title: To study the effects of gamma irradiation on single donor apheresis platelet units by measurement of cellular counts, functional indicators and a panel of biochemical parameters, in order to assess pre-transfusion platelet quantity and quality during the shelf life of the product.
abstract: BACKGROUND
  The occurrence of transfusion associated graft versus host disease can be prevented by gamma irradiation of blood components. This study was undertaken to assess the effects of gamma irradiation on single donor platelet (SDP) concentrate units.
  
  
  METHODS
  SDPs were collected by a continuous flow apheresis technique (n = 400). The SDPs from each donor were divided into two parts, one gamma-irradiated with 25 Gy and the other used as a non-irradiated control. Swirling and morphological features, cellular counts, biochemical parameters including blood gas analysis, and platelet activation levels (CD62P: p-selectin) by flow cytometry were analyzed on Day 1 and on Day 5.
  
  
  RESULTS
  Swirling and morphology were maintained in all products, in both the groups throughout the shelf life. No significant change was seen in both groups, on the first and fifth day, as far as pO2, pCO2, Na(+), K(+), HCO3 (-) & Ca(2+) were concerned. However, lactate increased and glucose decreased significantly in irradiated products over 5-day storage period. A small but significant decrease in pH and platelet count was found in the irradiated PCs after 5-day storage. The mean proportion of platelets expressing CD62P over 5-day storage increased significantly.
  
  
  CONCLUSIONS
  After an overall assessment of all our in vitro parameter results and observations, a few of which were significant, while most were not significant, we concluded that a well-preserved quality of gamma irradiated apheresis platelets is maintained throughout the entire 5-day shelf life of the platelet product, with minimal difference compared to non-irradiated platelets.
authors.affiliation: Associate Professor, Department of Immunohaematology & Blood Transfusion, Armed Forces Medical College, Pune 411040, India.
authors.forename: R S
authors.initials: RS
authors.lastname: Mallhi
authors.affiliation: Resident, Department of Immunohaematology & Blood Transfusion, Armed Forces Medical College, Pune 411040, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Biswas
authors.affiliation: Commanding Officer, Eastern Command Transfusion Centre, Kolkata, India.
authors.forename: J
authors.initials: J
authors.lastname: Philip
authors.affiliation: Commandant, 166 Military Hospital, C/O 56 APO, India.
authors.forename: T
authors.initials: T
authors.lastname: Chatterjee
keywords: Flow cytometry; Irradiation; P-selectin; Transfusion associated graft versus host disease