利用周產期母親血清之B肝病毒表面抗原濃度預測母子傳染

Abstract

為了降低B型肝炎母子傳染的發生，B型肝炎帶原並且為高病毒量的孕婦必須在生產前被偵測到，並給予額外的預防措施。B型肝炎表面抗原定量是近年逐漸普及的檢驗法，費用較檢驗病毒量低廉。本研究目標為評估B型肝炎表面抗原定量與病毒量之間相關性及B型肝炎表面抗原定量是否可預測其小孩發生母子傳染的發生。 本研究為前瞻性追蹤研究，共收案461對母親為B肝表面抗原陽性的母子。母親於生產後三天內抽血檢驗B型肝炎表面抗原濃度、病毒量及e抗原帶原情形。其子女追蹤到1-1.5歲並有兩次抽血，檢驗B肝表面抗原帶原情形。統計分析使用斯皮爾曼等級相關係數評估B型肝炎表面抗原定量與病毒量之相關性及邏輯斯迴歸評估B型肝炎表面抗原定量是否為母子傳染的危險因子。在收案的461位小孩中，共有16位小孩B肝表面抗原呈現陽性。所有被感染的小孩，皆為e抗原陽性母親所生，並且有較高的B型肝炎表面抗原濃度(4.7±0.2 log10 IU/ml)及病毒量濃度(7.9±0.74 log10 IU/ml)。相關係數分析中，B型肝炎表面抗原定量與病毒量呈強相關性(r=0.64，p<0.0001)，預測高病毒量理想切點為4.26 log10IU/ml，敏感度為 93%，特異度為97%；在e抗原陽性母親中，也同時呈現強相關性(r=0.62，p<0.0001)。調整其他變項後， B型肝炎表面抗原定量與母子傳染仍呈統計顯著相關，勝算比為16.33，為一危險因子。 B型肝炎表面抗原定量與病毒量之間呈高度相關，同時也可預測母子傳染發生。考慮篩檢費用情況下，B型肝炎表面抗原定量可視為一新的產檢工具。

Background: To eliminate hepatitis B virus mother-to-infant transmission, it is necessary to detect pregnant women with high hepatitis B virus (HBV) DNA and then give additional prevention strategy before delivery. Quantitative Hepatitis B surface antigen (HBsAg) is a newly developed method with a unit price much lower than that of HBV DNA. We aimed to evaluate the correlation between quantitative HBsAg and HBV DNA and to assess the feasibility of quantitative HBsAg as a predictor in high risk screening. Methods: We conducted a prospective cohort study, 461 pairs of HBsAg positive mothers and their infants were enrolled. Serum HBsAg, HBeAg and HBV DNA level of these mothers were measured. Infants were followed up to 1-1.5 years old and had two separate serum HBsAg tests. Spearman’s correlation coefficient was used to examine the correlation between quantitative HBsAg and HBV DNA. Logistic regression analyses were used to assess the predictive ability of HBV DNA, quantitative HBsAg, and other risk factors of mother-to-infant transmission. Results: Among the 461 infants, 16 infants were found to be infected with HBV. All of them were born to HBeAg positive mothers with high HBV DNA (7.9±0.74 log10 IU/ml) and high quantitative HBsAg (4.7±0.2 log10 IU/ml). Quantitative HBsAg had a significant positive correlation with HBV DNA level (r=0.64, p<0.0001) in all subjects and in HBeAg positive subjects group (r=0.62 p<0.0001). The optimum cut-off point for HBV DNA concentration of 7 log10 IU/ml was 4.26 log10 IU/ml, with a sensitivity of 93%, specificity of 97%. After adjusting possible confounders, quantitative HBsAg could significantly predict mother-to-infant transmission. Conclusion: Our study documents that quantitative HBsAg is highly correlated with, and as predictive as HBV DNA for mother-to-infant transmission. With the concern of the screening cost, quantitative HBsAg may be used as a new screening tool during pregnancy.