Bradley D W, Maynard J E, Hindman S H, Hornbeck C L, Fields H A, McCaustland K A, Cook E H
J Clin Microbiol. 1977 May;5(5):521-30. doi: 10.1128/jcm.5.5.521-530.1977.
A modified micro solid-phase radioimmunoassay (RIA) for antibody to hepatitis A virus (anti-HAV) was developed. This double antibody procedure was performed by coating the surface of a polyvinyl microtiter plate "well" with 200 microliter of a 1:1,000 dilution of a patient's test serum. Purified HAV and 125I-labeled immunoglobulin G (IgG) anti-HAV were then sequentially added to form an antibody sandwich. The specificity and sensitivity of the RIA procedure for anti-HAV were verified by examination of coded human and chimpanzee serum specimens. Radioimmunoassay of early-acute-phase serum specimens from human cases of hepatitis A revealed the presence of anti-HAV activity. Differential examination by RIA of IgG and IgM fractions of acute-phase sera from experimentally infected chimpanzees demonstrated that IgM contained the bulk of the anti-HAV activity. A modification of the RIA procedure for anti-HAV (RIA-IgM blocking), incorporating an incubation step with anti-IgM (Mu chain specific), was further shown to differentiate acute- from convalescent-phase hepatitis A sera. This adapted RIA-IgM blocking procedure required less than 1 microliter of a single acute-phase serum specimen for the diagnosis of viral hepatitis A.
开发了一种改良的微量固相放射免疫测定法（RIA）用于检测甲型肝炎病毒抗体（抗-HAV）。这种双抗体法通过在聚乙烯微量滴定板“孔”表面包被200微升患者检测血清1:1000稀释液来进行。然后依次加入纯化的甲型肝炎病毒和125I标记的抗甲型肝炎病毒免疫球蛋白G（IgG）以形成抗体夹心。通过检测编码的人类和黑猩猩血清标本验证了抗-HAV放射免疫测定法的特异性和敏感性。对甲型肝炎人类病例早期急性期血清标本的放射免疫测定显示存在抗-HAV活性。对实验感染黑猩猩急性期血清的IgG和IgM组分进行放射免疫测定鉴别检查表明，IgM含有大部分抗-HAV活性。进一步证明，采用抗IgM（μ链特异性）孵育步骤对检测抗-HAV的放射免疫测定法进行改良（RIA-IgM阻断法）可区分甲型肝炎急性期和恢复期血清。这种改良的RIA-IgM阻断法诊断甲型病毒性肝炎时单个急性期血清标本用量不到1微升。
