Very low platelet counts can lead to a bleeding diathesis and purpura. The T cell defect was initially shown to be an exaggerated interleukin-2 response when T cells were cultured with platelets in vitro. Subsequently, this cytokine abnormality was shown by others to be responsible for many of the autoimmune mechanisms causing the disorder.
Severe low platelet counts can lead to a bleeding disorder and purpura due to an underlying issue with T cell function, which is characterized by an exaggerated response to interleukin-2. This cytokine imbalance was found to be responsible for many of the autoimmune mechanisms driving the condition.