The acetylcholinesterase defect in paroxysmal nocturnal hemoglobinuria:
evidence that the enzyme is absent from the cell membrane
FL Chow, MJ Telen and WF Rosse
Paroxysmal nocturnal hemoglobinuria (PNH) is a myelodysplastic disease
characterized by erythrocytes that show abnormally increased sensitivity to
complement-mediated lysis. Complement-sensitive PNH erythrocyte membranes
have previously been shown to lack acetylcholinesterase (AchE) activity,
but the molecular basis of this deficiency has been unclear. We have used
monoclonal antibodies to four different epitopes on the AchE molecule to
show that abnormal PNH erythrocytes failed to bind these antibodies.
Moreover, abnormal PNH erythrocytes contained no protein immunoprecipitable
by these antibodies, while normal complement-insensitive erythrocytes from
PNH patients showed normal amounts of immunoprecipitable AchE which had
normal electrophoretic mobility. These data suggest that abnormal PNH
erythrocytes lack AchE enzyme activity due to the absence of the AchE
molecule from the cell membrane.
Volume 66,
Issue 4,
pp. 940-945,
10/01/1985
Copyright © 1985 by The American Society of Hematology
