THROMBOCYTOPEN: A SUBSTANCE IN THE EXTRACT FROM THE SPLEEN OF PATIENTS WITH IDIOPATHIC THROMBOCYTOPENIC PURPURA THAT REDUCES THE NUMBER OF BLOOD PLATELETS

The purpose of this article is to describe more fully an extract obtained from the spleen of patients suffering from idiopathic thrombocytopenic purpura which reduces the number of platelets in the circulating blood. A brief preliminary report has already been published. 1 All the material was obtained through the cooperation of Dr. Dean Lewis, who felt that it might be possible to make extracts of such a nature that the clinical picture of the disease could be reproduced experimentally. MATERIAL AND METHOD Chronologically, the first successful extract was made from the spleen of a patient, the essential points in whose case are as follows: Case 1.— M. O., a white woman, aged 22, was admitted to the Johns Hopkins Hospital on Jan. 25, 1937, because of rectal bleeding. The family history revealed no excessive bleeding or blood dyscrasia. She was first admitted to the hospital in 1933, at which time