Immunophenotypic analysis of peripheral blood stem cell harvests from patients with multiple myeloma.
OBJECTIVE
Four-color multiparameter immunophenotyping has recently proven to be an attractive technique for evaluating the plasma cell (PC) compartment since it allows discrimination between myelomatous and normal PC. This study was designed to investigate: i) whether peripheral blood is less contaminated than bone marrow as a source for an autologous transplant; ii) the effect of growth factors on mobilizing myelomatous PC into peripheral blood; iii) the degree of contamination by myelomatous PC in apheresis samples; and iv) whether the number of PC increases during the last days of apheresis.


METHODS
Using 4-color antigen staining we investigated the composition of the PC compartment in 90 apheresis products from 40 patients with MM; in 17 cases bone marrow and peripheral blood samples were also simultaneously evaluated.


RESULTS
(i) All pre-mobilization bone marrow samples analyzed were always contaminated with myelomatous PC whereas only 41% of the post-mobilization peripheral blood samples were contaminated. Moreover, the use of peripheral blood would lead to a reduction of >5x10(5) infused myelomatous PC; (ii) mobilization with cytokines increased the number of circulating PC, generally because of an expansion of the normal PC population; (iii) forty-eight percent of all peripheral blood stem cell harvests were contaminated with myelomatous PC, although normal PC usually represented the predominant population; (iv) no significant changes were observed in the amount of contaminating myelomatous PC during the first three days of apheresis.


CONCLUSIONS
Multiparameter immunophenotyping is a useful approach for investigating the PC compartment in apheresis products.
Mateo
Gema
G
Hematology Department, University of Salamanca, Spain.
Corral
Mercedes
M
Almeida
Julia
J
López-Berges
Consuelo
C
Nieto
maría Jesús
mJ
García-Marcos
Antonia
A
Vázquez
Lourdes
L
del Cañizo
Consuelo
C
Orfao
Alberto
A
San Miguel
Jesús F
JF
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology; D001781:Blood Component Removal / Q000379:methods / Q000706:statistics & numerical data; D001854:Bone Marrow Cells / Q000737:chemistry / Q000187:drug effects / Q000473:pathology; D005260:Female; D006133:Growth Substances / Q000494:pharmacology / Q000627:therapeutic use; D019650:Hematopoietic Stem Cell Mobilization / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000737:chemistry* / Q000187:drug effects / Q000473:pathology; D006801:Humans; D016130:Immunophenotyping / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D010950:Plasma Cells / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D020858:Tissue and Organ Harvesting / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data
D015703:Antigens, CD; D006133:Growth Substances