Anti-thyroperoxidase antibody levels >500 IU/ml indicate a moderately increased risk for developing hypothyroidism in autoimmune thyroiditis - Ehlers, M; Jordan, A L; Feldkamp, J; Fritzen, R; Quadbeck, B; Haase, M; Allelein, S; Schmid, C; Schott, M (Horm Metab Res, 2016)