Liver-grafted Patients Research Articles

Evidence for impaired glucose effectiveness in cirrhotic patients after liver transplantation

To evaluate the impact of acute and chronic liver disease and single immunosuppression (cyclosporine A [CSA] or FK506) on insulin sensitivity and glucose effectiveness in liver-grafted patients, we performed a frequently sampled intravenous glucose tolerance test (FSIGTT) in nondiabetic patients after orthotopic liver transplantation (OLT) with acute liver failure ([ALF] group, n = 9, with CSA therapy), in patients after OLT with chronic liver disease (CSA group, n = 8; FK506 group, n = 8), and in 9 healthy control subjects. Insulin sensitivity and glucose effectiveness were determined by analyzing glucose and insulin data from the FSIGTT with Bergman's minimal model technique for glucose. The intravenous glucose tolerance index ([KG] ie, the slope of the regression of the logarithm of blood glucose concentration) was not different between the ALF group (2.17 +/- 0.16 min(-1)) and controls (2.29 +/- 0.13 min(-1)), but was lower (P < .05) in both groups with chronic liver disease (CSA group, 1.46 +/- 0.1; FK506 group, 1.61 +/- 0.11 min(-1)) compared with the ALF group (P < .05). A positive relation for the KG and glucose effectiveness was found in all liver-grafted patients and controls. Insulin sensitivity was not different between all liver-grafted patients and controls. The body mass index (BMI) was the overall determinant of insulin sensitivity in all groups. Single immunosuppressive therapy does not impair insulin sensitivity in liver-grafted patients. The lower glucose effectiveness in liver-grafted patients with chronic liver disease but not in patients after ALF points to a defect in the regulation of glucose-mediated glucose uptake in peripheral tissue.

Analysis of MHC Class II Expression on Circulating T Cells by Flow Cytometry in Patients with Acute Rejection Following Solid Organ Transplantation

Aim: Following organ transplantation, acute steroid resistant graft rejection is one of the main predictors for long-term graft function. The development of new noninvasive diagnostic methods can be helpful for diagnosis and follow-up of episodes of acute graft rejection. Patients and Study Design: Peripheral lymphocytes obtained during serial blood drawings from 206 different patients after kidney, heart or liver transplantation were analyzed for HLA-DR expression on CD8+T cells by two-color flow cytometry. Patients were investigated during stable course as well as during episodes of graft rejection or infection. Results: In liver-grafted patients without evidence for rejection or infection, the frequency of circulating HLA-DR+ CD8+ T lymphocytes remained constant over time. The type of immunosuppressive treatment used (Tacrolimus or CyA with or without ATG) had no influence on the HLA-DR expression pattern observed. In contrast, a significant increase in HLA-DR expression was ob-served during acute biopsy-proven graft rejection. The time course of HLA-DR expression paralleled the clinical response of the individual patient to antirejection treatment. In contrast to patients after liver transplantation, in kidney or thoracic organ graft recipients with acute graft rejection the increase in HLA-DR expression failed to reach statistical significance. HLA-DR expression on CD8+ T cells was not specific to episodes of rejection; an increase in HLA-DR+ CD8+ T cells was also detectable during episodes of bacterial or viral infection. Conclusion: In liver graft recipients the analysis of HLA-DR expression on CD8+ T cells is a sensitive but nonspecific marker for immune activation and could be useful for monitoring of anti rejection therapy.

Influence of bile on cyclosporin absorption from microemulsion formulation in primary liver transplant recipients

Abstract We analysed the absorption, after oral application, of a new galenic form of cyclosporin A (CyA-NOF) in liver-grafted patients (n= 12) during the 1st week (days 2–4) after transplantation. Pharmacokinetic profiling was performed with an open or clamped T tube in situ or with the T tube absent. The pharmacokinetic parameters of CyA-NOF were influenced by T tube clamping and bile diversion. The highest AUC, Cmax and earliest Tmax values were found in patients without a T tube in situ, indicating that absorption of CyA-NOF in patients during the early course after liver transplantation is not bile-independent. CyA-NOF, at a dose of 7.5 mg/kg, was enterally absorbed with appropriate AUC and Cmax levels. Patients receiving a starting dose of 7.5 mg/kg were successfully maintained on CyA-NOF during the subsequent clinical course.

The use of plasma levels for FK 506 dosing in liver-grafted patients.

FK 506 plasma levels were analyzed in 89 liver-grafted patients under FK 506-based immunosuppression. Plasma levels were found to be influenced by the patients' liver function: compared to patients without major liver dysfunction, those with cholestasis had higher plasma levels and these plasma levels were able to differentiate between rejection and toxicity. In patients with stable liver function, no clear difference was observed with regard to the plasma levels detectable during toxicity or rejection. We conclude that plasma levels can be used to determine the FK 506 dose but only in patients with cholestasis (i.e., during the early post-transplant course, or in patients with cholestatic rejection). In patients with stable liver function, plasma levels are only of limited clinical relevance.

The use of plasma levels for FK 506 dosing in liver-grafted patients

Abstract FK 506 plasma levels were analyzed in 89 liver-grafted patients under FK 506-based immunosuppression. Plasma levels were found to be influenced by the patients' liver function: compared to patients without major liver dysfunction, those with cholestasis had higher plasma levels and these plasma levels were able to differentiate between rejection and toxicity. In patients with stable liver function, no clear difference was observed with regard to the plasma levels detectable during toxicity or rejection. We conclude that plasma levels can be used to determine the FK 506 dose but only in patients with cholestasis (i. e., during the early post-transplant course, or in patients with cholestatic rejection). In patients with stable liver function, plasma levels are only of limited clinical relevance.

Conversion from cyclosporin to FK 506 after liver transplantation.

Thirty-seven liver-grafted patients with steroid-resistant acute or chronic graft rejection or with cyclosporin-related complications were converted from CyA to FK 506. The clinical outcome of the patients primarily depended on the degree of liver dysfunction present at initiation of FK 506 treatment. In patients switched to FK 506 for treatment of acute or early chronic graft rejection, CyA nephrotoxicity, or CyA malabsorption, the FK 506 therapy was associated with a clear improvement in the clinical course. In contrast, in patients with advanced chronic graft rejection, a lower response rate to the conversion in immunosuppression was observed. The lower response rate was associated with a higher patient mortality. These studies demonstrate that FK 506 represents a valuable alternative immunosuppressant for liver-grafted patients. The conversion from CyA to FK 506 should take place before serious--and potentially irreversible--disturbances in liver function are observed.

PERSISTENCE OF DONOR LYMPHOCYTES IN LIVER ALLOGRAFT RECIPIENTS

Occasional cases of graft-versus-host disease after liver transplantation indicate a transfer of donor lymphocytes by human liver grafts. However, little is known about the usual fate and potential function of passenger lymphocytes in clinical liver transplantation. In this study, we have analyzed liver graft recipients for the presence of donor lymphocytes in the early course after transplantation. The presence of such cells in blood, the graft, and, occasionally, the skin was studied by the use of mAb to polymorphic HLA class I determinants and double-staining techniques in flow cytometry and immunocytology. The findings were compared with the clinical courses and with the results of routine graft biopsies. Within the first week after transplantation, in all 16 patients, between 1% and 24% donor lymphocytes (T, NK, and B cells) were detectable in blood, and in 14 of 22 patients (64%), between 2% and 23% donor T cells were found in the graft. After more than 2 weeks, donor cells were still present in blood in 2 of 14 patients at very low numbers. The presence of donor lymphocytes in the graft was associated with intragraft immune activation in 5 of 15 patients, but no clinical rejection occurred in these cases; mild graft-versus-host disease was observed in one patient. These findings demonstrate that donor lymphocytes regularly persist in liver-grafted patients for some time; this transient mixed lymphoid chimerism is only rarely associated with clinical graft-versus-host disease and some evidence even suggests that these donor-derived lymphocytes may exert beneficial immunomodulatory properties.

Contribution of cyclosporin metabolites to immunosuppression in liver-transplanted patients with severe graft dysfunction

The aim of this study was to analyse the immunosuppressive contribution of cyclosporin metabolites in liver-grafted patients. Therefore the immunosuppressive potency of 17 metabolites, alone and in combination, was tested in human mixed lymphocyte cultures, and the results were correlated with metabolite blood levels in liver-grafted patients. Of the 17 metabolites tested only six highly lipophilic metabolites showed a detectable immunosuppressive activity of up to 10% of the activity of cyclosporin; the effect of combining metabolites was additive. For calculation of the in vivo activity, blood levels of seven major cyclosporin metabolites were determined in liver-grafted patients with normal liver function (group A, 43 episodes) and with severe hyperbilirubinaemia (group B, 66 episodes). Both patient groups had comparable levels of parent drug (122.9 +/- 17.4 vs. 111.1 +/- 23.5 ng/ml by HPLC) and similar blood levels of the highly lipophilic metabolites 17, 1 and 18. By contrast, blood levels of the less lipophilic metabolites 8, 9, 26 and 203-218 were substantially increased in group B (P less than 0.05). High overall metabolite blood levels in group B were also indicated by a non-specific monoclonal RIA (520 +/- 199 ng/ml for group A vs. 1318 +/- 407 ng/ml for group B). Despite the very high levels in group B, however, the overall contribution of the metabolites to immunosuppression was similar in both groups (12.6 +/- 5.0% for group A vs. 13.8 +/- 5.6% for group B). These findings indicate that, despite a marked accumulation of cyclosporin metabolites in patients with severe cholestatic liver dysfunction, their immunosuppressive contribution remains low.(ABSTRACT TRUNCATED AT 250 WORDS)

Relevance of a positive crossmatch in liver transplantation

We studied 27 liver transplants in 24 patients performed between November 1984 and January 1988. We investigated retrospectively the importance of donor reactive HLA class I and class II and of non-HLA antibodies for graft survival in these patients. In order to determine the specificity and class of the antibodies, we used monoclonal antibodies to HLA-A, -B, -C and DR and DQ antigens to block cytotoxicity of sera and the reagent dithiothreitol to characterize the immunoglobulin class. We found that humoral immunity to HLA antigens in liver-grafted patients, demonstrable as the presence of cytotoxic antibodies reactive with donor splenic T and/or B cells in the pretransplantation period, is associated with significantly lower graft survival as compared with patients without demonstrable preformed HLA antibodies (P = 0.01). In addition we found that a substantial proportion of patients had donor-reactive cytotoxic antibodies which were not HLA specific. Thus, our study shows that HLA immunity can influence liver allograft survival, and that it is useful to have patient cytotoxic antibodies characterized with regard to HLA reactivity prior to transplantation.

Relevance of a positive crossmatch in liver transplantation

Abstract. We studied 27 liver transplants in 24 patients performed between November 1984 and January 1988. We investigated retrospectively the importance of donor reactive HLA class I and class II and of non-HLA antibodies for graft survival in these patients. In order to determine the specificity and class of the antibodies, we used monoclonal antibodies to HLA-A, -B, -C and DR and DQ antigens to block cytotoxicity of sera and the reagent dithiothreitol to characterize the immunoglobulin class. We found that humoral immunity to HLA antigens in liver-grafted patients, demonstrable as the presence of cytotoxic antibodies reactive with donor splenic T and/or B cells in the pre transplantation period, is associated with significantly lower graft survival as compared with patients without demonstrable preformed HLA antibodies (P= 0.01). In addition we found that a substantial proportion of patients had donorreactive cytotoxic antibodies which were not HLA specific. Thus, our study shows that HLA immunity can influence liver allograft survival, and that it is useful to have patient cytotoxic antibodies characterized with regard to HLA reactivity prior to transplantation.

Investigations on the metabolic pathways of cyclosporine: I. Excretion of cyclosporine and its metabolites in human bile—isolation of 12 new cyclosporine metabolites

1. Cyclosporine metabolites of known and unknown structures were isolated, by semi-preparative h.p.l.c., from human bile from the T-tube of liver-grafted patients, who received cyclosporine treatment. Their structures were elucidated by FAB mass spectrometry and 1H-n.m.r. spectroscopy. 2. Twelve of the cyclosporine metabolites, with known chemical structures, were isolated and identified using authentic standard material. 3. Four isolated fractions contained tri-hydroxylated metabolites; two fractions contained di-hydroxylated, demethylated metabolites; one fraction contained a tri-hydroxylated, demethylated metabolite; and one fraction a mono-hydroxylated, demethylated metabolite. The exact metabolism sites were partially defined. 4. Two carboxylated cyclosporine metabolites, of which one was hydroxylated in an unknown position, were isolated. 5. One new metabolite proved to be a glucuronylated phase II metabolite. Deglucuronylation of this metabolite by beta-glururonidase yielded metabolite AM1c. The proposed structure was AM1c-Glc; is a proposed extension of the Hawk's Cay nomenclature of the cyclosporine metabolites for glucuronylated metabolites. 6. One of the unknown metabolites was hydroxylated in two positions of amino acid 1. The proposed nomenclature was 'AM11d', where '1d' indicates hydroxylation at the delta C of amino acid 1. 7. A metabolite with an aldehyde functional group at amino acid 1, which had two isomeric forms, was isolated. I.r.-spectroscopy indicated that isomerism may be caused by conjugation of the aldehyde group with the double bond between C6 and C7 of amino acid 1.

Oral cholecystography after liver transplantation in man.

Orthotopic liver transplantation has been performed in Cambridge since 1967. In order to prevent complications resulting from the biliary drainage techniques, the donor gall bladder was interposed between the donor and recipient common bile duct as a vascularised pedical graft. The procedure, first performed in 1976, has been employed where possible ever since. Six patients having had this technique performed, and who remained well six months to six years after liver graft, underwent oral cholecystography. Four patients opacified the interposed gall bladder and the gall bladder contracted in response to cholecystography or a fatty meal. This is the first time oral cholecystography has been used in these patients. The detail is such that it can be used to follow non-jaundiced liver-grafted patients.