Frequent abnormalities of the immune system in gliomas and correlation with the WHO grading system of malignancy

Phenotypical analysis, relation to malignancy and prognostic relevance of ICOS+T regulatory and dendritic cells in patients with gliomas

“…In accordance with the relevant literature (Fecci et al, 2006;Gousias et al, 2010), our patients with glioblastomas demonstrated reduced absolute counts of CD4+ lymphocytes as well as an increased fraction of T regs/CD4+ lymphocytes. In addition, we describe for the first time T regs expressing ICOS in patients with brain tumors.…”

“…Reduced numbers of CD4+ cells and an increased fraction of inhibitory T regulatory cells (T regs)/CD4+ cells (Fecci et al, 2006;Gousias et al, 2010) contribute significantly to the well documented impairment of cellular immunity in patients with malignant gliomas (Tada and de Tribolet, 1996;Dix et al, 1999;Zisakis et al, 2007). T regs are physiologically responsible for the immune homeostasis and the maintenance of self-tolerance through inhibition of autoreactive responses (Erdman and Poutahidis, 2010;Mougiakakos et al, 2010;Sakaguchi et al, 2010;Wan, 2010;Wilke et al, 2010).…”

Immune Responses to Tumours in the CNS

“…Again, this phenomenon has been studied most extensively in patients with gliomas and glioblastomas. Patients with glioblastomas are reported to suffer from a decreased systemic activity of their immune system (Gousias et al, 2010), a phenomenon that is ascribed to the immunosuppressive effect of cytokines released by the tumour cells. More precisely, reduced cellular immune responses in brain tumour patients were reported with profound depression of CD4 + helper lymphocytes.…”

An algorithm for chemotherapy treatment of recurrent glioma patients after temozolomide failure in the general oncology setting

“…The reasons for the poor efficacy of these agents include the bloodbrain barrier which forms a pharmacological sanctuary, the expression of multidrug resistance proteins in glioma tumor cells and associated capillaries [2], the genetic, molecular, and metabolic heterogeneity of glioma tumor cells [3], resistance mechanism to commonly used alkylating agents, and, possibly, defects of both humoral and cellular immunity [4]. Tumor stem cells that exist within malignant gliomas, may provoke glioma development, perpetuation, and resistance to chemotherapy and radiation, accounting for the failure of conventional therapies and emergence of tumor recurrence [5].…”