Different time course of circulating adhesion molecules and hyaluran during hepatic allograft rejection

Hyaluronic Acid Is a Biomarker for Allograft Dysfunction and Predicts 1-Year Graft Loss After Liver Transplantation

BACKGROUND

Allograft dysfunction after liver transplantation has a profound impact on the risks of death and retransplantation within the first year. We tested whether elevated hyaluronic acid (HA; a glycosaminoglycan cleared by hepatic sinusoidal endothelium) levels may predict excess risk of graft loss.

METHODS

This was a retrospective single-center prognostic cohort study. Patients with either a plasma sample before transplantation, an early post-transplantation sample nearest day 30 (range 10-89 d, 80% within days 15-60), or both were included. Plasma HA was measured with the use of enzyme-linked immunosorbent assays. The primary end point was 1-year graft loss (all-cause mortality and retransplantation). A secondary end point was biliary stricture.

RESULTS

In this study, 169 of 196 patients who received a liver transplant in the study period were included. Pre-transplantation HA (n = 152) did not predict graft loss. Post-transplantation HA (n = 124) was higher among patients with graft loss (median, 177 μg/L [interquartile range (IQR), 89-465] vs 54 μg/L [IQR 37-93]) and was a strong predictor of this outcome (hazard ratio per 50 μg/L, 1.24 [95% confidence interval [CI], 1.14-1.34]). The discriminatory ability of HA was high (area under the receiver operating characteristic curve, 0.86 [95% CI, 0.77-0.94]) and noninferior to other liver function tests. When adjusted for known risk factors of graft loss, HA remained an independent predictor of graft loss.

CONCLUSIONS

High post-transplantation plasma HA level was a strong predictor of 1-year all-cause mortality and retransplantation, whereas pre-transplantation levels were not, despite variety in the time span of blood sampling. Prospective studies are warranted to assess the utility of HA in liver transplantation.

Pretransplant replacement of donor liver grafts with recipient Kupffer cells attenuates liver graft rejection in rats

BACKGROUND AND AIM

Rejection of liver grafts is a difficult issue that has not been resolved. Preoperative replacement of liver cells in the graft with cells from the intended recipient may attenuate rejection. We investigated whether preoperative transplant of recipient bone marrow cells (BMCs) to the donor replaced liver allograft cells and attenuated rejection.

METHODS

We used a rat model of allogeneic liver transplant (LT) from Dark Agouti (DA) to Lewis (LEW) rats. In BMC group, DA rats received BMC transplants from LacZ-transgenic LEW rats at 1 week before LT. In the control group, DA rats received no preoperative treatment. We evaluated graft damage at 7 days after LT and the survival of the recipient rats.

RESULTS

Rats in the BMC group experienced prolonged survival that was abrogated by the administration of gadolinium chloride to donors at 24 h before LT. Serum concentrations of total bilirubin and hyaluronic acid on day 7 were significantly lower in the BMC group, and histopathological analyses revealed that rejection of the liver graft was attenuated. X-gal staining and immunohistostaining of the liver graft revealed that BMCs engrafted in the sinusoidal space differentiated into Kupffer cells.

CONCLUSIONS

Preoperative transplant of recipient BMCs to LT donors replaced donor Kupffer cells and attenuated post-LT rejection, indicating that this strategy may increase the success of LT.

Serial monitoring of co-stimulating signals in double hand allograft: a case report

AIMS

The aim of this study was to evaluate the clinical significance of serial monitoring of co-stimulating signals in double hand transplantation.

METHODS

From September 2001 to December 2001, a patient who had double hand transplantation in our hospital was the subject of the experiment. Before the operation, a blood sample was collected before giving an immunodepressant and twice after giving the immunodepressant. A blood sample was also collected before arteriovenous connection during the operation, as well as once a day during the first week after the operation, once every other day in the second week, twice a week in the third and fourth week, followed by once a week for 2 months. The first week after operation was taken as the induction period with the other samples as the maintenance period. Then 2 mL peripheral venous blood collected from a healthy adult was anti-coagulated using EDTA of mass scores of 20 g/L. Flow cytometry was used for serial monitoring of T-cell surface co-stimulating molecules (CD28, CD54, and CD11a).

RESULTS

The changes in the 3 co-stimulating molecules-CD28, CD54, and CD11a-were consistent with each other after double hand transplantation, displaying a decrement during induction compared with preoperatively: 9.84 +/- 5.28%, 55.50 +/- 3.62%; 71.03 +/- 5.33% versus 95.10 +/- 1.26%; 9.40 +/- 9.17%, 29.70 +/- 3.23% with low levels during maintenance 22.54 +/- 6.56%, 91.28 +/- 8.12%, 11.22 +/- 4.08%.

CONCLUSION

The serial monitoring of the co-stimulating signals in the peripheral blood of limb allograft patients may be beneficial to evaluate postoperative immunologic reactions to guide immunosuppression as well as predict and diagnose postoperative immune rejection.

Role of lipid emulsion administration in acute lung injury during liver transplant rejection: a case report

We report the case of a 58-year-old woman who developed rejection and acute lung injury 10 days after an orthotopic liver transplantation while receiving total parenteral nutrition. Examination of bronchoalveolar lavage fluid revealed large lipid droplets in the alveolar macrophages. Intensification of the immunosuppressive therapy attenuated the liver allograft rejection followed by resolution of lung injury.

Protocol liver allograft biopsies

Protocol liver allograft biopsies are liver biopsies carried out at specific time points according to predetermined guidelines, rather than in response to specific indications such as change in the patient's clinical status or biochemical tests. Use of protocol liver allograft biopsy has been declining over the last decade: an informal survey of 35 transplant units showed that whereas 65% of units undertake protocol biopsies for those grafted for Hepatitis C virus infection, only 25% do so for patients grafted for other indications. In this overview, we consider the arguments against and those in favor of liver biopsies in adult liver allograft recipients. Arguments against the use of protocol liver biopsies are that they biopsies put the patient are associated with a small risk of morbidity and mortality, are expensive, do not provide useful information and do not alter clinical practice. The estimated rate of major complications is 0.6% and the estimated mortality rate 0.02%. However, the argument in favor of protocol biopsies is that even when standard liver tests are normal, there is on-going inflammation in the graft which, if immunosuppression is not altered, will lead to progressive fibrosis, cirrhosis and even graft loss. Conversely, normal liver histology may allow for reduction in the immunosuppression and so lower the risk of the complications associated with immunosuppression. Currently available diagnostic techniques are not yet sufficiently sensitive or specific to provide an accurate reflection of the state of the graft and the presence or absence of graft damage. We conclude that, while there are no clear data showing that protocol liver allograft biopsies are cost effective and lead to improved patient and graft outcome, such biopsies still have a role in the management of the liver transplant recipient.

The immunosuppressive effects of nicotine during human mixed lymphocyte reaction

Cell-to-cell interaction through binding intercellular adhesion molecule (ICAM)-1, B7.1, B7.2 and CD40 on monocytes and their ligands on T-cells plays roles in cytokine production and T-cell proliferation. Interleukin (IL)-18, which is elevated in the plasma during acute rejection after organ transplantation, induces the expression of ICAM-1, B7.1, B7.2 and CD40, production of interferon (IFN)-gamma and IL-12 and proliferation of lymphocytes during human mixed lymphocyte reaction. Nicotine is known to inhibit the production of pro-inflammatory cytokines from macrophages through the stimulation of nicotinic acetylcholine receptor alpha7 subunit. In the present study, we examined the effect of increasing concentrations ranging from 0.1 to 100 microM of nicotine on the expression of ICAM-1, B7.1, B7.2 and CD40, production of IFN-gamma and IL-12 and proliferation of lymphocytes during mixed lymphocyte reaction treated with IL-18 at 100 ng/ml for 48 h. Nicotine inhibited the expression of adhesion molecules, cytokine production and lymphocyte proliferation. The IC50 values of nicotine for inhibition of the IL-18-enhanced ICAM-1 expression, IFN-gamma production and proliferation were 1, 1 and 2 microM, respectively. A non-selective and a selective antagonist for nicotinic acetylcholine receptor alpha7 subunit, mecamylamine and alpha-bungarotoxin abolished the effects of nicotine. The actions of nicotine might depend on stimulation of nicotinic acetylcholine receptor alpha7 subunit. Nicotine induced prostaglandin E(2) production during mixed lymphocyte reaction. The inhibitors of cyclooxygenase (COX)-2 and protein kinase A (PKA) at 100 microM inhibited the actions of nicotine, suggesting that the endogenous prostaglandin E(2) might be, at least, partially involved the actions of nicotine.

Soluble adhesion molecule profiling in preoperative infants with biliary atresia

OBJECTIVE

Intercellular adhesion molecule (ICAM) expression in liver and bile duct remnant is a feature of the inflammatory component of biliary atresia (BA). Circulating levels of such soluble adhesion molecules (SAM) should reflect intrahepatic disease and would prove a useful adjunct in the evaluation of BA.

STUDY DESIGN

Serum ICAM-1 (sICAM-1), serum vascular cell adhesion molecule (sVCAM-1), and serum E selectin (sE-selectin) were measured by enzyme-linked immunosorbent assay in infants with BA at the time of portoenterostomy and stratified by outcome. Results are quoted as medians (range). Binary logistic regression analysis and actuarial survival curves were used to investigate the relationship of SAM profile to outcome. Significance was assumed at P values of < or = .05.

RESULTS

Sixty-one infants with BA were treated between 1996 and 2002 and at follow-up; 39 of these were alive and jaundice-free (good outcome, n = 39); 21 had been transplanted, and 1 died (poor outcome, n = 22). Preoperative values for sICAM-1 were 1233 (400-2000) ng/mL; sVCAM-1, 1204 (517-1921) ng/mL; and sE-selectin, 71 (26-192) ng/mL. sVCAM-1 (P < .0001) and sICAM-1 (P < .0001) significantly increased compared with normal control infants, although sE-selectin did not (P = .17). There was a significant correlation of age at surgery with sICAM-1 (r = 0.33, P = .01) but not with sVCAM-1 (r = 0.16, P = .23) or sE-selectin (r = 0.05, P = .70). Binary logistic regression analysis showed that the variables, sICAM-1, sE-selectin, or age at surgery, were not significant predictors of outcome, although sVCAM-1 approached significance (P = .069). A cutoff value for sVCAM-1 of 1380 ng/mL was defined by receiver operating characteristic curve analysis, and the cohort of patients with sVCAM-1 (> 1380 ng/mL) showed a significantly worse actuarial survival (P = .05).

CONCLUSION

Levels of sICAM-1 and sVCAM-1 are grossly elevated in BA, whereas sE-selectin levels are normal. Only sVCAM-1 levels have prognostic significance. SAM profiling has the potential to monitor the inflammatory process of BA and may guide more novel forms of pharmacological intervention or immunomodulation.

Blockade of vascular adhesion protein-1 inhibits lymphocyte infiltration in rat liver allograft rejection

Vascular adhesion protein-1 (VAP-1) has been shown to mediate lymphocyte adhesion to endothelia at sites of inflammation, but its functional role in vivo has not been tested in any rodent model. Here we report the effects of VAP-1 blockade on rat liver allograft rejection. BN recipients of PVG liver allografts (known to develop acute rejection by day 7) were treated with 2 mg/kg anti-VAP-1 (a new anti-rat VAP-1 mAb 174-5) or isotype-matched irrelevant antibody (NS1) every other day (n = 6/group) and one group with anti-VAP-1 2 mg/kg daily (n = 7). On day 7, samples were collected for transplant aspiration cytology, histology, and immunohistochemistry. Lymphocyte infiltration to the graft was clearly affected by VAP-blockade. The total inflammation, mainly the number of active lymphoid cells, in transplant aspiration cytology was significantly decreased in animals treated with anti-VAP-1 (4.7 +/- 1.0 and 2.4 +/- 1.0 corrected increment units, respectively) compared to control (6.6 +/- 1.0) (P < 0.05). In histology, the intensity of portal inflammation was significantly decreased (P < 0.05). The amount of T cells expressing activation markers diminished. This is the first demonstration in any prolonged in vivo model that VAP-1 plays an important role in lymphocyte infiltration to sites of inflammation, and, in particular, liver allograft rejection.

β2-Adrenergic Receptor Stimulation-Induced Immunosuppressive Effects Possibly through Down-Regulation of Co-Stimulatory Molecules, ICAM-1, CD40 and CD14 on Monocytes

We examined the effects of β2-adrenergic receptor (β2-AR) agonists on the expression of co-stimulatory molecules on lipopoly-saccharide (LPS)-stimulated human peripheral blood mononuclear cells. The study found that β2-AR agonists inhibited the expression of intercellular adhesion molecule-1 (ICAM-1), CD40 and CD14 on monocytes, and that AR agonist activity was antagonized by the selective β2-AR antagonist, butoxamine. The selective β2-AR agonists salbutamol and terbutaline induced a similar co-stimulatory molecule expression pattern. The LPS-induced production of tumour necrosis factor-α was inhibited by AR agonists, and this was also antagonized by butoxamine, and mimicked by salbutamol and terbutaline. The AR agonists also inhibited T-cell proliferation through β2-AR stimulation. This study clearly demonstrated that endogenous catecholamines elicited immunosuppressive effects through β2-AR stimulation, possibly due to down-regulation of the expression of ICAM-1, CD40 and CD14 on monocytes. These results suggested that the sympathetic nervous system might regulate the T-helper cell balance via the peripheral end-effectors of the stress system.

Serum hyaluronan and hyaluronidase: very early markers of toxic liver injury

BACKGROUND

Dimethylnitrosamine (DMN), a potent hepatotoxin, administered to rats, provides a convenient model for toxic liver injury. Indicators of early liver injury are important clinically, for surveillance, for screening new drugs that are potentially hepatotoxic and for identifying drugs that protect against liver injury. Both cirrhosis and wound healing culminate in deposition of fibrous connective tissue and scarring. Increased hyaluronan (HA) occurs in the earliest stage of wound healing. Hyaluronidase, the enzyme that degrades hyaluronan, is also elevated whenever rapid turnover of hyaluronan occurs. We test the hypothesis that elevated levels of circulating hyaluronan and hyaluronidase could provide indicators of very early liver damage.

METHODS

Dimethylnitrosamine was administered to adult male albino rats by intraperitoneal injections for 7 consecutive days.

RESULTS

Increased serum hyaluronan levels observed on day 2 reached a maximum on day 4. Hyaluronidase was elevated on the first day and reached a maximum on day 2 that was 30-times control levels. Hyaluronan-specific staining in liver sections was maximal on day 7, occurring predominantly in portal triads and in sinusoidal spaces. Individual hepatocytes were slightly enlarged and contained intracellular hyaluronan, which was not evident in control sections. Though circulating hyaluronan levels had decreased after day 4, continued hyaluronan staining persisted in liver sections through day 21. Conventional indicators of liver injury, such as serum aminotransferase enzymes, did not reach a peak until day 7. Conventional gross and histopathological changes, including severe centrilobular congestion and hemorrhagic necrosis, were observed only after day 7. Both hyaluronan and hyaluronidase are indicators of very early liver damage in the dimethylnitrosamine-treated rat, occurring well before conventional indicators appear, or before overt histopathologic changes of liver damage can be seen. However, levels are increased only transiently, indicating that serial assays are necessary.

CONCLUSIONS

Measures of circulating hyaluronidase activity may be used to assess liver damage.

Effect of beta2-adrenergic receptor agonists on intercellular adhesion molecule (ICAM)-1, B7, and CD40 expression in mixed lymphocyte reaction

BACKGROUND

The plasma interleukin (IL)-18 level is elevated in acute rejection after organ transplantation. Although beta2-adrenergic receptor (AR) agonists suppress the rejection of organ and tissue transplants, little is known about their action mechanisms. We examined the effects of endogenous catecholamines and beta2-AR agonists on the expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2, CD40, and CD40 ligand (CD40L) in human mixed lymphocyte reaction (MLR) and in an in vitro model of acute rejection in the presence or absence of IL-18.

METHODS

ICAM-1, B7.1 B7.2, CD40, and CD40L expression on monocytes was measured by flow cytometry, and the production of interferon (IFN)-gamma and IL-12 was determined by enzyme-linked immunosorbent assay. Lymphocytes proliferation in MLR was measured by [3H]-thymidine uptake. The relevant AR subtypes were characterized using subtype-selective agonists and antagonists.

RESULTS

beta2-AR agonists inhibited the expression of ICAM-1 and CD40 during MLR in the absence of IL-18. Among IL-18-induced expression of ICAM-1, B7.1, B7.2, CD40, and CD40L, beta2-AR agonists inhibited ICAM-1 and CD40 expression. beta2-AR agonists prevented the production of IFN-gamma and IL-12 in the presence of IL-18 but had no effect in the absence of IL-18. beta2-AR agonists inhibited lymphocyte proliferation in IL-18-treated MLR.

CONCLUSIONS

We found that beta2-AR agonists strongly inhibited the expression of ICAM-1 and CD40, irrespective of the presence or absence of IL-18, which is different from that of histamine and prostaglandin E2.

Increased expression of endoarterial vascular cell adhesion molecule-1 mRNA in an experimental model of lung transplant rejection: diagnosis by pulmonary arterial biopsy

BACKGROUND

Early detection of rejection after lung transplantation may prevent allograft failure. This study determines if mRNA from the cell adhesion molecules intercellular adhesion molecule-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin in pulmonary endovascular tissue samples could be markers of early rejection.

METHODS

Single left lung transplants were performed in five dogs. Each dog was treated for 2 weeks with immunosuppression, after which rejection was allowed to occur. Percutaneous biopsies from 2- to 3-mm distal branch pulmonary arteries were obtained in each dog from the normal and the transplanted lungs at the end of immunosuppression therapy and periodically (2-4 times) for 1 to 3 weeks until euthanasia. Levels of cell adhesion molecule mRNA in the biopsy samples were quantitated by reverse-transcriptase polymerase chain reaction and normalized to beta-actin mRNA levels.

RESULTS

Between three and five pulmonary endoarterial biopsy samples were obtained from each lung at each catheterization procedure. There was a significant increase in VCAM-1 mRNA levels in the biopsies of the transplanted lungs (which were undergoing rejection) compared with the native right lungs in all dogs. Progressive increases in VCAM-1 mRNA were observed with longer rejection times. VCAM-1 mRNA changes were detected earlier than histologic changes of rejection.

CONCLUSIONS

In pulmonary endoarterial biopsy samples obtained in a canine lung transplant model, there was a progressive increase in VCAM-1 mRNA levels with increasing rejection. Changes in VCAM-1 mRNA were observed earlier than histologic changes of rejection. VCAM-1 quantitation by endoarterial biopsy may be useful in surveillance and early diagnosis of rejection in patients who undergo lung transplantation.

Effect of histamine on intercellular adhesion molecule-1 expression and production of interferon-gamma and interleukin-12 in mixed lymphocyte reaction stimulated with interleukin-18

BACKGROUND

Interleukin (IL)-18 was identified as an interferon (IFN)-gamma-inducing factor and was demonstrated to up-regulate the expression of intercellular adhesion molecule (ICAM)-1 on human monocytes. In organ transplantation, elevation of plasma IL-18 levels has been reported during acute rejection. In the present study, we examined the effect of IL-18 on human mixed lymphocyte reaction (MLR), an in vitro model of acute rejection after organ transplantation. We also investigated the modulatory effects of histamine on IL-18 action because histamine has been demonstrated to be a modulator of IL-18 effect and a mediator of inflammation.

METHODS

We measured the expression of ICAM-1 on human monocytes in MLR in the presence or absence of IL-18 by flow cytometer and determined the associated production of IFN-gamma and IL-12 by ELISA. The modulatory effects of histamine and the relevant histamine receptor subtypes were characterized pharmacologically.

RESULTS

The expression of ICAM-1 on monocytes in MLR was markedly enhanced by the addition of IL-18 in a concentration- and time-dependent manner. In parallel to ICAM-1 up-regulation, IL-18 significantly enhanced the production of IFN-gamma and IL-12 in MLR. Histamine concentration-dependently inhibited ICAM-1 expression and cytokine production in MLR stimulated with IL-18, whereas histamine alone did not show any effects on these responses in the absence of IL-18. The effects of histamine on both ICAM-1 expression and cytokine production were mimicked by the selective H2-receptor agonists 4-methylhistamine and dimaprit and were antagonized by the H2-receptor antagonist famotidine but not by H1- and H3-receptor antagonists.

CONCLUSION

IL-18 strongly enhanced human MLR with respect to ICAM-1 expression and cytokine production. The fact that histamine could inhibit the IL-18-stimulated MLR implies that immunomodulation by histamine and selective H2-receptor agonists may have an important role in future immunosuppressive strategies.

The relationship between the level of expression of intercellular adhesion molecule-1 in placenta and onset of preeclampsia

OBJECTIVE

To investigate the differences in the expression of intercellular adhesion molecule-1 (ICAM-1) in the placenta and the concentration of soluble ICAM-1 between early-onset and late-onset preeclampsia.

METHODS

Preeclampsia was divided into early-onset type (EO: 20 to 31 weeks gestation) and late-onset type (LO: > or = 32 weeks gestation). Post delivery, placentas were obtained from 19 control pregnant women and from 9 EO and 8 LO preeclamptic women. The expression of ICAM-1 in placenta was determined by immunohistochemical staining. Blood samples were taken from 21 non-pregnant women, 16 control pregnant women, 13 EO and 8 LO preeclamptic women, and umbilical cord blood samples from 38 control pregnancies and from 16 EO and 14 LO preeclampsia. The concentration of ICAM-1 was measured by enzyme-linked immunosorbent assays.

RESULTS

The expression of ICAM-1 in placenta was higher in LO than in EO preeclampsia (48.2 +/- 8.2% vs 17.9 +/- 5.0%) (p < 0.05). ICAM-1 concentration in umbilical cord blood was higher in EO than in LO preeclampsia (umbilical artery, 150.6 +/- 34.0 ng/ml vs 90.3 +/- 9.4 ng/ ml) (umbilical vein, 128.3 +/- 31.2 ng/ml vs 91.3 +/- 10.2 ng/ml) (p < 0.05).

CONCLUSIONS

Significant differences were noted in the expression of ICAM-1 between patients with EO and LO preeclampsia, which suggest that the possibility that EO and LO preeclampsia may have different onset mechanisms.