Symposium Summary:
The response of laboratory medicine to the SAR-CoV-2 pandemic has been very fast and comprehensive. Direct detection of viral RNA by different nucleic acid amplification techniques is recommended as the reference and testing is usually performed by nucleic acid amplification techniques. Molecular diagnostics assays differ in design, sensitivity, specificity, throughput and time to result. Two highly automated and real-time PCR-based assays recently developed by Abbott were evaluated regarding their analytical and clinical performance. Both assays were shown to be highly sensitive and specific. While RNA detection allows for a diagnosis of COVID-19 disease in the early stages, patients admitted late may test negative on swabs taken from the upper respiratory tract. The early rise of humoral immune response may allow for an etiological diagnosis in such cases; IgG and IgM antibody response mounts early and peaks in the late stages of the disease, with specific IgG lasting longer after recovery, so the detection of the two Ig classes shall allow for both a timely diagnosis and to define the stage of infection. While the role of antibodies in generating a true protective immunity is yet to be clarified, several evidences indicate that a strong humoral response correlates with viral neutralization. Of note, while clinical sensitivity is relevant for diagnosis, a high specificity is crucial to guarantee a high positive predictive value when asymptomatic populations are screened. Finally, the combination of RNA and antibody detection shall be useful in all the potential testing scenarios.

Quanterix Corporation Industry Symposium