1493

CTLA4

CD|CD152|CELIAC3|CTLA-4|GRD4|GSE|ICOS|IDDM12;cytotoxic T-lymphocyte-associated protein 4;CTLA4;cytotoxic T-lymphocyte-associated protein 4

CD152 isoform|celiac disease 3|cytotoxic T lymphocyte associated antigen 4 short spliced form|cytotoxic T-lymphocyte antigen 4|cytotoxic T-lymphocyte protein 4|cytotoxic T-lymphocyte-associated antigen 4|cytotoxic T-lymphocyte-associated serine esterase-4

2q33

protein-coding

CTLA-4 is a key factor in regulating and maintaining self tolerance, providing anegative signal to the T cell and thus limiting immune responses. Several polymorphisms within the CTLA-4 gene have been associated with an increased riskof developing autoimmune diseases and, very recently, with susceptibility to human cancer. Acute lymphoblastic leukemia is a clonal disorder of lymphoid progenitors representing the most frequent malignancy of childhood. Here, we show the presence at significantly elevated levels of a circulating soluble form of CTLA-4 in 70% of B-ALL pediatric patients with active disease, the positive correlation between the percentage of leukemic B lymphocytes and the amount of serum sCTLA-4, and the expression of sCTLA-4 transcript by B cells in patients. Finally, a correlation between CD1d expression (a negative prognostic marker) and the sCTLA-4 in B-ALL patients was observed. This suggests a possible role of this soluble molecule as a marker of progression or severity of the neoplastic disease.