or those who had a low T cell number infused (< or = 8.0 x 10(3) cells/kg) experienced delayed hospital discharge. The regimen resulted in excellent rates of engraftment (95.2%) with only one failure to engraft and one graft rejection. The incidence of grade III-IV acute graft-versus-host disease was 0% with sibling and 26.1% with unrelated donors. There were no cases of veno-occlusive disease. Fifty percent of patients are alive with a mean follow-up of 26.4 months. We conclude that this regimen is well tolerated and results in excellent engraftment with a low incidence of severe graft-versus-host disease and few therapy-related toxicities.

A 29-year-old woman underwent a T cell-depleted unrelated donor transplant for CML in chronic phase. Sixty-three days after marrow infusion, the patient developed fevers and generalized lymphadenopathy. Lymph node biopsy was consistent with monoclonal EBV-associated immunoblastic lymphoma for which the patient received 10(5) CD3-positive donor leukocytes per kilogram. Six days after leukocyte infusion the patient developed mental status changes without focal neurological deficit. MRI revealed no mass lesions. Cerebral spinal fluid revealed a white blood cell count of 1650 cells/mm3 which were shown to be T lymphocytes of donor origin. The CSF was tested and found to be PCR positive for EBV virus interval repeat 1 sequence (IR1). The lymphocytosis and mental status changes resolved without specific intervention. Subsequently she developed marrow aplasia, which was believed to be secondary to the infusion of donor leukocytes. Possible mechanisms for these two previously unreported side-effects of donor leukocyte infusion are discussed.

Thirty-three patients with germ cell cancer (GCT) recurrent after two cisplatin-based regimens or cisplatin refractory (progression within 4 weeks of the last dose of cisplatin) were enrolled in a trial to establish the maximum tolerated doses (MTD) of carboplatin and etoposide given in combination with ABMT for two cycles. BM harvest of > or = 2 x 10(8) nucleated cells/kg preceded two cycles of therapy. Each agent was dose escalated, carboplatin from 1650 mg/m2 to 2100 mg/m2 and etoposide from 1200 mg/m2 to 2250 mg/m2 per cycle in successive cohorts. Twenty patients completed two cycles, 13 underwent only one due to: early death (4), toxicity (2), and progressive disease (6). There were four CR, three of whom achieved NED status with surgery, 14 PR, of whom eight have progressed. Four patients with stable disease and seven PD have died with a median survival of 6 months. There were six treatment-related deaths, four on course 1 and two on course 2. Causes of death on course 1 were: CNS hemorrhage (1), multiorgan failure (3); and on course 2: sepsis (1) and sudden death (1). Severe but reversible mucositis, transaminase and creatinine elevations were observed at the highest dose level. Three of five patients treated at this dose level had severe neurologic toxicity, manifested by both peripheral neuropathy and ototoxicity. The MTD in this patient population was carboplatin 2100 mg/m2 and etoposide 2250 mg/m2 on each of two cycles of therapy. Neurologic and mucosal toxicity were dose limiting.