MPO and myelodysplastic syndrome: In particular, we assessed the frequency of ANA and their antigenic specificity, involved in connective tissue autoimmune diseases, as well as the presence of autoantibodies frequently associated with other SIAD types reported in MDS cases, such as anti-MieloPeroxidase (MPO) and anti-Proteinase-3 (PR3), involved in vasculitis, and anti-Cyclic Citrullinated Peptide (CCP3), involved in rheumatoid arthritis.