Researchers Identify Potential Biomarker for Long COVID Diagnosis

Researchers from the Translational Genomics Research Institute (TGen) and the Lundquist Institute have identified a potential biomarker for long COVID, which could be the first specific and quantifiable indicator for confirming the condition. Long COVID, which affects an estimated 5 to 10 percent of COVID-19 cases, has been difficult to diagnose due to the absence of blood tests or biomarkers, with diagnoses typically based on persistent symptoms lasting 12 weeks or longer. The team discovered SARS-CoV-2 protein fragments within extracellular vesicles (EVs) in the blood of long COVID patients; these EVs carry remnants of the virus's replicase polyprotein 1ab (Pp1ab), essential for viral replication and unique to SARS-CoV-2. This finding was consistent across patients but not in each blood sample, and the viral peptides were absent in pre-pandemic control samples. If validated by further studies, this biomarker could transform the diagnosis and understanding of long COVID, which currently presents symptoms similar to autoimmune, lung, heart, neurological, or psychological disorders and can be debilitating for many. Despite widespread COVID-19 vaccination saving an estimated 2.5 million lives between 2020 and 2024, long COVID remains a significant health challenge, underscoring the need for improved diagnostic tools.