Interleukin-8 Level in Packed Red Blood Cells

The term cytokine was proposed by Stanley Cohen in 1974 and refers to peptides, proteins, and glycoproteins which play a role in controlling the survival/death of cells, their growth and differentiation as well as the effector functions in tissues and immune cells.

The cytokines are small cell-signaling protein molecules with several functions,e.g.: Intracrine, Autocrine and Intercrine actions (1).

They are synthesized by different immune cells, mainly by T cells, neutrophils and macrophages, which are responsible to promote and regulate immune response (i.e. activity, differentiation, proliferation and production of cells and other cytokines) (2).

Cytokines are described as being pro-inflammatory or antiinflammatory, both of which accumulate in blood products during storage mainly as a result of damaged leucocytes. The accumulation of pro-inflammatory cytokines, is regarded as one of the major causative factors For Transfusion-Associated Adverse Reactions (TAARs), particularly Febrile Non-Haemolytic Transfusion Reactions (FNHTRs) and Transfusion-Related Immunomodulation (TRIM). In addition, the transfusion of blood products containing cytokines has been associated with transfusion-induced systemic inflammation in patients with pre-activated endothelial cells (3).

Interleukin-8 (also known as neutrophil-activating peptide 1) is recognized as a potent effector of neutrophil functions. Several different cell types that contact blood, namely T lymphocytes, monocytes, and endothelial cells, secrete this polypeptide following stimulation by cytokines, or lipopolysaccharide (4).

Interleukin-8 (IL-8), a cytokine with chemotactic and activating properties for neutrophils, has recently been isolated, cloned, and expressed.5 IL-8 is produced by monocytes in response to lipopolysaccharide (LPS), tumor necrosis factor-α (TNF-α), and IL-1;6 and has been implicated in the pathogenesis of acute lung injury. Therefore, we hypothesized that IL-8 may be a mediator of the pathologic events in hemolytic transfusion reaction (HTR), and designed an in vitro model of red blood cell (RBC) incompatibility to investigate the possible role of IL-8 in this setting (5).

Leukoreduction (LR) is a potential means of preventing cytokine production (6).

Thus reducing the white blood cell (WBC) content (leukodepletion) in cellular blood components to a significant level has a direct impact on reducing the incidence of many adverse effects of transfusion-associated with leukocytes and cytokines present in higher levels in non leukodepleted blood component (7).