title: High Serum IgG4 Concentrations in Patients with Hashimoto's Thyroiditis.
abstract: Purpose. Since recent reports suggest that Hashimoto thyroiditis (HT) may be associated with IgG4-related disease, we aimed to find out whether the measurement of serum IgG4 allows for the identification of distinct types of HT, with different clinical, sonographic, and serologic characteristics. Methods. The group studied consisted of 53 patients with HT and 28 healthy individuals who underwent thyroid ultrasonography and body composition analysis. Serum concentrations of IgG4, TSH, anti-peroxidase antibodies (TPOAb), anti-TSH receptor antibodies, TNF-α, TGF-β1, Fas Ligand, TRAIL, and chemokines (CXCL9, CXCL11, and CXCL10) were measured by ELISA or radioimmunoassay. Results. The group with IgG4 level >135 IU/ml accounted for 32.5% of the patients. The signs of fibrosis were present in 27.0% of the high-IgG4 patients and in 9.1% of the normal-IgG4 group. The patients with elevated IgG4 required higher doses of L-thyroxine and had significantly lower level of TPOAb (P=0.02) than the non-IgG4-HT individuals and higher TNF-α level in comparison with the controls (P=0.01). Conclusions. Our results suggest that the measurement of serum IgG4 allows for an identification of patients with more rapid progression of HT, requiring higher doses of L-thyroxine. Low TPOAb level and the absence of coexisting autoimmune diseases may suggest distinct pathomechanism of this type of thyroiditis.
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Popławska-Kita
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Kościuszko-Zdrodowska
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Siewko
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Telejko
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Hryniewicka
authors.affiliation: Department of Statistics and Medical Informatics, Medical University of Bialystok, 15-276 Bialystok, Poland.
authors.forename: Robert
authors.identifier: 0000-0001-6241-8283
authors.initials: R
authors.lastname: Milewski
authors.affiliation: Department of Nuclear Medicine, Medical University of Bialystok, 15-276 Bialystok, Poland.
authors.forename: Saeid Soleman
authors.initials: SS
authors.lastname: Abdelrazek
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Szelachowska
authors.affiliation: Department of Endocrinology, Diabetology and Internal Medicine, Medical University of Bialystok, Sklodowskiej-Curie 24A, 15-276 Bialystok, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Górska