NCT07358897

Brief Summary

Our immune systems protect us from infection but can also cause disease, for example by attacking our own bodies (autoimmune disease), or driving chronic inflammation in conditions such as heart disease. The immune systems of men and women function differently, as evidenced by differing rates of disease with autoimmune disease being more common in women whilst men are more susceptible to infection. We don't know why these differences exist, but if we could understand we may be able to develop new treatments to treat or prevent immune driven diseases. So far, we know that both sex chromosomes and hormones affect how the immune system functions, but not the exact contribution of each or how they interact. One way to study this is to work with transgender people. Transgender people identify as a gender different from their sex assigned at birth and some may choose to take the sex hormones of the gender they identify with, which is known as gender affirming hormone therapy (GAHT). Given that these changes affect their sex hormone profile and not their chromosomes, any changes in their immune system would be driven by hormones only. This would help us understand not only how sex hormones shape the immune system more generally, but also the disease risk in transgender people and enable better patient counselling. In this study, transgender patients starting on GAHT at 56 Dean Street clinic in London would be invited to donate blood samples before starting therapy, at 1 month (optional) and at 3 and 6 months. These samples would be analysed at the Laboratory of Medical Sciences to examine how the different types of immune cells change with therapy and how they respond to different immune triggers (stimuli). We aim to recruit 500 individuals and anticipate the study will last up to 3 years.

Trial Health

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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
500

participants targeted

Target at P75+ for all trials

Timeline
32mo left

Started Feb 2026

Typical duration for all trials

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress8%
Feb 2026Jan 2029

First Submitted

Initial submission to the registry

January 14, 2026

Completed
8 days until next milestone

First Posted

Study publicly available on registry

January 22, 2026

Completed
25 days until next milestone

Study Start

First participant enrolled

February 16, 2026

Completed
2.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 7, 2029

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

January 7, 2029

Last Updated

January 22, 2026

Status Verified

January 1, 2026

Enrollment Period

2.9 years

First QC Date

January 14, 2026

Last Update Submit

January 14, 2026

Conditions

Transgender

Outcome Measures

Primary Outcomes (1)

  • Immune system adaptations to gender affirming hormone therapy

    We will measure how immune system populations change quantitatively (i.e. the relative proportions of each subpopulation) and in their responses to different immune stimuli with gender affirming hormone therapy.

    3 years

Secondary Outcomes (2)

  • Hormone concentrations

    3 years

  • Immune-related blood protein levels

    3 years

Eligibility Criteria

Age18 Years - 50 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64)
Sampling MethodNon-Probability Sample
Study Population

Adults between 18 and 50 years of age with diagnosed gender dysphoria about to start gender-affirming hormone therapy with either oestrogen or testosterone.

You may qualify if:

  • Adults between 18 and 50 years of age with diagnosed gender dysphoria about to start gender-affirming hormone therapy with either oestrogen or testosterone.

You may not qualify if:

  • Lack of capacity to consent.
  • Abnormalities in expected pubertal development and pharmacological interventions that could affect levels of gonadal steroids including suspected or confirmed self-treatment with steroid hormone preparations in preceding month (birth control excluded).
  • Serious immunological disease (immune deficiency, autoimmune disease requiring immunomodulatory treatment).
  • Regular immunomodulatory treatment such as prednisolone or biological drugs.
  • In the case of vaccination or symptomatic infection ≤5 days before the visit blood sampling should be postponed by 1 week.
  • Age \<18 years or \>50 years
  • Completed menopause (persons assigned female sex at birth).
  • Positivity for blood borne viruses (HIV, Hepatitis B, Hepatitis C, HTLV-1)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Biospecimen

Retention: SAMPLES WITH DNA

We will keep peripheral blood mononuclear cells, stabilised whole blood and serum and plasma samples for 10 years after the study has completed.

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

January 14, 2026

First Posted

January 22, 2026

Study Start

February 16, 2026

Primary Completion (Estimated)

January 7, 2029

Study Completion (Estimated)

January 7, 2029

Last Updated

January 22, 2026

Record last verified: 2026-01