Cell of Origin Classification of Diffuse Large B-Cell Lymphoma

Area of Science:

• Hematology
• Oncology
• Immunohistochemistry

Background:

• Diffuse Large B-cell Lymphoma (DLBCL) is a heterogeneous B-cell neoplasm with approximately 40% of patients experiencing treatment resistance or relapse.
• Gene expression profiling (GEP) classifies DLBCL into germinal center B-cell (GCB) and activated B-cell (ABC) subtypes, with a notable unclassified group.
• The Hans algorithm, utilizing immunohistochemistry (IHC) markers CD10, BCL6, and MUM1, is a widely accepted method for classifying DLBCL subtypes.

Purpose of the Study:

• To classify DLBCL cases into GCB and non-GCB subtypes using the Hans Algorithm.
• To evaluate the utility of IHC-based subtyping in resource-limited settings.

Main Methods:

• A retrospective analysis of 28 histologically diagnosed DLBCL cases (nodal and extranodal) over two years.
• Immunohistochemistry (IHC) was performed using a primary panel (CD20, CD3, LCA, EMA, CK) and a secondary panel (CD10, CD19, CD30, LMP1, BCL2, BCL6, MUM1, MYC, FOXP1).
• Classification into GCB and non-GCB subtypes was based on the Hans algorithm criteria.

Main Results:

• The non-GCB subtype was found to be more common than the GCB subtype in the studied Indian population.
• The study included patients aged 10-65 years, with a male to female ratio of 2.1:1.

Conclusions:

• Immunohistochemistry (IHC) serves as a practical and acceptable alternative to GEP for DLBCL subtyping, especially when GEP is limited by resources or time.
• The findings highlight the prevalence of the non-GCB subtype in the Indian population, suggesting potential differences in disease characteristics or response to therapy.