1. 2020;23;S381-S390Value and Validity of Coronavirus Antibody Testing
   Focused Review
   Amit Mahajan, MBBS, and Laxmaiah Manchikanti, MD.

BACKGROUND: The interventional pain management community saw the COVID-19 pandemic decimate elective interventional procedures and new patient visits across the United States until the reopening of America and the restarting of interventional procedures and elective surgical procedures began again. Health care providers, along with essential workers and patients, continue to be concerned about functioning in a safe and responsible manner. Consequently, a level of comfort is created by the testing health care workers with long exposure to new patients and patients undergoing interventions in high risk environments.

As the United States and the world suffers from an ongoing infodemic, there are substantial amounts of misinformation, and some appropriate information being produced on molecular, antigen and antibody testing. Consequently, this manuscript is undertaken to describe the value and validity of coronavirus antibody testing.

METHODS: Literature review.

RESULTS: Antibody tests detect antibodies or immunoglobulins that are produced as the human immune response to SARS-CoV-2 infection. A positive result suggests that the individual has potentially been exposed to SARS-CoV-2. When immunoglobulins M (IgM) antibodies are present, they can indicate an active or recent infection, whereas immunoglobulin G (IgG) antibodies show up later in the infection process and can often indicate a past infection, but does not exclude recently infected patients who can still be contagious, especially when IgM antibodies are also concurrently detected. While past knowledge indicates that for viral infections, IgG antibodies usually persist longer than IgM antibodies and provide immunity from re-infection, it is not clearly known if that is true for COVID-19.

LIMITATIONS: A narrative review with paucity of literature.

CONCLUSION: Antibody tests have been developed to detect IgG only, both IgG and IgM, or total antibodies. At present, multiple antibody tests are available for use in the United States. In a review of 54 available studies through the end of April, mostly from China, the accuracy of pooled results for combination IgG/IgM tests was 91.4% (95% CI, 87.0 - 96.6) for 15 to 21 days post-symptom onset. Thus, antibody tests provide a promise and a peril in the ongoing Covid-19 pandemic.

KEY WORDS: Corona, COVID-19, antigen testing, antibody testing, IgM antibodies, IgG antibodies