Aquaporin-1 antibody in neuromyelitis optical patients

To find out the prevalence of aquaporin-antibody (Aqp-Ab) and characterize Aqp-Ab associated clinical features in NMO, Aqp-1 and Aqp-4-Abs were examined using radioimmunoprecipitation and cell-based assays, respectively. Aqp-4 and Aqp-1-Abs were detected in 20/30 and 8/30 NMO patients, respectively. One patient was Aqp-1-Ab single-positive, 13 patients were Aqp-4-Ab single-positive, 7 patients were Aqp-4/Aqp-1-Ab double-positive and 9 patients were seronegative. All double-positive patients had optic neuritis during the first attack. Only 2/29 MS patients and none of the control idiopathic intracranial hypertension patients were Aqp-1-Ab positive. Aqp-1-Ab is usually detected in Aqp-4-Ab positive NMO patients and might be involved in optic neuritis pathogenesis.