ZAP-70 Expressed in CLL as Well as Other Blood Cancers

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Am J Clin Pathol. 2004 Oct;122(4):582-7.

ZAP-70 expression in B-cell hematologic malignancy is not limited to

CLL/SLL.

Sup SJ, Domiati-Saad R, Kelley TW, Steinle R, Zhao X, Hsi ED.

Department of Clinical Pathology, Cleveland Clinic Foundation, OH

44195, USA.

ZAP-70 is a tyrosine kinase expressed in normal T cells and NK

(natural killer) 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.

PMID: 15487457 [PubMed - in process]