Quantification of ZAP-70 expression in chronic lymphocytic leukemia: T/B-cell ratio of mean fluorescence intensity provides stronger prognostic value than percentage of positive cells
Abstract
Expression of ZAP-70 measured by flow cytometry belongs to the most powerful prognostic parameters in chronic lymphocytic leukemia (CLL). However, many technical factors such as setting of the positively treshold may significantly influence results.
Quantification using mean fluorescent intensity (MFI) may eliminate the subjective error which is inevitable in the isotype control method. The aim of the present project was therefore to assess the prognostic significance of ZAP-70 using different methods.
Our results suggest that measurement of ZAP-70 expression in CLL by MFI using T-cells/CLL cells ratio might be the optimal method for accurate prediction of clinical course. Combined analysis of ZAP-70 with CD38 or IgVH mutations status further refined individual patient''s prognosis.