Brunner M
The Children's Hospital of Philadelphia, Department of Rheumatology, Abramson Research Center 1104D, 3516 Civic Center Blvd., Philadelphia, PA 19104-4318, USA.
J Immunol Methods. 2001 Mar 1;249(1-2):185-90. doi: 10.1016/s0022-1759(00)00356-2.
Serologic tests for Lyme disease are problematic. Because of cross-reactive antigens Borrelia burgdorferi (Bb) shares with other organisms, Lyme disease can be overdiagnosed. However, in addition to specificity problems, serologic tests for early Lyme disease can be falsely negative due to lack of sensitivity of ELISAs and Western blots. Most routine antibody tests are designed to detect free antibodies, and in early, active disease, circulating antibodies may not be free in serum but sequestered in complexes with the antigens which originally triggered their production. This difficulty may be overcome by first isolating immune complexes (IC) from the serum and using this fraction for testing. Free Borrelia-specific antibodies can then be liberated from the immune complexes which may enhance test sensitivity in patients with active disease. We developed a technique that captures the antibody component of IC on immunobeads, and subsequently releases the antigen component of IC. Immunoblotting with monoclonal antibody detected at least one antigen to be OspA, thus definitively demonstrating a Borrelia-specific antigen in circulating IC in early Lyme disease. This test is also useful in demonstrating Bb antigen in otherwise seronegative Lyme disease patients.
莱姆病的血清学检测存在问题。由于伯氏疏螺旋体（Bb）与其他生物体存在交叉反应性抗原，莱姆病可能会被过度诊断。然而，除了特异性问题外，早期莱姆病的血清学检测由于酶联免疫吸附测定（ELISA）和免疫印迹法缺乏敏感性，可能会出现假阴性结果。大多数常规抗体检测旨在检测游离抗体，而在早期活动性疾病中，循环抗体在血清中可能并非游离状态，而是与最初引发其产生的抗原结合形成复合物。通过首先从血清中分离免疫复合物（IC）并使用该部分进行检测，这一难题或许能够得到解决。然后可以从免疫复合物中释放出游离的伯氏疏螺旋体特异性抗体，这可能会提高活动性疾病患者检测的敏感性。我们开发了一种技术，该技术可在免疫微珠上捕获免疫复合物的抗体成分，随后释放免疫复合物的抗原成分。用单克隆抗体进行免疫印迹检测到至少一种抗原为外膜蛋白A（OspA），从而明确证明早期莱姆病循环免疫复合物中存在伯氏疏螺旋体特异性抗原。该检测对于在其他血清学阴性的莱姆病患者中检测Bb抗原也很有用。
