B型肝炎病毒不同血清標誌者表面與e抗體IgG次型與AST/ALT數值之相關性

Relationship between IgG subclass profiles of anti-HBs and anti-HBe and AST/ALT levels in populations with different serum markers of HBV

蔡梓鑫(Tzu-Hsin Tsai)

指導教授 ： 周明智 ； 楊繼江

中山醫學大學/醫學院/醫學研究所/博士(2007年)

https://doi.org/10.6834/CSMU.2007.00090

摘要

B型肝炎病毒(HBV)感染是全球性的疾病，估計全世界有二十億人感染過，其中5%會變成慢性帶原者。HBV能因體液性免疫反應而有效控制，不論來自感染或疫苗注射。HBV之不同蛋白質抗原成分能引發不同免疫反應而產生不同的IgG次型，而不同之IgG次型的產生代表在HBV疾病之不同階段對抗不同抗原的刺激，發生不同免疫反應。本研究分析Anti-HBs及Anti-HBe之IgG次型來鑑別HBV的感染痊癒者及慢性帶原者或急性復發者；並比較慢性帶原者在肝功能異常時(如AST/ALT上升)與肝功能正常時(如AST/ALT正常)，其Anti-HBs及Anti-HBe之IgG次型分布是否不同。這些訊息將能讓我們了解HBV感染的機制及病毒感染後的清除情形。

本研究經中山醫學大學醫學倫理暨人體試驗委員會同意下完成，血液標本是由中山醫學大學附設醫院門診的病患中抽取，病人的性別、年齡及病史均詳細記載。共收集104個慢性帶原者(60個男性及44個女性)和439個感染痊癒者(247個男性及192個女性)，研究台灣人民的慢性帶原者和感染痊癒者Anti-HBs及Anti-HBe之IgG次型比較。並分析AST和ALT之異常與Anti-HBs及Anti-HBe之IgG次型的關聯。

研究結果顯示在104個帶原者中，有21個病人具有增高的AST和ALT (>25 IL/ml)，83位是AST和ALT正常，兩群相比較，其Anti-HBs IgG次型沒有不同。比較慢性帶原者及感染痊癒者之Anti-HBs IgG次型，可見兩者都呈現IgG1>IgG3≒IgG4，且在兩群中IgG1都是Anti-HBs IgG的主要成份。也發現在慢性帶原者其Anti-HBs IgG次型的分佈不會隨著肝臟發炎而改變，且和性別及年紀無關；但若AST和ALT增高時，則Anti-HBs IgG1及IgG3兩種次型的量沒有明顯差異。Anti-HBs IgG總量及IgG次型的吸光值，除了IgG2外，在感染痊癒者均大於慢性帶原者。

AST及ALT正常與增高的慢性帶原者比較，其Anti-HBe IgG總量的吸光值沒有統計上的差別，其Anti-HBe IgG次型的數值亦不隨肝臟發炎程度而有差異。不論男性或女性，分析Anti-HBe IgG次型，可見慢性帶原者為IgG1>IgG4>IgG3，而感染痊癒者為IgG1>IgG3>IgG4。但只有IgG1是慢性帶原者與感染痊癒者兩群主要的Anti-HBe IgG次型，且IgG2次型的含量最低。慢性帶原者比感染痊癒者的IgG4次型的量高(P<0.05)。與Anti-HBs IgG次型相反，HBV慢性帶原者比感染痊癒者的Anti-HBe IgG總量及IgG1次型的量都高。

我們的研究顯示在HBV感染中，IgG1及IgG3是保護人類的免疫反應IgG中的主要次型，以體液性免疫反應最重要的Anti-HBs來說，IgG1次型是清除病毒最主要的IgG次型。之前的研究則顯示Anti-HBc在感染痊癒者是IgG3>IgG1，慢性帶原者則是IgG1>IgG3，所以IgG1/IgG3的比例與感染狀態有關。現在知道Anti-HBs及Anti-HBe男女性的感染痊癒者與慢性帶原者IgG1均是最主要次型；可見引發特有的IgG1或/及IgG3才能產生強效的病毒中和反應。IgG2次型在多種病毒感染中的重要性有限，我們的資料顯示於Anti-HBs、Anti-HBc及Anti-HBe的IgG2次型分析都與此現象相符合。IgG4次型能提升Th2分泌細胞激素IL-4，而IL-4轉而抑制IFN-γ的合成。目前對於病毒感染後會產生IgG4次型的疾病尚還未知，但一般認為慢性抗原刺激反應導致次型被限定在IgG4的產生；HBV慢性帶原者比感染痊癒者的Anti-HBe IgG4次型的量高(P<0.05)，可能反映出持續性感染之效應。產生高量的Anti-HBe IgG4是否來自疾病的持續性感染及Anti-HBe是否與阻斷被HBV感染時Anti-HBe陽性患者的肝細胞毒性傷害有關，則需進一步研究。

關鍵字

慢性B型肝炎 ； IgG次型 ； B型肝炎表面抗體 ； B型肝炎e抗體

並列摘要

Hepatitis B virus (HBV) infections are a major global health burden, with an estimated prevalence of 2 billion people and as many as 5% of the world’s population living with chronic infection. HBV infections can be controlled effectively by the host humoral immune response, either naturally or elicited by vaccination. Different protein compositions for HBV can evoke different immune responses and, thus, induce the generation of different IgG subclass patterns. The different IgG subclasses generated against these antigens reflect the difference between stimulating antigens, immune response, and the stage of HBV disease.

The aim of this study was to measure and evaluate samples from different groups of patients were used to evaluate the Anti-HBs and Anti-HBe IgG patterns reflecting the immune status at different time points of HBV-infected individuals, from acute infection (i.e., ALT and AST abnormally elevated) to recovery or chronic infection (i.e., ALT and AST normal). This information would be helpful in understanding the immune modulating mechanism for HBV infection. The study of IgG-subclass patterns may promote an understanding of the relationship between these patterns and the immunity of virus clearance.

This study was approved by the institutional review board for medical ethics and human investigation at Chung Shan Medical University. Blood samples were obtained from outpatients attending Chung Shan Medical University Hospital. Patient sex, age, and history of medication were recorded for this study. To study IgG-specific subclasses of HBV Anti-HBs and Anti-HBe, in different populations in Taiwan, comparisons were made between 104 chronic carriers (60 male and 44 female) and 439 recovered individuals (247 male and 192 female). Biochemical analyses of AST and ALT were also performed.

Among the 104 chronic carriers, 21 patients had elevated AST and ALT levels (> 25 IU/mL). When comparing the patients with elevated AST and ALT levels to chronic carriers with normal AST and ALT levels, no statistical difference was observed for Anti-HBs levels. The IgG subclass pattern of the relative Anti-HBs IgG subclass titers was IgG1 > IgG3≒IgG4 in both chronic carriers and recovered individuals. IgG1 is the predominant Anti-HBs antibody after HBV infection, in either chronic carriers or in HBV-cured individuals(P<0.05). The IgG subclass profile of Anti-HBs in chronic carriers was not changed with liver inflammation and was independent of sex and age, except in individuals with elevated AST and ALT for whom Anti-HBs IgG1 was not significantly higher than IgG3 The mean OD values of Anti-HBs total IgG, and all IgG subclasses except for IgG2, of either males or females, were significantly higher in recovered individuals than in chronic carriers.

We also found that the IgG subclass profiles of Anti-HBe in the chronic carriers did not change with liver inflammation, and were independent of sex and age. The distribution pattern of Anti-HBe subclasses in HBV chronic carriers was IgG1>IgG4>IgG3, while in recovered individuals was IgG1>IgG3>IgG4, in both males and females.IgG1 subclass was the most predominant and IgG2 was the lowest subclass both in chronic carriers and recovered individuals. Significantly higher O.D. values of Anti-HBe IgG4 in the samples of chronic carriers than that of recovered individuals (P<0.05) was observed. Further, in inverse to that of Anti-HBs results, the samples from chronic carriers exhibited a higher concentration of total IgG and IgG1 than samples in recovered individuals.

Our study has shown that IgG1 and IgG3 are the main IgG subclasses found during HBV infections. For Anti-HBs, which is critical to the protective humoral immune response, the IgG1 subclass is the predominant Ig produced in individuals who successfully eliminate HBV. For Anti-HBc, previous report suggested that IgG3>IgG1 in recovered individuals and IgG1>IgG3 in chronic carriers thus IgG1/IgG3 ratio is related with HBV infection status. In this study, Anti-HBe and Anti-HBs IgG1 was shown to be predominant in both male and female of chronic carriers and recovered individuals. Therefore, induction of specific antibodies in the IgG1 or/and IgG3 subclasses is important for effective virus neutralization. IgG2 antibodies are known to be of limited importance in several viral infections. Our data are also in line with this finding for Anti-HBs, Anti-HBc, and Anti-HBe. IgG4 is up-regulated the Th2 cytokine IL-4, which in turn inhibits IFN-

並列關鍵字

chronic hepatitis B ； IgG subclass ； Anti-HBs ； Anti-HBe

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