ADAMTS-13 activity and von Willebrand factor levels in methylene-blue photo-inactivated plasma processed by either the Springe method or an 'in house' system.
OBJECTIVE
Methylene blue photo-inactivated plasma (MBPIP) has been reported to be less effective than fresh-frozen plasma (FFP) in the treatment of thrombotic thrombocytopenic purpura, which suggests a reduced content of the von Willebrand factor metalloprotease ADAMTS-13 in MBPIP.


METHODS
ADAMTS-13 activity and von Willebrand factor antigen (vWF:Ag) levels were measured in plasma before and after photo-oxidation by either the Springe method or a commercial 'in house' system as well as in cryoprecipitate-poor plasma (CPP) and FFP (20 units each).


RESULTS
Levels of ADAMTS-13 activity in MBPIP processed by the Springe method or the commercial 'in house' system were comparable to one another and did not significantly differ from levels found in FFP [median (range): 114% (57-139%), 99% (74-123%), and 106% (70-130%), respectively]. ADAMTS-13 activity was significantly reduced in CPP [median (range): 87% (70-107%) as compared with FFP (P < 0.05). Levels of vWF:Ag decreased after photo-oxidation by both methods.


CONCLUSIONS
In vitro ADAMTS-13 activity was conserved in MBPIP processed by the two photo-oxidation methods analysed and did not significantly differ from levels found in FFP.
Complexo Hospitalario, Ourense, Spain.
J
J
del Río-Garma
A
A
Pereira
J L
JL
Arroyo
J
J
Mateo
A
A
Alvarez-Larrán
C
C
Martínez
J
J
Muncunill
L
L
Barbolla
D051722:ADAM Proteins / Q000097:blood*; D000071120:ADAMTS13 Protein; D005169:Factor VIII; D005340:Fibrinogen; D005615:Freezing; D006801:Humans; D008751:Methylene Blue / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010777:Photochemistry; D017319:Photosensitizing Agents / Q000494:pharmacology*; D010949:Plasma / Q000737:chemistry* / Q000187:drug effects / Q000528:radiation effects; D011697:Purpura, Thrombotic Thrombocytopenic / Q000628:therapy; D038301:Virus Inactivation / Q000528:radiation effects; D014841:von Willebrand Factor / Q000032:analysis*
D017319:Photosensitizing Agents; C026912:cryoprecipitate coagulum; D014841:von Willebrand Factor; D005169:Factor VIII; D005340:Fibrinogen; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human; D008751:Methylene Blue