不同碘营养地区甲状腺球蛋白抗体亚类分布及其意义研究

Distribution and significance of serum anti-thyroglobulin antibody subclass among Regions with different iodine nutrition

目的研究不同碘营养地区甲状腺球蛋白抗体(TgAb)IgG亚类的分布,为疾病的早期预防和治疗提供线索。方法选择本研究组2004年对辽宁省盘锦、彰武社区以及河北省黄桦社区共3018名居民的流行病学调查资料。分别从轻度碘缺乏、超足量碘摄入和过量碘摄入地区选取TgAb>40 kU/L,甲状腺过氧化物酶抗体(TPOAb)<50kU/L,促甲状腺激素(TSH)为0.3～4.8 mU/L(即甲状腺功能正常)的研究对象共102例,另选取阴性对照83名。采用抗原特异性酶联免疫吸附法(ELISE)测定IgG亚类。结果超足量碘摄入组和过量碘摄入组的IgG4亚类浓度明显高于轻度碘缺乏组(P均<0.05)。超足量碘摄入组IgG4亚类阳性率明显高于轻度碘缺乏组(P<0.05)。其余各亚类浓度及阳性率组间比较差异无统计学意义。结论超足量及过量碘营养地区TgAb的IgG4亚类浓度明显升高,可能与长期暴露于碘所致的Tg抗原决定簇改变相关。该亚类的升高,可能提示疾病的前期或慢性状态。

Objective To investigate the distribution of IgG subclasses of anti-thyroglobulin antibody （TgAb） among re- gions with different iodine nutrition to offer clues for early prevention and disease treatment. Methods We screened the ep- idemiologic profiles of 3018 cases from Panjin （Liaoning province） ,Zhangwu （Liaoning province） and Huanghua （Hebei province） in 2004. A total of 102 subjects with TgAb 〉 40 kU/L,thyroid peroxidase antibody （TPOAb） 〈 50 kU/L and thyroid stimulating hormone （TSH） of 0. 3 -4. 8 mU/L （normal range） from mild iodine deficiency,above adequate and excessive iodine intake regions. In addition,83 negative controls were enrolled in the study. Enzyme-linked immunosorbent assay （ELISA） was employed to determine IgG subclasses of TgAb. Results Both above adequate and excessive iodine in- take group yielded considerably higher concentration of IgG4 subclass （ both P 〈 0. 05 for WTBX） than mild iodine defi- ciency group. Significantly higher positive rate of IgG4 subclass was found in above adequate iodine intake group （ P 〈 0. 05 for WTBX） , but not in mild iodine deficiency group. The difference in concentration and positive rate of remaining subclas- ses did not reach statistical significance among each group. Conclusion The regions with above adequate and excessive io- dine intake may have markedly higher concentration of IgG4 subclass. This could have arisen from altered Tg antigen epitope as a result of long-term iodine exposure that indicates premature development or chronic stage of thyroid diseases.