Study On Preparation Of Virus-inactivated Universal Plasma

Objective To gain time for wounded patients with high-volume application ofplasma in the war in peace，we reduced titers of antibody against anti-blood groupantigen of mixed plasma and inactivated virus through exploring optimal preparationpragram of universal plasma in Chinese Han population and the conditions in whichmost of transfusion-related virus were inactivated.Methods1.Firstly, type A plasma and type B plasma were mixed at the ratio of1:1,then set different ratios of A:B according to the change of antibody titers, at last, theoptimal ratio of A:B was determined. The optimal ratios of A:AB and B:AB wereassured according to the above methods.2.Three factors influencing the antibody titers of universal plasma, the proportionof plasma, reaction temperature and reaction time periods were analyzed byorthogonal design,then optimal production program was gained based on the aboveresults. The verification tests were made to verify the optimal production program.3.Viral inactivation conditionsThe approach using riboflavin with UV light was chosen as the pathogenreduction method. PRV,the model virus of the hepatitis B virus, was selected asindicator virus.The culture and virulence detemination of PRV was performed on itssensitive cells PK-15. Three factors influencing the effectiveness of inactivationwavelength of UV-light, the concentration of riboflavin, reaction time of riboflavinand virus were studied.What is more, the intial process of viral inactivation was made.4. Process of viral inactivation on quality of plasmaAccording to effects of viral inactivation,we chose the time point when morethan4lgTCID50/0.1ml PRV was reduced to determine activity or concentration ofcoagulation factors VIII, Fg and AT-III.Results1. The optimal plasma ratios were as follows:A:B=1:3, B:AB=1:3andA:AB=1:2. 2.Orthogonal design showed the universal plasma in Chinese Han populationmight be prepared by pooling plasma in proportion of A:B:AB=6:2.5:1.5at22℃for1h. Antibody titers could be reduced to≤1:2in three verification tests.3. The initial viral inactivation process were as follows: the effectivewavelength of UV light was365nm+308nm, the concentration of riboflavin wasapproximately60μmol/L, the reaction time of riboflavin and virus was10minutes.After20minutes’ irradiation, more than4lgTCID50/0.1ml virus was reduced.4. After20minutes’ irradiation, FVIII, Fg and AT-III are damaged significantly,therefore,it is necessary to reassure or improve the process of viral inactivation.Conclusions1. The optimal ratio of pooled plasma in our study are different fromthose of the two exiting products of universal plasma for the Caucasian population.Furthermore, antibody titers might be reduced to≤1:2which is even lower than whatis currently accepted.Preliminary evidence is provided for preparation of universalplasma in Chinese (Han) population.2.Riboflavin photochemical methods could effectively inactivatelipid-enveloped virus PRV within20minuts.The viral inactivation kinetics showedthe rate was first quick and then slow, which was consistent with guidelines onremoving/inactivating virus technology and methods for blood products.