Implementation of LVDS Platelets Leads to Increase in False-Positive Bacterial Detection Rate

October 19, 2021

The introduction of large-volume delayed sampling of platelets resulted in a seven-fold increase in the rate of false-positive bacterial detection at the New York Blood Center (NYBC), according to research presented in Monday’s Late-Breaking Oral Abstract Session.

NYBC introduced LVDS with collections in April 2021 in response to Food and Drug Administration guidance from September 2019 (updated in December 2020) related to bacterial risk control strategies for platelets. The center implemented pathogen reduction in 2018. In this study, Eric Senaldi, MD, and his co-investigators compared the rates of initial positive, true positive and false positive bacterial detection during three time periods: pre-LVDS (January 2020 – March 2021), post-LVDS (April – June 2021), and during the PASSPORT study (July – December 2007).

Initial-positive rates (per 1,000 samples) were 0.668 for pre-LVDS platelets, 3.720 for LVDS platelets and 4.834 for the PASSPORT study platelets. True-positive rates (per 1,000 samples) were 0.273 for pre-LVDS platelets, 0.886 for LVDS platelets and 1.562 the PASSPORT study platelets. False-positive rates were 0.395 for pre-LVDS platelets, 2.834 for LVDS platelets and 3.307 for PASSPORT study platelets. Among BPA bottles, the rates of true and false positives were equivalent. Anaerobic bottle (BPN) true-positive rates and false-positive rates between LVDS and 2007 were equivalent.

So what caused the elevation of false positives? The anaerobic bottles, Senaldi said. Results of BPN sampling were similar to 2007, when more than 75% of positive BPN bottles were non-pathogenic bacteria. Senaldi noted that the detection time is long after the patients have been transfused.

“The BPN bottles are kind of ‘back to the future’ to the time of the PASSPORT study in 2007: limited utility of less-than-useful information that results in needless discard of inventory,” Senaldi concluded.