Investigations using DNA microarrays (91) have shown that CLL cells exhibit a characteristic gene expression profile in which a small subset of genes, including ZAP-70, IM1286077, and C-type lectin, correlates with the mutational status of IgVH genes (91,92). ZAP-70, a member of the Syk/ZAP-70 protein tyrosine kinase family, is normally expresed in T cells and NK cells and plays a critical role in the initiation of T-cell signalling (93,94). Crespo et al. (95) and Wiestner et al. (96) demonstrated that among patients with CLL, expression of ZAP-70, as detected by flow-cytometric analysis or RT-PCR, correlated with IgVH mutational status, disease progression, and survival. Thus, ZAP-70 expression analysis is able to identify a subgroup of patients in Binet A stage with adverse prognosis (Fig. 3). As opposed to CD38 expression, ZAP-70 expression does not change over the time. Also ZAP-70 can be studies by cytofluorometry, which makes of this marker a more convenient parameter than IgVH mutations. For these reasons, ZAP-70 expression analysis should be included in the diagnositc workup of patients with CLL (95).
Was this article helpful?