title: Pitfalls and limitations of ZAP-70 detection in chronic lymphocytic leukemia.
abstract: Zeta-associated protein of 70 kDa (ZAP-70) is a tyrosine kinase that plays a role in signal transduction from the T-cell receptor. ZAP-70 is expressed in normal T-cells and NK-cells. Increased expression of ZAP-70 has been identified in chronic lymphocytic leukemia (CLL). CLL patients  with increased ZAP-70 expression have significantly worse prognosis in terms of both progression-free survival and overall survival. There are several methods to quantify ZAP-70: polymerase chain reaction (PCR), immunoblotting, immunohistochemistry, and flow cytometry. Use of flow cytometry  for ZAP-70 detection seems to be advantageous as this technique enables us to assess the presence of ZAP-70 separately on CLL clone, T-cells, and NK-cells. On the other hand, detection of ZAP-70 by flow cytometry is substantially influenced by many variables. The principal drawback of flow  cytometry is the absence of consensus regarding selection of optimal anti-ZAP-70 antibody, fluorochrome conjugate, the most reliable staining technique, and optimal positivity threshold. This article summarizes pitfalls of flow cytometric analysis of ZAP-70 in CLL.
authors.affiliation: Faculty of Medicine and University Hospital, Charles University, Hradec Kralove, Czech Republic. vroblvla@fnhk.cz
authors.forename: V
authors.initials: V
authors.lastname: Vroblova
authors.forename: L
authors.initials: L
authors.lastname: Smolej
authors.forename: J
authors.initials: J
authors.lastname: Krejsek
mesh_terms: D018572:Disease-Free Survival; D005434:Flow Cytometry / Q000379:methods*; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000379:methods; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction; D015996:Survival Rate; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D009363:Neoplasm Proteins; D011948:Receptors, Antigen, T-Cell; D051746:ZAP-70 Protein-Tyrosine Kinase