Treatment of Idiopathic Thrombocytopenic Purpura in Children With Subcutaneously Administered Anti-D

Background:

Idiopathic thrombocytopenic purpura (ITP) in children is considered a benign hematological disease. The incidence is approximately 50 cases a year in Denmark. Approximately 25 % will experience chronic disease. Follow up and treatment of these patients is not centralized.

The drug of choice is intravenous IgG (IVIG) for treatment of ITP. The side effects are flu-like symptoms, and in rare cases aseptic meningitis. Another option is intravenous anti-D, if the child is rhesus positive. Anti-D is primarily used in North America. The effect of Anti-D is comparable with IVIG when considering the time it takes to bring the platelet count above 50,000/μL. Anti-D also causes flu-like symptoms. Establishing an i.v. access is a disadvantage to both IVIG and anti-D. For both treatments mechanism of action is not finally described.

Subcutaneous IgG substitution therapy is used for patients suffering from agammaglobulinaemia. It is therefore known, that immunoglobulin uptake is possible after subcutaneous administration. Subcutaneous anti-D has been tried in few patients suffering from chronic thrombocytopenia with positive results.

IVIG treatment is expensive compared to anti-D. Treatment of a 20 kg child costs approximately 17,000 Dkr for IVIG and 2,500 Dkr. for anti-D.