Abstract
Background and Objectives
Platelet concentrate is one of the important blood products. The platelets are stored at  that is an optimum temperature for bacterial growth, so the platelet bacterial contamination is considered to be the most common infective risk factor in blood transfusion.
 
Materials and Methods
In this experimental study, we selected ten platelet concentrates from healthy donors prepared by Iranian Blood Transfusion Inovation Center and stored at 22º C with gentle agitation up to 5 days. Then, the antibacterial effects of LC on the platelet concentrates inoculated with the gram-positive Staphylococcus epidermidis as well as the effects of LC on the metabolic parameters of the platelets were measured.
 
Results
The results showed that L-carnitine in concentration of 50 mM could significantly decrease the growth of 1.5×106CFU/ml Staphylococcus epidermidis (p < 0.01). Moreover, the concentration of 50 mM could better maintain the LDH enzyme activity in the platelet concentrate during storage (P day3 = 0.003, P day5 = 0.002). Lactate concentration in LC treated platelet was lower than the control group at day 5 of storage (P day5 = 0.008) and also pH of the platelet was better maintained in LC treated platelets. In addition, the platelet count showed less decrease in LC treated platelets compared with control group at day 5 of storage (P day5 = 0.007).
 
Conclusions 
L-carnitine can improve the metabolism and quality of the platelet concentrates, as an additive, during the storage and it can decrease bacterial growth in the platelet concentrates during the storage.