No abstract

Fifty patients with recurrent Hodgkin's disease have been treated with high-dose therapy followed by autologous bone marrow transplantation. Forty-one patients had extranodal sites of relapse and 31 patients had constitutional symptoms. Two patients had been treated with mechlorethamine, vincristine, procarbazine, and prednisone (MOPP), lomustine, vinblastine, procarbazine, and prednisone (CcVPP), and radiation; 16 patients with MOPP, doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD), radiation, and lomustine, etoposide, and prednisone (CEP); 20 patients with alternating MOPP/ABVD, and 12 patients with alternating MOPP/ABVD followed by CEP and radiation. Eighteen patients had progressive disease during alternating MOPP/ABVD protocol alone or during conventional salvage therapy; 32 patients had had a complete remission with first-line therapy but later relapsed, 25 of them having received conventional salvage therapy; 12 achieved no response or progression ("resistant-relapse" patients); and 13 responded partially or completely ("sensitive-relapse" patients). Complete remission occurred in 24 patients (48%) with a median duration of 24 months and 16 patients (32%) achieved partial response with a median duration of 9 months, for an overall response rate of 80%. Ten patients failed to respond and died in progressive disease 1 to 10 months (median, 6 months) after transplantation. Toxicity was significant including infections (20%), liver enzymes and alkaline phosphatase elevations (100%), and carmustine lung toxicity (7%). There were two treatment-related deaths; one patient died of Pseudomonas aeruginosa septicemia and another patient died of cerebral hemorrhage. These results validate the procedure of high-dose therapy followed by autologous bone marrow transplantation in inducing remission in these advanced, highly-treated patients. Clearly, the question of whether high-dose therapy and transplantation will eventually supersede new conventional salvage therapies will be addressed after controlled clinical studies.

In the attempt to induce graft-vs-host disease (GVHD) in patients undergoing autologous bone marrow transplantation (ABMT) or blood stem cell transplantation (BSCT), 12 consecutive patients received cyclosporin A (CyA) post transplant. CyA was given at a dose of 1.5 mg/kg/day intravenously for 28 days, starting on the day of transplant. Histologically proven acute GVHD of the skin occurred in seven patients 9-14 days after ABMT and lasted 7-11 days. CyA-induced GVHD after ABMT resembles mild GVHD after allogeneic bone marrow transplantation (BMT). Although the preliminary data reported here show that it is possible to induce GVHD in patients undergoing ABMT, it is not yet known whether GVHD after ABMT will have an antitumor activity.

Marrow cells were exposed to the LNL6 or G1N safety-modified variants of the N2 retrovirus, which contain the G418 bacterial resistance gene neo. The frequency of acquisition of the G418 resistance phenotype following exposure to LNL6 or G1N was compared among hematopoietic progenitor cells from the marrow of patients with chronic phase chronic myelogenous leukemia (CML), blast crisis CML, or from nonleukemic individuals. Under the conditions of our experiments, the myeloid committed progenitor cells from 3 of 6 nonleukemic individuals, 9 of 18 chronic-phase CML patients, and 2 of 4 blast crisis CML patients acquired resistance to at least 1 mg/ml G418 following incubation with cell-free supernatants from the PA317 LNL6 or PA317 G1N producer cell lines. Ten of the 32 colonies growing up in 0.8 mg/ml G418 from chronic-phase marrow exposed to LNL6 were shown to contain the neo gene by polymerase chain reaction (PCR) assay of DNA. These results were consistent with estimates of the transduction frequency based on acquisition of resistance to G418 as the number of colonies growing under G418 selection was always greater at 0.8 mg/ml G418 than at higher concentrations of G418 (1.0-1.4 mg/ml). The average transduction frequency at each G418 concentration (1.0, 1.2, and 1.4 mg/ml) in cells from blast crisis CML cells ranged from 2 to 14%, as measured by acquisition of G418 resistance. Chronic-phase CML showed slightly lower average frequencies of transduction (0.6-2.8% of the colonies are G418 resistant). The average transduction frequency of cells from nonleukemic marrow was as high as that seen from the marrow of chronic-phase CML individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

In this study we determined whether human stromal cells could be engineered with a retroviral vector carrying the interleukin 7 (IL-7) gene and investigated the effects on T cells in vitro and in vivo in a murine model. Transduced mesenchymal cells strongly express CD90 (98.15%), CD105 (87.6%), and STRO-1 (86.7%). IL-7 production was 16.37 (+/-2 SD) pg/ml, which remained stable for 60 days. In vitro-immunoselected naive T cells maintained the CD45RA+ CD45RO- naive phenotype (4.2 times more than controls) after 7 days of culture with IL-7-engineered stromal cells. The apoptosis rate (4.7%) of the naive T cells cultured with transduced stromal cells overlapped with that of freshly isolated cells. Immunohistological analysis detected stromal cells in bone marrow, spleen, and thymus. Cotransplantation of IL-7-engineered stromal cells with CD34+ cells improved engraftment in terms of CD45+ cells and significantly increased the CD3+ cell count in peripheral blood, bone marrow, and spleen. These data demonstrate the following: (1) human stromal cells can be transduced, generating a normal layer; (2) transduced stromal cells in vitro maintain the naive T cell phenotype; and (3) IL-7-transduced stromal cells in vivo home to lymphoid organs and produce sufficient IL-7 in loco, supporting T cell development in a cotransplantation model. Because of their efficient cytokine production and homing, IL-7-engineered stromal cells might be an ideal vehicle to hasten immunological reconstitution in T cell-depleted hosts.