title: Very Long Term Stability of Mixed Chimerism after Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Hematologic Malignancies.
abstract: The objective of this study is to analyze the evolution of chimerism of all patients transplanted for hematologic malignancies in our unit during a 20-year period, alive without relapse at 1 year after allogeneic hematopoietic stem cell transplantation (HSCT). Chimerism was tested using short tandem repeat polymorphisms after separation into mononuclear cells and granulocytes by Ficoll density gradient centrifugation. Of 155 patients studied, 89 had full chimerism (FC), 36 mononuclear cells mixed chimerism (MNC-MC), and 30 granulocytic MC with or without mononuclear cells MC (Gran-MC). Survival was significantly better in MNC-MC than in Gran-MC patients, with FC patients being intermediate. There was more disease relapse in the Gran-MC group but not in the MNC-MC group as compared to FC. MC was stable up to 21 years in the MNC-MC group and up to 19 years in the Gran-MC group. Of MC patients alive at 10 years, MC persisted in 83% in the MNC-MC and 57% in the Gran-MC groups. In conclusion, mixed chimerism may remain stable over a very long time period. In survivors without relapse at 1 year after HSCT, determining lineage specific chimerism may be useful as outcome differs, MNC-MC being associated with better outcome than Gran-MC.
authors.affiliation: Department of Hemato-Oncology, Hôpital Fribourgeois, 1708 Fribourg, Switzerland.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Levrat
authors.affiliation: Division of Hematology, Geneva University Hospital, 1205 Geneva, Switzerland.
authors.forename: Eddy
authors.initials: E
authors.lastname: Roosnek
authors.affiliation: Division of Hematology, Geneva University Hospital, 1205 Geneva, Switzerland.
authors.forename: Stavroula
authors.initials: S
authors.lastname: Masouridi
authors.affiliation: Transplantation and Cellular Therapy Unit, Paoli-Calmettes Institute, 13009 Marseille, France.
authors.forename: Bilal
authors.initials: B
authors.lastname: Mohty
authors.affiliation: Division of Hematology, Geneva University Hospital, 1205 Geneva, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Ansari
authors.affiliation: Division of Hematology, Geneva University Hospital, 1205 Geneva, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: Villard
authors.affiliation: Division of Hematology, Basel University Hospital, 4056 Basel, Switzerland.
authors.forename: Jakob R
authors.initials: JR
authors.lastname: Passweg
authors.affiliation: Division of Hematology, Geneva University Hospital, 1205 Geneva, Switzerland.
authors.forename: Yves
authors.initials: Y
authors.lastname: Chalandon