BACKGROUND: Serum antibodies against thyroglobulin (TgAbs) are common in patients with differentiated thyroid cancer (DTC) and can interfere in thyroglobulin (Tg) assays. We identified the epitopes on Tg recognized by TgAb-positive sera from patients with DTC and examined the association between epitope specificity patterns and Tg recovery. METHODS: We tested 50 DTC sera for Tg epitope specificity, TgAbs, and Tg recovery. Epitope recognition was determined by use of a panel of 10 well-characterized Tg monoclonal antibodies directed against 6 Tg antigenic clusters (I-VI) in competitive reactions with test sera. Tg was measured by the Thyroglobuline IRMA (CIS bio international). Recovery of added Tg (TgREC) was determined by an in-house assay. RESULTS: Epitope recognition was restricted to immunodominant clusters in 58% of patients, whereas the rest were either broadly heterogeneous (16%) or nonreactive (26%). Median Tg recovery did not differ between sera with restricted and unrestricted specificities (69% vs 80%; P >0.05). TgREC was inversely correlated with the total number of epitopes recognized by sera (r = -0.66; P <0.001). CONCLUSIONS: TgAbs with both restricted and broad specificities are present in patients with DTC. TgAb interference is related to the number of epitopes recognized by sera rather than the pattern of epitope recognition.
BACKGROUND: Serum antibodies against thyroglobulin (TgAbs) are common in patients with differentiated thyroid cancer (DTC) and can interfere in thyroglobulin (Tg) assays. We identified the epitopes on Tg recognized by TgAb-positive sera from patients with DTC and examined the association between epitope specificity patterns and Tg recovery. METHODS: We tested 50 DTC sera for Tg epitope specificity, TgAbs, and Tg recovery. Epitope recognition was determined by use of a panel of 10 well-characterized Tg monoclonal antibodies directed against 6 Tg antigenic clusters (I-VI) in competitive reactions with test sera. Tg was measured by the Thyroglobuline IRMA (CIS bio international). Recovery of added Tg (TgREC) was determined by an in-house assay. RESULTS: Epitope recognition was restricted to immunodominant clusters in 58% of patients, whereas the rest were either broadly heterogeneous (16%) or nonreactive (26%). Median Tg recovery did not differ between sera with restricted and unrestricted specificities (69% vs 80%; P >0.05). TgREC was inversely correlated with the total number of epitopes recognized by sera (r = -0.66; P <0.001). CONCLUSIONS: TgAbs with both restricted and broad specificities are present in patients with DTC. TgAb interference is related to the number of epitopes recognized by sera rather than the pattern of epitope recognition.
Authors: Deolinda Madureira; Susana Prazeres; Márcia São Pedro; Teresa Pereira; Ana Paula Font; Maria João Bugalho Journal: Endocrine Date: 2008-03-29 Impact factor: 3.633
Authors: Brian C Netzel; Stefan K G Grebe; B Gisella Carranza Leon; M Regina Castro; Penelope M Clark; Andrew N Hoofnagle; Carole A Spencer; Adina F Turcu; Alicia Algeciras-Schimnich Journal: J Clin Endocrinol Metab Date: 2015-06-16 Impact factor: 5.958
Authors: Mark M Kushnir; Alan L Rockwood; William L Roberts; Dev Abraham; Andrew N Hoofnagle; A Wayne Meikle Journal: Clin Chem Date: 2013-02-08 Impact factor: 8.327