Demonstration of increased platelet-bound IgG in infectious mononucleosis complicated by severe thrombocytopenia.

In an attempt to confirm the immune nature of the thrombocytopenia complicating infectious mononucleosis, the amount of IgG bound to the platelets of 2 affected patients was measured. Using a sensitive quantitative antiglobulin consumption technique, increased amounts of IgG were demonstrated during the thrombocytopenic phase of the illness. This observation represents convincing evidence in favour of platelet destruction by an immune mechanism.