An acquired form of Bernard Soulier syndrome associated with acute myeloid leukemia.
OBJECTIVE
To investigate glycoprotein-1b (GP-1b) expression on platelets from patients with acute myeloid leukemia (AML).


METHODS
Purified platelets, obtained from AML-patients and normal control subjects, were examined for surface membrane GP1b-expression by flow cytometry and GP1b-mediated aggregation responses by aggregometry. The level of elastase in plasma from patients and controls was measured by enzymed-linked immunosorbent assay. The whole of this work was carried out at the University of Liverpool, Liverpool, United Kingdom during the period of 1994-2001.


RESULTS
Platelets from the majority of AML-patients showed reduced GP1b-expression and reduced GP1b-mediated aggregation responses. Reduction in platelet GP1b-expression was associated with increased plasma elastase levels.


CONCLUSIONS
The present study suggests that elastase, released from leukemic blasts, degrades platelet GP1b, resulting in dysfunctional circulating platelets in AML-patients. These results could explain the bleeding disorders observed in these patients.
Aziz
Khalil A
KA
Regional Department of Immunology, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, United Kingdom. khalilazizh@yahoo.co.uk
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001606:Bernard-Soulier Syndrome / Q000209:etiology; D001792:Blood Platelets / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007951:Leukemia, Myeloid / Q000150:complications / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010196:Pancreatic Elastase / Q000097:blood; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*
D019038:Platelet Glycoprotein GPIb-IX Complex; D010196:Pancreatic Elastase