Use of dermatan sulfates and/or desulfated heparins to treat or prevent heparinoid-induced autoimmune responses

Dermatan sulfates and/or O-desulfated heparins useful in treating and preventing heparinoid-induced autoimmune responses, in particular heparin-induced thrombocytopenia (HIT) and its associated disease states. The dermatan sulfates comprise repeating disulfated and/or trisulfated disaccharide units of L-iduronic acid and N-acetyl-D-galactosamine. The O-desulfated heparins comprise heparin molecules selectively O-desulfated at the 2-O and/or 3-O positions of the uronic acid and glucosamine saccharide residues. Particularly effective dermatan sulfate HIT antagonists have a mean molecular weight of from about 2000 to about 10,000 Daltons.