Detection of antibodies interacting with glycosaminoglycan polysulfate in patients treated with heparin or other polysulfated glycosaminoglycans.

A new method has been developed for the demonstration of the antibody nature of a factor occurring in some patients during treatment with heparin or other polysulfated glycosaminoglycans (GAGPS). So far, antibodies reacting with GAGPS, except heparin, have not been described. We used heparin- or GAGPS-coated normal blood group O thrombocytes for the detection of suspected antibodies. After addition of patients' plasma or serum to a suspension of purified heparin- or GAGPS-coated platelets, agglutination was determined microscopically. In indirect immunofluorescence, positive staining of agglutinated platelets was observed with fluorescein isothiocyanate anti-Ig and anti-IgG conjugates, but not with anti-IgA or anti-IgM, with one exception in which IgM antibodies were also involved. Binding of complement was also shown using a tetramethylrhodamin isothiocyanate-labelled anti-C3 conjugate in double-staining experiments. Fibronectin could be excluded as a possible factor responsible for thrombocyte agglutination.