Prognostic relevance of HSP70 antigen and antibody measurement in patients with acute myeloid leukemia of intermediate and unfavorable cytogenetic risk

INTRODUCTION Heat shock proteins (HSPs) are overexpressed in many types of cancers and are implicated in tumor cell proliferation, differentiation, invasion, metastasis, death, and recognition by the immune system. It has been postulated that the HSP70 protein can be used as a prognostic indicator of overall patient survival in many types of cancer including leukemia. 
OBJECTIVES The aim of the study was to evaluate the concentrations of anti‑HSP70 antibody and its antigen in the peripheral blood of patients with acute myeloid leukemia (AML), as well as to assess the usefulness of this measurement.
PATIENTS AND METHODS The study included 80 patients with AML of intermediate and high cytogenetic risk, scheduled for allogenic stem cell transplantation after initial intensive chemotherapy. Plasma concentrations of anti‑HSP70 antibodies and HSP70 antigen were measured by enzyme‑linked immunosorbent assay. The antigen was additionally measured by Western blot analysis. The control group consisted of healthy subjects.
RESULTS Patients with AML had significantly higher anti‑HSP70 antibody concentrations compared with the control group. The concentration of HSP70 antigen as well as anti‑HSP70 antibody showed no associations with the type of response after induction chemotherapy. However, patients with higher antigen levels and lower anti‑HSP70 antibody levels had significantly shorter overall survival.  
CONCLUSIONS The study suggests that anti‑HSP70 antibodies and HSP70 antigen may be valuable indicators of a poor prognosis in patients with AML.