People who tend to preserve immune resilience or the capacity to resist or recover from infections and other sources of inflammatory stress are more likely to live longer, finds a study.

"Immune resilience is the capacity to maintain good immune function, called immunocompetence, and minimises inflammation while experiencing inflammatory stressors," scientists explained in the study published in the journal Nature Communications.

The study introduced the novel concept of immune resilience, which looks at the balance between immunocompetence and inflammation as a critical contributor to health outcomes, regardless of age.

"Although age plays an important role in the body's response to infectious and other inflammatory stressors, some persons preserve and/or restore optimal immune resilience regardless of age," said Sunil K. Ahuja, Professor at the University of Texas - San Antonio.

To understand, the team conducted laboratory tests to assess levels of immune resilience in nearly 50,000 persons of differing ages and types of challenges to their immune systems.

This evaluation demonstrated that individuals with optimal levels of immune resilience were more likely to: Live longer, resist HIV and influenza infections, resist AIDS, resist recurrence of skin cancer after kidney transplant, and survive COVID-19 infection and sepsis.

The researchers measured immune resilience by measuring the balance between CD8+ and CD4+ T-cells, which are types of white blood cells.

T-cells fight infections, but an imbalance in their levels occurs in many infectious and autoimmune diseases. The balance between CD8+ and CD4+ T-cells, divided into four distinct categories called immune health grades, was measured in varied infection cohorts and across the age spectrum.

They also measured the expression levels of genes linked with immunocompetence and found a greater chance of survival versus those linked with inflammation and a higher risk of death.

The gene expression markers signifying high immunocompetence and low inflammation were identified with the immune health grade tracking optimal immune resilience.

"This is an advantage and a step forward because by looking beyond inflammation, we may uncover new prevention and treatment strategies for chronic diseases such as cardiovascular disease, COVID-19, HIV and cancers," said co-author Grace C. Lee, Assistant Professor at the varsity's College of Pharmacy.