Despite the promising findings, the study's limitations include a small sample size of 23 participants, indicating the need for further research on long-term health effects of hormone therapies.

Professor Petter Brodin, who led the study, noted the implications for understanding disease differences and developing new treatments, emphasizing the relevance for both cisgender and transgender individuals.

A recent study published in Nature is the first to comprehensively examine the impact of gender-affirming hormone therapy (GAHT) on the immune system of transgender individuals.

The research highlights significant immune system changes in transgender men undergoing testosterone therapy, suggesting that hormones play a crucial role in shaping immune responses.

The authors hypothesize that these immune responses may have evolved to adapt throughout different life stages, indicating a complex interaction between hormones and immune function.

Findings revealed that testosterone treatment did not alter total immune cell counts but reduced the abundance of plasmacytoid dendritic cells, which are linked to autoimmune diseases.

The study also indicates that sex hormones may cross-regulate immunological pathways, with testosterone influencing tumor necrosis factor (TNF) responses.

Long-term clinical follow-ups for transgender individuals undergoing hormone therapy are emphasized, given the treatment's significant effects on their immune systems and disease risk.

The research underscores the importance of monitoring patients on hormone therapy for potential unintended health consequences.

The review highlights the need for individualized treatment approaches and further research to better understand the effects of GAHT on health outcomes.

The study also sheds light on how biological sex influences immune function, with men generally facing higher risks from infections like COVID-19, while women are more susceptible to autoimmune disorders.

Laboratories face challenges in interpreting tests for transgender individuals due to a lack of published reference intervals, necessitating sex-specific reference ranges for accurate diagnosis.