Analysis of 3.8 million immune cells from nearly 2,000 people reveals distinct periods of immune ageing and sex-specific changes that could help explain differences in age-related and autoimmune diseases.

Scientists at Duke-NUS Medical School have gained new insights into how the immune system changes as men and women grow older. By combining large-scale immune-cell datasets, researchers identified distinct patterns of immune ageing that vary according to both age and sex. The findings, published in Nature Communications, could contribute to more personalised approaches to age- and immune-related diseases.

Autoimmune diseases such as lupus and rheumatoid arthritis occur when the immune system attacks the body's own tissues and are strongly associated with age and sex. The researchers found that immune ageing does not progress steadily. Instead, immune cells undergo periods of more rapid change, with major shifts in gene activity occurring around age 40 and again after 60, particularly in genes involved in RNA and protein production.

T cells, which play a central role in coordinating immune responses, showed some of the most pronounced age-related changes. They were also major contributors to the second wave of immune changes after age 60. Different T-cell populations were affected during the two periods, suggesting that their roles may vary at different stages of life. The researchers also identified differences in how these specialised T cells changed between men and women.

The study analysed the genetic activity of approximately 3.8 million individual immune cells from nearly 2,000 healthy people aged 19 to 97. The participants included people of Asian ancestry, including Singaporeans. By integrating data from multiple publicly available studies, researchers created an immune-cell atlas showing how immune activity changes across the lifespan.

Understanding these age-related changes in T cells could provide insights into why older adults are more vulnerable to infections and inflammatory conditions and may help explain differences in autoimmune disease patterns between men and women.

Researchers from Duke-NUS Medical School's Centre of Biomedical Data Science collaborated with teams working in cardiovascular and metabolic disorders, cancer and stem cell biology, and emerging infectious diseases, along with researchers from the NUS Yong Loo Lin School of Medicine.

The team also developed artificial intelligence models capable of estimating biological age, which reflects the biological condition of the body and may differ from chronological age. These tools could help researchers identify biological pathways and periods when interventions might eventually be tailored according to age and sex.

Overall, the study offers a more detailed view of immune ageing and shows that the process follows different trajectories in men and women. The findings could support future research into more precise approaches for maintaining health and managing age-related and autoimmune diseases.

Source: https://www.asiaresearchnews.com/content/immune-ageing-accelerates-around-40-and-60-key-differences-between-men-and-women