Pretransplantation tumor necrosis factor-alpha production predicts acute rejection after liver transplantation

Neutrophil-to-lymphocyte ratio predicts early acute cellular rejection in living donor liver transplantation

Purpose

The aim of this study was to evaluate the predictive value of neutrophil-to-lymphocyte ratio (NLR) in acute cellular rejection (ACR) after living donor liver transplantation (LDLT).

Methods

All consecutive patients who underwent ABO-compatible (ABOc) LDLT from September 2014 to December 2017 were retrospectively reviewed. NLR was calculated on 3 occasions; (1) 4 weeks prior to liver transplantation (LT), (2) the day of LT, and (3) the day before liver biopsy.

Results

Among 66 patients who underwent ABOc LDLT, ACR was identified in 15 patients (22.7%) on protocol liver biopsy performed routinely on the postoperative day 7. There was no significant difference in NLR at 4 weeks prior to LT and the day of LT between no-ACR and ACR group (2.98 ± 1.92 vs. 2.54 ± 1.15, P = 0.433; 17.9 ± 8.31 vs. 20.5 ± 13.4, P = 0.393). However, NLR was significantly lower in ACR group compared to non-ACR group just prior to liver biopsy (5.82 ± 3.42 vs. 18.4 ± 17.2, P = 0.035). NLR tends to decrease 3.5 days before the onset of ACR. The area under the receiver operating characteristic curve for optimal cut-off value of NLR was 6.49, with sensitivity and specificity of 80.4% and 73.3% respectively.

Conclusion

NLR has a potential as a noninvasive predictor of early ACR in ABOc LDLT.

Impact of imbalanced graft-to-spleen volume ratio on outcomes following living donor liver transplantation in an era when simultaneous splenectomy is not typically indicated

The impact of an imbalanced graft-to-spleen volume ratio (GSVR) on posttransplant outcomes other than postreperfusion portal hypertension remains unknown. The importance of GSVR might vary according to whether simultaneous splenectomy (SPX) is performed. This retrospective study divided 349 living donor liver transplantation (LDLT) recipients from 2006 to 2017 into 2 groups: low GSVR (≤0.70 g/mL) and normal GSVR (>0.70 g/mL). The cutoff value of GSVR was set based on the first quartile of the distributed data. Graft survival and associations with various clinical factors were investigated between the groups according to whether SPX was performed. Low GSVR did not affect outcomes when SPX was performed. In contrast, it was associated with an increased incidence of early graft loss (EGL) and poor graft survival by presenting posttransplant thrombocytopenia, cholestasis, coagulopathy, and massive ascites when the spleen was preserved. Among patients with a preserved spleen, the multivariable analysis results revealed that older donor age and low GSVR were independent risk factors for graft loss. In conclusion, low GSVR was an independent predictor of graft loss after LDLT when the spleen was preserved. Preserved spleen with extremely low GSVR may be related to persistent hypersplenism, impaired graft function, and consequent EGL.

Acute and Chronic Rejection After Liver Transplantation: What A Clinician Needs to Know

While antibody mediated hyper-acute vasculitic rejection is rare in liver transplant recipients, acute and chronic rejection have clinical significance. The liver allograft behaves differently to other solid organ transplants as acute rejection generally does not impair graft survival and chronic rejection (CR) is uncommon. The incidence of acute and chronic rejection has declined in current era due to improved immunosuppressive regimens. Acute rejection generally improves with steroid boluses and steroid resistant rejection is uncommon. CR may improve with escalation of immunosuppression or may result in irreversible loss of graft function leading to retransplantation or death. The current review discusses diagnosis and management of acute and chronic liver allograft rejection.

Role of natural killer cells in liver transplantation treatment of liver cancer

Liver cancer caused by diet or life style is a significant public health problem. Liver transplantation (LT) is a commonly used method of treatment for the liver cancer. The present study aimed to determine whether assessing the net state of natural killer (NK) cell function following LT distinguishes patients at risk for transplantation rejection. A total of 53 patients were involved; all underwent LT for hepatocellular carcinoma with (n=13) or without (n=40) transplantation rejection. The density of interferon-γ (IFN-γ) in blood serum was examined and patients were divided into two groups: Higher (H) and lower (L), on the basis of IFN-γ density. The percentage of NK cells and their producing cytokines was detected using fluorescence-activated cell sorting in peripheral blood and liver samples. As evaluation indexes of liver function, aspartate transaminase (AST) and alanine transaminase (ALT) were detected in blood serum. NK cell activation of the H-group was observed to be higher than the L-group, specifically the expression of NK group 2D, cluster of differentiation 69 and IFN-γ were higher than the L-group. The H-group exhibited a higher level of AST and ALT, which indicates the potential for acute transplantation rejection. The results of the present study indicate that NK cells and NK-derived IFN-γ serve an important function in regulating the rejection of LT and tumor metastasis in response to LT.

Markers of acute rejection and graft acceptance in liver transplantation

The evaluation of the immunosuppression state in liver transplanted patients is crucial for a correct post-transplant management and a major step towards the personalisation of the immunosuppressive therapy. However, current immunological monitoring after liver transplantation relies mainly on clinical judgment and on immunosuppressive drug levels, without a proper assessment of the real suppression of the immunological system. Various markers have been studied in an attempt to identify a specific indicator of graft rejection and graft acceptance after liver transplantation. Considering acute rejection, the most studied markers are pro-inflammatory and immunoregulatory cytokines and other proteins related to inflammation. However there is considerable overlap with other conditions, and only few of them have been validated. Standard liver tests cannot be used as markers of graft rejection due to their low sensitivity and specificity and the weak correlation with the severity of histopathological findings. Several studies have been performed to identify biomarkers of tolerance in liver transplanted patients. Most of them are based on the analysis of peripheral blood samples and on the use of transcriptional profiling techniques. Amongst these, NK cell-related molecules seem to be the most valid marker of graft acceptance, whereas the role CD4+CD25+Foxp3+ T cells has still to be properly defined.

TNF blockade abrogates the induction of T cell-dependent humoral responses in an allotransplantation model

TNF blockade modulates many aspects of the immune response and is commonly used in a wide array of immune-mediated inflammatory diseases. As anti-TNF induces anti-dsDNA IgM antibodies but not other antinuclear reactivities in human arthritis, we investigated here the effect of TNF blockade on the induction of TD humoral responses using cardiac allograft and xenograft models. A single injection of an anti-rat TNF antibody in LEW.1A recipients grafted with congenic LEW.1W hearts almost completely abrogated the induction of IgM and IgG alloantibodies. This was associated with decreased Ig deposition and leukocyte infiltration in the graft at Day 5. TNF blockade did not affect germinal-center formation in the spleen or expression of Th1/Th2 cytokines, costimulatory and regulatory molecules, and TLRs in spleen and graft of the recipient animals. Clinically, the abrogation of the induction of the alloantibodies was associated with a marked prolongation of graft survival. In contrast, anti-TNF did not alter acute xenograft rejection mediated by TI antibodies in a hamster-to-rat model. Taken together, these data indicate that TNF blockade abrogates the induction of TD humoral responses and accordingly, may have a beneficial effect in antibody-mediated inflammatory pathologies.

Potent early immune response after kidney transplantation in patients of the European senior transplant program

BACKGROUND

The increasing age of organ donors and the transplantation of older recipients have become clinical practice. Age-adapted immunosuppressive protocols considering these changes are currently not established. This study analyzed the age-dependent immune response after human kidney transplantation.

METHODS

One hundred renal allograft recipients were prospectively evaluated from 2004 to 2005. Patients older than 65 years of the European Senior Program receiving kidneys from donors older than 65 years were compared with recipients younger than 65 years receiving kidneys from donors younger than 65 years. Age-dependent modifications of the immune response were evaluated before transplantation and 7 days and 6 months after grafting by flow cytometry analysis of lymphocyte surface markers in peripheral blood. The cytokine pattern was determined by Cytometric Bead Array, T-cell alloreactivity by enzyme-linked immunospot analysis.

RESULTS

There were no differences between the groups regarding patient survival, graft survival, and function at 6 months after transplantation. Before transplantation, 7 days and 6 months thereafter recipients older than 65 years demonstrated significantly elevated numbers of memory T-cells while counts for naive T-cells were significantly reduced. Numbers of activated cytotoxic cells were elevated with increasing age before and 7 days after transplantation. T-cell alloreactivity was more pronounced in older recipients at all time points. Seven days after transplantation tumor necrosis factor-alpha (TNF-alpha) levels were significantly higher, whereas TNF-alpha and interleukin-10 (IL-10) concentrations were significantly reduced after 6 months in older recipients.

CONCLUSIONS

Our data demonstrate an initially pronounced immune response in elderly recipients receiving grafts from elderly donors. This observation supports the concept of a donor and recipient age-adapted immunosuppression.

Early expression of hepatocyte growth factor, interleukin-6, and transforming growth factor-beta1 and -beta2 in symptomatic infection in patients who have undergone liver transplantation

INTRODUCTION

Early septic complications may be a deciding factor for successful recovery among patients who have undergone orthotopic liver transplantation. Therefore, monitoring liver function parameters plays an important role in postoperative treatment to achieve an early diagnosis of postsurgical complications. We ought to measure standard liver function parameters and the expression levels for selected cytokines among patients exhibiting symptoms of infection after orthotopic liver transplantation.

MATERIALS AND METHODS

The study was performed on 30 patients who were divided into two groups: SI-0 consisted of patients free of infection, and SI-1, those who had symptoms of infection. We determined standard liver function parameters and expression of hepatocyte growth factor (HGF), interleukin (IL)-6, transforming growth factor (TGF)-beta1, and TGF-beta2.

RESULTS

There were no significant differences in standard liver function parameters between the two groups of patients. There were no significant differences in the levels of expression for the cytokines in question between the two groups of patients.

CONCLUSIONS

Although standard liver function parameters provide diagnostically valuable information on the patient's condition, they cannot be used to determine the extent of systemic infection among patients showing signs of infection after liver transplantation. Determining gene expression levels in circulating lymphocytes is a sensitive method to monitor patients' condition after liver transplantation. The expression levels of HGF, IL-6, TGF-beta1, and TGF-beta2 in circulating lymphocytes were not sufficiently specific to diagnose transitory postsurgical complications such as symptomatic infection.

Clinical significance of lymphocytes hepatocyte growth factor mRNA expression in patients after liver transplantation

Hepatocyte growth factor (HGF) plays a key role in the regulation of liver regeneration after hepatocyte damage. Changes in HGF gene expression reflect the status of the regeneration process.

AIM

The aim of this study was to ascertain the clinical significance of the expression of HGF among liver transplant patients.

METHODS

Expression of the mRNA of HGF among peripheral blood lymphocytes were measured prior to as well as at 1, 2, 6, and 10 days after liver transplantation in a group of 30 liver recipients.

RESULTS

In first 24 hours after reperfusion, the patients with compromised graft function (group 1) showed persistently higher HGF gene expression after reperfusion compared with patients displaying well-functioning grafts (group 0; P = .0189). Between postoperative days 1 and 10, there was a rapid decrease in gene expression among group 0 compared with group 1 (P = .0155). The significant decrease observed in the both groups reached a certain plateau after 48 hours postoperatively. There was no statistical difference in aminotransaminase levels over the days after liver transplantation. The decreased mRNA HGF expression in lymphocytes preceded the decrease in aminotransferase levels.

CONCLUSIONS

HGF was more sensitive to predict early graft function than prothrombin time, aspartate aminotransferase, and alanine aminotransferase levels. The determination of HGF expression level in lymphocytes after liver transplantation may yield valuable information for evaluation of early graft function.

Nuclear factor-kappaB decoy oligodeoxynucleotides attenuates ischemia/reperfusion injury in rat liver graft

AIM

To evaluate the protective effect of NF-kappaB decoy oligodeoxynucleotides (ODNs) on ischemia/reperfusion (I/R) injury in rat liver graft.

METHODS

Orthotopic syngeneic rat liver transplantation was performed with 3 h of cold preservation of liver graft in University of Wisconsin solution containing phosphorothioated double-stranded NF-kappaB decoy ODNs or scrambled ODNs. NF-kappaB decoy ODNs or scrambled ODNs were injected intravenously into donor and recipient rats 6 and 1 h before operation, respectively. Recipients were killed 0 to 16 h after liver graft reperfusion. NF-kappaB activity in the liver graft was analyzed by electrophoretic mobility shift assay (EMSA). Hepatic mRNA expression of TNF-alpha, IFN-gamma and intercellular adhesion molecule-1 (ICAM-1) were determined by semiquantitative RT-PCR. Serum levels of TNF-alpha and IFN-gamma were measured by enzyme-linked immunosorbent assays (ELISA). Serum level of alanine transaminase (ALT) was measured using a diagnostic kit. Liver graft myeloperoxidase (MPO) content was assessed.

RESULTS

NF-kappaB activation in liver graft was induced in a time-dependent manner, and NF-kappaB remained activated for 16 h after graft reperfusion. NF-kappaB activation in liver graft was significant at 2 to 8 h and slightly decreased at 16 h after graft reperfusion. Administration of NF-kappaB decoy ODNs significantly suppressed NF-kappaB activation as well as mRNA expression of TNF-alpha, IFN-gamma and ICAM-1 in the liver graft. The hepatic NF-kappaB DNA binding activity [presented as integral optical density (IOD) value] in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (2.16+/-0.78 vs 36.78+/-6.35 and 3.06+/-0.84 vs 47.62+/- 8.71 for IOD value after 4 and 8 h of reperfusion, respectively, P<0.001). The hepatic mRNA expression level of TNF-alpha, IFN-gamma and ICAM-1 [presented as percent of beta-actin mRNA (%)] in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (8.31+/-3.48 vs 46.37+/-10.65 and 7.46+/- 3.72 vs 74.82+/-12.25 for hepatic TNF-alpha mRNA, 5.58+/-2.16 vs 50.46+/-9.35 and 6.47+/-2.53 vs 69.72+/-13.41 for hepatic IFN-gamma mRNA, 6.79+/-2.83 vs 46.23+/-8.74 and 5.28+/-2.46 vs 67.44+/-10.12 for hepatic ICAM-1 mRNA expression after 4 and 8 h of reperfusion, respectively, P<0.001). Administration of NF-kappaB decoy ODNs almost completely abolished the increase of serum level of TNF-alpha and IFN-gamma induced by hepatic ischemia/reperfusion, the serum level (pg/mL) of TNF-alpha and IFN-gamma in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (42.7+/-13.6 vs 176.7+/-15.8 and 48.4+/-15.1 vs 216.8+/-17.6 for TNF-alpha level, 31.5+/-12.1 vs 102.1+/-14.5 and 40.2+/-13.5 vs 118.6+/-16.7 for IFN-gamma level after 4 and 8 h of reperfusion, respectively, P<0.001). Liver graft neutrophil recruitment indicated by MPO content and hepatocellular injury indicated by serum ALT level were significantly reduced by NF-kappaB decoy ODNs, the hepatic MPO content (A655) and serum ALT level (IU/L) in the NF-kappaB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat (0.17+/-0.07 vs 1.12+/-0.25 and 0.46+/-0.17 vs 1.46+/-0.32 for hepatic MPO content, 71.7+/-33.2 vs 286.1+/-49.6 and 84.3+/-39.7 vs 467.8+/-62.3 for ALT level after 4 and 8 h of reperfusion, respectively, P<0.001).

CONCLUSION

The data suggest that NF-kappaB decoy ODNs protects against I/R injury in liver graft by suppressing NF-kappaB activation and subsequent expression of proinflammatory mediators.

Biologics in the treatment of transplant rejection and ischemia/reperfusion injury: new applications for TNFalpha inhibitors?

Tumor necrosis factor (TNF)-alpha inhibitors have proven efficacy in various autoimmune diseases such as Crohn disease, rheumatoid arthritis, psoriasis, and ankylosing spondylitis. Indeed, some TNFalpha inhibitors have already been approved for the management of the inflammatory manifestations associated with Crohn disease and rheumatoid arthritis. These agents are increasingly used for treatment of corticosteroid-resistant graft-versus-host disease after bone marrow transplantation, and case reports have documented their efficacy in treating corticosteroid- and muromonab-resistant rejection after intestinal transplantation. Thus, the potential role of TNFalpha inhibitors in transplantation of other vascularized solid organs is worthy of investigation. Experimental evidence indicates that TNFalpha plays a key role in mediating ischemia/reperfusion (IR) injury after liver, kidney, intestine, heart, lung, and pancreas transplantation. TNFalpha was also identified as a marker cytokine during organ rejection. Single-center studies evaluating the role of TNFalpha inhibitors in kidney transplantation have been initiated but the results are not yet available. TNFalpha is known to be a contributing factor in kidney allograft rejection, and may have value in predicting the onset of steroid-resistant acute rejection after liver transplantation. Experimental and preliminary clinical data have shown that circulating levels of TNFalpha are increased during cardiac graft rejection, and indicate that TNFalpha plays a role in the pathogenesis of acute cardiac allograft rejection. Anti-TNFalpha therapy was shown to prolong cardiac allograft survival when used alone or in combination with other drugs. TNFalpha genotype has been strongly associated with mortality in humans due to acute cell-mediated heart transplant rejection. In addition, there is evidence for a genetic predisposition toward acute rejection after kidney and simultaneous kidney-pancreas transplantation. TNFalpha inhibition has been used successfully as part of an induction therapy for pancreatic islet cell transplantation. Apart from IR injury and acute rejection after lung transplantation, TNFalpha was also found to be involved in the pathoimmunology of obliterative bronchiolitis. In conclusion, a substantial body of experimental evidence and preliminary clinical data suggest that TNFalpha inhibitors may play an important role in solid-organ transplantation, both in the amelioration of IR injury and in the treatment and prevention of acute rejection. Pharmacodynamic monitoring and pharmacogenetic screening may help to identify patients most likely to benefit from TNFalpha blockade. Randomized controlled trials in patients undergoing solid-organ transplantation are needed to further elucidate the clinical value of TNFalpha inhibition.

Prognostic assays for rejection and tolerance in organ transplantation

In this review, I have summarised our understanding of acute rejection of organ transplants, and for convenience I have identified three processes, recognition, rejection and regulation. In stark contrast to this text-book picture of acute rejection, I have drawn attention to some of the clinical realities, where processes are altered by powerful immunosuppressive drugs, and where many transplant recipients are pre-sensitised to transplantation antigens prior to engraftment. The ultimate goal is to encourage the emergence of a utopian immunological state, wherein patients tolerate organ transplants for life after being weaned from all immunosuppressive drugs. Assays that may be used in the future to reliably monitor this process are still at a very exciting stage of development.

Correlation of CD95 and soluble CD95 expression with acute rejection status of liver transplantation

AIM: To analyze the expression levels of soluble form of CD95, CD95 ligand (sCD95 and sCD95L, respectively) in plasma and CD95 expression on CD3⁺ cells in liver-transplanted recipients with acute rejection (AR).

METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 30 clinically liver transplanted recipients. CD95 expression on CD3⁺ cells was quantitatively measured by two-color fluorescence activated cell sorter (FACS) analysis. Lymphocyte surface phenotypes of CD4, CD8, CD16 and CD56 were determined by flow cytometry. Plasma levels of sCD95 and sCD95L were detected by Enzyme Linked-Immuno-Sorbent Assay (ELISA). The results were compared with that from normal healthy volunteers (n = 15 individuals).

RESULTS: FACS analysis showed that CD95 expression on CD3⁺ T cells was significantly increased in liver transplanted recipients with AR compared to that in stable recipients without rejection and infection or healthy individuals who did not undergo transplantation (18676.93±11588.34/molecule, 6848.20±1712.96/molecule, 6418.01±2001.95/molecule, respectively, P<0.01). Whereas no significant difference was seen between liver-transplanted stable recipients and healthy individuals. Furthermore, no significant differences were detected between each group with CD4/CD8 ratio or the percentage of CD16⁺56⁺ cells. Plasma levels of sCD95 were significantly higher in transplanted recipients with AR compared to that in stable recipients or healthy individuals (391.88±196.00, 201.37±30.30, 148.83±58.25 pg/mL, respectively, P<0.01). In contrast, the plasma levels of sCD95L in liver- transplanted recipients were not significantly different from that in healthy individuals.

CONCLUSION: The present results indicate that the increased CD95 expression on CD3⁺ cells and the increased levels of sCD95 in plasma may modify the immunological situation of the recipients after transplantation or represent the ongoing graft rejection.

Strain-specific in vitro cytokine production profiles do not predict rat liver allograft survival

The aim of this study was to assess whether differences in cytokine production between inbred rat strains could explain differences in liver allograft survival. Splenocytes from five different strains were cultured with Concanavalin A to determine in vitro cytokine production profiles. Strain-specific TNF-alpha, IFN-gamma, IL-6 and IL-10 responses in naive animals were not associated with survival after rat liver transplantation. To investigate whether in vitro cytokine responses changed during the allogeneic inflammatory response, Brown Norway livers were transplanted to Lewis and Pivold Virol Glaxo recipients. During the early postoperative phase IL-6 and IL-10 (Th2-like) responses were significantly up-regulated in Lewis recipients, whereas Th2-like responses were not increased in Pivold Virol Glaxo. Our results do not support the generally held view that differential in vitro cytokine responses are related to liver allograft survival but suggest that cytokine responses are affected by the allogeneic inflammatory response after liver allografting.

Alterações metabólicas induzidas por isquemia hepática normotérmica experimental e o efeito hepatoprotetor da ciclosporina

RACIONAL: Transplante de fígado é inevitavelmente associado com períodos de isquemia completa. No entanto, o tempo de oclusão do pedículo hepático é limitado pelas conseqüências da injúria pós-isquêmica do fígado. OBJETIVO: Determinar as principais alterações metabólicas ocasionadas pela isquemia hepática e a provável ação hepatoprotetora da ciclosporina. MÉTODOS: Isquemia hepática normotérmica por 60 minutos foi induzida em ratos. Em seguida, as alterações com o tempo (0, 1, 6, 24 horas) das concentrações sangüíneas e hepáticas de lactato, piruvato, glicose, corpos cetônicos e razão acetoacetato/3-hidroxibutirato, bem como o estado redox citoplasmático e mitocondrial do tecido hepático foram determinados. Outro grupo de animais foi pré-tratado com ciclosporina (10 mg/kg), sendo estudadas as alterações metabólicas no tempo 1 hora após revascularização hepática. RESULTADOS: A isquemia hepática causou elevação da concentração de lactato no fígado, sugerindo que pronunciado grau de metabolismo anaeróbico ocorreu durante o período de isquemia. Isquemia hepática acarretou ainda queda da concentração e da razão dos corpos cetônicos (acetoacetato/3-hidroxibutirato) no sangue arterial no tempo de 1 hora após revascularização. Tal fato reflete que a injuria isquêmica do fígado interfere na cetogênese. CONCLUSÃO: O tratamento com ciclosporina causa elevação das concentrações dos corpos cetônicos e da razão acetoacetato/3-hidroxibutirato no sangue arterial após 1 hora de reperfusão hepática, sugerindo que esta droga acelera a cetogênese e, conseqüentemente, a recuperação da lesão isquêmica do fígado.

Mycophenolate mofetil-based immunosuppression and cytokine genotypes: effects on monokine secretion and antigen presentation in long-term renal transplant recipients

BACKGROUND

It has been suggested that increased monocyte responses might play a role in chronic allograft rejection.

METHODS

We investigated in vitro monokine responses in 112 patients with long-term stable kidney graft function (ST patients; n=80, non-mycophenolate mofetil [MMF]; n=32, MMF) and 25 patients with chronic renal transplant rejection (CR patients; non-MMF). Interleukin 10 and tumor necrosis factor (TNF)-alpha promoter gene polymorphisms were tested by polymerase chain reaction and sequence-specific primers; antigen-presenting capacity (AC) of monocytes was tested by incubation with staphylococcal superantigens (SEA, SEE, SED).

RESULTS

Although non-MMF-based immunosuppression in ST patients did not result in compromised AC or lipopolysaccharide (LPS)-stimulated monokine responses compared with healthy controls, we found MMF therapy to be associated with significantly reduced TNF-R1 expression on monocytes (P<0.001), suppressed AC (P<0.02, SED), and suppressed LPS-stimulated IL-1 beta, IL-10, and TNF-alpha secretion (P<0.01). Coinciding with a significantly higher steroid dosage in CR patients, IL-6 receptor and TNF-R1 expression on monocytes were down-regulated (P< or =0.02) and AC was suppressed in CR compared with ST (non-MMF) patients (P<0.01, SED; P<0.05, SEE). However, LPS-stimulated monokine secretion was not decreased or even enhanced (IL-6, granulocyte-macrophage colony-stimulating factor [GM-CSF]; P<0.05). Enhanced in vitro IL-10 responses (>500 pg/mL) were found predominantly in non-MMF-treated patients with the IL-10 genotype GCC (GCC: 23/62 [37%], non-GCC: 2/27 [7%], P<0.005; GCC and non-MMF: 22/47 [47%], GCC and MMF: 1/15 [7%], P<0.005].

CONCLUSION

Steroids and azathioprine did not sufficiently suppress monokine responses, whereas MMF treatment might inhibit chronic graft rejection because of suppression of TNF-R1 expression and vigorous inhibition of monokine secretion. MMF treatment may especially be indicated in patients with the IL-10 "high-producer" genotype GCC.

Cytokine gene polymorphisms in children successfully withdrawn from immunosuppression after liver transplantation

BACKGROUND

Cytokine genetic polymorphisms have been associated with transplant outcome in some experimental and clinical studies, but the cytokine profile of patients who are clinically tolerant has not been investigated.

AIM

Allelic variations in tumor necrosis factor (TNF)-alpha, interferon (INF)-gamma, transforming growth factor (TGF)-beta1, interleukin (IL)-6, and IL-10 were evaluated in patients successfully withdrawn from immunosuppression.

METHODS

Pediatric liver transplant recipients who were successfully withdrawn from immunosuppression (n=12) or who are on minimal immunosuppression (n=7) were genotyped. A control group of liver recipients who required maintenance immunosuppression served as a control group (n=37).

RESULTS

Compared to the control group, low TNF- alpha and high/intermediate IL-10 profiles were seen in all 12 children maintained off immunosuppression and in 6 of 7 children requiring minimal immunosuppression.

CONCLUSION

Children successfully maintained off immunosuppression are more likely to have a genetic predisposition toward low TNF-alpha and high/intermediate IL-10 production. Children maintained on minimal immunosuppression exhibit a similar cytokine profile to those successfully weaned.

In vitro cytokine production of TNFalpha and IL-13 correlates with acute liver transplant rejection

Individuals may differ in their capacity to produce cytokines. Since cytokines play a key role in allograft rejection, we investigated whether inter-individual differences in cytokine production by in vitro stimulated PBMC are related to the occurrence of acute liver transplant rejection. Our study group comprised 49 liver transplant recipients and 30 healthy individuals. Rejection, which occurred within one month after liver transplantation, was defined in 22 patients ("rejectors") as biopsy-proven rejection, treated with high dose prednisolone. Patients who never experienced rejection episodes were termed as "nonrejectors" (n=27). PBMC of healthy individuals and of liver transplant recipients, collected late after transplantation (mean 3.5 years), were cultured in the presence and absence of Concanavalin A. The production of TNF-alpha, IFN-gamma, IL-10, and IL-13 was measured in supernatant after 1, 2, 3, 4, and 7 days of cell culture. In cell culture, stimulated PBMC of rejectors were found to produce significantly higher levels of TNF-alpha, while there was a trend towards higher production of IFN-gamma and IL-10 as compared to nonrejectors. After grouping patients into high or low cytokine producers based upon reference levels of the healthy individuals using multivariate analysis it was found that occurrence of acute liver transplant rejection correlated to high production of TNF-alpha and low production of IL-13. After stimulated cell culture PBMC of liver transplant recipients show a differential production of TNF-alpha and IL-13 which is correlated with the occurrence of acute liver transplant rejection.