CD8+ T-cell PET/CT Imaging in COVID-19 Patients (Tangelo)
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ClinicalTrials.gov Identifier: NCT04874818 |
Recruitment Status :
Recruiting
First Posted : May 6, 2021
Last Update Posted : June 7, 2022
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Condition or disease | Intervention/treatment |
---|---|
Lymphopenia Due to COVID-19 T-cell PET Imaging | Diagnostic Test: [89Zr]Df-IAB22M2C PET/CT scan |
Rationale: A subset of patients diagnosed with SARS-CoV2 infection present with lymphopenia. The degree of lymphopenia, and in particular reduced CD8+ T-cell numbers, is strongly correlated with clinical deterioration and ICU admission .
The underlying reasons for lymphopenia in COVID-19 is currently unclear, but several hypotheses have been put forward; 1) sequestration of CD8+ T-cells in peripheral tissues (e.g. lung) either during the effector phase of their lifespan or passively by local chemotactic signals, 2) accelerated maturation and apoptosis either induced by storm of inflammatory cytokines or direct infection or 3) resulting from decreased lymphopoiesis induced by reduced levels of stem cell factor. The lack of data on in vivo distribution of CD8+ T-cells hampers a more thorough understanding of this critical prognostic factor.
Aim: We aim to assess differences in the in vivo distribution of CD8+ T-cells in patients with proven SARS-CoV2 presenting with lymphopenia or with normal lymphocyte counts, using [89Zr]Df-IAB22M2C PET/CT imaging.
Study design: This is a prospective, observational non-randomized pilot study in 20 patients with microbiologically proven SARS-CoV2 infection. All patients will undergo a whole body [89Zr]Df-IAB22M2C PET/CT scan.
Study population: Twenty patients ≥50 years of age with proven COVID-19, who are admitted to the ward will be included, patients will be stratified according to lymphocyte counts on admission to ensure an even distribution: presenting with lymphopenia (<1.0 x10e9/L) (n=10) and with lymphocyte numbers within normal range (1.0 - 3.5 x10e9/L) (n=10).
Study procedure: All patients will undergo a [89Zr]Df-IAB22M2C PET/CT scan 21-27 hours post intravenous injection of 1.5mg protein dose labelled with 37 megabecquerel (MBq) (1 mCi) 89Zr; and one additional blood sample at the day of scanning.
Primary study objective: The primary objective of this study is to assess differences in the in vivo distribution of CD8+ T-cells in patients with proven SARS-CoV-2 presenting with lymphopenia or with normal lymphocyte counts, using [89Zr]Df-IAB22M2C PET/CT imaging.
Secondary study objectives:
- To assess the spatial correlation between [89Zr]Df-IAB22M2C uptake and abnormal findings on routine contrast-enhanced CT scan of the chest
- To assess the correlation between in vivo biodistribution of [89Zr]Df-IAB22M2C and concurrent flowcytometric phenotypic and quantitative assessment of lymphocyte populations
- To explore the correlation between in vivo biodistribution of [89Zr]Df-IAB22M2C and clinical course of disease
Study Type : | Observational |
Estimated Enrollment : | 20 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | [89Zr]Df-IAB22M2C Anti-CD8 Minibody PET/CT Imaging to Assess the in Vivo Distribution of CD8+ T-cells in COVID-19 Patients |
Actual Study Start Date : | February 14, 2022 |
Estimated Primary Completion Date : | December 2022 |
Estimated Study Completion Date : | December 2022 |

Group/Cohort | Intervention/treatment |
---|---|
lymphopenia
lymphocyte counts (<1.0 x10e9/L)
|
Diagnostic Test: [89Zr]Df-IAB22M2C PET/CT scan
PET imaging procedure |
normal lymphocyte numbers
lymphocyte counts ((1.0 - 3.5 x10e9/L))
|
Diagnostic Test: [89Zr]Df-IAB22M2C PET/CT scan
PET imaging procedure |
- The primary objective of this study is to quantify uptake of [89Zr]Df-IAB22M2C, as a surrogate for the presence of CD8+ T-cells, in major organ systems of patients with proven SARS-CoV-2 presenting with lymphopenia or with normal lymphocyte counts. [ Time Frame: 18 months ]The main study parameter is the SUVmean uptake of [89Zr]Df-IAB22M2C in major organs systems, e.g. lungs, spleen, bone marrow, liver and bloodpool
- Based on imaging [ Time Frame: 18 months ]1) Spatial correlation of SUVmean per lung segment with CORADS score per lung segment
- Based on laboratory parameters [ Time Frame: 18 months ]2) In vivo biodistribution of [89Zr]Df-IAB22M2C will be correlated to laboratory test 3) In vivo biodistribution of [89Zr]Df-IAB22M2C will be correlated with lymphocyte counts (x10e9/L)
- Based on clinical characteristics [ Time Frame: 18 months ]4) In vivo biodistribution of [89Zr]Df-IAB22M2C will be correlated with duration of hospital stay (days)

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Ages Eligible for Study: | 50 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- a microbiologically proven SARS-CoV2 infection
- More than 50 years of age;
- Ability to provide written informed consent.
Exclusion Criteria:
- Contra-indication for PET: Pregnancy, Breast-feeding, Severe claustrophobia.
- Contra-indication for administration of iodine-containing contrast agents
- Other serious illness, e.g. history of malignancies or auto-immune disorders
- Known pre-existing lymphopenia from an unrelated other medical condition
- Estimated creatinine clearance ≤ 30 mL/min according to the Cockcroft-Gault formula (or local institutional standard method) OR oligo-uric patients (<400 mL/24hr)

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04874818
Contact: Erik Aarntzen, PhD, MD | +31(0)243614840 | erik.aarntzen@radboudumc.nl | |
Contact: Michel De Groot | +31(0)243614840 | michel.degroot@radboudumc.nl |
Netherlands | |
Radboud university medical center | Recruiting |
Nijmegen, Gelderland, Netherlands, 6500HB | |
Contact: Erik Aarntzen, MD, PhD |
Responsible Party: | Radboud University Medical Center |
ClinicalTrials.gov Identifier: | NCT04874818 |
Other Study ID Numbers: |
NL76248.091.20 2020-005984-29 ( EudraCT Number ) |
First Posted: | May 6, 2021 Key Record Dates |
Last Update Posted: | June 7, 2022 |
Last Verified: | May 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
COVID-19 lymphopenia T-cells PET imaging |
COVID-19 Lymphopenia Respiratory Tract Infections Infections Pneumonia, Viral Pneumonia Virus Diseases Coronavirus Infections Coronaviridae Infections |
Nidovirales Infections RNA Virus Infections Lung Diseases Respiratory Tract Diseases Leukopenia Leukocyte Disorders Hematologic Diseases Immunologic Deficiency Syndromes Immune System Diseases |