gms | German Medical Science

Objective: Aquaporins (AQP) are a growing family of water-channel proteins. Thirteen AQPs have been identified in mammals. AQP4 is the principal water-channel in the central nervous system. Recent studies show that it plays a role in the development and resolution of brain edema. But also other AQPs have been discovered in the brain tissue. Their function in brain edema is not known yet. We investigated the association of the A(-1364)C polymorphism in the APQ5-promoter and peritumoral edema in meningiomas.

Methods: 95 patients suffering from meningioma were investigated. Peritumoral edema was classified in three degrees based on the preoperative imaging and current literature. DNA was extracted from paraffin-embedded histologically confirmed tumor tissue. The results were evaluated in respect to clinical data as well as WHO classification, pathologic classification and brain edema.

Results: In 47 patients peritumoral edema was found (grade 1: 15 patients, grade 2: 15 patients, grade 3: 17 patients). 48 patients revealed no brain edema. There were no genotype dependent differences in regard to gender, age, outcome, pathologic and WHO classification just as the development of a peritumoral edema.

But in case of developing an edema significant genotype differences can be identified in respect of the classification of peritumoral edema. 60% of patients with grade 1 brain edema were C-allele carriers whereas only 23.5% of the patients with grade 3 edema are C-allele carriers in the -1364 region of the APQ5-promoter (p=0.0358).

Conclusions: The development of peritumoral edema in meningiomas is independent of the genotype in the -1364 region of the APQ5-promoter. But the grading of peritumoral edema in meningiomas seems to be dependent on the genotype.

The A(-1364)C polymorphism of the APQ5-promoter goes along with less peritumoral edema in meningiomas.