Neuromyelitis optica (NMO), a specific form of multiple sclerosis (MS), is associated with antibodies against aquaporin 4 (AQP4). An ELISA assay was used to measure IgG, IgA, and IgM antibodies against human AQP4, plant aquaporins, and several neural antigens, in MS patients and controls. Our goal was to determine whether patients suffering from relapsing- remitting multiple sclerosis (RRMS) have simultaneous elevations in antibodies against these antigens. In comparison to controls, a significant elevation in antibodies against AQP4 and neural antigens were detected in MS patients, indicating a high correlation in antibody reaction between plant aquaporins and neural antigens. We conclude that in addition to patients with NMO, there is a subclass of patients with MS that react to both plant as well as human AQP4 peptides.