Constitutive Activity of Nuclear Transcription Factor κB is Observed in Follicular Lymphoma

Constitutive activity of nuclear transcription factor κB (NF-κB) is observed in many pathological types of lymphoma that are associated with a poor clinical course. This suggests that NF-κB and pathways involving NF-κB are possible targets for successfully treating lymphoma. We examined 28 lymph nodes from 28 patients in whom follicular lymphoma was diagnosed from 1996 to 2006 at our institution, which were formalin-fixed and paraffin-embedded. The specimens were stained with an antibody that could recognize activated NF-κB and p65 to determine whether they were positive or negative for NF-κB activation. The clinical courses of the 28 patients were then correlated with the results of the NF-κB staining. The 10 men and 18 women had a mean age of 57.3 years (range, 25-87 years). By follicular lymphoma grade, 10 patients had grade 1, 16 had grade 2, and 2 had grade 3a. Ten patients died due to lymphoma. NF-κB was positive in 6 of the 28 cases. Analysis of the positive and negative staining groups while taking into account the clinical course, sex, age, grade of follicular lymphoma, prognostic index, CD10, CD23, Bcl-2, karyotype t(14;18), and survival showed that no significant differences. Six of the 28 lymph nodes (21.4%) exhibited consistent NF-κB activity. Three of the eleven cases that transformed to aggressive lymphoma were positive for activated NF-κB. Further research to clarify the significance of constitutive NF-κB activity in follicular lymphoma is therefore warranted. [J Clin Exp Hematopathol 50(1) : 45-50, 2010]