The role of zinc protoporphyrin measurement in the differentiation between primary myelofibrosis and essential thrombocythaemia.

The differentiation between primary myelofibrosis (PMF) and essential thrombocythaemia (ET) may be difficult especially in early-stage disease. In PMF, increased levels of inflammatory cytokines induce impaired iron utilisation and disturbed erythropoiesis. In conditions with impaired iron support to erythropoiesis, zinc protoporphyrin (ZPP) is produced instead of heme.