The clinical significance of ZAP-70 and CD38 expression in B-cell chronic lymphocytic leukaemia

Hus, Iwona; Podhorecka, Monika; Bojarska‐Junak, Agnieszka; Roliński, Jacek; Schmitt, Michael; Sieklucka, Małgorzata; Wąsik-Szczepanek, Ewa; Dmoszyńska, Anna

doi:10.1093/annonc/mdj120

Cited by 75 publications

(74 citation statements)

References 21 publications

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“…The levels of ZAP-70 observed in our reporting system (negative, positive, and intermediate) is also reported in the literature with respect to CD38 levels and may represent a continuum as noted by other groups (4,5,(16)(17)(18)(19)(20). This finding would be best addressed in a clinical trials setting by following the ''intermediate'' patients to see whether they convert to a positive state.…”

Section: Discussionsupporting

confidence: 81%

A standardized ZAP‐70 assay—Lessons learned in the trenches

Shults

Miller²,

Davis³

et al. 2006

Cytometry Part B Clinical

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Background: The disease of chronic lymphocytic leukemia (CLL) has been shown to exhibit varying clinical outcomes based on reported laboratory parameters. One of these parameters involves the measurement of the protein levels of zeta-associated protein (ZAP-70) in CLL cells. A standardized assay has not yet reached consensus in the clinical cytometry community.Methods: We developed a system using the 8-peak Rainbow beads as our fluorescence calibrator along with a fixed cell control. Using a panel of CD19-PE, CD5-FITC, and ZAP-70-Alexa 647, we stained normal whole blood, and blood and bone marrow from patients with CLL to determine the level of ZAP-70 expression in T-cell, B-cell, and CLL-cell populations. ZAP-70 expression was reported in molecules equivalent fluorescence (MEFL) based on the calibration of the flow cytometer with the 8-peak Rainbow beads.Results: Daily assay performance as well as operating MEFL defined ranges for ZAP-70 detection in CLL were developed. A rank-order, nonparametric approach to reference ranges was used to assign a cutoff for ''negative'' as well as ranges for ''intermediate'' and ''positive'' staining using T and B cells from a pool of 50 normal subjects, and CLL cells from 395 patients. The assay was validated in a multi-institutional study and has demonstrated correlation with published techniques. Since its initial development, the assay has been implemented at two additional laboratory sites and has been shown to produce reproducible, correlated data at all sites.Conclusions: Strict adherence to standardization can yield an assay that is predictable, reliable, and reproducible as well as capable of multisite implementation. The Rainbow beads provide a common platform for system calibration. The fixed cell culture controls provide a common target to test antibody. The final level of control tests the sensitivity of ZAP-70 detection in a normal peripheral blood sample stained along with the submitted CLL patients. The acceptance/rejection of test results must meet all three levels of control before patient results are reported. q

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Section: Discussionsupporting

confidence: 81%

A standardized ZAP‐70 assay—Lessons learned in the trenches

Shults

Miller²,

Davis³

et al. 2006

Cytometry Part B Clinical

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“…The expression of ZAP-70 in peripheral blood lymphocytes depends on the cell lineage, the highest levels of ZAP-70 being observed in NK and T cells, while the expression on B cells is low or absent, the assessment of ZAP-70 in neoplastic CLL B-cells by flow cytometry implies therefore multiparametric stainings to independently identify CLL B-cells from normal residual T and NK cells. For this reason, antigens able to recognize CLL B-cells and both T and NK lymphocytes are used in combination with an intracellular staining for the ZAP-70 protein (20), and this technique is likely to be simplified by using directly labeled anti-ZAP-70 monoclonal antibodies and/or fluorochrome-conjugated secondary antibodies specifically recognizing the isotype of the anti-ZAP-70 monoclonal antibody (23,24). In our study it was also found that there was a very good correlation between ZAP-70 expression and IgV H mutations and, not surprisingly, that ZAP-70 had a prognostic value equivalent to that of IgV H mutations (20).…”

Section: Zap-70 Expressionmentioning

confidence: 99%

Clinical implications of ZAP‐70 expressionin chronic lymphocytic leukemia

Bosch

Muntañola

Giné

et al. 2006

Cytometry Part B Clinical

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“…However, they found more significant differences between ZAP-70 positive and ZAP-70 negative patients in CLL poor prognosis parameters (stage of disease, WBC, lymphocytosis, and LDH levels) than between CD38 positive and negative patients. In addition, in their study, ZAP-70 expression appeared to be more relevant than CD38 expression in defining cases of CLL responding and not responding to first line chemotherapy (40).…”

Section: Considerations For the Combined Measurement Of Cd38 And Zap-70mentioning

confidence: 88%