Pathogen Reduction Methods Research Articles

Evaluation of the sensitivity of red blood cell markers to detect photodynamic membrane damage.

Photodynamic dyes have been used to investigate pathogen reduction methods in RBC suspensions, but treatment with sensitizers and light can produce unwanted membrane damage during routine blood bank storage. This study compares the relative sensitivity of three assays for detecting RBC membrane damage. RBCs were treated with dimethylmethylene blue and red light-emitting diode light under four conditions differing in photodynamic stringency and subsequently stored under refrigerated conditions for up to 42 days. Hemolysis, potassium release, and the apoptosis marker annexin V binding were assayed immediately after phototreatment and following storage. In terms of increasing sensitivity for detecting photodynamic RBC membrane damage was enhanced ion leakage >> hemolysis > annexin V binding. Although very stringent photodynamic treatment conditions generate annexin V-positive RBCs, the assay will not detect more subtle membrane damage that is readily detected by other well-established methods. In addition, many RBCs destined for photo-induced hemolysis later in storage are annexin V-negative throughout the storage period, suggesting that the two measures are not directly related.

Transfusion-transmitted bacterial infection: risks, sources and interventions.

Records of the transmission of bacterial infections by transfusion date back to the beginning of organized blood banking. Despite tremendous strides in preventing viral infection through careful donor screening and viral testing, there has been little improvement in reducing the risk of bacterial sepsis since the introduction of closed collection systems. Based on the French Haemovigilance study, the British Serious Hazards of Transmission (SHOT) study and fatality reports to the United States Food and Drug Administration, the risk of clinically apparent sepsis exceeds the risk of HIV, HBV, and HCV transmission. Sources of contamination include the skin, blood, disposables, and the environment. Potential interventions to reduce transfusion-associated bacterial sepsis include improvements to donor arm preparation, diversion of the first aliquot of whole blood, introduction of bacterial testing and/or implementation of pathogen reduction methods.

The mantra of blood safety: time for a new tune?

The mantra of blood safety: time for a new tune?

Current and emerging infectious risks of blood transfusions.

THE BLOOD SUPPLY IN THE UNITED States and other developed countries has never been as safe as it is now. During the past several decades, there have been dramatic progressive reductions in the risk of transfusion-transmitted clinically significant blood-borne infections. This has been accomplished as a result of extensive research to characterize transfusiontransmitted pathogens, development of strategies to measure infection rates in blood donor and recipient populations, characterization of the dynamics of early viremia, and implementation of progressively more restrictive donor eligibility criteria and increasingly sensitive laboratory screening methods. In addition, regulatory oversight by the US Food and Drug Administration (FDA) has been strengthened, resulting in enhanced quality assurance programs in blood collection and transfusion facilities. Pathogen reduction methods, already successfully applied to pooled plasma derivatives (eg, albumin, clotting factor concentrates, immunoglobulin preparations) are now in development for cellular blood components and fresh-frozen plasma. If these methods are approved by the FDA and widely implemented, they could virtually eliminate the risk of transmission by transfusions of both known and emerging infectious agents in technologically advanced countries. This progress needs to be balanced against the continued emergence of potential new transfusiontransmissible pathogens and the disparity in blood safety in developing countries where resources are insufficient to enable basic infectious disease donor screening.