High levels of immunoglobulin expression predict shorter overall survival in patients with acute myeloid leukemia.

Objectives It has been believed that immunoglobulins can only be produced by B lymphocytes and plasma cells. We have previously reported that IgG can be expressed in myeloblasts from patients with acute myeloid leukemia (AML) and plays a role in the proliferation and apoptosis of leukemic cells. However, its clinical impact has not been assessed. Methods We assessed the expression of different classes of immunoglobulin in peripheral blood and bone marrow samples from 132 AML patients and correlated the levels of expression with clinicopathologic and molecular genetic features, as well as clinical outcome. Results We found that, in addition to IgG, all classes of immunoglobulin are expressed in myeloblasts, including IgG, IgM, IgA, IgD, IgE, Ig kappa, and Ig lambda. The levels of IgG expression (coupled with Ig kappa or Ig lambda) are higher than those of IgM, IgA, IgD, and IgE. Using receiver operating characteristic (ROC) curve analysis, we identified two distinct groups of AML patients with differential expression of immunoglobulin and different clinical outcomes. Conclusions High levels of immunoglobulin expression are associated with monocytic differentiation, multilineage dysplasia,TET2andKRASmutations, and poor overall survival. Assessment of immunoglobulin may serve as a useful marker for prognostic stratification and target therapy.