Latent Membrane Protein 1 (LMP1) Expression in Hodgkin Lymphoma and Its Correlation with Clinical and Histologic Parameters

Background: Hodgkin lymphoma is one of the most prevalent lymphoproliferative disorders in Pakistan; however, no risk factors for this disease have yet to be established in our population. Epstein-Barr virus (EBV) is a well-known risk factor for Hodgkin lymphoma in endemic regions of the world; however, frequency of its association in our population has not been widely studied. Latent membrane protein 1 (LMP1) expression by immunohistochemistry (IHC) is a surrogate marker of EBV in Hodgkin lymphoma. Therefore, we aimed to evaluate the frequency of expression of LMP1 in cases of Hodgkin lymphoma at our institute and its correlation with other clinical and histologic parameters.

Methods: The study included 66 cases of Hodgkin lymphoma diagnosed at Liaquat National Hospital over a duration of 2 years from January 2014 to December 2015. The slides and blocks of all cases were retrieved, and representative blocks were selected for LMP1 by IHC. LMP1 expression of >10% of cells was considered as positive expression and correlated with histologic subtypes and clinical parameters like age, gender, and site of involvement.

Results: The mean age of patients was 35.11 (+20.22). LMP1 expression was found in 68.1% (45/66) of cases of Hodgkin lymphoma. Mean age of the patients with LMP1 expression was 32.04 (+21.02). LMP1 expression was found in 40% cases of lymphocyte-rich, 66.7% of lymphocyte-depleted, 73.9% of mixed cellularity, 66.7% of nodular sclerosis, and 73.7% of classic Hodgkin lymphoma, NOS. No significant correlation of LMP1 expression with any clinical or histological parameter could be established in our studied patient population.

Conclusions: A high frequency of expression of LMP1 is seen in cases of Hodgkin lymphoma at our setup comparable to endemic regions of the world; therefore, preventive and treatment protocols should be designed accordingly.