Detection of anti-platelet antibodies in patients with idiopathic thrombocytopenic purpura (ITP) and in patients with rubella and herpes group viral infections

A highly sensitive enzyme-linked immunosorbent assay (ELISA) technique was developed for serological detection of antibodies against platelets. Protein A covalently bound to Sepharose CL-4B was used to enrich sera in the IgG3 subclass of antibodies. The ELISA procedure was applied to detect anti-platelet antibodies in patients with herpes or rubella viral infections and in patients with idiopathic thrombocytopenic purpura (ITP). Twenty-eight sera from 13 thrombocytopenic patients showed high levels of anti-platelet antibodies. Two splenectomized patients in remission became negative for anti-platelet antibodies. Seventy-four sera from patients with serological diagnosis of herpes group viral infections comprising 10 cases of cytomegalovirus, nine cases of varicella or zoster, six cases of herpes simplex and four cases of Epstein-Barr virus were examined for the presence of anti-platelet antibodies. Except for two patients with varicella and zoster and one patient with rubella infection, all cases examined showed positive titres of anti-platelet antibodies. Sera from a group of 51 healthy controls were evaluated for anti-platelet antibodies. Forty-nine (96%) were negative (<40), whereas the other two were only slightly positive.