Researchers led by John Tsang at Yale University are developing a comprehensive test to quantify immune system health, producing a single score they call the immune health metric. Writer David Ewing Duncan, who took the experimental test, described the experience in an article published by MIT Technology Review and Aventine. The effort tackles a long-standing challenge in medicine: defining and measuring what it means to have a healthy immune system, a concept that spans absence of disease, resilience, and the effects of aging.
To ground their scoring system, the team analyzed blood samples from 228 people with immune diseases caused by single-gene mutations alongside 42 people without disease, covering a spectrum of immune health. They performed an unusually broad suite of assays, including measurements of diverse immune cell populations, gene expression in blood cells, and levels of more than 1,300 proteins. Using machine learning, the researchers identified patterns that correlate these measurements with health status, enabling them to assign an immune health metric to each individual.
When applied to participants from other studies, the immune health metric tracked with independent indicators of well-being, including how people respond to diseases, treatments, and vaccines. These findings, published in Nature Medicine last year, suggest that the score captures meaningful aspects of immune function that are difficult to assess with standard clinical tests. The work also underscores how complex the immune system is, involving hundreds of interacting proteins and cell types whose collective behavior influences health.
The researchers envision the test helping to identify people at risk of cancer and other diseases, and to explain why individuals respond differently to therapies and immunizations. However, the approach remains experimental and is not yet suitable for clinical use. For now, those curious about their own immune health score will have to wait as the method undergoes further validation and development.
