NEW DELHI– U.S. researchers have identified a potential biomarker for long Covid that could pave the way for more accurate diagnoses and targeted treatments.
Currently, long Covid is diagnosed based on a patient’s reported symptoms appearing 12 weeks or more after initial SARS-CoV-2 infection, without a confirmatory test. The new study, published in Infection, found fragments of SARS-CoV-2 proteins within extracellular vesicles (EVs) — tiny packages used by cells to share proteins, metabolites, and other materials.
“If a patient presents with persistent symptoms typical of long Covid, I can only give a presumptive diagnosis,” said William Stringer of the Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center. “We don’t yet have blood tests or biomarkers to confirm it.”
Analyzing 56 blood samples from 14 long Covid patients over 12 weeks of aerobic exercise training, researchers detected 65 distinct protein fragments from the virus’s Pp1ab protein — an RNA replicase enzyme critical to viral replication. These viral peptides appeared in EVs from long Covid patients but not in pre-pandemic control samples.
While the findings suggest a unique and quantifiable marker for the condition, researchers caution it remains unclear whether the peptides represent residual “molecular trash” or signs of ongoing viral activity. Further studies are needed to determine their origin and role in long Covid. (Source: IANS)
