Supernatant from stored red cells activates neutrophils

Abstract

Bioreactive substances including cytokines and lipids accumulate during storage of red blood cells (RBCs) but their clinical importance is uncertain. The goal of this study was to evaluate the effect of stored RBC supernatant on neutrophil activity in vitro. Packed RBCs (PRBCs) were collected and divided into two aliquots, one leukodepleted and the other nonleukodepleted. Plasma supernatant from PRBCs were collected on days 1, 8, 15, 29 and 35 and its effect on neutrophil expression of CD11b, CD16 and oxidative burst was measured by flow cytometry. Levels of tumour necrosis factor alpha (TNFα) and interleukin‐8 (IL8) were also measured. The supernatant from PRBC units stored for greater than 15 days activated and primed neutrophils as evidenced by an increase CD11b and CD16 expression and oxidative burst. The greatest effect was seen in the oldest concentrates (35‐day‐old) (P < 0.008). Leukodepletion abrogated the effects of stored supernatant on CD11b and CD16 expression (P < 0.02) but did not reduce priming of the neutrophil oxidative burst (P > 0.1). Very low levels of IL8 and TNFα were detected in stored supernatants. Stored PRBC supernatant contains substances which directly enhance neutrophil expression of adhesion protein CD11b, CD16 and prime neutrophil oxidative burst. The exceedingly low level of IL8 and TNFα found in this study suggests that other factors may play a more important role in neutrophil priming and activation.

Red blood cells increase secretion of matrix metalloproteinases from human lung fibroblasts in vitro

“…For example, RBC can efficiently bind inflammatory mediators such as interleukin-8 (IL-8); regulated on activation, normal T-expressed and secreted (RANTES); and monocyte chemotactic protein 1. These mediators can also be released from the RBC, indicating a role for RBC in the regulation of inflammation (8,9,12,33,53). In line with these data, we have recently demonstrated that RBC can stimulate fibroblast-mediated collagen gel contraction in a time-and concentration-dependent manner and that coculture results in increased release of fibronectin (16).…”

Fresh Red Blood Cell Transfusion and Short-Term Pulmonary, Immunologic, and Coagulation Status

“…A number of observational clinical studies also suggest an association between RBC transfusion and respiratory complications such as transfusion-related acute lung injury (38,39), transfusion-associated circulatory overload (40), and respiratory insufficiency with the need for prolonged mechanical ventilation (8). It has been suggested that the duration of RBC storage may be an important contributing factor in these associations (6,8,22,41,42). An important limitation with the majority of these studies has been their observational study design, with the unavoidable potential for bias and residual confounding.…”

Transfusion-related Acute Lung Injury: Report of Two Cases

“…Alveolar lesions that lead to pulmonary oedema are the result of neutrophil enzyme release and the subsequent synthesis of highly toxic reactive oxygen species. This "double-strike" (two-hit hypothesis) mechanism has been demonstrated in animal models (Silliman et al, 1997;Chin-Yee et al, 1998).…”