Tobler L H, Busch M P, Wilber J, Dinello R, Quan S, Polito A, Kochesky R, Bahl C, Nelles M, Lee S R
Irwin Memorial Blood Centers, University of California, San Francisco.
Transfusion. 1994 Feb;34(2):130-4. doi: 10.1046/j.1537-2995.1994.34294143940.x.
Approximately 25 percent of blood donor sera that are repeatably reactive for hepatitis C virus (HCV) on second-generation enzyme immunoassay (EIA 2.0) are indeterminate on second-generation recombinant immunoblot assay (RIBA 2.0), and over 76 percent of these results are due to single reactivity to the HCV recombinant antigen c22-3.
Data are presented on 46 volunteer allogeneic blood donors who were reactive on EIA2.0 and c22-3 indeterminate in RIBA 2.0. Index and follow-up samples were evaluated by using a panel of five synthetic peptide EIAs, a prototype strip immunoblot assay that uses synthetic peptides in addition to recombinant protein (RIBA 3.0), and polymerase chain reaction (PCR) for HCV RNA.
All 46 donations had normal alanine aminotransferase values; only 2 (4.3%) reacted for antibody to hepatitis B core antigen. With a panel of 12 synthetic peptides spanning the entire sequence of the c22-3 recombinant antigen, 33 plasmas (72%) reacted to one peptide or none, including 19 plasmas with reactivity restricted entirely to the N-terminal peptide (1-15 amino acids) of c22-3. With RIBA 3.0, 28 donations (61%) were nonreactive, including 25 that reacted with one peptide or none in EIA. Of these 25 plasmas, 18 reacted with the N-terminal sequence only. All 46 index donations were tested by PCR; the single PCR-positive unit reacted with four HCV peptides, was positive by RIBA 3.0, and reacted for antibody to hepatitis B core antigen. Twenty-six index donors were successfully recalled 3 to 7 months after their index donation. None seroconverted to positivity in RIBA 2.0, 1 was nonreactive, and 25 remained positive for c22-3 only. The restricted epitope reactivity in peptide EIA and RIBA 3.0 was maintained over time in all cases. All 26 of the follow-up samples tested negative by PCR.
On the basis of the restricted peptide reactivity and PCR negativity of index and follow-up samples, it is concluded that the majority of c22-3 RIBA 2.0-indeterminate results are due to nonspecific cross-reactivity to restricted (principally, N-terminal) regions of HCV core antigen.
在第二代酶免疫测定法（EIA 2.0）中对丙型肝炎病毒（HCV）呈反复反应性的约25%的献血者血清，在第二代重组免疫印迹测定法（RIBA 2.0）中结果不确定，其中超过76%的这些结果是由于对HCV重组抗原c22 - 3的单一反应性。
呈现了46名在EIA2.0中呈反应性且在RIBA 2.0中c22 - 3结果不确定的异体志愿献血者的数据。通过一组五种合成肽酶免疫测定法、一种除重组蛋白外还使用合成肽的原型条带免疫印迹测定法（RIBA 3.0）以及针对HCV RNA的聚合酶链反应（PCR）对索引样本和随访样本进行评估。
所有46份献血样本的丙氨酸氨基转移酶值均正常；只有2份（4.3%）对乙型肝炎核心抗原抗体呈反应性。使用一组涵盖c22 - 3重组抗原整个序列的12种合成肽，33份血浆（72%）对一种肽呈反应性或无反应，其中19份血浆的反应性完全局限于c22 - 3的N端肽（1 - 15个氨基酸）。使用RIBA 3.0时，28份献血样本（61%）无反应，其中25份在EIA中对一种肽呈反应性或无反应。在这25份血浆中，18份仅与N端序列呈反应性。所有46份索引献血样本均进行了PCR检测；唯一PCR阳性的样本与四种HCV肽呈反应性，RIBA 3.0呈阳性，且对乙型肝炎核心抗原抗体呈反应性。26名索引献血者在其索引献血后3至7个月成功被召回。在RIBA 2.0中无人血清转化为阳性，1份无反应，25份仅c22 - 3仍为阳性。在所有情况下，肽EIA和RIBA 3.0中受限的表位反应性随时间保持不变。所有26份随访样本的PCR检测均为阴性。
基于索引样本和随访样本受限的肽反应性及PCR阴性结果，得出结论：大多数c22 - 3 RIBA 2.0结果不确定是由于对HCV核心抗原受限（主要是N端）区域的非特异性交叉反应。
