Blood manufacturing methods affect red blood cell product characteristics and immunomodulatory activity

Abstract

Transfusion of red cell concentrates (RCCs) is associated with increased risk of adverse outcomes that may be affected by different blood manufacturing methods and the presence of extracellular vesicles (EVs). We investigated the effect of different manufacturing methods on hemolysis, residual cells, cell-derived EVs, and immunomodulatory effects on monocyte activity. Thirty-two RCC units produced using whole blood filtration (WBF), red cell filtration (RCF), apheresis-derived (AD), and whole blood-derived (WBD) methods were examined (n = 8 per method). Residual platelet and white blood cells (WBCs) and the concentration, cell of origin, and characterization of EVs in RCC supernatants were assessed in fresh and stored supernatants. Immunomodulatory activity of RCC supernatants was assessed by quantifying monocyte cytokine production capacity in an in vitro transfusion model. RCF units yielded the lowest number of platelet and WBC-derived EVs, whereas the highest number of platelet EVs was in AD (day 5) and in WBD (day 42). The number of small EVs (<200 nm) was greater than large EVs (≥200 nm) in all tested supernatants, and the highest level of small EVs were in AD units. Immunomodulatory activity was mixed, with evidence of both inflammatory and immunosuppressive effects. Monocytes produced more inflammatory interleukin-8 after exposure to fresh WBF or expired WBD supernatants. Exposure to supernatants from AD and WBD RCC suppressed monocyte lipopolysaccharide-induced cytokine production. Manufacturing methods significantly affect RCC unit EV characteristics and are associated with an immunomodulatory effect of RCC supernatants, which may affect the quality and safety of RCCs.

Red cell supernatant effects on endothelial cell function and innate immune activation is influenced by donor age and sex

“…Monocytes were treated with 1 ml of day 7, day 21 or day 42 RCC supernatants (20% v/v in culture media) followed by 4‐h incubation (37°C, 5% CO 2 ). The 20% v/v of RCC supernatants chosen was an approximate volume ratio of a 20 ml/kg RCC transfusion . To evaluate the phagocytic function of the pooled cryopreserved BC‐derived monocytes, monocyte monolayers were incubated for 2 h with 1 ml of 5% anti‐D‐sensitized group O Rh‐positive RBCs.…”

The impact of red blood cell manufacturing variables on bacterial growth dynamics: a pilot study

“…Jordan et al found similar results and showed that RBC from female donors had lower haemolysis than those from male donors [23]. It has also been shown that extracellular vesicle (EV) release varies by RBC manufacturing method, that EV release levels are lower in RBC produced by the RBC filtration method [24], and that there are subsequent differences in these products' immunomodulatory effects [25]. Differences in levels of residual plasma among RBC manufacturing methods have also been found, with WB filtration methods having significantly higher levels than RBC filtration methods [7].…”

Transfusion‐related immune modulation: functional consequence of extracellular vesicles?

“…Both PLT‐ and WBC‐derived EVs have been shown induce endothelial cell activation, inflammatory cytokine release, and enhanced expression of WBC adhesion factors . However, PLT‐derived EVs have also been shown to promote release of anti‐inflammatory TGF‐β from monocytes, and immune‐suppressive effects of RBC products on monocytes across component preparation methods correlate with PLT‐derived EV quantities . Given these differences, it is not surprising that documented immunomodulatory effects of transfused EVs are highly varied.…”