Neutrophil traps, anti-myeloperoxidase antibodies and cancer: Are they linked?

Myeloperoxidase is an enzyme present in neutrophils and has been demonstrated to be an important molecule for neutrophil extracellular traps (NETs) formation and function. Yet, it is also a source of autoantigens for anti-neutrophil or anti-myeloperoxidase antibodies (ANCAs), which are capable of activating these immune cells and provoke tissue damage in a sterile microenvironment. The presence of these antibodies in cancer has been related by case reports, but a few studies addressed the significance of this finding beyond autoimmunity context. In this review, we discuss the evidences regarding ANCAs and cancer and its putative clinical meaning in the context of tumor immunology.