title: Negative immunomagnetic ex vivo purging combined with high-dose chemotherapy with peripheral blood progenitor cell autograft in follicular lymphoma patients: evidence for long-term clinical and molecular remissions.
abstract: The feasibility and efficacy of a novel immunomagnetic ex vivo negative purging method was evaluated on peripheral blood progenitor cells (PBPC) from 13 non-Hodgkin's lymphoma patients (eight follicular, FL; three mantle cell, MCL; two FL with histologic transformation). A peculiar feature of the study was the collection of PBPC after prolonged tumor debulking. Our method included a stem cell enrichment phase followed by cell incubation with anti-B cell MoAbs (anti-CD19, CD20, CD22, CD23), addition of immunobeads, and then positive cell removal by passage on a Max-Sep (Baxter Immunotherapy) cell separator. Engraftment was rapid and stable. Hematological values were assessed 1 and 2 years after the autograft. Purging efficacy was molecularly assessed in a panel of 11 patients who showed persistence of PCR-detectable lymphoma cells on PBPC harvests despite intensified chemotherapeutic debulking. PCR-negativity was obtained in vitro and persisted in vivo after autograft in three FL patients; five more FL patients, whose purged PBPC were PCR+, converted to stable (3 patients) or fluctuating (two patients) PCR negativity after autograft. MCL patients never reached PCR negativity. Thus, ex vivo purging may have a role for FL patients harvesting PCR-positive PBPC after intensified chemotherapy. In contrast, the addition of ex vivo purging seems to be of little if any benefit for MCL patients.
authors.affiliation: Dipartimento di Medicina e Oncologia Sperimentale, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Tarella
authors.forename: P
authors.initials: P
authors.lastname: Corradini
authors.forename: M
authors.initials: M
authors.lastname: Astolfi
authors.forename: P
authors.initials: P
authors.lastname: Bondesan
authors.forename: D
authors.initials: D
authors.lastname: Caracciolo
authors.forename: C
authors.initials: C
authors.lastname: Cherasco
authors.forename: M
authors.initials: M
authors.lastname: Ladetto
authors.forename: F
authors.initials: F
authors.lastname: Giaretta
authors.forename: I
authors.initials: I
authors.lastname: Ricca
authors.forename: U
authors.initials: U
authors.lastname: Vitolo
authors.forename: A
authors.initials: A
authors.lastname: Pileri
authors.forename: D
authors.initials: D
authors.lastname: Ferrero
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D018189:Immunomagnetic Separation; D008224:Lymphoma, Follicular / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012074:Remission Induction / Q000379:methods*; D015203:Reproducibility of Results; D013997:Time Factors; D014182:Transplantation, Autologous