Abstracts

Rationale: The LGI1 gene has been linked to malignant progression of glioma tumors, and a role for this gene in the development of glioma-related epilepsy has been hypothesized. To investigate the possible involvement of LGI1 in glioblastoma-associated epilepsy, we analyzed the expression of the Lgi1 protein in tumor tissue and searched for Lgi1 autoantibodies in patients with and without epilepsy.Methods: Twenty-four patients affected with glioblastoma (11 with and 13 without epilepsy) were recruited for study. Tumor tissue samples were obtained following surgery and Lgi1 protein levels were analyzed by immunoblot. Detection of serum autoantibodies against Lgi1 was performed by a cell-based assay in 5 patients.Results: We detected variable amounts of Lgi1 protein in the tumor tissues from 9/24 (37%) patients. Lgi1 was detected in 6/11 (54%) patients with epilepsy, and in 3/13 (23%) patients without epilepsy (p-value nonsignificant). In addition, we tested the sera of 5 patients for Lgi1 autoantibodies and found these autoantibodies in 2 patients, both suffering from epilepsy and expressing Lgi1 in tumor tissue.Conclusions: Our data suggest that 1) about 1/3 of glioblastoma tumors express Lgi1; 2) expression of Lgi1 might be considerably more frequent in tumors of patients with epilepsy than in those of patients without epilepsy; 3) occurrence of Lgi1 autoantibodies may characterize a proportion of patients with glioblastoma. Future studies on larger patient cohorts are needed to determine the relationship between tumor Lgi1 expression, Lgi1 autoantibodies and epilepsy in glioblastoma patients.