Explaining and treating immune thrombocytopenia (ITP)

An important clinical problem is immune thrombocytopenia (ITP), a potentially life-threatening condition wherein platelets are eliminated by the immune system and which is due to the development of autoantibodies against platelets. Paradoxically, autoantibodies against certain platelet cell surface molecules (e.g., GPIIb/IIIa) induce ITP whereas autoantibodies against others platelet molecules do not, despite high density of antibody binding.

Our studies suggest that ITP inducing autoantibodies mask ligands (e.g., CD47) for ‘don’t eat me’ receptors (e.g., SIRP) on macrophages. Additional studies are required to test this hypothesis and develop therapies that prevent ITP by harnessing ‘don’t eat me receptors’.