RESUMO
BACKGROUND: To improve clinical access to platelet concentrates (PCs), prolonging the storage period is one alternative, provided that they are free from bacteria. The quality of platelets (PLTs) stored for 1 versus 7 days was compared by in vitro analyses and in vivo recovery and survival in blood donors. STUDY DESIGN AND METHODS: Apheresis PCs from 10 donors were divided and stored in PLT additive solution in 2 equal units for a paired comparison. PLTs in one unit were (111)In-labeled at 1 day of storage, and PLTs in the other unit were labeled after 7 days of storage. PLTs were injected into the donor after labeling and samples were drawn after 30, 60, and 150 minutes and thereafter once a day for 14 days for recovery and survival measurements. RESULTS: PLT recovery on Day 7 was 80 percent of the recovery on Day 1 (p<0.05), and the survival on Day 7 was 65 percent of survival on Day 1 (p<0.005). No significant differences were seen regarding mean PLT volume (MPV), pH, pCO2, pO2, bicarbonate, or hypotonic shock response. Lactate increased and lactic dehydrogenase increased slightly, whereas glucose and ATP decreased, but not to a critical level. A significant increase in RANTES (110.7+/-76.6 vs. 277.6+/-50.8 pg/10(6) PLTs [p<0.005]) and PLT factor 4 (19.9+/-9.6 vs. 59.8+/-7.5 IU/10(6) PLTs [p<0.0001]) was noticed during storage. CONCLUSION: Recovery and survival of PCs stored for 7 days decreased, but met suggested criteria. Analyzed in vitro parameters showed acceptable results. Randomized patient transfusion studies will provide additional verification of the suitability of 7-day storage of PLTs.