CD1d Expression Is Higher In Chronic Lymphocytic Leukemia Patients With Unfavorable Prognosis

Chronic lymphocytic leukemia (CLL) is characterized by a very heterogeneous clinical course, which is slow and indolent in most of the patients, however some patient experience rapid disease progression and anticancer therapy is required shortly after the diagnosis. Many issues in CLL development and progression are still unclear. The functional consequences of CD1d expression on tumour cells are not well understood. However, increasing evidence suggests that they may affect iNKT cells.The role of CD1d expression in CLL immunopathogenesis remains undefined. In this study, we investigated the potential role of CD1d in CLL by analyzing the level of CD1d expression on leukemic B cells in peripheral blood of120 patients and assessed its correlation with prognostic markers such as ZAP-70 and CD38 expression, Rai stages and unfavourable cytogenetic changes.Measuring CD1d expression by flow cytometry and qRT-PCR, we showed lower CD1d molecule and CD1d mRNA expression in B cells of CLL patients than of healthy controls. The frequency of CD1d⁺/CD19⁺ cells, CD1d staining intensity and CD1d transcript levels increased with the disease stage. CD1d expression was positively associated with ZAP-70 and CD38 expressions as well as with unfavourable cytogenetic changes (17p deletion, 11q deletio),. We established the relationship between high CD1d expression and shorter time to treatment and overall survival. The percentage of CD1d⁺/CD19⁺cells inversely correlated with the percentage of iNKT cells. iNKT cells ζ-chain expression was downregulated in the high-CD1d group.These results suggest that high CD1d expression is associated with poor prognosis of CLL and might be involved in disease progression.