The relationship between monoclonal myeloma precursor B cells in the peripheral blood stem cell harvests and the clinical response of multiple myeloma patients.
The aim of this study was to determine the presence of monoclonal myeloma precursor B cells in peripheral blood stem cell harvests and to investigate their role in the clinical outcome of multiple myeloma patients. A total of 39 multiple myeloma patients were treated with a sequential therapy including double high-dose melphalan therapy followed by a double transplant procedure. The apheresis products for the second transplant were purged using a panel of four or five different mouse monoclonal antibodies against B-cell antigens (CD10, CD19, CD20, CD22 and CD37). In 19/39 patients a tumour-specific CDR III signal was identified in the diagnostic bone marrow. Gene scan analysis after CDR III PCR of the magnetic bead isolated B-cell fraction from the apheresis products in these 19 patients revealed three different patterns: 32% of patients had a predominantly monoclonal B-cell population; 63% of patients had an identifiable monoclonal signal within an oligoclonal B-cell population. In only 1/19 patients were no monoclonal B cells identified in the B-cell population of the apheresis product. A correlation between the clonal pattern and the clinical response after sequential chemotherapy was found. Patients with a predominance of monoclonal myeloma or myeloma precursor B cells had an early relapse or achieved a minimal response or a partial remission. Patients with an oligo- and/or polyclonal pattern achieved a high percentage of partial as well as complete remissions.
Mitterer
M
M
Department of Haematology and Bone Marrow Transplantation Centre, Bozen/Bolzano, Italy. mitman@dnet.it
Oduncu
F
F
Lanthaler
A J
AJ
Drexler
E
E
Amaddii
G
G
Fabris
P
P
Emmerich
B
B
Coser
P
P
Straka
C
C
D000328:Adult; D001402:B-Lymphocytes / Q000473:pathology*; D005260:Female; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D008297:Male; D008558:Melphalan / Q000627:therapeutic use; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology* / Q000628:therapy; D010950:Plasma Cells / Q000473:pathology; D016896:Treatment Outcome
D008558:Melphalan