Measuring TSPO Expression in the Lungs of Patients with Pulmonary Arterial Hypertension

Quantifying 18kDa TSPO Expression in the Lung in Pulmonary Artery Hypertension (PAH)

Imperial College London · NCT05745961

This study is testing if a special imaging technique can help see how a protein in the lungs behaves in people with pulmonary arterial hypertension compared to healthy individuals.

Quick facts

Study typeObservational
Enrollment6 (estimated)
Ages25 Years to 75 Years
SexAll
SponsorImperial College London (other)
Drugs / interventionsradiation
Locations1 site (London)
Trial IDNCT05745961 on ClinicalTrials.gov

What this trial studies

This observational study aims to assess the expression of the 18kDa translocator protein (TSPO) in the lungs of patients with pulmonary arterial hypertension (PAH) using PET imaging with the radioligand [11C]PBR28. Participants will undergo two PET scans: the first to measure the total TSPO PET signal and the second after administration of an unlabelled TSPO ligand to differentiate between specific and nonspecific signals. This approach may help in non-invasively monitoring the response to therapy in PAH patients compared to age-matched healthy controls.

Who should consider this trial

Good fit: Ideal candidates include individuals diagnosed with pulmonary arterial hypertension who can provide informed consent and meet the study's eligibility criteria.

Not a fit: Patients with clinically significant renal or liver disease, or those unable to provide informed consent, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a non-invasive method to monitor treatment responses in patients with pulmonary arterial hypertension.

How similar studies have performed: While this approach is novel in the context of PAH, similar imaging techniques have shown promise in other conditions, suggesting potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Able to provide written informed consent prior to any study mandated procedures.

Able to lie comfortably on back for up to 90 minutes at a time.

Fertile females (women of childbearing potential) are eligible to participate after a negative highly sensitive pregnancy test, if they are taking a highly effective method of contraception other than the oral contraceptive pill until the end of relevant systemic exposure.

Male participants who are fertile are eligible to participate if they are willing to comply with the contraceptive requirements

Exclusion Criteria:

Unable to provide informed consent and/or are non-fluent speakers of the English language

TT Genotype at the rs6971 locus

Clinically-significant renal disease (confirmed by creatinine clearance \<30 ml/min per 1.73m2)

Clinically-significant liver disease (confirmed by serum transaminases \>2 times than upper normal limit)

Anaemia confirmed by haemoglobin concentration \<10 g/dl

Sickle cell disease or thalassaemia

History of uncontrolled systemic hypertension

Acute infection (including eye, dental, and skin infections)

Chronic inflammatory disease including HIV, and Hepatitis B

Women of childbearing potential who are pregnant or breastfeeding

Patients who have received an Investigational Medicinal Product (IMP) within 5 half-lives of the last dose of the IMP or 1 month (which ever is greater) before the baseline visit

Participation in a research study involving significant ionisation radiation within the last 3 years

Significant radiation exposure other than dental X-rays in last 1 year

Positive Allen's test.

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Where this trial is running

London

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Pulmonary Arterial Hypertension, Healthy

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.