Evaluation of bacterial inactivation in prestorage pooled, leukoreduced, whole blood-derived platelet concentrates suspended in plasma prepared with photochemical treatment.
BACKGROUND
Photochemical treatment (PCT) with amotosalen and ultraviolet light was developed to inactivate pathogens in platelet (PLT) components suspended in 35 percent plasma and 65 percent additive solution (AS). Because PLT additive solutions (ASs) are not used in the United States, this study evaluated the ability of the PCT process to inactivate low levels of bacteria in pooled whole blood-derived PLTs (RDP) suspended in 100 percent plasma.


METHODS
Four replicate experiments were performed with two Gram-positive organisms, Staphylococcus epidermidis and Staphylococcus aureus, and two Gram-negative organisms, Klebsiella pneumoniae and Escherichia coli. For each experiment, 6 ABO-identical RDP units were pooled, leukoreduced before or after pooling, inoculated to approximately 1 to 10 colony-forming units per mL with plasma-resistant bacteria, and treated with the PCT process. Residual viable bacterial levels were measured before and after each step and 4 and 6 days after inoculation. For each bacterium studied, a fifth RDP pool was prepared and contaminated, but not treated. These units served as controls for bacterial growth.


RESULTS
Growth of S. epidermidis, S. aureus, and K. pneumoniae was eliminated in all four treated pools while growth continued in the control pools. There was no growth of E. coli in the treated pools and the control pool.


CONCLUSIONS
These pilot experiments demonstrate inactivation of bacteria in PLTs suspended in plasma, suggesting that the PCT process may address contamination in conventional RDPs. Additional experiments with a wider range of bacteria and evaluation of PLT function in 100 percent plasma will be needed before implementation.
Brecher
Mark E
ME
Department of Pathology and Laboratory Medicine, University of North Carolina, 101 Manning Drive, Chapel Hill, NC 27514, USA. brecher@med.unc.edu
Hay
Shauna
S
Corash
Laurence
L
Hsu
Jocelyn
J
Lin
Lily
L
D000017:ABO Blood-Group System; D001769:Blood / Q000382:microbiology*; D001792:Blood Platelets / Q000382:microbiology*; D006090:Gram-Negative Bacteria / Q000302:isolation & purification / Q000528:radiation effects*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification / Q000528:radiation effects*; D006801:Humans; D007962:Leukocytes / Q000382:microbiology; D010777:Photochemistry
D000017:ABO Blood-Group System