Soluble CD95 (Fas/APO-1) in malignant glioma: (no) implications for CD95-based immunotherapy?

CD95 targeting is a novel approach of immunotherapy for malignant glioma that might be antagonized by the release of soluble CD95 by the tumor cells. An alternatively spliced CD95 mRNA that encodes a secreted CD95 variant has been detected in glioma cell lines in vitro and in human tumors in vivo. Here, we report that the levels of soluble CD95 in the serum of malignant glioma patients do not differ from those of lumbar disk disease patients. Soluble CD95 was detected in the CSF in 2 of 20 malignant glioma patients by ELISA. Bioassay studies indicate that these low levels of soluble CD95 in the CSF of some patients with malignant glioma cells are unlikely to interfere with CD95-based immunotherapy of malignant gliomas in vivo.