CO-Rebreathing in Comparison to Isotopic Red Cell Volume Determination in the Diagnosis of Primitive and Secondary Polycythemia (Poly-CO)
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ClinicalTrials.gov Identifier: NCT03008642 |
Recruitment Status : Unknown
Verified February 2019 by Centre Hospitalier Universitaire, Amiens.
Recruitment status was: Not yet recruiting
First Posted : January 2, 2017
Last Update Posted : February 4, 2019
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Condition or disease | Intervention/treatment | Phase |
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Polycythemia | Other: CO-Rebreathing technique at diagnosis of polycythemia | Not Applicable |
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:
- In patients with a hematocrit level between 52 and 60% (men) or between 48 and 56% (women) in order to limit invasive investigations to patients with a confirmed polycythemia diagnosis
- In JAK2V617F positive myeloproliferative neoplasms (MPN) with hematocrit and hemoglobin levels under the PV cut-off in order to discriminate between masked PV and essential thrombocythemia CO-Rebreathing is a fast, non invasive alternative method for RCM evaluation. It is based on the high affinity of carbon monoxide (CO) for hemoglobin. The decrease in the HbCO percentage after CO inhalation is dependent on the total hemoglobin mass from which RCM can be obtained. The investigators propose a tri-centric study evaluating CO-Rebreathing as an alternative tool to measure RCM in the diagnosis of polycythemia in the two categories of patients described above.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 60 participants |
Allocation: | N/A |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Prevention |
Official Title: | CO-Rebreathing in Comparison to Isotopic Red Cell Volume Determination in the Diagnosis of Primitive and Secondary Polycythemia: a Multicentric Study. Co-Rebreathing for the Measurement of Total Red Cell Mass in Polycythemia. |
Estimated Study Start Date : | April 1, 2019 |
Estimated Primary Completion Date : | May 1, 2020 |
Estimated Study Completion Date : | May 1, 2020 |

Arm | Intervention/treatment |
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Experimental: CO-Rebreathing
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.
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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 [ Time Frame: 1 month ]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.
- AE / SAE / EI [ Time Frame: 1 month ]Incidence, grade type according to NCI-CTCAE v4.0
- Cumulative incidence of thrombotic and hemorrhagic complications [ Time Frame: 1 month ]Cumulative incidence of thrombotic and hemorrhagic complications List according to PT1 protocol.
- Deaths and causes [ Time Frame: 1 month ]Deaths and causes
- Analysis of the results of VGTCO and VGTi [ Time Frame: 1 month ]Analysis of the results of VGTCO and VGTi as a function of hemoglobin and hematocrit

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Ages Eligible for Study: | 18 Years to 80 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Adult patient
- Informed consent obtained
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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.
- No recent vascular event (<6 mois)
- No unstable coronaropathy
- Non smoking since 24 hours.
- ECOG <2
- Negativity of pregnancy test/effective contraception for childbearing age women,
- Health insurance
Exclusion Criteria:
- Recent venous event <1 months, cerebral stroke < 6 mois)
- Evolutive cardiopathy (< 6 months)
- Chronic Respiratory failure
- Smokers with no withdrawal in the last 24 hours before CO-Rebreathing
- Basal HbCO>7% the day of CO-Rebreathing
- Pregnant or breast feeding women
- Patient enable to give an informed consent
- Inclusion in an interventional clinical trial in the last three months.
- Any contraindication to lung function testing

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): NCT03008642
Contact: Loïc GARCON, professor | +33 322 087 056 | garcon.loic@chu-amiens.fr | |
Contact: Mohamed AIT AMER MEZIANE, Phd | +33 322 088 384 | aitamermeziane.mohamed@chu-amiens.fr |
Study Director: | Loïc GARCON, professor | CHU Amiens-Picardie | |
Principal Investigator: | Lydia ROY, Doctor | CHU Henri Mondor, France | |
Principal Investigator: | Marjolaine GEORGES, Doctor | Centre Hospitalier Universitaire Dijon |
Responsible Party: | Centre Hospitalier Universitaire, Amiens |
ClinicalTrials.gov Identifier: | NCT03008642 |
Other Study ID Numbers: |
PI2016_843_0032 |
First Posted: | January 2, 2017 Key Record Dates |
Last Update Posted: | February 4, 2019 |
Last Verified: | February 2019 |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Polycythemia CO-Rebreathing red cell mass determination myeloproliferative neoplasms |
Polycythemia Hematologic Diseases |