Heterogeneity among the non-Hodgkin's lymphomas. Implications for autologous bone marrow transplantation with in vitro purging using monoclonal antibodies

Bone marrow metastases

This article discusses the clinical significance of bone marrow metastases and the current methods being used to detect tumor cells in marrow. The strategies being investigated for eradicating cancer cells from marrow in patients receiving hematopoietic cell autografts also are reviewed.

Purging of autografts: methods and clinical significance

High-dose chemoradiotherapy with autologous haematopoietic progenitor cell support is being used with increasing frequency to treat patients with a variety of malignancies. The most common reason for the ultimate failure in patients treated with high-dose therapy with stem cell support is not lack of engraftment, toxicity of therapy, or infection, but rather relapse of disease. There is solid evidence that reinfusion of autografts containing clonogenic tumour cells can contribute to relapse and influence patient outcome after high-dose treatment. In patients undergoing high-dose treatment, tumour cell contamination can be observed in histologically normal bone marrow or peripheral blood by sensitive micrometastatic detection techniques. Consequently, methods for detection of minimal residual disease in the autografts, together with techniques to remove tumour cells from the harvest are considered to be important in patients receiving high-dose therapy with stem cell support.

Antibody mediated targeting of radioisotopes, drugs and toxins in diagnosis and treatment

The recent resurgence of interest in site specific delivery of radioisotopes, chemotherapeutic drugs and toxins for the diagnosis and treatment of cancer, and for the selective manipulation of the immune system, can be directly related to the need for improved diagnosis and the fact that for many cancers, for example lung, colon and gastric, the conventional treatments of surgery, radiotherapy and chemotherapy have reached a plateau in terms of the number of patients cured. To date, because of their specificity, the major emphasis has been on the use of antibodies as carriers and extensive in vitro, in vivo preclinical and clinical evaluation is underway. The aim of this article is to review recent progress, highlight avenues being explored to overcome limitations and to indicate new approaches that are evolving in antibody mediated targeting.

The elimination of malignant B lymphocytes from human bone marrow using monoclonal antibodies DLC-48 and LN-1 and human serum: a preclinical study

Monoclonal antibodies DLC-48 and LN-1 were evaluated for use in purging malignant lymphoma cells from human bone marrow. Using a 51Cr-release assay and sensitive clonogenic assay for the SU-DHL-2 and -4 cell lines, it was established that greater than four logs of malignant lymphoid cells can be eliminated from human bone marrow autografts with three treatments of antibody and autologous human serum at a final cell concentration of 1 X 10(7) cells/ml. A combination of DLC-48 and LN-1 was more effective than either antibody alone. Treatment with antibody and autologous serum had no effect on the growth of human hematopoietic progenitor cells. The clinical effects of marrow treatment with DLC-48 and LN-1 will be evaluated in upcoming clinical trials.