An interventional study of CO-Rebreathing technique at diagnosis of polycythemia in Polycythemia, sponsored by Centre Hospitalier Universitaire, Amiens. Completed at 1 site in France. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2025-09-19.
Sponsored by Centre Hospitalier Universitaire, Amiens · Not applicable, Interventional, and Prevention
The optimized CO-Rebreathing is an efficient method to evaluate the red cell mass and has been used in the vast majority of studies in sport medicine. However, this method has never been evaluated on a large scale in the diagnosis of primitive or secondary polycythemia. The standard procedure to evaluate the red cell mass is based on isotopic measurement using Cr51-labelled red cells, but its lack of availability in many centers highlights the need for a non-invasive and rapid alternative method. The purpose of this study is to evaluate and validate the CO-Rebreathing method in this set of indications.
The definition of a true polycythemia is stricto sensu an increased red cell mass (RCM) above 125% of the expected value depending on the size and the weight of the patient. However, this measurement requires an isotopic labeling of red cells and is not available in most of the hospitals. Therefore, the diagnosis of polycythemia, and particularly Polycythemia Vera (PV) is based on routine red blood cells parameters, i.e. hemoglobin level and hematocrit. If these parameters are efficient in marked polycythemia, discrepancies have been observed in milder cases. Two situations where a RCM evaluation is particularly required can be described:
32 studies on the registry are indexed under Polycythemia; 12 are open to participants now.
This study's enrollment of 60 is below the median of 67 across 22 interventional studies indexed under Polycythemia.
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Requirement of an isotopic red cell mass determination:
a - Hematocrit between 52 and 60% (men) or 48 and 56% (women) with no argument for a PV (JAK2V617F negative, EPO level normal/high).
b - Patients with a JAK2V617F positive MPN and a hematocrit level between 46 and 50% (women) or 48 and 52% for men.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
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A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The intervention consists in one red cell mass determination using the CO-Rebreathing technique at diagnosis of polycythemia, in addition to the regular tests performed in this indication, including RCM isotopic measurement.
Other: CO-Rebreathing technique at diagnosis of polycythemia
The intervention consists in one red cell mass determination using the CO-Rebreathing technique at diagnosis of polycythemia, in addition to the regular tests performed in this indication, including RCM isotopic measurement.
equivalence of RCM determination by CO-Rebreathing in comparison to the traditional isotopic measurement in the diagnosis of polycythemia
The primary outcome is to prove the equivalence of RCM determination by CO-Rebreathing in comparison to the traditional isotopic measurement in the diagnosis of polycythemia.
Time frame: 1 month
AE / SAE / EI
Incidence, grade type according to NCI-CTCAE v4.0
Time frame: 1 month
Cumulative incidence of thrombotic and hemorrhagic complications
Cumulative incidence of thrombotic and hemorrhagic complications List according to PT1 protocol.
Time frame: 1 month
Deaths and causes
Deaths and causes
Time frame: 1 month
Analysis of the results of VGTCO and VGTi
Analysis of the results of VGTCO and VGTi as a function of hemoglobin and hematocrit
Time frame: 1 month
This study is completed, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
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