Detection methods of ZAP-70 in chronic lymphocytic leukemia

Abstract

The clinical course of patients with chronic lymphocytic leukemia (CLL) is highly heterogeneous, with some patients experiencing rapid disease progression and others living for decades without requiring treatment. Immunoglobulin heavy chain variable region (IGHV) mutation status is a powerful prognostic factor in patients with CLL. The presence or absence of IGHV mutation status is currently the gold-standard prognostic factor, but this technique is labor-intensive and costly. The expression of ζ-chain-associated protein kinase 70 kDa (ZAP-70), detected by flow cytometry, has been served as a potential surrogate for the absence of IGHV mutation status since 2003. Given the current problems with the standardization of ZAP-70 assessment by flow cytometry, this chapter reviews the analysis of ZAP-70 expression by flow cytometry and the relative experimental conditions using the associated publications for "ZAP-70" and "detection method" on Medline since 2003. Thus, mean fluorescence intensity (MFI) ratio method yielded a more reproducible and easily adaptable method to routine use in the clinical diagnostic laboratory. In conclusion, though ZAP-70 is a valuable prognostic factor in CLL, detection methods of ZAP-70 remain to be fully standardized.

Clinical Monoclonal B Lymphocytosis versus Rai 0 Chronic Lymphocytic Leukemia: A Comparison of Cellular, Cytogenetic, Molecular, and Clinical Features

“…A cutoff of more than 30% was used for ZAP-70 positivity as previously reported (24) and calculated by receiver-operating characteristic analysis as the most suitable ZAP-70 cutoff value for distinguishing IGHV-UM from IGHV-M cases. This cutoff is different from that originally described (around 20%) in previous studies (22,23); the difference could be due to the higher sensitivity of the antibody we used (2F3.2 clone) compared with the 1E7.2 clone, as already suggested by previous studies (25,26); see Wang and colleagues for critical review (27).…”

Quantification of ZAP-70 mRNA by real-time PCR is a prognostic factor in chronic lymphocytic leukemia

“…Therefore, the Although various Xow cytometric ZAP-70 analysis were compared, a standard operating procedure of ZAP-70 expression detection by Xow cytometry has not concluded (Wang et al 2011).…”

“…Measurement of ZAP-70 protein by Xow cytometry presents some technical diYculties (Wang et al 2011) and has not been standardized until now. It can be inXuenced by the gating procedure (Sheikholeslami et al 2006), diVerent technological aspects, and antibody choice (Gibbs et al 2005).…”

A novel diagnostic biosensor for distinguishing immunoglobulin mutated and unmutated types of chronic lymphocytic leukemia

“…There are several methods to quantify ZAP-70 including: polymerase chain reaction (PCR), immunoblotting, immunohistochemistry, fluorescence in-situ hybridization (FISH) analysis and flow cytometry (Slack et al, 2007, Wang et al, 2012, Put et al, 2009, Vroblova et al, 2012, Matthews et al, 2004, Moreno and Montserrat, 2010. 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.…”

“…But the remarkable thing is that, in general, the above methods are costly and time consuming methods compared to simpler methods such as label free electrochemical method. Also, while the presence and absence of IgVH mutation state is currently the gold-standard prognostic factor, but this distinction is labor-intensive and costly (Wang et al, 2012). Generally, analysis of IgVH mutation state is a relatively expensive and time-consuming test with restricted availability.…”