SMOLY : Phenotype and Functions of Monocyte Subtypes in High Grade B Lymphoma: Towards New Biomarkers?
Condition: DLBCL
MeSH terms: Lymphoma
Study type: Observational

Summary: 
      Large-cell B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma and accounts for
      about 40% of new cases. Although the DLBCL is a single entity in the WHO classification,
      several subgroups with different prognoses are recognized. These subgroups take into account
      the tumor localization (primitive cerebral lymphoma, serous lymphoma, intravascular or
      exclusive lymph node) or a particular molecular signature (GCB profile, germline center B
      cell or ABC, activated B cell). Despite the introduction of immunotherapy, treatment failures
      are common. Overall survival at 5 years is estimated to be between 26 and 73%. This
      highlights the important heterogeneity of this pathology and therefore the need for
      biomarkers prognosis. Recently, an increase in monocytes in the blood of DLBCL patients has
      been proposed as a prognostic factor for independent survival. This marker of poor prognosis
      is also found in many solid.

      Monocytes are effectors of the inflammatory response. They have different functional profiles
      depending on the level of expression of CD14 and CD16. Four subtypes of monocytes are
      distinguished: classical (CD14posCD16neg), intermediate (CD14posCD16pos) and non-classical
      (CD14lowCD16pos); the latter population is divided into two sub-groups depending on the
      expression of the SLAN protein. The different monocytic subpopulations have very diverse
      functions ranging from an immunosuppressive profile to an activation of the immune system.
      CD14posCD16neg monocytes are specialized in phagocytosis, production of oxygen derivatives
      (ROS) and pro-inflammatory cytokine secretion in response to microbial infection.
      CD14dimCD16pos monocytes are specialized in immune surveillance and produce proinflammatory
      cytokines such as TNFα and IL-1β in response to LPS stimulation.7 The Slanpos subpopulation
      produces IL-12 and thus has pro-inflammatory properties. Finally, CD14posCD16pos monocytes
      have controversial functions. For some authors, they produce the immunomodulatory cytokine
      IL-10, inhibit the proliferation of CD4 T lymphocytes and induce the recruitment of
      regulatory T lymphocytes, while for others they produce TNF-α, a pro- inflammatory.From a
      practical point of view CD14 and CD16 expression forms a continuum, which translates into
      complexity in the phenotypic definition of these cells and explains the contradictory data on
      their functionalities. Interestingly, in a laboratory work and in the course of publication,
      this fraction is increased in the blood of DLBCL patients compared to healthy donors
      (manuscript in preparation), on the contrary the monocytic fraction CD14dimCD16 pos is
      decreased in these patients.

      In the end, if the increase in monocytes is known to be poor prognosis in patients with
      DLBCL, the monocyte fraction involved and the monocytic functions involved in this phenomenon
      are not known.

      Since 2011, the Clinical and Biological Hematology Services have a database from a research
      protocol (BMS_LyTrans). This protocol includes patients with DLBCL as well as healthy
      patients, in order to allow the biological characterization of biomarkers in this pathology.
      Thus, we have blood samples and analysis of certain monocyte subtypes by flow cytometry at
      diagnosis, in more than 100 patients with DLBCL.
    

Detailed description: 
      Primary objective :

      Describe and compare the distribution of the different monocytic subpopulations according to
      the chemosensitivity profile (group 1) or chemoresistance (group 2) of patients with DLBCL
      and healthy donors (group 3), and identify their specific functionalities.

      Secondary objective :

      To determine the prognostic impact in terms of progression-free survival (EFS) of the
      distribution of the monocytic sub-population (s) defined i during the primary objective, in a
      retrospective study (BMS Ly Trans)

      Design/Methodology : Retrospective, observational, monocentric study.

        1. - Part 1: Phenotypic and functional study of monocytic sub - populations of patients
           with DLBCL.

           - Patient selection from the BMS_LyTrans database : Group 1: 15 patients with DLBCL with
           chemoresistance or relapse less than 2 years after completion of first-line therapy.

           Group 2: 15 patients with DLBCL with chemosensitivity without relapse within 2 years
           following the end of first-line treatment.

           Group 3: 15 healthy patients.

           A - Irish Lab (Nashville)

           - Phenotypic analysis by mass cytometry: This new technology allows the integration of
           multiple data with membrane markers, intracytoplasmic proteins as well as transcription
           factors, thus providing global modeling of signaling pathways

           B - UMR 917 (Rennes) 8 months Cell sorting: The four subtypes of monocytes described
           above will be sorted by flow cytometry according to the expression of CD14, CD16 and
           Slan.

           - High-throughput transcriptional analysis: cell lysis and real-time PCR in order to
           study the expression of genes involved in the mechanisms of
           immunomodulation.Bio-informatics, Integrated analysis: The set of clinical,
           transcriptomic and proteomic data will be analyzed in an integrated way using tools and
           algorithms working within the Irish lab.

        2. - 2nd part (Rennes) - 6 months : Populations differentially expressed between groups in
           part 1 will be analyzed on a cohort of 100 samples. These parameters will be analyzed
           jointly after integration in a database, uni- and multivariate analysis and the survival
           probability will be calculated for groups with a log-rank test.

      Expected benefits :

        1. - To allow a better understanding of the monocyte compartment in DLBCL, particularly
           with regard to the immunosuppressive capacity of some of these cellular subtypes.

        2. - To refine the interest of the biomarker "monocyte level" on EFS in patients with
           DLBCL, highlighting the monocyte subtype involved.

        3. - To continue the collaboration between the two sites, which will allow to combine
           technologies and expertise present in Rennes (patient recruitment, cell sorting,
           molecular analysis (Biomark)) or in Nashville (CyTOF, bioinformatics, integrated
           analysis).
    

Observational model: Other
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Patient selection from the BMS_LyTrans database :

        Group 1: 15 patients with DLBCL with chemoresistance or relapse less than 2 years after
        completion of first-line therapy.

        Group 2: 15 patients with DLBCL with chemosensitivity without relapse within 2 years
        following the end of first-line treatment.

        Group 3: 15 healthy patients.
      
Biospecimen description: 
      Patient selection from the BMS_LyTrans database
    
Keywords: DLBCL; chemosensitivity; chemoresistance