The Effect And Mechanism Of Inactivation Of Lymphocyte And Pathogen In Blood Or Blood Component By Riboflavin Photochemical Treatment With Visible Light

Background Transfusion is one of important medical sources in the medical therapy field and a indispensable method in modern medicine. But there are some risks in transfusion. Transfusion-associated graft versus-host disease and infection of pathogens are two kinds of most important transfusion risks. Pathogen inactivation technology of blood components is one of the important preventing methods. Riboflavin photochemical treatment (RPT) was a new technology in pathogen inactivation of blood and blood components. Up to now, RPT may serve as the one method to inactivate pathogens in 3 blood components (red cells, platelets, and plasma). Riboflavin is a naturally occurring essential nutrient and safety for people. Objectives In this study RPT by visible light range from 400nm-500nm was used to inactivate lymphocytes, bacteria and virus in blood and blood components. The models bacteria and virus were Escherichia coli (ACTT 25922) and sindbis virus (XJ-160) individually. Evaluation of pathogen inactivation and lymphocytes inactivation of RPT and analyse and discussion of mechanism of inactivation of lymphocytes, Escherichia coli and sindbis virus. Methods Lymphocytes (or Escherichia coli or sindbis virus) and riboflavin were added together in medical PVC transparent bags. Control groups were not exposed to light in the absence of riboflavin. Experimental groups were exposed to light in the present of riboflavin (10 umol/L) at a final dose of 8-32J/ml. Lighting group were exposed to light in the absence of riboflavin. The effect and the mechanism of lymphocyte inactivation was analyzed by direction of cell death, proliferation inhibition rate, cell cycles, the level of cytokines, change of conformation, assay of cell apoptosis and assay of nuclear acid damage. The effect and the mechanism of Escherichia coli inactivation was analyzed by culture, observation of transmission electron microscope and nuclear analysis. The effect and the mechanism of sindbis virus inactivation was analyzed by cytopathic effect, observation of transmission electron microscope and nuclear analysis. Results By RPT, the proliferation inhibition rate of lymphocyte was more than 99% stimulated by PHA or anti-CD3 monoclonal antibody. Lymphocyte was inhibited to enter cell cycle and secrete cytokines stimulated by antigen. The DNA of lymphocyte was damaged hardly. The lymphocytes were inactivation to non-programmed death. Escherichia coli reduced 6 log and sindbis virus reduced 5 log by RPT. The nuclear acid were damaged in Escherichia coli and sindbis virus and couldn't be amplified. Conclusions Riboflavin photochemical treatment with visible light can inactivate lymphocyte, Escherichia coli and sindbis virus and damage their nuclear acid. The research suggested RPT may be a efficient and feasible method of preventing TA-GVHD and pathogens in one step and supplied experimental supports for application in transfusion.