CD47 protein expression in acute myeloid leukemia: A tissue microarray-based analysis.
Binding of CD47 to signal regulatory protein alpha (SIRPα), an inhibitory receptor, negatively regulates phagocytosis. In acute myeloid leukemia (AML), CD47 is overexpressed on peripheral blasts and leukemia stem cells and inversely correlates with survival. Aim of the study was to investigate the correlation between CD47 protein expression by immunohistochemistry (IHC) in a bone marrow (BM) tissue microarray (TMA) and clinical outcome in AML patients. CD47 staining on BM leukemia blasts was scored semi-quantitatively and correlated with clinical parameters and known prognostic factors in AML. Low (scores 0-2) and high (score 3) CD47 protein expression were observed in 75% and 25% of AML patients. CD47 expression significantly correlated with percentage BM blast infiltration and peripheral blood blasts. Moreover, high CD47 expression was associated with nucleophosmin (NPM1) gene mutations. In contrast, CD47 expression did not significantly correlate with overall or progression free survival or response to therapy. In summary, a BM TMA permits rapid and reproducible semi-quantitative analysis of CD47 protein expression by IHC. While CD47 expression on circulating AML blasts has been shown to be a negative prognostic marker for a very defined population of AML patients with NK AML, CD47 expression on AML BM blasts is not.
Institute of Pathology, University of Bern, Bern, Switzerland; Department of Oncology, University Hospital Bern, Bern, Switzerland.
Serena
S
Galli
Institute of Pathology, University of Bern, Bern, Switzerland.
Inti
I
Zlobec
Institute of Pathology, University of Bern, Bern, Switzerland; Department of Clinical Research, University of Bern, Bern, Switzerland.
Christian
C
Schürch
Institute of Pathology, University of Bern, Bern, Switzerland.
Aurel
A
Perren
Department of Oncology, University Hospital Bern, Bern, Switzerland; Department of Clinical Research, University of Bern, Bern, Switzerland.
Adrian F
AF
Ochsenbein
Institute of Pathology, University of Bern, Bern, Switzerland; Department of Clinical Research, University of Bern, Bern, Switzerland. Electronic address: yara.banz@pathology.unibe.ch.
Yara
Y
Banz
D051928:CD47 Antigen / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism* / Q000473:pathology; D000090243:Nucleophosmin; D011379:Prognosis; D046888:Tissue Array Analysis
D051928:CD47 Antigen; C497894:CD47 protein, human; C000716967:NPM1 protein, human; D000090243:Nucleophosmin
Acute myeloid leukemia; Bone marrow; CD47; Tissue microarray