Coccidioidomycosis is most frequently diagnosed serologically, and the quantitative test for complement-fixing antibodies is considered prognostically useful. Because complement-fixing antibody testing is complex, labor-intensive, and poorly standardized, an enzyme-linked immunoassay (ELISA) alternative would be attractive. In this report, we restrict the complement-fixing, antibody-binding domain to a 200-amino-acid recombinant peptide of the known antigen. Over-lapping truncations of this peptide do not bind complement-fixing antibodies, suggesting that the responsible epitope(s) are conformational. Further, anchoring the antigenic peptide to the ELISA plate by means of a C-terminal biotin-mimic peptide tag instead of allowing the peptide to randomly adhere to the plastic plate improves sensitivity of antibody detection by 1–2 logs in different sera. The newly developed ELISA shows a significant quantitative correlation with complement-fixing antibody titers. This ELISA shows potential as the basis for a new quantitative assay for coccidioidal antibodies.

球孢子菌病最常通过血清学诊断，补体固定抗体的定量检测在预后上是有用的。由于补体固定抗体测试非常复杂，劳动强度大且标准化程度不高，因此酶联免疫测定（ELISA）替代品将很有吸引力。在本报告中，我们将补体固定抗体结合域限制为已知抗原的200个氨基酸的重组肽。该肽的重叠截短不结合补体固定抗体，表明负责的表位是构象的。进一步，通过C端生物素模拟肽标签将抗原性肽固定在ELISA板上，而不是让肽随机粘附在塑料板上，从而通过在不同血清中检测1-2个对数来提高抗体检测的灵敏度。新开发的ELISA与补体固定抗体滴度显示出显着的定量相关性。此ELISA显示了潜力，可作为新的球虫抗体定量测定的基础。