VIRUS INACTIVATION OF BLOOD PRODUCTS BY PHENOTHIAZINE DYES AND LIGHT

Methylene blue (MB) and its derivatives azure A, B, C and thionine are photoactive and, in principle, are suitable for photodynamic virus in activation of blood and blood products, such as therapeutic plasma. Me thylene blue was selected for plasma decontamination because it is bei ng clinically used and because of its known toxicological and other pr operties, The standard procedure for photodynamic treatment of single units of fresh plasma involves illumination with visible light at an M B concentration of 1 mu M. Polymerase chain reaction analysis revealed that, in addition to model viruses, the bloodborne viruses hepatitis B virus, hepatitis C virus, human immune deficiency virus-1 and probab ly also the nonenveloped parvovirus B19 are sensitive to MB/light trea tment, The procedure is further improved when the fluorescent tubes ro utinely used for illumination are replaced by more intense light sourc es, e.g. light-emitting diodes or low-pressure sodium lamps, Surprisin gly, the improved virus kill is accompanied by reduced damage to plasm a proteins.