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:
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:
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.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Centre Hospitalier Universitaire, Amiens