ODSH but not dabigatran or rivaroxaban reduces anti-PF4/heparinAbbinding to immobilized PF4/heparin complexes. ODSH and UFH equally reduced Ab binding to PF4/heparin complexes. Dabigatran and rivaroxaban had no effect. Sera from patients with anti-PF4/heparin IgG were tested in an in-house PF4/heparin ELISA in the presence of increasing concentrations of UFH, ODSH, dabigatran, or rivaroxaban. The signal of anti-PF4/heparin Ab binding without anticoagulant was set 100%. Data are mean ± SD of 6 (rivaroxaban = 5) independent experiments.