The inducible T-cell co-stimulator molecule is expressed on subsets of T cells and is a new marker of lymphomas of T follicular helper cell-derivation HAEMATOLOGICA-THE HEMATOLOGY JOURNAL Marafioti, T., Paterson, J. C., Ballabio, E., Chott, A., Natkunam, Y., Rodriguez-Justo, M., Plonquet, A., Rodriguez-Pinilla, S. M., Klapper, W., Hansmann, M., Pileri, S. A., Isaacson, P. G., Stein, H., Piris, M. A., Mason, D. Y., Gaulardll, P. 2010; 95 (3): 432-439

Abstract

T follicular helper (T(FH)) cells reside in the light zone of germinal centers and are considered the cell of origin of angioimmunoblastic T-cell lymphoma. Recently, CXCL13, PD-1 and SAP were described as useful markers for T(FH) cells and angioimmunoblastic T-cell lymphoma but also reported in some peripheral T-cell lymphomas, not otherwise specified.In the present study the expression pattern of ICOS protein was investigated by immunohistochemistry-based techniques in routine sections of normal lymphoid tissues and 633 human lymphomas.Cells strongly positive for ICOS were restricted to the light zone of germinal centers and co-expressed T(FH)-associated molecules. In addition, weak to moderate ICOS expression was observed in a small proportion of FOXP3-positive cells. In lymphomas, ICOS expression was confined to angioimmunoblastic T-cell lymphoma (85/86), peripheral T-cell lymphomas of follicular variant (18/18) and a proportion of peripheral T-cell lymphomas, not otherwise specified (24/56) that also expressed other T(FH)-associated molecules.ICOS is a useful molecule for identifying T(FH) cells and its restricted expression to angioimmunoblastic T-cell lymphoma and a proportion of peripheral T-cell lymphomas, not otherwise specified (showing a T(FH)-like profile) suggests its inclusion in the antibody panel for diagnosing T(FH)-derived lymphomas. Our findings provide further evidence that the histological spectrum of T(FH)-derived lymphomas is broader than previously assumed.

View details for DOI 10.3324/haematol.2009.010991

View details for Web of Science ID 000276292100015

View details for PubMedID 20207847

View details for PubMedCentralID PMC2833073