title: Cryoprecipitate prepared from plasma treated with methylene blue plus light: increasing the fibrinogen concentration.
abstract: When cryoprecipitate is prepared from plasma which has been treated with methylene blue plus light (MB) for the purpose of virus inactivation, clottable fibrinogen content is 40% lower compared with units prepared from untreated plasma. Initial studies showed that when frozen MB plasma units were removed to +2 to +6 degrees C for 4 h and then returned to -40 degrees C prior to cryoprecipitation, fibrinogen recoveries increased from 24 to 42%. Although fibrinogen yield improved when plasma units were stored at +2 to +6 degrees C for varying lengths of time, FVIII levels decreased with increasing time. Conditioning for 8 h was studied in more detail. Groups of two plasma units were mixed together, divided into two equal units, frozen/thawed and treated with MB. One of each pair was stored continually at -40 degrees C, whereas the other was removed to +2 to +6 degrees C for 8 h. Samples were assayed for fibrinogen, FVIII, VWF:Ristocetin cofactor activity (RCo), VWF:Ag and VWF:Collagen binding (CB). The cryoprecipitate fibrinogen content increased to a mean of 207 mg unit(-1). VWF:Ag, VWF:RCo and VWF:CB recoveries also increased. FVIII recovery decreased from 50 to 45% (mean 124 iu unit(-1)). Conditioning has been validated for routine production of cryoprecipitate from imported plasma.
authors.affiliation: SNBTS, National Science Laboratory, Edinburgh, EH17 7QT, Scotland, UK. valerie.hornsey@snbts.csa.scot.nhs.uk
authors.forename: V S
authors.initials: VS
authors.lastname: Hornsey
authors.forename: D A
authors.initials: DA
authors.lastname: Young
authors.forename: A
authors.initials: A
authors.lastname: Docherty
authors.forename: W
authors.initials: W
authors.lastname: Hughes
authors.forename: C V
authors.initials: CV
authors.lastname: Prowse
mesh_terms: D001777:Blood Coagulation; D005169:Factor VIII / Q000302:isolation & purification*; D005340:Fibrinogen / Q000302:isolation & purification* / Q000378:metabolism*; D005353:Fibronectins / Q000097:blood / Q000302:isolation & purification; D006801:Humans; D008027:Light; D008751:Methylene Blue / Q000494:pharmacology*; D010949:Plasma / Q000187:drug effects*
chemical_list: D005353:Fibronectins; C026912:cryoprecipitate coagulum; D005169:Factor VIII; D005340:Fibrinogen; D008751:Methylene Blue