Treatment of Idiopathic Thrombocytopenic Purpura (ITP) With Subcutaneously Administered Anti-D
Condition: Idiopathic Thrombocytopenic Purpura
MeSH terms: Purpura; Purpura, Thrombocytopenic; Purpura, Thrombocytopenic, Idiopathic
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of this study is to describe the effect of anti-D on symptoms and platelet count
      in children suffering from unexplainable low platelet counts, when anti-D is administered as
      an injection under the skin. The hypothesis is that the injection with anti-D under the skin
      is as effective as anti-D given in a vein.
    

Detailed description: 
      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.

      Hypothesis:

        -  Subcutaneous administered anti-D is as effective as IVIG/i.v. anti-D;

        -  Subcutaneous administered anti-D has fewer less severe side effects than IVIG/i.v.
           anti-D.

      Purpose:

        -  To document the effect of subcutaneous anti-D;

        -  Describe complications;

        -  Describe aspects of the mechanism of action.

      Material and Methods:

      Children are eligible if admitted to a pediatric department in Denmark for diagnosis,
      observation or treatment of acute or chronic ITP. Examination and diagnostic work up is
      similar throughout the country, but not identical. No specific tests are required for
      diagnosis. If treatment is indicated rhesus positive children are treated with subcutaneous
      anti-D. Rhesus negative children are treated according to local guidelines. Specified
      follow-up on all children is mandatory. For research purposes one blood sample form all
      children is collected, and from children, who receive medical treatment, several blood
      samples are collected. Analysis for changes in immunological signaling peptides will be
      performed with special attention to the mechanism of action of anti-D.
    

Intervention name(s): Anti-D
Intervention type(s): Drug
Intervention description(s): Subcutaneous injection
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Idiopathic Thrombocytopenic Purpura; Treatment; Anti-D; Subcutaneous; Clinical evaluation; Platelet count; IVIG