COVID-19 False-Positives Rampant in Those with Autoimmune Disease

March 11, 2024

A research correspondence published in the New England Journal of Medicine, titled Persistent False Positive Covid-19 Rapid Antigen Tests, highlights a phenomenon observed in rapid antigen testing for SARS-CoV-2, where some individuals, particularly women with autoimmune disorders, repeatedly test positive on rapid antigen tests despite negative molecular tests.

The study involved two longitudinal cohort studies with participants undergoing serial rapid antigen and RT-PCR testing. Persistent false positives were more common among women and individuals with autoimmune disorders, particularly those with rheumatoid factor. The study suggests that the cross-reactivity of test antibodies with rheumatoid factor may lead to persistent false positivity. It recommends repeat testing with a different brand of rapid antigen test for individuals with autoimmune diseases and persistent false positive results.

This finding is crucial for clinical practice and public health efforts to distinguish between cross-reactive false positivity and actual SARS-CoV-2 infection.

Citation for report:

Herbert, C., McManus, D. D., & Soni, A. (2024). Persistent False Positive Covid-19 Rapid Antigen Tests. The New England journal of medicine, 390(8), 764–765. https://doi.org/10.1056/NEJMc2313517