Men Have a Stronger Monocyte-Derived Cytokine Production Response upon Stimulation with the Gram-Negative Stimulus Lipopolysaccharide than Women: A Pooled Analysis Including 15 Study Populations.

The incidence of bacterial infections and sepsis, as well as the mortality risk from sepsis, is sex specific. These clinical findings have been attributed to sex differences in immune responsiveness. The aim of the present study was to investigate sex differences in monocyte-derived cytokine production response upon stimulation with the gram-negative stimulus lipopolysaccharide (LPS) using cytokine data from 15 study populations. Individual data on ex vivo cytokine production response upon stimulation with LPS in whole blood were available for 4,020 subjects originating from these 15 study populations, either from the general population or from patient populations with specific diseases. Men had a stronger cytokine production response than women to LPS for tumour necrosis factor-α, interleukin (IL)-6, IL-12, IL-1ß, IL-1RA, and IL-10, but not for interferon-γ. The granulocyte-macrophage colony-stimulating factor production response was lower in men than in women. These sex differences were independent of chronological age. As men had higher monocyte concentrations, we normalized the cytokine production responses for monocyte concentration. After normalization, the sex differences in cytokine production response to LPS disappeared, except for IL-10, for which the production response was lower in men than in women. A sex-based approach to interpreting immune responsiveness is crucial.

Antifibrinolytics attenuate inflammatory gene expression after cardiac surgery.

OBJECTIVES: Anti-inflammatory effects of tranexamic acid and aprotinin, used to abate perioperative blood loss, are reported and might be of substantial clinical relevance. The study of messenger ribonucleic acid synthesis provides a valuable asset in evaluating the inflammatory pathways involved. METHODS: Whole-blood messenger ribonucleic acid expression of 114 inflammatory genes was compared pre- and postoperatively in 35 patients randomized to receive either placebo, tranexamic acid, or aprotinin. These results were further confirmed by reverse transcription-polymerase chain reaction. RESULTS: Of the 23 genes exhibiting independently altered postoperative gene expression levels, 8 were restricted to the aprotinin group only (growth differentiation factor 3, interleukin 19, interleukin 1 family member 7, transforming growth factor α, tumor necrosis factor superfamily 10, tumor necrosis factor superfamily 12, tumor necrosis factor superfamily 13B, vascular endothelial growth factor α), whereas both aprotinin and tranexamic acid altered gene expression of 3 genes as compared with placebo (FMS-related tyrosine kinase 3 ligand, growth differentiation factor 5, interferon-α8). In general, less upregulation of pro-inflammatory, and more upregulation of anti-inflammatory, genes was observed for patients treated with antifibrinolytics. Gene expression affected by aprotinin coded mostly for proteins that function through serine proteases. CONCLUSIONS: This study demonstrates that the use of tranexamic acid and aprotinin results in altered inflammatory pathways on the genomic expression level. We further demonstrate that the use of aprotinin leads to significant attenuation of the immune response, with several inhibitory effects restricted to the use of aprotinin only. The results aid in a better understanding of the targets of these drugs, and add to the discussion on which antifibrinolytic can best be used in the cardiac surgical patient.

Tranexamic acid and aprotinin in low- and intermediate-risk cardiac surgery: a non-sponsored, double-blind, randomised, placebo-controlled trial.

OBJECTIVE: Tranexamic acid has been suggested to be as effective as aprotinin in reducing blood loss and transfusion requirements after cardiac surgery. Previous studies directly comparing both antifibrinolytics focus on high-risk cardiac surgery patients only or suffer from methodological problems. We wanted to compare the effectiveness of tranexamic acid versus aprotinin in reducing postoperative blood loss and transfusion requirements in the patient group representing the majority of cardiac surgery patients: low- and intermediate-risk patients. METHODS: We conducted a non-sponsored, double-blind, randomised, placebo-controlled trial in which 298 patients scheduled for low- or intermediate-risk (mean logistic EuroSCORE 4.1) first-time heart surgery with use of cardiopulmonary bypass were randomised to receive either tranexamic acid, high-dose aprotinin, or placebo. All patients had preoperative normal renal function. End points of the study were monitored from the time of surgery until patient discharge. This trial was executed between June 2004 and October 2006. RESULTS: Both antifibrinolytics significantly reduced blood loss and transfusion requirements when compared with placebo. Aprotinin was about twice as effective as tranexamic acid in reducing total postoperative blood loss (estimated median difference 155 ml, 95% confidence interval (CI) 60-260; p < 0.001). Accordingly, aprotinin reduced packed red blood cell transfusions more than tranexamic acid, although the difference did not reach statistical significance. Only aprotinin significantly reduced the proportion of transfused patients when compared with placebo (mean difference -20.9%, 95% CI 7.3-33.5; p = 0.013), and only aprotinin completely abolished bleeding-related re-explorations (mean difference 6.8%, 95% CI 1.6-13.4%; p = 0.004). Neither antifibrinolytic agent increased the incidence of mortality (mean difference tranexamic acid -0.4%, 95% CI -4.6 to 4.4; p = 0.79, mean difference aprotinin -1.3%, 95% CI -6.2 to 3.5; p = 0.62) or other serious adverse events when compared with placebo. CONCLUSION: Aprotinin has clinically significant advantages over tranexamic acid in patients with normal renal function scheduled for low- or intermediate-risk cardiac surgery.