Homozygous NF-kB1 mutation causing combined immunodeficiency: a histopathological analysis

Introduction: The nuclear factor-kB (NF-kB) signaling pathway plays a major role in mediating multiple cellular processes, including immune and inflammatory responses. Aims: We describe the histopathological findings of lymph nodes from a patient with a homozygous NF-kB subunit 1 (NF-kB1) mutation causing a combined immunodeficiency phenotype. Results: A nodal biopsy was performed for lymphadenopathy evaluation, in the context of development of persistent EBV infection. Our findings show that this patient has normal lymph node tissue present, however, abnormal histopathology features were observed, including atrophic germinal centers. B cell subset components within the B cell domain were also analyzed. The development of the B cell response during EBV infection was found to be significantly impaired. Conclusion: Aberrant signaling due to NF-kB1 deficiency has a significant impact on the development of B cell immunoproliferative responses. Statement of novelty: We report on the abnormal histopathology findings of lymph node biopsy from a patient with homozygous NF-kB1 mutation.