Revista Brasileira de Hematologia e Hemoterapia (Aug 2009)
Quantificação das citocinas séricas Th1/Th2 por citometria de fluxo no linfoma de Hodgkin clássico Measurement of Th1/Th2 serum cytokines by flow cytometry in classical Hodgkin lymphoma
Abstract
O linfoma de Hodgkin clássico (LHC) é uma neoplasia com distúrbio na produção de citocinas. Estudos demonstram que o padrão anormal das citocinas no linfonodo acometido pela lesão contribui não somente com a proliferação das células malignas H-RS, como também com o característico infiltrado hiper-reativo que compõe o tecido no LHC. Esta disfunção pode ser observada tanto no quadro clínico dos pacientes, como nas características histopatológicas: sintomas B, deficiência na resposta imune celular, bandas de colágeno e eosinofilia. As concentrações séricas das citocinas Th1 (IL-2, TNF, INF-γ) e Th2 (IL-4, IL-5, IL-10) foram estudadas em 45 pacientes com LHC, ao diagnóstico, e em 34 doadores saudáveis, por citometria de fluxo (CBA - cytometric beads array). Houve aumento das concentrações das citocinas TNF (pClassical Hodgkin lymphoma (CHL) is a malignancy with an abnormal or unbalanced secretion/production of cytokines, which might support the growth of H-RS cells, their surrounding reactive bystander cells and may be responsible for the typical clinical and histopathologic features of CHL: systemic B symptoms, an apparent defect in cell-mediated immune response, tumor fibrosis and eosinophilic infiltrate. Serum concentrations of IL-2, IL-4, IL5, IL-10, TNF and IFN-γ (Th1/Th2) were measured in 45 patients at diagnosis of classical Hodgkin lymphoma and in 34 healthy controls by cytometric beads array (CBA). Levels of TNF (p<0.01), INF-γ(p<0.01), IL-4 (p=0.01), IL-5 (p<0.01) e IL-10 (p<0.01) were significantly higher in patients compared to the control group. No difference was observed for IL-2 between the two groups. On correlating Th1/Th2 cytokine concentrations with clinical risk factors, elevated IL-10 (Th2) levels are associated with variables that suggest worse prognoses including III/IV stage (p=0.01), B-symptoms (p=0.04), hemoglobin < 10.5g/dL (p=0.01), lymphocytes < 600/mm³ (p=0.01) and according to the seven-factored international prognostic score (IPI), a subset of patients with a particularly high risk of failure (p=0.01). Furthermore, the serum levels of IL-2 (Th1) were significantly higher in a group of I/II stage patients compared to III/IV patients (p=0.03) which implies that, the levels of IL-2 might decrease with disease progression. The elevated IL-10 levels in a subset of patients with poor clinical risk factors might down regulate a Th1 immune response by inhibiting IL-2 production causing survival disadvantage by suppression of the cytotoxic immune response against the tumor. This suggests an association between progression of CHL and higher levels of the IL-10 cytokine. This study showed that measurement of serum cytokines using the CBA methodology is highly reproducible, and that changes in concentrations seem to be involved in the biology of this diseas.
