Effect of Interleukin-10 Gene Polymorphisms on Clinical Outcome of Patients with Aggressive Non-Hodgkin's Lymphoma: An Exploratory Study

Abstract

Current chemotherapy can achieve high response rates in aggressive non-Hodgkin's lymphoma (NHL), but the factors that influence regression and survival remain unknown. The present exploratory study tested the hypothesis whether interleukin-10 (IL-10) polymorphisms predict clinical outcome, leukocytopenia, or infectivity during therapy. IL-10 was chosen because immune alterations are a major risk factor for NHL, and IL-10 is a cytokine involved in inflammatory processes associated with clinical outcome. Five hundred patients with aggressive NHL treated with CHOP/CHOEP were analyzed for IL-10 gene polymorphisms, including distal loci -7400InDel, -6752AT (rs6676671), and -6208CG (rs10494879) in comparison with proximal loci -3538AT (rs1800890), -1087AG (rs1800896), and -597AC (rs1800872) according to the incidence and outcome of the lymphoma. No differences in allele frequencies or haplotypes were found comparing a cohort of patients with aggressive NHL/diffuse large B-cell lymphoma with a healthy control group. Patients with aggressive NHL characterized by IL-10(-7400DelDel) had shorter overall survival periods compared with the other genotypes (P = 0.004). The 3-year rate is 43.4% for IL-10(-7400DelDel) and 73.4% for IL-10(-7400InIn) and IL-10(-7400InDel) together. A significant increased risk for event-free survival is found for carriers of the genotype IL-10(-6752TT-6208CC-3538AA) (P = 0.047). Multivariate analysis of IL-10(-7400) gene variation in relation to overall survival adjusted to international prognostic index revealed a relative risk of 1.9 for carriers of IL-10(-7400DelDel) (P = 0.037). No associations were found analyzing diffuse large B-cell lymphoma patients separately. Our results indicate that IL-10 gene variations could be associated to the clinical course of aggressive NHL, which points out the importance of host factors and respective genetic elements for treatment response.