Premium
MFI ratio estimation of ZAP‐70 in B‐CLL by flow cytometry can be improved by considering the isotype‐matched antibody signal
Author(s) -
MARQUEZ M.E.,
DEGLESNE P.A.,
SUAREZ G.,
ROMANO E.
Publication year - 2011
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/j.1751-553x.2010.01263.x
Subject(s) - flow cytometry , isotype , antibody , signal (programming language) , immunology , biology , microbiology and biotechnology , computer science , monoclonal antibody , programming language
Summary Introduction: The IgV H mutational status of B‐cell chronic lymphocytic leukemia (B‐CLL) is of prognostic value. Expression of ZAP‐70 in B‐CLL is a surrogate marker for IgV H unmutated (UM). As determination of IgV H mutational status involves a methodology currently unavailable for most clinical laboratories, it is important to have available a reliable technique for ZAP‐70 estimation in B‐CLL. Flow cytometry (FC) is a convenient technique for this purpose. However, there is still no adequate way for data analysis, which would prevent the assignment of false positive or negative expression. Methods: We have modified the currently most accepted technique, which uses the ratio of the mean fluorescent index (MFI) of B‐CLL to T cells. The MFI for parallel antibody isotype staining is subtracted from the ZAP‐70 MFI of both B‐CLL and T cells. We validated this technique comparing the results obtained for ZAP‐70 expression by FC with those obtained with quantitative PCR for the same patients. Results: We applied the technique in a series of 53 patients. With this modification, a better correlation between ZAP‐70 expression and IgV H UM was obtained. Conclusions: Thus, the MFI ratio B‐CLL/T cell corrected by isotype is a reliable analysis technique to estimate ZAP‐70 expression in B‐CLL.