title: Effect of X-irradiation on the quality of red cell concentrates.
abstract: BACKGROUND
  The irradiation of blood components is used to inactivate T-lymphocytes to prevent transfusion-associated graft-versus-host (GVH) disease in susceptible recipients. X-irradiation can be used as an alternative to gamma irradiation and does not involve the use of a radioactive source. This study investigated the effect of X-irradiation on the quality of various red cell concentrates (RCC).
  
  
  METHODS
  Whole blood units were processed into RCC in additive solution (SAG-M) or RCC in plasma suitable for intra-uterine (IUT) or neonatal exchange transfusion. RCC-SAG-M were irradiated at day 14 and sampled before and 0, 7 and 14 days following irradiation. RCC-IUT and RCC-Exchange were irradiated on day 4 and sampled before and 0 and 24 h following irradiation. Extracellular potassium levels and free plasma haemoglobin (haemolysis) were compared in X or gamma-irradiated units during storage.
  
  
  RESULTS
  X-irradiation of RCC in SAG-M, or RCC for IUT or Exchange resulted in haemolysis comparable with gamma irradiation and levels were below the current UK/CE limit of 0.8% at the end of shelf life. X-irradiation of RCC-SAG-M or RCC-IUT with haematocrit of 75% and 85% resulted in potassium leakage comparable with gamma-irradiation. However, X-irradiation of RCC for neonatal exchange transfusion showed statistically significantly higher supernatant potassium levels after 24 h than gamma irradiation, although this difference is considered to be clinically insignificant.
  
  
  CONCLUSIONS
  X-irradiation of RCC in SAG-M or IUT or RCC in plasma suitable for neonatal exchange transfusion resulted in acceptable levels of haemolysis and potassium leakage compared with the current process of gamma irradiation.
authors.affiliation: NHS Blood and Transplant, Brentwood, Essex, UK. saber.bashir@nhsbt.nhs.uk
authors.forename: S
authors.initials: S
authors.lastname: Bashir
authors.forename: F
authors.initials: F
authors.lastname: Naik
authors.forename: R
authors.initials: R
authors.lastname: Cardigan
authors.forename: S
authors.initials: S
authors.lastname: Thomas
mesh_terms: D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism; D005720:Gamma Rays; D006086:Graft vs Host Disease / Q000517:prevention & control*; D006461:Hemolysis / Q000528:radiation effects*; D006801:Humans; D013601:T-Lymphocytes / Q000166:cytology; D014965:X-Rays