Thymus removal and immune aging in people with Down syndrome

Natural History of Dysregulation and Aging of the Immune System in People With Trisomy 21 With and Without Thymectomy

This study will try to see if removing part of the thymus affects immune health over time in people aged 1 and older with Down syndrome, comparing those who had thymectomy to those who did not and to unaffected household relatives.

Quick facts

• Study type: Observational
• Enrollment: 700 (estimated)
• Ages: 1 Year to 120 Years
• Sex: All
• Sponsor: National Institutes of Health Clinical Center (CC) (NIH)
• Locations: 1 site (Bethesda, Maryland)
• Trial ID: NCT07416201 on ClinicalTrials.gov

What this trial studies

This is a longitudinal observational cohort study enrolling people with trisomy 21 (Down syndrome), including individuals who have had partial thymectomy and those who have not, plus unaffected household relatives as controls. Participants have a baseline visit and yearly follow-up visits (at least annually for up to 15 years) with physical exams and collection of biospecimens such as blood and stool, and clinical data from routine care may also be used. The study aims to define immune signatures linked to infections, autoimmunity, lung disease progression, and malignancy, and to analyze how immunomodulatory treatments and prior thymectomy influence these outcomes. All visits occur at the NIH Clinical Center in Bethesda, Maryland, and extra visits can be scheduled as clinically indicated.

Who should consider this trial

Good fit: Ideal candidates are people aged 1 year or older with documented trisomy 21, including both those who have undergone partial thymectomy and those who have not, plus their unaffected household relatives for control comparisons.

Not a fit: People without Down syndrome, or those unable or unwilling to provide consent, attend yearly visits, or give biospecimens, are unlikely to receive direct benefit from participation.

Why it matters

Potential benefit: If successful, this work could identify immune markers and long-term risks related to thymectomy in people with Down syndrome, helping guide monitoring and treatment decisions.

How similar studies have performed: Prior studies have documented immune abnormalities in Down syndrome and shown that thymectomy can alter immunity in other populations, but the long-term effects of thymectomy specifically in people with Down syndrome are not well established.

Eligibility criteria

* INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

1\. Aged \>=1 year.

2\. Willingness to allow storage of specimens and data for future research.

* Additional Inclusion Criteria for Affected Participants

  1. Documented T21 based on chromosomal karyotype test.
  2. Ability of participant or LAR to provide informed consent.
* Additional Inclusion Criteria for Unaffected Relatives

  1. Ability of participant to provide informed consent or, for individuals \<18 years of age, to provide informed assent as applicable.
  2. Reside in the same household as the corresponding affected participant.

EXCLUSION CRITERIA:

An individual who meets any of the following criteria will be excluded from participation in this study:

1\. Any condition that, in the judgment of the investigator, may put the participant at undue risk or make them unsuitable for participation in the study.

Where this trial is running

Bethesda, Maryland

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States (Recruiting)

Study contacts

• Principal investigator: Luigi D Notarangelo, M.D. — National Institute of Allergy and Infectious Diseases (NIAID)
• Study coordinator: Luigi D Notarangelo, M.D.

Conditions Down Syndrome; Immunologic Deficiency Syndromes; THYMECTOMY