ESPE Abstracts

The exploration of sex differences in the human immune system and how these pertain to health- and disease-related outcomes is a growing field, with a steadily increasing number of papers published in this area (~5k per year in 2000 to ~50k per year in 2020). Cisgender females are generally known to mount stronger responses to most infections, including COVID-19 (Peckham et al, 2020), and more effective responses to many vaccines. However, cis-females are also at greater risk of developing numerous humoral autoimmune disorders compared to cisgender males, such as systemic lupus erythematosus (SLE). Disease outcomes in transgender people in receipt of gender-affirming hormone treatments (GAHT) are poorly documented. Both the sex hormones and the sex chromosomes are known to be involved in these sex differences, and through long-collaboration with the young person’s endocrine service at UCL hospital, (comprising the Gender Identity Development Service (GIDS) and DSD clinics), our lab have sought to investigate the relative contributions of these factors to immune differences. Our cohort of healthy pre- and post-pubertal cis-females and -males, healthy young trans people at different stages of GAHT, young people with Klinefelter or Turner Syndrome, and young people suffering from sex-biased autoimmune diseases, permits the in vivo exploration of how the sex hormones and chromosomes affect our immune responses. This session will summarise our findings to date from this unique, gender-diverse cohort. Attendees will learn:

• Why sex and gender should be considered critical factors in immune-related outcomes.

• How the sex hormones and sex chromosomes can affect particular immune cells and processes.

• How these effects may be of significance to clinical outcomes in infection, autoimmunity and other immune-mediated diseases.