Long COVID Blood Biomarkers Identified: Diagnostic Breakthrough

Researchers published findings identifying specific soluble immune biomarkers — including IL-20, MCP-1, and NBL1 — that reliably distinguish Long COVID patients from fully recovered individuals in blood samples. The discovery, published in Nature Immunology, was hailed as a major step toward clinical diagnostic tools and treatment targets for the estimated 65 million people globally with Long COVID. The biomarker signature was consistent across age groups and variant exposures, suggesting a common immunological mechanism underlying the chronic condition.