DSG1 and acquired polycythemia vera: In this context, it is interesting that anti-TPO and anti-Tg show the highest prevalence in patients that are anti-Dsg3 and anti-Dsg1 negative (A.R. 26.9 and 23.1%, respectively) and are negative or barely detectable in patients that are double-positive for anti-Dsg3 and anti-Dsg1, suggesting that anti-TPO antibodies may have a compensatory or additive function in the absence of the classical PV-related autoantobodies.