White particulate matter found in blood collection bags consist of platelets and leukocytes

Abstract

WPM originated from PLTs and WBCs. Foreign matter (e.g., plastic) was not observed in any of the units. Leukoreduction and transfusion filters can be used to remove macroscopic WPM.

White particulate matter in a packed red blood cells unit

“…[12] Swank[3] reported that high pressures were necessary to force stored whole blood through a filter and increase in pressure correlates with increase in storage time. He attributed this to formation of compact aggregates of platelets and white blood cells due to increased adhesiveness during routine storage of blood, and therefore, was responsible for increased filter occlusion.…”

“…Particulate matter visible to naked eye, white in color, has been described in detail by Rentas et al . [1] White particulate matter (WPM) in blood bags is reported to be composed of normal blood elements, namely aggregates of platelets, with variable amounts of fibrin and trapped red and white cells and not of extraneous material or organisms. [2]…”

“…Enhanced visual inspection has been implemented by American Red Cross[1] for the observation of WPM at all the blood transfusion centers. Under this, the blood bag is kept with the labeled side down on flat surface, undisturbed for 10 minutes.…”

White particulate matter: this time too much precaution

“…A s documented in four papers in this issue, 1‐4 2003 was notable in transfusion medicine for the report of unexplained white particulate matter (WPM) found in red cell (RBC) components. Initially observed by the American Red Cross Southeastern region in Atlanta, Georgia, such observations spread rapidly to other parts of the country.…”

“…As the investigations reported in this issue of TRANSFUSION indicate, WPM was predominately platelets (PLTs) with other recognized forms of cellular debris including fragments and granules from white blood cells and occasional fibrin strands 1,2 . In other words, WPM is nothing new or unexpected.…”