The US Food and Drug Administration (FDA) announced that it has issued recommendations to the blood industry for additional blood inspection measures and will shortly issue interim guidance recommending enhanced visual inspection of all blood and blood components. This interim guidance is a precautionary measure as the FDA continues to actively investigate reports of units of blood and blood components containing white particulate matter.

Most of the reports of particulates have, to date, been associated with blood and blood components contained in bags with a sampling port manufactured by Baxter Healthcare Corporation, and have come from Red Cross blood centers in the southeastern United States, including parts of Tennessee and Georgia.

The exact nature of the particulate matter is under investigation. Preliminary results reported to FDA suggest that some particles represent clumping of platelets, which are a normal blood cell. Testing completed to date by the Centers for Disease Control and Prevention (CDC) has found no evidence of infectious agents.

FDA has also received a smaller number of preliminary reports of possible particulates involving some other bag types, locations, and blood banks. It is unclear at this time whether all reported observations are similar, or whether all represent abnormalities.

Blood is a complex substance and some units may, at times, contain small numbers of particles composed of clumped cells or globules of normal substances. Some clearly abnormal particles and increased numbers of particles have recently been noted in some blood units by experienced observers. However, the recently increased intensity and enhanced methods of inspections are likely contributing to reporting of some particles that may, in fact, be normal occurrences. Ongoing clinical and laboratory studies are in progress to help evaluate these observations.

As a precautionary measure while FDA's investigation continues, FDA is asking all blood establishments to implement enhanced visual inspection procedures. If abnormalities are detected, FDA is requesting that blood establishments quarantine the products and report their findings expeditiously to FDA by sending an e-mail message to BP_Deviations@cber.fda.gov or by calling FDA at 800-835-4709. Adverse events potentially related to the presence of particulate matter should also be reported to FDA using the aforementioned e-mail address or phone number.

The American Red Cross has implemented specialized visual inspection procedures for examining liquid blood for particulate matter that are in addition to visual inspection procedures already required by FDA regulations. The additional procedures include placing the bag, label down, on a flat counter undisturbed for 10 minutes and then performing a visual examination for particles. At this time, FDA considers these additional procedures appropriate as a precautionary measure.

FDA has received a small number of adverse event reports in patients who had also received transfusions utilizing such bags including one fatality involving a patient with underlying severe health problems that FDA is examining to see if it is possibly associated with this problem. These reports are also under investigation. It is not clear whether the reported adverse events are related to or unrelated to the possible presence of particulates. Similar adverse events in the transfusion setting can occur for many reasons, including reasons related to and unrelated to the transfusion.

FDA has no indication of a heightened risk of adverse events associated with blood transfusions at this time, and is recommending temporary additional blood inspection procedures as a precautionary measure. For patients who need blood, the benefits of transfusion continue to outweigh the risks.

FDA will continue to provide updates as additional information becomes available. FDA is working with the Centers for Disease Control and Prevention, state health authorities, the American Red Cross and Baxter Laboratories of Deerfield, Ill., in its in-depth investigation.

While the investigation continues, FDA wants to emphasize that blood donation is a safe procedure. Continued donations are critical to maintaining a safe and adequate blood supply.