Treatment for patients with autoimmune destruction of blood cells is poor. The part of the
body that fights infections is called the immune system and white blood cells (WBCs) are part
of the immune system. Normally, a person's body creates WBCs to fight infections and
eliminates WBCs which have stopped helping the body function. Patients with autoimmune
destruction of blood cells have difficulty eliminating old WBCs. The abnormal WBCs build up
and can damage other healthy cells, which can lead to anemia, fatigue, jaundice, internal
bleeding, infection, and cancer. Few effective medications exist for treatment for patients
with autoimmune cytopenias and those commonly used are fraught with side effects.
Nevertheless, as scientific understanding of autoimmune diseases has improved, more directed
and less toxic therapies are becoming available. A number of groups have been studying the
efficacy of a medication called sirolimus in patients with autoimmune diseases. This medicine
has been FDA-approved for over 20 years. Sirolimus is a medicine used in children with other
diseases. Sirolimus works, in part, by eliminating old and abnormal WBCs. Our group and
others have shown that sirolimus is effective in mice with autoimmunity and in children with
a rare condition called Autoimmune Lymphoproliferative Syndrome (ALPS). We believe sirolimus
will help children with autoimmune cytopenias. We believe it will improve their symptoms and
make them less sick. We propose to study sirolimus in children with chronic and/or refractory
autoimmune cytopenias.