High-sensitivity flow cytometric analysis for the evaluation of systemic mastocytosis including the identification of a new flow cytometric criterion for bone marrow involvement.
We used high-sensitivity flow cytometry to assess 93 bone marrow aspirates for involvement by systemic mastocytosis. Aberrant CD2/CD25 expression by CD117-gated mast cells was seen in 34 samples (37%), with the majority of mast cells expressing both markers (n = 23; 68%). In 24 cases, a discrete population of mast cells within the CD117-bright gate correlated with a positive morphologic finding in the biopsy, even in the absence of an aberrant immunophenotype. A discrete CD117-bright population, when considered a positive criterion, increases analytic sensitivity from 77% to 95%, exceeding the sensitivity of morphologic analysis (69% for aspirate and 85% for biopsy). We conclude that flow cytometry is a sensitive and specific test for the presence of systemic mastocytosis, particularly when the presence of a discrete CD117-positive mast cell population is regarded as a diagnostic criterion.
Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Amory 3, Boston, MA 02115, USA. opozdnyakova@partners.org
Olga
O
Pozdnyakova
Svetlana
S
Kondtratiev
Betty
B
Li
Karry
K
Charest
David M
DM
Dorfman
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000473:pathology; D034721:Mastocytosis, Systemic / Q000175:diagnosis* / Q000276:immunology; D008875:Middle Aged