General description

Diffuse large B-cell lymphoma (DLBCL) represents different clinicopathologic entities which are difficult to separate using standard techniques. From the clinical standpoint, the introduction of immunochemotherapy in the treatment of DLBCL has dramatically improved the outcome of these patients compared with chemotherapy alone. Gene expression profiling (GEP) studies have shown that DLBCL can be reproducibly divided into the important subtypes of germinal center B-cell–like (GCB), activated B-cell–like (ABC), and unclassified DLBCL. It is beneficial to translate the GEP classification into protein expression by tumor cells through immunohistochemical (IHC) staining of formalin-fixed, paraffin-embedded tissues. A panel of antibodies: CD10, BCL6, MUM1/IRF4, GCET1, FoxP1, LMO2, and BCL2 has been used to determine GCB or ABC and each has different percentage thresholds for positive staining. Choi et al. demonstrated that the cases positive for GCET1 (≥ 80% of tumor cells) and MUM1/IRF4 (≥ 80%) and/or FoxP1 (≥ 80%) or negative for CD10 and BCL6 (≤ 30%) were assigned to the group. The cases positive for CD10 (≥ 30%), GCET1 (≥ 80%) without MUM1 expression, or positive for BCL6 without FoxP1 expression were classified as GCB. This study indicated the importance of FoxP1 in the subclassification of DLBCL. Choi et al then modified their approach to DLBCL subclassification by focusing on FoxP1. The tumors that are positive for both FoxP1 and GCET1 are assigned to GCB subgroup, but, if FoxP1 is positive and GCET1 is negative, the tumors belong to the ABC phenotype. If a case is FoxP1 negative but MUM-1/IRF4 positive, it still belongs to the ABC phenotype as long as CD10 is not expressed. This modified method emphasized the role of FoxP1, MUM1/IRF4, and GCET1 in the subclassification of DLBCL. The Choi’;s algorithm had a very high concordance with the GEP results (87%). Therefore, FoxP1 is useful in subclassification of DLBCL and a high cutoff (≥80%) for FoxP1 is needed to achieve high specificity for the ABC subtype.

Legal Information

Cell Marque is a trademark of Sigma-Aldrich Co. LLC

Linkage

FoxP1 Positive Control Slides, Product No. 350S, are available for immunohistochemistry (formalin-fixed, paraffin-embedded sections).

Other Notes

For Technical Service please contact: 800-665-7284 or email: [email protected]

Physical form

Solution in Tris Buffer, pH 7.3-7.7, with 1% BSA and ﹤0.1% Sodium Azide

Preparation Note

Download the IFU specific to your product lot and formatNote: This requires a keycode which can be found on your packaging or product label.

Quality