Imported platelets demonstrate decreased pH and glucose by reagent strip testing when compared to locally derived platelets.
The most common infectious risk from blood transfusion in the United States is bacterial contamination of platelet components. Although detection of bacterially contaminated platelet components is best achieved with a culture system, AABB standards permit alternatives including the use of staining methods or reagent strips. In this study, 13,216 consecutive platelet components were screened using reagent strips for evidence of the presence of bacteria. Testing was performed immediately prior to release of the platelet components for transfusion; 10,836 were collected locally and 2,380 were imported from other blood banks. A mix of whole-blood-derived and apheresis products was included. If either the glucose concentration was <250 mg/ml or the pH was <7.0, the platelet component was quarantined and a specimen was obtained for Gram's stain and culture. Every transfused platelet component that was associated with a reported transfusion reaction was also tested by Gram's stain and culture. Overall, 1.47% of imported platelet components were reactive while only 0.12% of locally collected platelets were reactive. Of 48 reactive platelet components, 44 were tested by Gram's stain and culture. None was found to be bacterially contaminated. In summary, imported platelet components were significantly more likely to be falsely reactive by reagent strip screening as compared to locally prepared platelet components.