Braito A, Bianchini A M, Mattei C, Benci A, Marri D, Toti M
Istituto di Malattie Infettive, Università degli Studi di Siena.
Boll Ist Sieroter Milan. 1991;70(1-2):449-51.
The long-term persistence of anti-HBsAg above 10 mUI is conventionally believed to protect against natural infection with hepatitis B virus, while it is not yet clear what is the clinical significance of the fall to below 10 mUI in antibody levels. In our opinion, an important method for evaluating the effectiveness of the vaccine lies in comparing the duration of vaccine-immunity with that following the disease, the later being held to provide life-long protection. In this view, we examined the sera samples of 69 subjects (56 healthy people, and 13 drug-addicts) previously affected from HBV infection looking for anti-HBsAg with an Elisa method. The subjects were aged between 4 months and 73 years and had all suffered from acute fully recovered icteric hepatitis in the previous 2 to 10 years. All the drug addicts (13 males) and 4 healthy children from the group had no or negligible levels of antibodies; 3 out of 8 old people (60 or more yrs old) showed no antibodies only 4-5 yrs after having been infected. In the remaining group of 44 healthy people 14 cases were observed which had antibody levels 10 mUI, regardless of age, sex or occupation; the greater the time between the infection and the test, the greater the probability of finding negligible antibody levels. We conclude that the reduction in antibody levels may not be indicative of a loss of immunity: many of our cases have shown low or undetectable antibody levels, a few years after full recovery from an acute attack of hepatitis B.
传统观点认为，抗-HBsAg水平长期维持在10 mUI以上可预防乙型肝炎病毒的自然感染，而抗体水平降至10 mUI以下的临床意义尚不清楚。我们认为，评估疫苗有效性的一个重要方法是比较疫苗免疫持续时间与感染疾病后的免疫持续时间，后者被认为可提供终身保护。基于这一观点，我们用酶联免疫吸附测定法检测了69名曾感染过乙肝病毒的受试者（56名健康人，13名吸毒者）的血清样本，以寻找抗-HBsAg。受试者年龄在4个月至73岁之间，均在过去2至10年中患过急性黄疸型肝炎且已完全康复。所有吸毒者（13名男性）及该组中的4名健康儿童抗体水平无或可忽略不计；8名老年人（60岁及以上）中有3名在感染后仅4至5年就检测不到抗体。在其余44名健康人的组中，观察到14例抗体水平低于10 mUI，与年龄、性别或职业无关；感染与检测之间的时间间隔越长，抗体水平可忽略不计的可能性就越大。我们得出结论，抗体水平的降低可能并不意味着免疫力丧失：我们的许多病例在乙肝急性发作完全康复后的几年里，抗体水平较低或检测不到。
