Correlation between CD117+ myeloma plasma cells and hematopoietic progenitor cells in different categories of
Fanny Pojero1,2, Alessandra Casuccio3, Francesco Di Bassiano4
1Dipartimento di Biopatologia e Biotecnologie Mediche, Universita' degli Studi di Palermo, Corso Tukory 211, 90134 Palermo, Italy.
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.
Insights
Treatment and disease status significantly alter hematopoietic progenitor cell distribution in multiple myeloma patients, particularly those negative for CD117. CD117+ patients show no such treatment-related changes.
Area of Science:
- Hematology
- Immunology
- Oncology
Background:
- Multiple myeloma (MM) is an incurable plasma cell cancer characterized by complex interactions between malignant cells and the bone marrow microenvironment.
- Multiparameter flow cytometry (MFC) enables simultaneous analysis of plasma cells and other bone marrow cells, but integrated data interpretation remains limited.
- Previous research linked CD117 expression on plasma cells to hematopoietic progenitor cell (HPC) distribution in newly diagnosed MM.
Purpose of the Study:
- To investigate the distribution of bone marrow CD34+ HPCs in healthy controls, monoclonal gammopathy of undetermined significance (MGUS) patients, and various MM patient categories (treated, relapsed, responding).
- To analyze these distributions based on CD117 expression on plasma cells.
Main Methods:
- Utilized multiparameter flow cytometry (MFC) to analyze bone marrow samples.
- Categorized patients into healthy controls, MGUS, newly diagnosed MM, responding MM, and progressive/relapsed MM.
- Stratified analyses based on CD117 expression on clonal plasma cells (cPCs).
Main Results:
- In patients with disease progression, CD117-negative (CD117-) individuals showed a lower ratio of CD34+CD19- to CD34+CD19+ cells compared to CD117-positive (CD117+) subjects.
- Among CD117- cases, newly diagnosed patients exhibited distinct HPC distributions compared to responding or progressive MM patients, with significant differences noted between newly diagnosed and responding CD117- patients.
- No significant differences in HPC distribution were observed between treated and untreated CD117+ patients.
Conclusions:
- Treatment administration and response depth/relapse status distinctly regulate CD34+ HPC subset distribution in CD117- and CD117+ multiple myeloma patients.
- These regulatory differences are evident in CD117- patients comparing untreated and treated groups but are undetectable in CD117+ patients.
