An abnormal platelet membrane glycoprotein pattern in three cases of Glanzmann’s thrombasthenia.

Eduard Glanzmann was a Swiss pediatrician who in 1918 reported an inherited platelet functional disorder associated with a defective clot retraction. The clinical phenotype of this autosomal recessive bleeding disorder, later known as Glanzmann thrombasthenia (GT), was largely defined in the 1960s with major contributions from Jacques Caen in Paris and Marjorie Zucker in New York. My involvement in platelet research began in Oxford in 1968. Our project at that time was to define the components of the platelet “glycocalyx”, a carbohydrate-rich layer first highlighted on platelets by an electron microscopes, Olaf Behnke, in Copenhagen. I applied cytochemical techniques to identify negatively charged elements digested from this surface layer and separated by polyacrylamide gel electrophoresis (PAGE). Use of the detergent sodium dodecyl sulfate (SDS) and SDS-PAGE soon enabled the separation of the major intrinsic membrane glycoproteins (GP). Teams led by Ralph Nachman (New York) and David Phillips (Memphis) highlighted three major bands termed GPI (a sialic acid rich GP), GPII and GPIII. I continued my research in London and identified these GP in a range of mammals. However, I quickly realized that inherited platelet disorders held the key to identifying their function.