Doctors have no routine test for immune health, but researchers want one

Clinical takeaway: Nothing replaces the white blood cell count and C-reactive protein as immune readouts yet. Watch for a small, inexpensive set of measurements shown to improve treatment decisions, the bar the authors set. 

People of the same age can carry immune systems shaped very differently by genetics, air pollution, smoking, diet and past infections. Differences in how fast the immune system ages have been linked to cancer, neurodegeneration and mortality risk. Clinicians have no routine way to measure immune health, the authors argue, because the immune system is a dynamic network that changes over time. 

Advances in immunology, molecular profiling, imaging and AI are opening new ways to measure immune health. Four investigators now want those tools aimed at a narrower goal: a small set of inexpensive measurements that can guide clinical decisions. Their commentary reports no new data and lays out the steps they say stand between the idea and the clinic. 

Early AI models already appear to predict outcomes, but none has been shown to improve care. One model drew on routine blood tests and clinical details such as age, sex, body weight and medical history to predict outcomes after immunotherapy in people with cancer. Imaging analysis found that a healthy thymus in adults was associated with lower cancer incidence and a lower risk of dying from cardiovascular disease. 

Success, the authors argue, should be judged by whether a small, manageable set of measurements improves decisions, not by how many immune variables can be measured. 

Longitudinal data from large biobanks should come first, tracking several immune measures alongside broader health indicators in the same people, the authors suggest. They also want studies of immune responses before and after vaccination to test whether a routine shot could enable a read-out of immune competence. Many existing immune-profiling data sets are concentrated in populations from high-income countries, so they urge teams worldwide to use the same protocols and make results comparable. 

Simplification comes next, the authors say, with AI tools tested across hospitals and populations before routine use, and their outputs shown to improve treatment decisions. They also call for regulators, health-care organizations and the research community to set standards for consent, data sharing and protection against discriminatory use of immune-health information before any measurement reaches wide clinical use. 

“If scientists can work out which measurements matter, validate them across diverse populations and establish when acting on them improves disease outcomes, immune health could become a routine dimension of medicine, considered not only after the immune system has failed, but also as a tool to help preserve health before it does,” the authors conclude. 

Source: Aerts HJWL, et al. (2026 Oct 27) Nature. Could measuring immune health reshape medical care?