Glucosamine sulfate does not crossreact with the antibodies of patients with heparin-induced thrombocytopenia

Objective. To assess the crossreactivity of glucosamine sulfate, used for t reatment of degenerative joint disease with antibodies induced in heparin-i nduced thrombocytopenia (HIT). Background: HIT is a severe adverse effect o f heparin therapy induced by an immunological mechanism. The antibodies in HIT are induced by a complex of heparin and, in most cases, platelet factor 4. Hereby generation of the antigen is not strictly dependent on heparin. Heparin can be substituted by a variety of polysulfated carbohydrates. in v itro and in vivo crossreactivity of HIT antibodies has been demonstrated fo r a chemically polysulfated chondroitin-like substance (Arteparon((R)), Lui tpoldwerke, Munich, Germany), formerly used for chondroprotection. Another drug widely used in the treatment of degenerative joint disease is glucosam ine sulfate. Glucosamine is a building block of glycosaminoglycans, of whic h heparin is the clinically most important. Many patients with degenerative joint disease use glucosamine sulfate. This group is also at the highest r isk to develop HIT following joint replacement surgery. Methods. We examine d the interactions of glucosamine sulfate (DONA 200-S, Opfermann, Wiehl, Ge rmany) with platelets and antibodies of patients with HIT in and without th e presence of heparin. Sera of 5 HIT patients and platelets of 4 healthy do nors were used. The binding of HIT antibodies to PF4/glucosamine sulfate co mplexes was assessed by an ELISA. Results: HIT antibodies did not activate platelets in the presence of glucosamine sulfate in a serotonin-release ass ay. Preincubation with glucosamine sulfate did not inhibit platelet activat ion by HIT antibodies in the presence of heparin (0.2 IU/ml). Antibodies bo nded to PF4/heparin but trot to PF4/glucosamine sulfate complexes. Conclusi ons: In contrast to sulfated glycosaminoglycans, there is no evidence for a n immunological crossreactivity of HIT antibodies between heparin and gluco samine sulfate.