Antigen enzyme-linked immunosorbent assay tests are widely used for the diagnosis of heartworm infection in dogs. While commercially-available heartworm antigen tests have high sensitivity and specificity, false-negative test results can occur in dogs with low worm burdens, female-only infections, or prior to patency. The use of immune complex dissociation (ICD) methods have demonstrated increased sensitivity in the detection of Dirofilaria immitis antigens and the reversal of false-negative antigen results. However, there are concerns pertaining to false-positive antigen results due to infections of other nematode parasites, especially post-ICD. Therefore, this study evaluated the effect of heat-treatment on serum samples of dogs experimentally-infected with Dirofilaria repens during the course of infection, to assess for potential cross-reactivity on heartworm antigen tests. Archived serum samples from three dogs experimentally-infected with D. repens were utilized. All samples were tested for cross-reactivity pre- and post-heat-treatment using the DiroCHEK® Heartworm Antigen test kit throughout infection (day -9 through 404 days post-infection; dpi). All heat-treated samples tested false-positive starting at 164 dpi and continuing through 404 dpi, thereby testing positive prior to patency. No cross-reactivity was observed for any dog at any time point prior to heat-treatment. Our results suggest that the ICD method decreased the specificity of heartworm antigen tests and caused cross-reactivity of serum from dogs experimentally infected with D. repens. In conclusion, heat-treatment of serum in areas co-endemic for D. repens and D. immitis has limited clinical value, and should be used with caution.

抗原酶联免疫吸附试验已广泛用于犬心丝虫感染的诊断。虽然市售的心丝虫抗原测试具有很高的灵敏度和特异性，但蠕虫负担低，仅雌性感染或在通畅之前，假阴性测试结果可能会发生。免疫复合物解离（ICD）方法的使用已证明在检测Dirofilaria免疫炎抗原和逆转假阴性抗原结果中具有更高的灵敏度。然而，由于其他线虫寄生虫的感染，特别是ICD后感染，假阳性抗原结果令人担忧。因此，本研究评估了热处理对实验性感染白粉虱的狗血清样品的影响。在感染过程中，要评估丝虫抗原测试中潜在的交叉反应性。利用了三只经白僵菌感染的狗的存档血清样本。在整个感染期间（感染后第-9天至404天； dpi），使用DiroCHEK®Heartworm Antigen测试试剂盒对所有样品进行了交叉反应前后热处理的测试。从164 dpi开始一直到404 dpi，所有热处理过的样品均测试为假阳性，从而在通畅之前测试为阳性。在热处理之前的任何时间点，任何狗都没有观察到交叉反应。我们的结果表明，ICD方法降低了丝虫抗原测试的特异性，并导致实验性感染白僵菌的狗的血清产生交叉反应。。总之，在区域血清热处理共同流行为D.三叶和D.丝虫具有有限的临床价值，并且应当谨慎使用。