Methods of detecting antibodies to one or more glycosphingolipid(s) of interest in a sample are disclosed which comprise using a solid-phase reactant having carbonyl groups attached thereon, and the glycosphingolipid(s) of interest linked to the solid-phase reactant by an amide bond between an amino group of the glycosphingolipid of interest and a carbonyl group attached to the solid-phase reactant. The methods of detecting antibodies to glycosphingolipid(s) of interest can be used in methods of diagnosing autoimmune diseases in an individual.