Effect of ascorbic acid concentrations on hemodynamics and inflammation following lyophilized plasma transfusion.

BACKGROUND: Compared with lyophilized plasma (LP) buffered with other acids, LP with ascorbic acid (AA) attenuates systemic inflammation and DNA damage in a combat relevant polytrauma swine model. We hypothesize that increasing concentrations of AA in transfused LP will be safe, will be hemodynamically well tolerated, and will attenuate systemic inflammation following polytraumatic injury and hemorrhage in swine. METHODS: This prospective, randomized, blinded study involved 52 female swine. Forty animals were subjected to our validated polytrauma model and resuscitated with LP. Baseline control sham (n = 6), operative control sham (n = 6), low-AA (n = 10), medium-AA (n = 10), high-AA (n = 10) groups, and a hydrochloric acid control (HCL, n = 10) were randomized. Hemodynamics, thrombelastography, and blood chemistries were assessed. Inflammatory cytokines (tumor necrosis factor α, interleukin 6 [IL-6], C-reactive protein, and IL-10) and DNA damage were measured at baseline, 2 hours, and 4 hours after liver injury. Significance was set at p < 0.05, with a Bonferroni correction for multiple comparisons. RESULTS: Hemodynamics, shock, and blood loss were similar between groups. All animals had robust procoagulant activity 2 hours following liver injury. Inflammation was similar between groups at baseline, and AA groups remained similar to HCL following liver injury. IL-6 and tumor necrosis factor α were increased at 2 hours and 4 hours compared with baseline within all groups (p < 0.008). DNA damage increased at 2 hours compared with baseline in all groups (p < 0.017) and further increased at 4 hours compared with baseline in HCL, low-, and high-AA groups (p < 0.005). C-reactive protein was similar between and within groups. IL-10 increased at 2 hours compared with baseline in low- and high-AA groups and remained elevated at 4 hours compared with baseline in the low-AA group (all, p < 0.017). CONCLUSION: Concentrations of AA were well tolerated and did not diminish the procoagulant activity of LP. Within our tested range of concentrations, AA can safely be used to buffer LP.

Reconstitution fluid type does not affect pulmonary inflammation or DNA damage following infusion of lyophilized plasma.

BACKGROUND: Dysfunctional inflammation following traumatic hemorrhage can lead to multiple-organ failure and death. In our polytrauma swine model, lyophilized plasma (LP) reconstituted with sterile water and ascorbic acid suppressed systemic inflammation and attenuated DNA damage. However, it remains unknown whether the inflammatory response is affected by the type of fluid used to reconstitute LP. We hypothesized that common resuscitation fluids such as normal saline (LP-NS), lactated Ringer's solution (LP-LR), Hextend (LP-HX), or sterile water (LP-SW) would yield similar inflammation profiles and DNA damage following LP reconstitution and transfusion. METHODS: This was a randomized, prospective, blinded animal study. LP was reconstituted to 50% of original volume with NS, LR, HX, or SW buffered with 15-mM ascorbic acid. Forty swine were subjected to a validated model of polytrauma, hemorrhagic shock, and Grade V liver injury and resuscitated with LP. Serum interleukin 6 (IL-6), IL-10, plasma C-reactive protein, and 8-hydroxy-2-deoxyguanosine concentrations were assessed for systemic inflammation and DNA damage at baseline, 2 hours, and 4 hours following liver injury. Lung inflammation was evaluated by Real Time Polymerize Chain Reaction (RT-PCR). RESULTS: Reconstituted LP pH was similar between groups before resuscitation. IL-6 and IL-10 increased at 2 hours and 4 hours compared with baseline in all groups (p < 0.017). DNA damage increased at 2 hours and 4 hours compared with baseline and from 2 hours to 4 hours in the LP-NS, LP-LR, and LP-SW groups (all p < 0.017). Animals resuscitated with LP-HX not only demonstrated increased DNA damage at 4 hours versus baseline but also had the lowest C-reactive protein level at 2 hours and 4-hours (p < 0.017). Overall, differences between groups were similar for DNA damage and lung inflammation. CONCLUSION: Reconstitution fluid type does not affect inflammatory cytokine profiles or DNA damage following LP transfusion in this swine polytrauma model. Based on universal availability, these data suggest that sterile water is the most logical choice for LP reconstitution in humans. LEVEL OF EVIDENCE: Prognostic, level II.

Differential regulation of fibrinogen γ chain splice isoforms by interleukin-6.

INTRODUCTION: Fibrinogen is a major structural protein in blood clots, and is also a well-known acute phase reactant. The γ chain gene of fibrinogen has two alternative splice variants, γA and γ' chains. γ' fibrinogen constitutes about 7% of total fibrinogen. Total fibrinogen levels and γ' fibrinogen levels have been associated with cardiovascular disease, but the mechanisms regulating the production of the two isoforms are unknown. Several inflammatory cytokines are known to influence the production of total fibrinogen, but the role of cytokines in the production of γ' fibrinogen has not been examined. However, epidemiologic studies have shown an association between γ' fibrinogen levels and inflammatory markers in humans. MATERIALS AND METHODS: The expression of γ' fibrinogen and total fibrinogen by HepG2 liver cells was quantitated after treatment with interleukin-1ß, transforming growth factor-ß, tumor necrosis factor-α, and interleukin-6. RESULTS: Interleukin-1ß, transforming growth factor-ß, and tumor necrosis factor-α, known down-regulators of total fibrinogen synthesis, also downregulate γ' fibrinogen synthesis in HepG2 cells. However, interleukin-6 differentially up-regulates the production of total and γ' fibrinogen, leading to a 3.6-fold increase in γA mRNA, but an 8.3-fold increase in γ' mRNA. CONCLUSIONS: These findings indicate that γ' fibrinogen is disproportionately up-regulated by inflammatory responses induced by interleukin-6.