ZAP-70 Assay for Clinical Application in CLL

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Folia Histochem Cytobiol. 2005;43(1):19-23.

Modification of immunocytochemical ZAP-70 assay for potential

clinical application in B-cell chronic lymphocytic leukemia.

Bojarska-Junak A, Rolinski J, Kawiak J.

Department of Clinical Immunology, University School of Medicine,

Lublin, Poland. agnieszkajunak@...

The ZAP-70 protein is a member of the Syk/ZAP protein tyrosine kinase

family, normally expressed in T cells and NK cells but not found in

normal, mature B cells. The protein plays a critical role in the

initiation of T-cell signaling.

Leukemic cells from patients with B-cell chronic lymphocytic leukemia

(B-CLL) that expressed nonmutated immunoglobulin V genes were found

to express levels of ZAP-70 protein that were comparable to those

detected in T cells of healthy adults.

The ZAP-70 protein expression can be evaluated by flow cytometry and

may be used as a prognostic marker in B-CLL patients. We modified the

method of immunocytochemical assessment of ZAP-70 expression.

The traditional two-step method with monoclonal anti-ZAP-70 antibody

in the first step followed by FITC-conjugated goat anti-mouse IgG was

changed for one-step method with monoclonal anti-ZAP-70 antibody

labeled by Zenon a Fluor 488.

The method is simple and fast. The major advantage of Zenon labeling

technique is its compatibility with simultaneous staining of surface

antigens. The cells may be earlier immunostained for CD3, CD19 and/or

CD5 to compare of the ZAP-70 kinase expression in B and T cells.

PMID: 15871558 [PubMed - in process]