Difficulty of recruiting

Cancer-specific splice variants gain significant interest as they generate neo-antigens, that could be targeted by immune cells. CD20, a membrane antigen broadly expressed in mature B cell lymphomas, is subject to an alternative splicing named Delta-CD20 leading to loss of membrane expression of the spliced isoform.

The investigators group would now determine if it's possible, in patients with lymphoproliferative B, to detect the presence of a specific memory response to delta-CD20 peptides.

If this memory response exists, it will confirm the interest of this antigen as a target for tumor immunotherapy.

Inclusion Criteria:

• For all patient :

  •Written informed consent

• For Cohort A :

  • Patient with hematological malignancy of high grade phenotype B (non Hodgkin's lymphoma diffuse large cell) or low grade (mantle cell lymphoma, follicular lymphoma, marginal zone lymphoma or Waldenstrom disease), regardless the initial extension stage.
  • Histologically or cytologically and immunophenotypical confirmed
  • Patient candidate to a second-line or more therapy
  • First-line treatment with rituximab

• For Cohort B :

  • Absence of prior treatment with an anti-CD20 antibody
  • Histologically or cytologically and immunophenotypical confirmed

Exclusion Criteria:

• For all patients :

  • Patient with any medical or psychiatric condition or disease,
  • Patient under guardianship, curatorship or under the protection of justice and pregnant women

• For Cohort A :

  • Patient with chronic lymphocytic leukemia
  • Patient with indolent lymphoma relapsed more than 1 year after treatment with Rituximab
  • Patient allogeneic hematopoietic cells
  • Patient with linked lymphoproliferative syndrome with congenital immunosuppression (eg SCID, XLP ...) or acquired (post-transplant lymphoma)

The patients studied will be carrying a malignant lymphoproliferative B high grade or low grade treated with an anti-CD20 antibody (cohort A) or hematological whatever type not treated with an anti-CD20 antibody ( cohort B).