Comparative Analysis of Immunohistochemical Algorithms for Subtyping Nodal DLBCL According to Cell-of-Origin: Comparison with the Germinal Center B-Cell Marker HGAL
LIvia M Bacchi, Gabriela Gualco, Yaso Natkunam, Carlos E Bacchi. Universidade de São Paulo, São Paulo, SP, Brazil; Consultoria em Patologia, Botucatu, SP, Brazil; Stanford University, Stanford, CA
Background: Diffuse large B-cell lymphoma (DLBCL) can be molecularly separated into germinal center B-cell (GCB) and activated B-cell (ABC) subtypes. immunohistological algorithms have been proposed in order to facilitate the separation of these subtypes at the protein level in routine specimens. We analyzed 424 cases of nodal DLBCL applying three previously described algorithms (Hans, Choi and TALLY) and compared their results with a new combination including the germinal center B cell-associated marker, HGAL.
Design: TMA sections containing 424 cases of nodal DLBCL were stained using antibodies against CD10, BCL6, MUM1, FOXP1, GCET1, LMO2 and HGAL. All cases were classified as GCB or non-GCB by applying Hans (CD10, BCL6, MUM1), Choi (GCET1, MUM1, CD10, BCL6, FOXP1) and TALLY (CD10, GCET1/MUM1, FOXP1, with LMO2 as discriminator when score is equal) algorithms. Monoclonal anti-HGAL was used as an additional GC marker combined with the 3 algorithms above.
Results: Comparative results of different algorithms in 424 cases of nodal DLBCL are summarized in the table below.