When (if ever) do you check for anti-platelet antibodies for workup of thrombocytopenia?  

Routinely available anti-platelet antibody tests have a sensitivity too high and specificity too low to be of much clinical use. A patient's response to first line therapy (steroids or IVIg) is most telling and if there is no response, a bone marrow is warranted as it would be atypical for ITP. The...