Elevated circulating levels of tumor necrosis factor predict unresponsiveness to treatment with interferon alfa-2b in chronic myelogenous leukemia.

Abstract

PURPOSE The study was undertaken to analyze circulating tumor necrosis factor (TNF) levels in patients with chronic-phase chronic myelogenous leukemia (CML) undergoing interferon (IFN) alfa-2b therapy, and to correlate pretreatment serum levels of TNF with response to IFN alfa-2b therapy. PATIENTS AND METHODS Fourteen patients with CML in chronic phase were treated with recombinant human IFN alfa-2b for 7 to 39 months. RESULTS In eight patients IFN alfa-2b treatment failed due to lack of hematologic response. A complete or partial hematologic remission was achieved in the remaining six patients, of whom two patients experienced a complete cytogenetic response. Retrospective analysis of serum samples obtained from all patients before the onset of IFN alfa-2b administration revealed that levels (mean +/- SEM) of circulating TNF were higher (P less than .001) in the group of patients who did not respond to IFN alfa-2b treatment (157 +/- 15 U/mL) than in the responders (10.3 +/- 4 U/mL) or healthy control subjects (9.1 +/- 3 U/mL). However, there was no correlation between TNF serum levels and other patient characteristics at study enrollment including age, sex, duration of disease, performance status, splenomegaly, WBC count, platelet count, hemoglobin value, prior therapy, and prognostic category. CONCLUSION These findings indicate that circulating levels of TNF are increased in a subset of patients with chronic-phase CML and that this elevation is associated with poor response to IFN alfa-2b therapy.