Prevalence of AAbs against type I IFN in the MPN cohort according to MPN driver mutation and MPN subtype. (A) AAbs were present in 17 of 163 (58.6%) patients with JAK2 mutation, 7 of 41 (24.1%) patients with CALR mutation, 0 of 4 (0%) patients with MPL mutation, and 5 of 11 (17.2%) patients who were triple negative. Significant difference was observed in terms of driver mutations (P = .019). Comparing mutational subgroups by pairs, the only significant difference was observed between the percentage of AAbs in patients who were triple negative and that observed in patients with JAK2 mutation (45.5% vs 10.4%; P = .036). (B) AAbs were present in 20 of 101 (69%) patients with essential thrombocythemia (ET), 4 of 76 (13.8%) patients with polycythemia vera (PV), 5 of 36 (17.2%) patients with primary myelofibrosis (MF), and 0 of 6 (0%) patients with myeloproliferative unclassifiable (MPN-u). A significant difference was observed in terms of distribution of MPN diagnosis (P = .029).