Prestorage leucocyte reduction of red cell components prevents release of bactericidal permeability increasing protein and defensins

Use of leukoreduced blood does not reduce infection, organ failure, or mortality following trauma

Background

Leukoreduced (LR) blood has been demonstrated to reduce morbidity and mortality in high-risk surgical patients, but not in trauma patients. The objective of the present study was to determine the effect of LR blood on morbidity and mortality. We hypothesized that the use of LR blood does not improve outcome in trauma patients.

Methods

This study was a retrospective cohort analysis of trauma patients transfused at a level 1 Trauma Center from 2001 to 2004. Between 2002 and 2003, LR blood was transfused. Prior to that time and subsequent to it, non-leukoreduced (NLR) blood was transfused. This created two historical comparison groups. Data collected included patient demographics, units of blood transfused, intensive care unit (ICU) and hospital days, ventilator days, injury severity score (ISS), mortality, presence of acute respiratory distress syndrome (ARDS), and infectious complications. A multiple organ dysfunction syndrome (MODS) score was calculated.

Results

The distribution of patients was as follows: 284 patients received only NLR blood, 153 received only LR blood, and 58 received at least one unit of each. The mean ISS was similar (NLR: 26, LR: 24; P > 0.1). No differences were seen between groups in units transfused (6.2 vs. 5.5), number of ICU days (8.2 vs. 9.0), number of hospital days (16.9 vs. 18.6), number of ventilator days (6.1 vs. 5.7), incidence of ARDS (8.3% vs. 8.5%), MODS score (5.5 vs. 5.9), mortality rate (15.1% vs. 15.7%), or infection rate (36% vs. 30%) (P > 0.1).

Conclusions

This study represents the largest series comparing trauma patients who received either LR or standard blood transfusions. The use of LR blood does not improve outcome in trauma patients.

Inactivation of Orientia tsutsugamushi in red blood cells, plasma, and platelets with riboflavin and light, as demonstrated in an animal model

BACKGROUND

Treatment of blood products with riboflavin and light has been used to reduce the number of certain pathogens. Orientia (formerly Rickettsia) tsutsugamushi, the scrub typhus agent, is an obligate intracellular bacterium that grows free in the cytoplasm of infected cells. This study evaluated the capability of riboflavin and light to inactivate O. tsutsugamushi in red blood cells (RBCs), platelets (PLTs), and plasma, as measured by mouse infectivity.

STUDY DESIGN AND METHODS

A total of 108 mice, equally divided into groups receiving RBCs, plasma, and PLTs, received untreated products infected with 10(0) to 10(5) organisms. Eighteen mice received products infected with 10(5) organisms and were subsequently treated with riboflavin and light. Mice were monitored daily for up to 17 days for signs and symptoms of infection (e.g., lethargy, labored breathing, rough coat) and killed upon appearance of symptoms or on Day 17 after infection. Real-time polymerase chain reaction (PCR) on blood and Giemsa stains from peritoneal exudates were performed.

RESULTS

A total of 102 of 108 mice receiving the untreated products developed signs and symptoms of infection and had positive PCR and Giemsa stain results. None of the 18 animals receiving riboflavin and light-treated blood products exhibited signs or symptoms of infection, nor was infection observed by PCR testing or Giemsa staining.

CONCLUSIONS

Riboflavin and light are effective in reducing O. tsutsugamushi. Mice injected with blood products inoculated with 10(5) organisms and treated with riboflavin and light did not experience any signs or symptoms of infection, 17 days after inoculation. A 5-log reduction of this organism in blood was achieved as assayed in an animal model.

Supernatant from stored red blood cell primes inflammatory cells: influence of prestorage white cell reduction

BACKGROUND

The contribution of RBC transfusion to adverse patient outcomes is controversial. There is conflicting clinical data and limited biologic data that provide an underpinning biologic rationale for any adverse impacts from RBC transfusion. This study used in-vitro measures of PMN stimulation to determine the ability of supernatant from RBCs to stimulate allogeneic WBCs and to determine the influence of residual donor WBCs and storage time on the proinflammatory potential of RBCs.

STUDY DESIGN AND METHODS

Three types of RBCs were assessed: standard non-WBC-reduced RBCs (S-RBCs), buffy coat-poor RBCs (BCP-RBCs), and prestorage WBC-filtered RBC (LF-RBCs). Supernatant was collected weekly up to Day 42 of storage. PMN priming by supernatant from RBCs was determined by three methods: induction of CD11b expression on PMNs, induction of IL-8 release from PMNs, and the chemotactic effect of supernatant on PMNs.

RESULTS

Supernatant from S-RBCs induced the expression of CD11b on PMNs, primed PMNs to release IL-8, and was chemotactic for PMNs. The magnitude of this PMN-priming progressively amplified with storage time. In contrast, supernatant from BCP-RBCs or LF-RBCs did not significantly prime PMNs. The PMN-priming effect of supernatant from RBCs correlated more closely with the level of MNCs in the RBCs than PMN content.

CONCLUSION

Supernatant from stored S-RBCs prime unstimulated allogeneic PMNs in vitro. Prestorage buffy-coat WBC reduction was as effective as WBC depletion in abrogating this proinflammatory response elicited by supernatants from RBCs. The clinical consequences, if any, of these findings for transfusion recipients are unknown.