The present prospective study was designed to evaluate the possible predictive value of aCL and anti-β2GPI for APS at the time of acute DVT and to evaluate the possible added value of non-criteria aPL testing (i.e., aPS/PT, IgA aCL and IgA anti-β2GPI) in the diagnostic management of DVT at the acute event. This evidence concerns the gene APOH and autoimmune polyendocrinopathy.