Proinflammatory and antiinflammatory cytokine production during ischemia-reperfusion injury in a case of identical twin living donor liver transplantation using no immunosuppression

Concentration of Tumor Necrosis Factor-α and Interleukin-1β in Isolated Porcine Liver Depending on Type of Transgenesis

BACKGROUND

Transgenic animals may serve as organ donors in human organ transplantation. However, the number of the studies addressing all doubts related to this issue is currently insufficient for the clinical application of this approach. The aim of this study was to analyze the hepatic tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) synthesis during a 24-hour cold preservation of the transgenic pig liver, depending on the type of transgenesis.

MATERIALS AND METHODS

The study was carried out on wild-type and transgenic pig livers with transferred human α1,2-fucosyltransferase (FUT) and/or α-galactosidase (GAL) gene (four groups; n = 6). Harvested livers were perfused for 30 minutes and stored for 24 hours in Biolasol (Biochefa) solution at 4°C with a subsequent 30-minute reperfusion (reflush). TNF-α and IL-1β concentrations were analyzed with an enzyme-linked immunosorbent assay. Perfusates were collected during the initial perfusion as well as after 24 hours of preservation and during the reperfusion. Tissue samples were harvested just after animal sacrifice, and after organ perfusion and reperfusion.

RESULTS

A decrease in TNF-α concentration in homogenates was noted after both perfusion and reperfusion in all experimental groups. In contrast, there was a significant decrease in IL-1β concentration in the group with combined human FUT and GAL transgenes. Concurrently, increases in TNF-α and IL-1β concentrations were observed in the reperfusion perfusates in all groups.

CONCLUSION

This study shows that IL-1β is synthesized in the ischemic livers of the transgenic animals with both human α1,2-fucosyltransferase and α-galactosidase transgenes. Further analysis is required to determine the importance of this observation.

Interleukin-6 concentration in the transgenic pig's liver preserved for 24 hours in Biolasol solution

INTRODUCTION

Increasing the human lifespan contributes to a higher number of patients with end-stage organ failure, which in turn stimulates the search for alternative sources. Xenotransplantation seems to be a promising approach in this respect.

OBJECTIVE

Analysis of changes in interleukin (IL)-6 concentration during 24-hour preservation of transgenic swine livers, depending on the kind of transgenesis and preservation solution used.

MATERIALS AND METHODS

The experiment was carried out in swine livers with transferred human genes that were divided into 5 groups. The following human genes were transferred: α1,2-fucosyltransferase (group I and II), α-galactosidase (III), combined α1,2-fucosyltransferase/α-galactosidase transgene (IV), and livers without modification (V). The livers were perfused and subsequently stored for 24 hours in Ringer's (group I) or Biolasol solutions (II-V). Reflush was then performed. IL-6 concentration was analyzed in the solution samples collected at the beginning and end of perfusion, and after 24 hours of preservation. ELISA was used to evaluate IL-6 concentration.

RESULTS

In liver homogenates from group I, IL-6 concentration after 24 hours of preservation increased by 8.24% compared to the levels observed after perfusion, whereas in the other groups IL-6 concentration decreased. The most significant decrease, 49.51%, was observed in group II; the least significant in group IV, 10.72%. In case of supernatants, a statistically significant increase of AUC0-30min level in relation to perfusion was observed in every group after 24-hour preservation and reperfusion. The highest values of AUC0-30min were observed in group I (α1,2-fucosyltransferase, Ringer's solution).

CONCLUSION

The study indicates the hepatoprotective action of Biolasol solution.

Cytokine response to ischemia/reperfusion injury in an ex vivo perfused porcine liver model

BACKGROUND

We evaluated the degree of inflammatory response after ischemia/reperfusion injury by an extracorporeal normothermic autologous hemoperfusion of porcine livers.

MATERIALS AND METHODS

Livers explanted from 7 pigs were perfused extracorporeally at 39 degrees C with autologous blood. Serum samples were obtained hourly until 6 hours from the beginning of reperfusion and assayed for 9 different cytokines.

RESULTS

Significant elevations in interleukin 6 (IL-6) and IL-8 were noted following reperfusion (P < .001), with both demonstrating an increase which followed a sigmoid curve; other cytokines that were assessed showed no significant change.

CONCLUSIONS

The ex vivo model excludes the liver from the influence of external systemic factors such as hormones, the autonomic nervous system, and other regulatory molecules produced elsewhere in the body, allowing the response to the ischemia/reperfusion injury to be studied in isolation and in considerable detail. Although this study examined a relatively short period, the increases in only IL-6 and IL-8 suggested that these are important molecules in the early phase after reperfusion.

Biological variation and prognosis usefulness of new biomarkers in liver transplantation

An observational retrospective study has been conducted, including 52 patients (37 male and 15 female), ranging from 22 to 65 years old, who underwent an orthotopic liver transplantation (OLT) at the Hospital Universitario Central de Asturias (HUCA) between 2007 and 2010.

The main objective was to evaluate the post-OLT critical complication prognosis usefulness of the precursors of three new biomarkers: mid-regional proadrenomedullin (MR-proADM), carboxy-terminal-proendothelin-1 (CT-ProET-1) and mid-regional proatrial natriuretic peptide (MR-ProANP). As all of them are blood pressure mediators, stress-associated physiological phenomena are expected to affect their expression and secretion, mainly those related to blood circulation. Therefore, as a second goal, the biological variability of the biomarkers has been studied in a set of OLT patients without complications during the first postoperative week. The knowledge of the reference change value of the new biomarkers will be interesting for their correct interpretation in future investigations. The prognostic value of the new biomarkers was also compared to that of procalcitonin (PCT).

It has been shown that the basal concentration of the biomarkers is higher in patients that undergo OLT than in the normal population, correlating with the severity of the pathology. The intra-individual biological variation of these biomarkers is similar to other biochemical parameters, the reference change value for OLT patients being 90% for CT-proET-1, 112% for MR-proADM and 127% for MR-proANP.

Multivariate analysis showed that MR-proADM was the best biomarker for the prognosis of severe complications.

Allograft inflammatory factor-1 and its immune regulation

The allograft inflammatory factor-1 (AIF-1) is a 17 kDa interferon-gamma (IFN-gamma) inducible Ca(2+)-binding EF-hand protein that is encoded within the HLA class III genomic region. Three proteins including ionized Ca(2+)-binding adaptor 1, microglia response factor-1, and daintain are identical with AIF-1. The expression of AIF-1 was mostly limited to the monocyte/macrophage lineage, and augmented by cytokines such as IFN-gamma. It was assumed that AIF-1 was a novel molecule involved in inflammatory responses, allograft rejection, as well as the activation and function of macrophages. However, it has been reported that AIF-1 is also expressed in macrophages and microglial cells in autoimmune diseases such as experimental autoimmune encephalomyelitis, neuritis and uveitis models, suggesting that AIF-1 may play a pivotal role in autoimmunity. In the present manuscript, the genomic and functional characteristics of AIF-1 family proteins as well as their immune regulatory effects are reviewed.