Aquaporin-4 antibodies are not present in patients with idiopathic intracranial hypertension

Abstract

We aimed to investigate anti-aquaporin-4 (AQP-4) water channel antibodies, affecting cerebrospinal fluid (CSF) secretion and absorption, in idiopathic intracranial hypertension (IIH) patients. Patients fulfilling the modified Dandy's diagnostic criteria for IIH were included and their clinical features and CSF findings were reviewed. Their serum samples and control groups were investigated by immunofluorescence and a cell-based assay for anti-AQP-4 antibodies and by immunohistochemistry for IgG binding patterns. Twenty-nine patients diagnosed with IIH were investigated. We could not detect any anti-AQP-4 antibodies in our series. However, we identified different serum IgG binding patterns in 11 IIH patients. There is only one report investigating the anti-AQP4 antibodies in IIH. Our study with a larger sample confirmed the results of this report and indicated that AQP4 antibodies did not have a primary role in IIH pathogenesis, but provided some support for the contribution of inflammatory mechanisms in IIH.