Flow Cytometric Analysis of Peripheral Blood Neutrophil Myeloperoxidase Expression for Ruling Out Myelodysplastic Syndromes: Protocol for a Diagnostic Accuracy Study

NCT ID: NCT05175469

Last Updated: 2024-03-13

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 400 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2022-03-01
• Study Completion Date: 2025-01-31

Brief Summary

Myelodysplastic syndromes (MDS) are clonal bone marrow neoplasms characterized by dysplasia and ineffective hematopoiesis leading to peripheral blood cytopenias, with an increased risk of progression to acute myeloid leukemia. The conventional diagnostic work-up of MDS relies on cytomorphological evaluation of bone marrow, which may be complemented by conventional cytogenetic, flow cytometry, and molecular analysis by next generation sequencing techniques.

Suspicion of MDS is the commonest reason for bone marrow aspirate in older patients with unexplained peripheral blood cytopenias. Yet many patients are exposed to unnecessary bone marrow aspiration-related discomfort and harms, because of the limited prevalence of disease among subjects referred for suspected MDS. In this context, a valid and reliable assay based on peripheral blood sample that accurately discriminates MDS from other cytopenia etiologies without requiring invasive bone marrow aspiration is warranted.

The accuracy of peripheral blood neutrophil myeloperoxidase expression quantified by flow cytometric analysis for the diagnosis of MDS is supported by three primary studies totaling 211 individuals. An intra-individual robust coefficient of variation (RCV) value for neutrophil myeloperoxidase expression lower than 30.0% accurately ruled out MDS, with both sensitivity and negative predictive value point estimates of 100%, in consecutive patients with suspected disease. This biomarker might obviate the need for cytomorphological evaluation of bone marrow aspirate for up to 35% of patients referred for suspected MDS. Although promising, these preliminary results require replication in an independent external validation sample.

The broad aim of the multicenter MPO-MDS-Valid study project is to prospectively validate the diagnostic accuracy of intra-individual RCV for peripheral blood neutrophil myeloperoxidase expression quantified by flow cytometric analysis among consecutive patients referred for suspected MDS.

Detailed Description

The primary objective of the MPO-MDS-Valid study is to estimate the discriminative accuracy (i.e., area under the ROC curve point estimate along with 95% confidence interval [CI]) of the intra-individual RCV for neutrophil myeloperoxidase expression in peripheral blood for the diagnosis of MDS in consecutive patients.

The secondary objectives are:

1. To estimate the negative predictive value of the intra-individual RCV for neutrophil myeloperoxidase expression in peripheral blood (with a prespecified threshold of 30.0%) for ruling out MDS in consecutive patients.

2. To estimate the prevalence of alternate diagnoses established by bone marrow cytomorphology among true negative patients (i.e., patients with intra-individual RCV value lower than 30.0% and for whom MDS was ruled out by the reference method).

Study design: The MPO-MDS-Valid study project is a multicenter diagnostic accuracy study of an index test by comparison with a reference standard in unselected consecutive patients. An institutional review board (Comité de Protection des Personnes Nord Ouest III) reviewed and approved the study protocol and the information form, prior to study initiation. No specific intervention is assigned to participants. All diagnostic testing, procedures, and medication ordering are performed at the discretion of attending physicians. The index test result will have no impact on patient management.

Screening: All consecutive patients referred for suspicion of MDS to the immuno-hematology lab at the study sites will be screened for eligibility. A lab physician will review inclusion and exclusion criteria, using computerized medical and laboratory records.

Recruitment: Participants will be included in the study once all the screening activities have been conducted and only if the patient meets all inclusion and none exclusion criteria. The consent for flow cytometry analysis of peripheral blood sample and data collection through chart review will be sought under a regime of "non-opposition" (opt-out): after appropriate written information is delivered, data will be collected except in case of opposition from the patient. All patients included in the study will be assigned a unique patient identification number. This number will be used to identify the patient throughout the study.

Index test: Flow cytometric analysis of neutrophil myeloperoxidase expression in peripheral blood will be blinded to the reference standard. Myeloperoxidase expression in the peripheral blood neutrophil population within an individual subject will be expressed as RCV. The intra-individual RCV is calculated as the robust standard deviation divided by the median. The robust standard deviation is a function of the deviation of individual data points to the median of the study population. Intra-individual RCV is expressed as percentage and reflects the variability in myeloperoxidase expression in the peripheral blood neutrophil population within an individual subject.

Reference standard: At each study site, cytomorphological evaluation of bone marrow aspirate will be performed by experienced hematopathologists blinded to the index test.

Morphologic assessment may be complemented by bone marrow flow cytometric score, karyotype, and molecular profiling, where relevant. The reference criteria for MDS are 1) the presence of ≥10% dysplastic cells in any hematopoietic lineage on bone marrow aspirate, and 2) the exclusion of acute myeloid leukemia (defined by the presence of ≥20% bone marrow blasts). Consistent with WHO classification, MDS subcategorization will be based on the degree of dysplasia (unilineage versus multilineage), blast percentages, presence of ring sideroblasts, and cytogenetic analysis (del(5q)).

The reference criteria for chronic myelomonocytic leukemia (CMML) diagnosis are 1) the presence of persistent peripheral blood monocytosis ≥1 x109/L, and 2) monocyte accounting for more than 10% of the white blood cell differential count. Idiopathic cytopenia of uncertain significance (ICUS) will be defined by unexplained mild persistent cytopenia for 4 to 6 months and the failure to establish the diagnosis of MDS according to reference criteria.

Patients with confirmed suspicion of MDS: Participants for whom the diagnosis of MDS (or CMML) is confirmed by the reference standard will be categorized as patients with confirmed suspicion of MDS.

Patients with unconfirmed suspicion of MDS: Participants for whom the diagnosis of MDS (or CMML) is ruled out by the reference standard will be categorized as patients with unconfirmed suspicion of MDS. This latter subgroup will include patients with ICUS, as defined in accordance with published guidelines.

Conditions

Myelodysplastic Syndromes

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: CROSS_SECTIONAL

Interventions

Flow cytometric analysis of neutrophil myeloperoxidase expression

Performance of flow cytometric analysis of neutrophil myeloperoxidase expression in peripheral blood samples will be blinded to the reference standard. Peripheral blood samples will be collected in 5 ml (EDTA) anticoagulant plastic tubes and processed on the same day of collection.

Blood samples will be incubated with a panel of antibodies conjugated to fluorochromes, according to the manufacturers' recommendations.

At least 10,000 cell events will be acquired on a 3-laser, 8/12-color flow cytometer and analyzed using flow cytometry software. Myeloperoxidase expression in the peripheral blood neutrophil population within an individual subject will be expressed as intra-individual robust coefficient of variation (RCV).

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• Age at enrollment ≥18 years
• Referral for suspicion of myelodysplastic syndrome
• Indication for bone marrow examination
• ≥1 peripheral blood cytopenia defined by hemoglobin concentration <12 g/dL for female and <13g/dL for male patients, platelet count <150 x109/L, absolute neutrophil count <1.8 x109/L
• Inpatient or outpatient care

Exclusion Criteria

• Refusal to participate
• History of or active documented MDS or CMML
• Enrollment in intensive or critical care unit
• Incarcerated or individuals protected by French regulation (Article L1121.5 and following, Code de la Santé Publique)
• Not affiliated with social security system
• Previous enrollment in the study

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 100 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Hospital, Grenoble

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Tatiana RASKOVALOVA

Role: PRINCIPAL_INVESTIGATOR

University Hospital, Grenoble

Locations

University Hospital, Clermont-Ferrand

Clermont-Ferrand, , France

Site Status: NOT_YET_RECRUITING

Grenoble_Alpes UniversityHospital

Grenoble, , France

Site Status: RECRUITING

University Hospital Lyon Sud, HCL

Lyon, , France

Site Status: RECRUITING

Institut Paoli Calmettes

Marseille, , France

Site Status: RECRUITING

University Hospital Saint-Eloi

Montpellier, , France

Site Status: RECRUITING

Chu Nantes

Nantes, , France

Site Status: RECRUITING

University Hospital NICE

Nice, , France

Site Status: RECRUITING

University Hospital, Saint-Étienne

Saint-Etienne, , France

Site Status: RECRUITING

Countries

France

Central Contacts

Tatiana RASKOVALOVA

Role: CONTACT

traskovalova@chu-grenoble.fr

04 76 76 63 34

Facility Contacts

Richard VEYRAT-MASSON

Role: primary

Tatiana RASKOVALOVA

Role: primary

TRaskovalova@chu-grenoble.fr

+3347676

Delphine MANZONI

Role: primary

Anne-Catherine LHOUMEAU

Role: primary

Caroline BRET

Role: primary

Caroline MAYEUR-ROUSSE

Role: primary

caroline.mayeurrousse@chu-nantes.fr

Michel TICCHIONI

Role: primary

michel.ticchioni@unice.fr

33+ (0)4 92 03 55 02

Chrystelle ABDO

Role: primary

Chrystelle.Abdo@chu-st-etienne.fr

References

Planta C, Bret C, Manzoni D, Lhoumeau AC, Mayeur Rousse C, Ticchioni M, Campos L, Eischen A, Gonnet N, Merle R, Seigneurin A, Paul F, Comte E, Allieri-Rosenthal A, Tondeur S, Regnart C, Jacob MC, Labarere J, Park S, Raskovalova T. Flow cytometric analysis of peripheral blood neutrophil myeloperoxidase expression in myelodysplastic neoplasms (MPO-MDS-Valid): protocol for a multicentre diagnostic accuracy study. BMJ Open. 2024 Jun 17;14(6):e081200. doi: 10.1136/bmjopen-2023-081200.

Reference Type: DERIVED

PMID: 38889946 (View on PubMed)

Other Identifiers

2021-A01101-40

Identifier Type: OTHER

Identifier Source: secondary_id

38RC21.145

Identifier Type: -

Identifier Source: org_study_id