Detection of platelet-binding anti-measles and anti-rubella virus IgG antibodies in infants with vaccine-induced thrombocytopenic purpura.

A 15-month-old infant presented with thrombocytopenic purpura after sequential administration of measles-rubella combined vaccine, varicella vaccine and mumps vaccine every 4 weeks. Her thrombocytopenia persisted for more than 12 months. Both anti-measles and anti-rubella virus IgG antibodies were detected in the patient's-isolated platelets on day 154 of illness, which were not detected when there was a reduction of the serum IgG antibody titers on days 298 and 373 of illness, respectively.We also detected the isolated platelet-binding anti-measles and anti-rubella virus IgG antibodies in two other pediatric patients. This is the first report demonstrating direct evidence of vaccine-induced thrombocytopenic purpura.