title: Correlation between CD117+ myeloma plasma cells and hematopoietic progenitor cells in different categories of patients.
abstract: BACKGROUND
  Multiple myeloma (MM) is a neoplastic disorder of plasma cells interesting mainly the elderly. MM remains an incurable disease, mostly because of the strong interplay between clonal plasma cells (cPCs) and bone marrow (BM) microenvironment. Multiparameter flow cytometry (MFC) allows the simultaneous study of the cPC immunophenotype and alterations involving other cells in BM, but rarely these data are interpreted as connected. One exception to this habit are previous studies about relationship between CD117 cPC positivity and hematopoietic progenitor cell (HPC) distribution in newly diagnosed patients. Thus we were interested in verifying the distribution of BM CD34+ HPCs in healthy controls, and monoclonal gammopathy of undetermined significance (MGUS) patients and various categories of responding/relapsing MM subjects divided according to CD117 positivity.
  
  
  RESULTS
  Our data completely agree with precedent reports as regards untreated patients. In the group with progression of disease, CD117- patients exhibited a lower CD34 + CD19-/CD34 + CD19+ ratio vs CD117+ subjects. Among CD117- cases, newly diagnosed patients exhibited differences in distribution of HPCs vs responding myeloma subjects and patients with progressive disease. These differences reached statistical significance comparing CD117- newly diagnosed with CD117- responding cases, as reflected by CD34 + CD19-/CD34 + CD19+ ratio. In turn, no differences emerged comparing CD117+ treated and untreated patients.
  
  
  CONCLUSIONS
  We demonstrate that administration of treatment and depth of reached response/presence of relapse imply a distinct regulation in distribution of CD34+ HPC subsets in CD117- and CD117+ patients. These differences become evident comparing untreated and treated CD117- patients, but they are impossible to detect in CD117+ cases.
authors.affiliation: Dipartimento di Biopatologia e Biotecnologie Mediche, Universita' degli Studi di Palermo, Corso Tukory 211, 90134 Palermo, Italy.|Dipartimento dei Servizi, U.O.S.D. Laboratorio Specialistico Oncologia, Ematologia e Colture Cellulari per Uso Clinico, ARNAS Civico, Piazza Nicola Leotta 4, 90127 Palermo, Italy.
authors.forename: Fanny
authors.initials: F
authors.lastname: Pojero
authors.affiliation: Dipartimento di Scienze per la Promozione della Salute e Materno Infantile "G. D'Alessandro", Universita' degli Studi di Palermo, Via del Vespro 133, 90133 Palermo, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Casuccio
authors.affiliation: U.O.C. di Oncoematologia, ARNAS Civico, Piazza Nicola Leotta 4, 90127 Palermo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Bassiano
authors.affiliation: Dipartimento dei Servizi, U.O.S.D. Laboratorio Specialistico Oncologia, Ematologia e Colture Cellulari per Uso Clinico, ARNAS Civico, Piazza Nicola Leotta 4, 90127 Palermo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Gervasi
authors.affiliation: Dipartimento di Biopatologia e Biotecnologie Mediche, Universita' degli Studi di Palermo, Corso Tukory 211, 90134 Palermo, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Colonna Romano
authors.affiliation: Dipartimento di Biopatologia e Biotecnologie Mediche, Universita' degli Studi di Palermo, Corso Tukory 211, 90134 Palermo, Italy.
authors.forename: Calogero
authors.initials: C
authors.lastname: Caruso
keywords: CD117; Flow cytometry; Hematopoietic progenitor cell; MGUS; Multiple myeloma