Do leukoreduction filters passively reduce the transmission risk of human granulocytic anaplasmosis?

Abstract

The recent increase in TTA suggests that A. phagocytophilum may represent an emerging blood safety issue. However, the current study indicates that the widespread practice of leukoreduction might passively reduce, but not eliminate, TTA risk. In the absence of viable testing or pathogen inactivation and/or reduction options, leukoreduction may offer some protection from transmission risk.

Transfusion‐transmitted anaplasmosis from a leukoreduced platelet pool

“…Leukoreduction could reduce but not eliminate the risk of TTA, possibly due to the presence of extracellular bacteria in blood compo-nents or the small inoculum size needed to cause symptomatic disease in vulnerable recipients. 7,21 A similarly small inoculum is considered to cause transfusion-transmitted babesiosis (TTB). In the case of TTB, the incubation period is longer than tick-borne cases, while in TTA the incubation period appears similar to tick-borne disease.…”

Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis — United States

“…Transmission of E. ewingii infection via leukoreduced, irradiated platelet transfusion also has been reported (233). Although the risk for transmission of certain rickettsial pathogens might be reduced by leukoreduction of blood products (234), the risk for transfusion-acquired infection is not eliminated (227,228,231,233,235). In vitro studies demonstrate that A. phagocytophilum and E. chaffeensis survive in refrigerated packed erythrocytes for up to 18 and 11 days, respectively (236,237).…”

Survival of Rickettsia conorii in artificially contaminated whole and leukoreduced canine blood units during the storage period

“…Long-term survival was also reported for A. phagocytophilum, with a viability in blood observed until day 18 at 4 °C [9]. In addition, viable bacteria were detected after leukoreduction in blood units experimentally spiked with infected cells [15]. However, the duration of A. phagocytophilum survival in LR-WB was not determined.…”

“…The primary effect of leukoreduction is to limit storage lesions, due to leukocyte degradation during storage; a secondary effect could be to remove white blood cells potentially infected by intracellular infectious agents, such as rickettsiae, which can be transmitted to the recipient by the blood transfusion. Leukoreduction seemed to reduce the risk of transfusion-transmitted infections in laboratory models using Orientia tsutsugamushi [14] and Anaplasma phagocytophilum [15], even though pathogens were not completely eliminated from blood units.…”