Blood-Analysis has developed a number of pathogen tests in blood and blood products using its unique skill base and proprietary technology. Our first target market is the detection of bacteria in blood platelets prior to transfusion – called “point of release” (PoR), “pre-release”, or “point of issue” (PoI) testing. There is an urgent medical need for this type of test.
In contrast to the majority of blood components, which can be frozen, blood platelets are required to be stored at ambient temperature to remain viable. This environment is ideal for the growth of bacteria. Despite the introduction in many countries of routine culture testing and improved sterile technique in collection and processing, there remains a significant incidence of platelet contamination. Culture methods can fail to detect bacteria due to sample error from samples taken early for storage, when bacterial contamination may initially be low. They may also fail to detect bacteria which are in lag phase or are slow growing. Current culture methods have an unacceptable level of both false negatives and false positives.
Since 2005 the AABB (American Association of Blood Banks) has mandated that bacterial screening detection should be undertaken prior to transfusion. Despite this screening – predominantly with culture-based tests – , the incidence of bacterial contamination is believed to be significant and the cause of both morbidity and mortality, much of which may go unreported because of the presence of the patient’s underlying illness. In July 2012, at the AABB meeting in Boston, Kleinman reported that, based on a review of a number of different studies performed in the U.S. and abroad, the per unit rate of bacterial contamination undetected by early culture appeared to be approximately 1 in 1,500 units. A review of data from the conventional arms of two additional studies (PLADO and SPRINT) revealed that hematology-oncology patients receiving many units of apheresis platelets could have a risk as high as 1 in 250 of receiving a contaminated unit.
There exists globally, therefore, a serious risk of transfusion patients receiving bacterially contaminated platelets, a risk that is far greater than receiving platelets contaminated by viruses such as HIV or HCV. This risk is reflected in different approaches to testing and platelet storage, with different countries discarding platelets on the expiry of a period ranging from 4 days (Germany), 5 days (USA) and 7 days (UK). In all markets the risk of bacterial contamination leads to enormous challenges to inventory control with economic consequences in the forms of both shortages and wastage.
In response to these unacceptable levels of risk, the regulations are becoming more stringent. In 2016, the FDA put forward draft Guidelines that pointed out the serious shortcomings of culture-based tests and called for effective PoI testing. The Guidelines were expected to be implemented this year (2017), but the Association of American Hospitals requested a postponement, because of the lack of a suitable PoI test – fearing that the alternative methods specified in the Guidelines would result in a significant reduction of platelet stocks. It follows that, as soon as a suitable PoI test is available, there will be great demand for it.
While there may be clear benefits in daily testing of platelets until release for transfusion, it has also been made clear that the FDA, and most likely the authorities in other countries, will be unwilling to extend the shelf life of platelets until improved bacterial detection methods become available.
It is our goal to provide transfusion services with the technology, not only to be able to improve patient safety and the economics of the transfusion donor to patient cycle, but also to increase the shelf lives of platelets and make stock availability more manageable. Our solution to these challenges is Bac-DetectTM.