The significance of soluble HLA-G plasma levels as well as messenger HLA-G for B-cell chronic lymphocytic leukemia (B-CLL)

The immunosuppression accompanies B-cell chronic lymphocytic leukemia (B-CLL) but might be also responsible for disease progression by enabling CLL cells to escape from the immunosurveillance. Some particles involved in the regulation of an immune system might represent prognostic value for B-CLL. Recently we found no correlation between HLA-G on messenger and protein level, suggesting that HLA-G is released in soluble form. To confront this hypothesis we characterized soluble HLA-G (sHLA-G) by the prognostic factors in the first cohort of 34 CLL patients. No correlation was observed between sHLA-G levels in ZAP-70(+) and ZAP-70(−) CLL as well as in CD38(+) CLL and CD38(−) CLL patients. Next, we wondered whether gene expression of HLA-G, which represent the whole HLA-G pool in the cell, posses prognostic value for CLL. In the second cohort of 41 CLL patients we assessed messenger levels of HLA-G by the strongest prognostic factors in CLL including cytogenetics, IgVH mutational status, ZAP-70 as well as CD38. No changes of HLA-G expression levels were found in different CLL groups characterized by IgVH gene mutational status, ZAP-70 as well as CD38. We observed no differences in expression of HLA-G in various cytogenetic groups of CLL including del17p, del13q, del11q, +8q, +3q, del14q and del6q when compared to those with normal karyotype or with 12+. Both, mRNA expression of HLA-G and levels of its soluble form in plasma bring no additional prognostic value for B-CLL patients.