LAUSR

BACKGROUND The clinical laboratory continues to play a critical role in managing the coronavirus pandemic. Numerous FDA emergency use authorization (EUA) and laboratory developed test (LDT) serologic assays have become available. The performance characteristics of these assays and their clinical utility continue to be defined in real-time during this pandemic. The American Association for Clinical Chemistry (AACC) convened a panel of experts from clinical chemistry, microbiology, and immunology laboratories, the in vitro diagnostics (IVD) industry, and regulatory agencies to provide practical recommendations for implementation and interpretation of these serologic tests in clinical laboratories. CONTENT The currently available EUA serologic tests and platforms, information on assay design, antibody classes including neutralizing antibodies, and the humoral immune responses to SARS-CoV-2 are discussed. Verification and validation of EUA and LDTs are described along with quality management approach. Four indications for serologic testing are outlined. Result interpretation, reporting comments, and the role of orthogonal testing are also recommended. SUMMARY This document aims to provide a comprehensive reference for laboratory professionals and healthcare workers to appropriately implement SARS-CoV-2 serologic assays in the clinical laboratory and interpret test results during this pandemic. Given the more frequent occurrence of outbreaks associated with either vector-borne or respiratory pathogens, this document will be a useful resource in planning for similar scenarios in the future.