乙型肝炎高流行区母亲HBsAg阳性和阴性的儿童乙肝疫苗免疫后抗体水平动态观察

Dynamic study on the anti-HBs level of immunized children born to HBsAg-positive and HBsAg-negative mothers in hyperendemic area of hepatitis B

目的探讨乙型肝炎（乙肝）高流行区母亲不同携带状况的新生儿乙肝疫苗免疫后抗体消长规律。方法在广两隆安县对常规乙肝疫苗免疫并于1岁时证实抗-HBs阳性的儿童，按其母亲HBsAg阳性与否分组。在5-8岁期间对每人随访3次，用SPRIA法检测HBsAg、抗-HBs和抗-HBc。结果免疫儿童5-8岁时，母亲HBsAg阳性儿童和阴性儿童的随访抗-HBs阳性率分别波动于52．00％-78．00％和43．84％-54．74％之间，GMT为55．36-95．66mIU／ml和39．90-65．47mIU／ml，各年龄间差异无统计学意义。同年龄组内呈现母亲HBsAg阳性儿童的随访抗体水平高于母亲HBsAg阴性儿童趋势。母亲HBsAg阴性的6-8岁儿童初次免疫（初免）抗体高滴度者，随访抗体阳性率分别是同年龄组初免抗体低滴度者的2．29-2．84倍。无论母亲HBsAg携带状况如何，儿童随访抗-HBs滴度与初免抗体滴度比较均以下降为主，但母亲HBsAg阴性儿童下降率（84．91％）显著高于母亲HBsAg阳性儿童（61．54％）（X^2=28．7982，P=0．000）。随访抗体滴度较初免抗体≥4倍增高者在母亲HBsAg阳性儿童中发生率（25．64％）显著高于母亲HBsAg阴性儿童（7．37％）（校正X^2=6．7661，P=0．009），是后者的3．5倍。HBsAg阳转者均为初免抗-HBs低滴度者。结论免疫成功儿童在5-8岁期间的抗，HBs水平下降缓慢。母亲携带HBsAg时，会增加免疫儿童自然感染的机会而引起自然加强免疫。初免抗-HBs水平对预防HBsAg阳转极为重要。

Objective To investigate the dynamic changes of the anti-HBs level among immunized newborn infants born to HBsAg-positive and HBsAg-negative mothers in hyper-endemic area of Hepatitis E Methods Infants who were regularly vaccinated with Hepatitis B vaccine and tested to be anti-HBs positive were divided into two groups according to HBsAg-positive or negative mothers in Long-an, Guangxi. Each subject was followed up 3 times during age 5 to 8. SPRIA was used to test HBsAg, anti- HBs and anti-HBc. Results During the follow-up period, positive rates of anti-HBs in children born to HBsAg-positive mothers ranged between 52.00 % and 78.00 %, and those with HBsAg-negative mothers was between 43.84 % and 54.74 %. GMT in two groups was between 55.36 mIU/ml and 95.66 mIU/ml as well as between 39.90 mIU/ml and 65.47 mIU/ml, respectively. There was no statistical significance in both positive rates and GMT between age groups. The anti-HBs level in the follow-up period of children born to HBsAg-positive mothers was higher than that of those born to HBsAg-negative mothers in the same age group. In the age group of 6-8 years with HBsAg-negative mothers, the positive rates in the follow-up period of children with high anti-HBs titers in the primary vaccination were 2.29-2.84 times of those with low titers. The anti-HBs titer of children in a follow-up period was lower than that in the primary vaccination, no matter whether they were born to HBsAg-positive mothers. However, the decline rate of children born to HBsAg-negative mothers was significantly higher than those born to HBsAg-positive mothers （84.91% vs. 61.54%;X^2=：28.7982,P=0.000）. The incidence rate （25.64%） of a 4-fold increase in antibody titers of children born to HBsAg-positive mothers was significantly higher than that of children born to HBsAg-negative mothers （7.37 % ） from the primary vaccination to the follow-up period （X^2=6.7661, P=0.009） with was 3.5 times of the latter. Subjects with HBsAg seroconvertion were those with low anti-HBs titers in primary vaccination. Conclusion The anti-HBs level decreased slowly in successfully immunized children from age 5 to 8. The chance of natural booster yielded by natural infection increased in immunized children born to HBsAg-positive mothers. The anti-HBs level in the primary vaccination played an important role in prevention of seroconversion of HBsAg.