Chronic disease in Immune Thrombocytopenia of Childhood

Newly diagnosed immune thrombocytopenia (ITP) in childhood is characterized by
auto-immune destruction of platelets and a typical history of acute development
of purpura and bruising in an otherwise healthy child. Most children with newly
diagnosed ITP will recover within 6-12 months. However, 20-25% of the patients
will remain thrombocytopenic and are diagnosed with chronic ITP, defined as a
platelet count of less than 100 x 109/L for longer than 12 months.
Despite important progress in the understanding of ITP and the mechanisms of
action of several therapeutic strategies in ITP, some clinical dilemmas can be
recognized in both newly diagnosed and chronic ITP. These include 1)
identification of patients at risk for severe bleeding, and 2) the inability to
predict the disease course and the response to therapy in the individual
patient at the time of diagnosis.
Although severe bleeding occurs only in about 2-3% of all patients with ITP,
thrombocytopenia has a major influence on daily life activities. All activities
which carry a risk of causing severe bleeding have to be avoided. Therefore,
ITP has a significant impact on quality of life of children and their parents.

The primary objective of this study is to identify parameters that predict
bleeding risk in children with chronic ITP. Secondary objectives are: 1) To
investigate whether children with long lasting chronic ITP differ from children
with newly diagnosed ITP and adults with chronic ITP, with regard to quantity
and function of regulatory T cells. 2) To determine the clinical and laboratory
response to treatment(s) given in children with chronic ITP, and to identify
biological parameters that determine this response and that possibly are
involved in the differences in outcome between acute vs. chronic disease in
childhood. 3) To measure the health related quality of life (HR-QoL) in
children with chronic ITP and their parents.

This study comprises a multicenter prospective observational study

In this study, a history and physical examination will be performed in children
with chronic ITP during a regular outpatient clinic visit. During blood
sampling, an extra amount of 30 mL will be taken for study purposes. This
amount is <0.1% of overall blood volume and therefore limited to such a degree
that adverse consequences for patients are not to be expected. Finally, all
parents, and from the age of seven years also the patients themselves, will be
asked to fill out a questionnaire regarding the HR-QoL in chronic ITP.
ITP in children is a different disease than ITP in adults with regard to
clinical course, response to therapy, as well as presumed etiology. The
response to different kinds of treatment, especially immunomodulating
treatment, also differs between children and adults with ITP. Therefore, to
answer our questions, this study cannot be performed in an adult population.