IMMUNOHISTOCHEMICAL PROFILE OF DIFFUSE LARGE B-CELL LYMPHOMA IN A PAKISTANI COHORT: A CROSS-SECTIONAL STUDY

Abstract

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma with variable clinical presentation and prognosis. Immunohistochemical classification into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes is widely used for prognostic stratification. This study aimed to evaluate the immunohistochemical profile and demographic characteristics of DLBCL patients in Karachi, Pakistan.

Methods: This cross-sectional study included 116 patients diagnosed with DLBCL at Dow University of Health Sciences Hospital, Karachi, between 2015 and 2018. Immunohistochemical staining for CD10, BCL6, and MUM1 markers was performed on formalin-fixed paraffin-embedded tissue samples. The Hans algorithm was applied to classify cases into GCB and ABC subtypes.

Results: The mean age of patients was 49.79±16.41 years, with 60.3% males and 39.7% females. Based on the Hans algorithm, 70.7% cases were classified as GCB-DLBCL and 29.3% as ABC-DLBCL. CD10 was positive in 65.51% cases, BCL6 in 78.44%, and MUM1 in 59.48%. The majority of patients (69.9%) had received prior treatment, with 61.2% having undergone chemotherapy, 9.5% radiotherapy, and 12.1% both. No significant association was found between immunohistochemical subtype and age, gender, ethnicity, or treatment history (p>0.05).

Conclusion: Our study reveals a higher prevalence of the GCB subtype among DLBCL patients in Karachi, Pakistan, which differs from patterns reported in some other populations. These findings contribute to the growing body of evidence suggesting regional variations in DLBCL subtype distribution and highlight the importance of local epidemiological data for tailoring treatment approaches.