The 2nd Biannual ISHAGE Conference on Applications of Flow Cytometry in Blood and Marrow Stem Cell Transplantation

Abstract

Flow cytometry has long been recognized as an important tool in the determination of cell phenotype in the diagnosis of leukemias, lymphomas and acquired or congenital immunodeficiencies. Its emerging role in all phases of blood and marrow stem cell transplantation were discussed at the first meeting in Atlanta, where it was decided that these techniques were progressing quickly enough to warrant a biannual discussion. With this in mind, the second biannual conference was held in San Diego, in conjunction with the Seventh Annual Conference on Hematopoietic Stem Cell Transplantation. The use of flow cytometric techniques in BM and stem cell transplantation has moved well beyond the initial applications noted above. The use of lymphocyte phenotyping in the follow-up of patients for immunophenotypic reconstitution is well established, but new technology now gives the user a powerful tool for real-time evaluation of immune function which move beyond traditional techniques, such as [H]-thymidine incorporation into DNA following plant mitogen stimulation. T. Fleisher, L. Picker and D. Liebowitz discussed these techniques in presentations in the first plenary session. Phenotypic characterization of leukemia as a supplement to morphologic diagnosis is also a well-established use of flow cytometry. In the past few years, techniques have been developed that allow detection of minimal residual leukemia and lymphoma (MRD) in leukemia patients following highdose chemotherapy and/or radiotherapy and transplantation. With the advent of sophisticated immunotheraputic protocols, techniques for the detection of MRD take on a renewed importance in allowing the possibility of successful intervention prior to overt relapse. M. Stetler-Stevenson and C. Stewart discussed techniques and pitfalls of MRD detection in lymphoma and AML respectively. J. Uhr concluded this session with the presentation of an exciting application of flow cytometry in the detection of carcinoma cells in peripheral blood. The continuing controversy on the use and procedures for flow cytomeric enumeration of CD34þ cells generated a lively discussion at a pre-meeting seminar featuring S. Serke, R. Southerland and C. Stewart. The third plenary session presented other aspects of graft evaluation. S. Serke presented results from the European Survey on laboratory determination of hematopoietic stem and progenitor cells. P. Lansdorp presented a novel application of fluorescent in situ hybridization and surface-antigen staining followed by flow cytometry to evaluate telemere length. This technique appears to be a powerful tool to address questions about the turnover of hematopoietic cells and involvement of telomere length in immune senescence. Finally, M. Watts discussed the use of flow cytometry in determining the progenitor cell requirements for early hematopoietic recovery, with special attention to patients who do not mobilize well. The final plenary session was devoted to regulatory issues. G. Marti gave an overview of the emerging use of quantitative flow cytometry in the determination of the number of antigen-binding sites for dendritic cells, stem cells and antigen specific T cells. L. Harvath then reviewed the Food and Drug Administration document entitled Proposed approach to regulation of cellular and tissue-based products which is a comprehensive, risk-based system of regulation for cellular and tissue-based products, ranging from conventional tissues through innovative cellular and gene therapy products. Her presentation described issues and proposed requirements for hematopoietic stem/progenitor cells derived from peripheral blood and placental/