Calreticulin (CALR) mutations have been identified as a major driver in myeloproliferative neoplasms (MPNs). In contrast to JAK2 mutations that are mainly associated with polycythaemia vera (PV), CALR mutations are specifically associated with primary myelofibrosis (PMF) and essential thrombocythaemia (ET).
All known types of CALR mutations result in a novel C-terminus of the protein. This harbors a common epitope expressed in all kinds of CALR mutations. The CAL2 antibody is directed against this neoepitope. Therefore, it can be concluded that the CAL2 antibody is able to detect all CALR mutations.
It labels the megakaryocytes in myeloproliferative neoplasms (essential thrombocythaemia (ET) and primary myelofibrosis (PMF)) with CALR mutation and enables to distinguish them from polycythemia vera (PV), from CALR mutation negative ET and PMF and from reactive bone marrow.