Platelet glycolytic flux increases stimulated by ultraviolet-induced stress is not the direct cause of platelet morphology and activation changes: possible implications for the role of glucose in platelet storage.

BACKGROUND: Stress-enhanced platelet (PLT) storage lesions include increased glycolysis, discoid-to-sphere morphology change, and spontaneous PLT activation. It is not clear if reduction in glycolysis can alleviate storage lesion development. STUDY DESIGN AND METHODS: Apheresis PLT concentrates were exposed to 17.2 J/mL UV light and 50 microM riboflavin, followed by storage with various concentrations of 2-deoxyglucose (2-DOG) for 5 days. The control had no UV or 2-DOG exposure. RESULTS: Lactate production and glucose consumption were increased significantly to 0.1371 +/- 0.0281 and 0.0724 +/- 0.0151 mmol per 10(12) cells per hour for UV-treated PLTs, respectively, when compared to control samples. UV treatment induced a decline in pH to 6.55 +/- 0.26 for treated PLTs on Day 5, hypotonic shock response (HSR) 33 +/- 25 percent, extent of shape change (ESC) to 3.8 +/- 3.6 percent, swirl 1.0 +/- 1.0 and increased P-selectin expression 85.2 +/- 9.4 percent. Addition of 2-DOG up to 20 mmol per L significantly reduced lactate production to 0.0515 +/- 0.0045 mmol per 10(12) cells per hour (p < 0.05) and glucose consumption to 0.0293 +/- 0.0060 mmol per 10(12) cells per hour and increased pH to 7.35 +/- 0.09 in a dose-dependent manner. 2-DOG, however, had no effects on HSR, ESC, swirl, and P-selectin expression. Furthermore, an exaggeration of UV-stressed PLT aggregation by addition of 2-DOG was also observed. CONCLUSIONS: Increased glycolytic flux is not a direct cause for PLT morphology change and spontaneous activation during storage lesion development. Reduction of glucose utilization may increase PLT loss during storage.

Photochemical inactivation of selected viruses and bacteria in platelet concentrates using riboflavin and light.

BACKGROUND: A medical device is being developed for the reduction of pathogens in PLT concentrates (PCs). The device uses broadband UV light and the compound riboflavin (vitamin B(2)). STUDY DESIGN AND METHODS: Pathogens were added to single-donor PLTs. After treatment, the infectivity of each pathogen was measured using established biologic assays. In vitro PLT performance was evaluated after treatment and after 5 days of storage using a panel of 10 in-vitro cell quality assays. RESULTS: In studies with viral pathogens, the Pathogen Reduction Technology (PRT) system provided average log reduction factors of 4.46 +/- 0.39 for intracellular HIV, 5.93 +/- 0.20 for cells associated HIV, and 5.19 +/- 0.50 for West Nile virus. For the nonenveloped porcine parvovirus, a reduction factor greater than 5.0 log was observed. Staphylococcus epidermidis and Escherichia coli bacteria were also tested with observed reduction factors to the limits of detection of 4.0 log or greater. PLT cell quality was adequately maintained after treatment and during storage. Although P-selectin expression, glucose consumption, and lactate production increased relative to controls, this was not beyond accepted levels. The pH of treated PCs also decreased slightly relative to control PLTs on Days 1 and 5. CONCLUSION: The data indicate that the device successfully reduced the number of selected pathogens in PCs. Despite the fact that significant differences exist between treated and control in-vitro variables, it is speculated that the clinical effectiveness of both products will not be significantly different, based on comparison to historical data for products in routine clinical use today.