凋亡相关蛋白Bcl2、Bax在IgG4相关性乔本甲状腺炎中的表达及其临床病理意义

Clinicopathological significances of protein expression in IgG4 relative Hashimoto's thyroiditis

目的探讨IgG4相关性乔本甲状腺炎(Hashimoto's thyroiditis,HT)的临床病理特征,并进一步分析凋亡相关蛋白Bcl2、Bax的表达与其临床、病理特征的相关性。方法用免疫组化检测46例HT和15例滤泡性腺瘤瘤旁甲状腺组织中IgG4+浆细胞、IgG+浆细胞及Bcl2、Bax蛋白的表达,依据IgG4+浆细胞>20/HPF及IgG4+/IgG+>30%的标准,将HT分为IgG4组和非IgG4组,分析两组间临床病理特征及Bcl2、Bax蛋白分布、表达的差异。结果 46例HT患者中11例为IgG4-HT(占23.9%)。与非IgG4组比较,IgG4组患者更容易出现亚临床甲状腺功能减退(P=0.02)、甲状腺纤维化程度更显著(P=0.006);IgG4-HT甲状腺滤泡上皮中Bax蛋白的表达显著高于非IgG4-HT组(P=0.001),且与甲状腺纤维化的程度呈正相关(r=0.622,P=0.04)。结论 IgG4-HT代表了更具破坏性的一种乔本甲状腺炎亚型,更容易出现甲状腺功能减退;凋亡促进蛋白Bax可能在IgG4-HT的病理进程中发挥了作用。

Objective To investigate the clinicopathological features of IgG4 relative Hashimoto＇s thyroiditis （HT ）;to find out the clinicopathological significances of Bcl2 and Bax proteins expression in IgG4 relative HT . Methods Immunohistochemistry was used to examine the expression of IgG4 ,IgG ,Bcl2 and Bax in 46 HT tissue samples and 15 thyroid glands tissue samples adjacent to follicular adenoma .On the basis of the cutoff value of〉20/HPF IgG4‐positive plasma cells and〉30% IgG4/IgG ratio ,the patients with HT were subclassified into IgG4‐HT and non IgG4‐HT .Statistical analysis was performed to analyze the differences in clinicopathological features and the expression and location of Bcl2 and Bax protein between the two groups . Results The patients with IgG4‐HT accounted for 23.9% of the HT patients .Compared with non IgG4‐HT group ,the patient with IgG4‐HT were associated with more subclinical hypothyroidism（P= 0.02） and a higher grade of stromal fibrosis（P=0.006） .Moreover ,the expression of Bax in the follicular cells of IgG4‐HT group ,was significantly up‐regulated compared with that of non IgG4‐HT group （P=0.001） and positively correlated with the degree of stromal fibro‐sis （r=0.622 ,P=0.04） . Conclusion Our results suggest that IgG4‐relative HT represents a more destructive subtype of HT .Bax protein may play a role in the pathological progress of IgG4‐HT .