Imunoexpressão de granzima B em linfócitos citotóxicos de linfonodos de pacientes com linfomas B agressivos e correlação de variáveis de prognóstico

Abstract

Background: Cytotoxic lymphocytes (CD8+ T lymphocytes and natural killer cells) are able to induce apoptosis of virus-infected and transformed cells through the secretion of cytotoxic granules rich in granzyme B. Data on the infiltration of these cells into the tumor tissue of aggressive B lymphomas are controversial, and the relationship with pre-treatment data, used for staging purposes, is poorly understood. Thus, this study is aimed at evaluating the expression of granzyme B in lymphocytes in the classic Hodgkin’s lymphoma tumor and diffuse large B-cell non-Hodgkin's lymphoma and correlating this expression with clinical and prognostic variables as well as with the response to initial treatment. Methods: Samples of lymph nodes compromised by Hodgkin's lymphoma or diffuse large B-cell non-Hodgkin's lymphoma were analyzed by immunohistochemistry for granzyme B expression. Results were compared with respect to age, sex, Ann Arbor tumor staging, the presence of B-symptoms, CD8 expression, bone marrow infiltration by lymphoma, serum lactic dehydrogenase, serum β2-microglobulin, and response to initial treatment. Results: Granzyme B expression was lower in samples from patients with advanced tumor staging (p=0.025) and in those with bone marrow infiltrated by lymphoma (p<0.0001). An inverse correlation between granzyme B expression and serum β2-microglobulin levels (p=0.0375; r=-0.4270) was observed. Conclusion: Analysis of granzyme B expression in lymph nodes compromised by aggressive B lymphomas may be a useful prognosis tool for these cancers.