Gene expression analysis provides a potential rationale for revising the histological grading of follicular lymphomas

Pier Paolo Piccaluga, Andrea Califano, Ulf Klein, Claudio Agostinelli, Beatriz Bellosillo, Eva Gimeno, Sergi Serrano, Francisco Sole, Yonghui Zang, Brunangelo Falini, Pier Luigi Zinzani, Stefano A. Pileri

Research output: Contribution to journalArticlepeer-review

Abstract

Background Follicular lymphomas are currently subdivided into grades I, II, IlIa and IIIb. This distinction is, however, questioned. Design and Methods We studied the gene expression profile of 43 follicular lymphomas, 50 B-cell non-Hodgkin's lymphomas of different histotype, and 20 samples of normal B-lymphoeytes in order to assess: (i) the relationship of follicular lymphoma with normal B cells and other B-cell non-Hodgkin's lymphomas; (ii) whether follicular lymphoma is a unique disease; and (iii) whether follicular lymphoma grade IIIb is closer to follicular lymphoma or diffuse large B-cell lymphoma of the germinal center B-cell type. Results First, we found that the molecular profile of follicular lymphoma is intimately related to that of normal germinal center B cells, irrespectively of the histological grade. Secondly, we observed that follicular lymphoma has a relatively homogeneous gene expresion profile that is distinct from that of other B-cell non-Hodgkin's lymphoma and does not include discrete molecular subgroups. However, by further clustering samples according to signatures differentially expressed among follicular lymphomas or in follicular lymphomas versus diffuse large B-cell lymphoma, we showed that grade l-llla tumors tend to cluster together, while grade Illb follicular lymphoma constitutesa distinct subgroup, whose molecular signature is closer to that of the remaining follicular lymphomas than to that of diffuse large B-cell lymphoma of the germinal center B-cell type. Conclusions These data support the hypothesis that grade Illb follicular lymphoma does indeed belong to the group of follicular lymphomas ratherthan diffuse large B-cell lymphomas, and also suggests a possible revision of the histological grading of follicular lymphomas, with their simple distinction into follicular lymphoma (grade l-llla) and follicular lymphoma/large cell (grade Illb).

Original languageEnglish
Pages (from-to)1033-1038
Number of pages6
JournalHaematologica
Volume93
Issue number7
DOIs
Publication statusPublished - Jul 2008

Keywords

  • DNA microarray
  • Follicular lymphoma
  • Histological grading
  • Non Hodgkin's lymphoma

ASJC Scopus subject areas

  • Hematology

Fingerprint Dive into the research topics of 'Gene expression analysis provides a potential rationale for revising the histological grading of follicular lymphomas'. Together they form a unique fingerprint.

Cite this