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Overexpression of CD49f in precursor B‐cell acute lymphoblastic leukemia: Potential usefulness in minimal residual disease detection
Author(s) -
DiGiuseppe Joseph A.,
Fuller Sheila G.,
Borowitz Michael J.
Publication year - 2009
Publication title -
cytometry part b: clinical cytometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 61
eISSN - 1552-4957
pISSN - 1552-4949
DOI - 10.1002/cyto.b.20440
Subject(s) - minimal residual disease , immunophenotyping , flow cytometry , cancer research , cd19 , leukemia , antigen , cell , chemistry , pathology , microbiology and biotechnology , medicine , biology , immunology , biochemistry
Background: The persistence of minimal residual disease (MRD) following therapy is an established prognostic factor in precursor B‐cell acute lymphoblastic leukemia (pB‐ALL). Detection of MRD in pB‐ALL by flow cytometric immunophenotyping requires demonstration of abnormal antigen expression in leukemic B‐cell precursors relative to that of normal B‐cell precursors. The gene encoding CD49f (integrin α‐6) is one of several whose overexpression in pB‐ALL at diagnosis has been associated with the subsequent detection of MRD. However, whether CD49f might be a useful reagent in the immunophenotypic detection of MRD in pB‐ALL has not been evaluated. Methods: We evaluated CD49f expression by 4‐color flow cytometry in normal B‐cell precursors, and in a series of cases of pB‐ALL, both at diagnosis and at intervals following the initiation of therapy. Results: In 10 control marrow samples, CD49f was undetectable or extremely dim in all but a minor subset of normal CD19+ B‐lineage cells, whereas in 11 of 15 cases (73%) of pB‐ALL, CD49f was moderate or bright at diagnosis, and persisted or became brighter after initiation of therapy. MRD detected using CD49f corresponded precisely with that obtained using a standard panel of antibodies, and permitted the detection of leukemic populations comprising as little as 0.02% of cells. Of the four pB‐ALL cases in which CD49f was undetectable or dim at diagnosis, MRD was detected in two; in one of these, CD49f expression was substantially increased in the leukemic cells that persisted following initiation of therapy. Conclusions: CD49f is commonly overexpressed in p‐B‐ALL, and represents a potentially useful marker for the immunophenotypic detection of MRD. © 2008 Clinical Cytometry Society How to cite this article: DiGiuseppe JA, Fuller SG, Borowitz MJ. Overexpression of CD49f in precursor B‐cell acute lymphoblastic leukemia: potential usefulness in minimal residual disease detection. Cytometry Part B 2008.