Intravenous immunoglobulin therapy in thrombocytopenic infectious mononucleosis.

Severe haemorrhagic thrombocytopenia in infectious mononucleosis with positive Epstein-Barr virus (EBV) serology remains a threatening clinical problem. Although rare, fatalities have been reported. We present clinical, haematological and serological details of two patients with diffuse bleeding associated with this disease who failed conventional steroid treatment and who both responded promptly and effectively to infusions of intravenous immunoglobulin (i.v. Ig). A platelet immunofluorescence test was used to detect platelet antibodies in acute and recovery phase patient sera against autologous recovery platelets and against normal allogeneic group O platelets. In one patient, indirect immunofluorescence using recovery platelets detected an IgG platelet autoantibody with acute phase autologous serum. No platelet antibody was detected in the second patient. The data presented demonstrate that response to i.v. Ig is independent of serological detection of platelet autoantibodies. Therapy with i.v. Ig should be considered in any case of haemorrhagic thrombocytopenia associated with EBV infection shown to be refractory to steroid treatment.