The invention includes antibodies or antigen-binding fragments thereof which bind specifically to glycated CD59, compositions containing one or a combination of such antibodies or antigen-binding fragments thereof, hybridoma cell lines that produce the antibodies, and methods of producing and using the antibodies or antigen-binding fragments thereof for diagnosis and treatment of diabetic conditions and diabetic complications or diabetes-associated conditions. The invention also involves in some embodiments assays, diagnostics, kits, and assay components for determining levels of glycated CD59 in subjects. Treatments for subjects based upon levels of glycated CD59 also are provided.
