ZAP-70 expression in B-cell hematologic malignancy is not limited to CLL/SLL.
ZAP-70 is a tyrosine kinase expressed in normal T cells and NK cells. Expression of ZAP-70 has been associated with poor prognosis in B-cell chronic lymphocytic leukemia and might be a surrogate marker for immunoglobin heavy chain (IGH) mutational status in that disease. Little is known about ZAP-70 expression in other hematologic malignant neoplasms. We examined 446 specimens representing a range of hematopoietic malignant neoplasms for ZAP-70 expression by immunohistochemical analysis. As expected, most T cell-lineage disorders and a subset of small lymphocytic lymphomas were positive. IGH mutational status corresponded to ZAP-70 expression in a small subset of small lymphocytic lymphoma cases subjected to sequence analysis. Of note, however, ZAP-70 was expressed in a minority of other types of B-cell lymphomas, including precursor B-cell acute lymphoblastic leukemia, diffuse large B-cell lymphoma, mantle cell lymphoma, and very rare cases of classic Hodgkin lymphoma. Immunohistochemical analysis represents an alternative method for assessing ZAP-70 expression and reveals that other B-cell malignant neoplasms express ZAP-70.
Department of Clinical Pathology, Cleveland Clinic Foundation, OH 44195, USA.
Stephen J
SJ
Sup
Rana
R
Domiati-Saad
Todd W
TW
Kelley
Roxanne
R
Steinle
Xinyu
X
Zhao
Eric D
ED
Hsi
D015153:Blotting, Western; D006801:Humans; D007150:Immunohistochemistry; D019169:Jurkat Cells; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000032:analysis*; D051746:ZAP-70 Protein-Tyrosine Kinase
D011505:Protein-Tyrosine Kinases; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human