Glycosylation of Sera Thyroglobulin Antibody in Patients with Thyroid Diseases. Department of Endocrinology, Peking University First Hospital, Beijing 100034, China Ying Gao, Lanlan Zhao, Mingming Liu, Youyuan Huang, Guizhi Lu, Yanming Gao, Xiaohui Guo. Backgrounds.
Glycosylation of Sera Thyroglobulin
Antibody in Patients with
Department of Endocrinology,
Peking University First Hospital,
Beijing 100034, China
Ying Gao,Lanlan Zhao, Mingming Liu, Youyuan Huang, Guizhi Lu, Yanming Gao, Xiaohui Guo
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Hashimoto' thyroiditis (HT) and Graves' disease (GD)
Neu5AC: sialic acid
TgAb is predominantly of IgG class
IgG is a glycoprotein with a sugar moiety attached to each of the asparagin 297 residues in the CH2-domains of the two Fc-fragments.
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The absence of core fucose residues in the Fc glycans substantially increases the ADCC activity of IgG.
Increased sialylation of Fc glycans results in decreased ADCC activity.
Alteration of IgG-Fc galactosylation have been described not only in autoimmune diseases, but also in some malignancy diseases.
These glycoforms can differ in their efﬁcacy of effector function activation as it influences binding of IgG molecules to Fc receptors and C1q .
The aim of our study was to investigate the glycosylation of sera TgAb in patients with different thyroid diseases including HT, GD, and PTC.
Eu: euthyroidism; sH: subclinical hypothyroidism; H: hypothyroidism
Sera samples were collected in Peking University First Hospital.
the percentage of fucose positive control
the percentage of TgAb IgG positive control
Thyroid function: Chemiluminescence immunoassays
TgAb IgG: antigen specific ELISAs
carbohydrate residues on sera TgAb: Lectin-ELISAs
The relative amount of fucose in each TgAb IgG was calculated as:
Comparisons were carried out by the Mann–Whitney test,ANOVA, Chi-Square test and Kruskal-Wallis H test.
Table 1. Demographic data, thyroid functional status and TgAb IgG levels of the patients in different groups.
a P < 0.05 vs. GD; b P < 0.05 vs. thyroid cancer group.
Table2. Demographic data, thyroid functional status and TgAb IgG levels of the patients in HT subgroups.
a P < 0.05 vs. sH.; b P < 0.05 vs. H.
Fig.1. Comparisons of the relative amount of carbohydrate residues on each sera TgAb from patients with different thyroid diseases.
Fig.2. Comparisons of the relative amount of carbohydrate residues on each serum TgAb from Hashimoto’s thyroiditis patients with different thyroid functional status.
Fig.3. The correlation between the relative amount of carbohydrate residues on each TgAb and TgAb IgG in all the patients (n = 109).
The levels of fucosylation and sialylation on TgAb varied in different thyroid diseases.
We speculated that TgAb with lower content of core fucose and terminal sialic acid might have stronger ability to participate in ADCC in HT.
Terminal galactose content of IgG does not affect ADCC but complement dependent cytotoxicity (CDC).
There were no significant differences in the levels of glycosylation on each TgAb among the three HT subgroups.
The levels of glycosylation on TgAb might not representthyrocyte hyperplasia but merely reflect the capacity of inducing thyroid destruction
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The levels of glycosylation on each TgAb had a negative relationship with TgAb IgG levels
a consequence of elevated Ig synthesis by B cells.
the individuals with thyroid antibodies might be at high risk of developing thyroid failure.
Glycosylation of sera TgAb varied in the patients with different thyroid diseases.
The levels of glycosylation of TgAb might decrease with increasing TgAb levels.
Beijing Natural Science Foundation
Beijing Nova Program
Program for New Century Excellent Talents in University
Sector funds of ministry of health (no. 201002002).
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