Francisco Sánchez-Bueno

FoxP3 in peripheral blood is associated with operational tolerance in liver transplant patients during immunosuppression withdrawal.

Background. Human liver allografts do sometimes survive in a recipient after withdrawal of immunosuppression (IS), commonly referred to as “operational tolerance.” Preliminary clinical data have suggested an increase in the frequency of regulatory T cells (Treg) CD4+CD25high and FoxP3 expression in operationally tolerant liver transplant recipients (Gr-T). In the context of human liver transplantation, the dynamics of Treg have not been studied. We designed a prospective study to ascertain the profile of the Treg population and FoxP3 expression during IS withdrawal. Methods. To identify such parameters, we analyzed peripheral blood mononuclear cell populations and FoxP3 mRNA expression in 12 liver allograft recipients under cyclosporine A-based IS, who showed stable function of the allograft for more than 2 years. Results. An increase was observed in the frequency of CD4+CD25high cells when the IS was withdrawn in Gr-T patients (n=5). These patients exhibited a 3.5-fold increase for relative mRNA FoxP3 expression before the complete IS withdrawal and this continued when IS therapy was stopped. In patients who suffered rejection (n=7) there was no increase in the CD4+CD25high cells or FoxP3 expression. Conclusions. With the present study, the first evidence is provided that the increase of CD4+CD25high T cells and FoxP3 transcripts is associated with operational tolerance in liver transplanted patients during IS withdrawal.

Inhibition of poly(ADP-ribose) polymerase attenuates the severity of acute pancreatitis and associated lung injury

The severity of acute pancreatitis results from the transmigration and activation of leukocytes within the pancreas and the local synthesis and release of proinflammatory-soluble mediators that transform a local injury into a systemic inflammatory response. Poly(ADP-ribose)polymerase-1 (PARP-1) is a nuclear DNA-binding protein that has been shown to play a relevant role in cell necrosis and organ failure in various diseases associated with inflammation. Therefore, we set out to investigate whether the genetic deletion of PARP-1 or PARP-2 (a new member of the PARP family) genes, or pharmacological inhibition of PARP activity might affect the development and severity of acute pancreatitis and pancreatitis-associated lung injury. Secretagogue-induced acute pancreatitis was achieved by 12 hourly intraperitoneal injections of cerulein in mice deficient in PARP-1 or PARP-2 genes, and wild-type (WT) littermate mice untreated or treated with PARP activity inhibitors. The severity of pancreatitis was assessed by measurements of serum amylase, lipase, interleukin-1β and IL-6, pancreatic water content, histologic grading and pancreas myeloperoxidase (MPO) activity. Lung injury was evaluated by quantifying MPO activity and morphological changes. We found that the severity of acute pancreatitis and pancreatitis-associated lung injury was significantly attenuated in mice lacking PARP-1, but not PARP-2, compared with WT mice. Interestingly, administration of PARP inhibitors, 3-aminobenzamide or PJ34 (N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-N,N-dimethyacetamide HCl), in WT mice markedly decreased acute pancreatitis severity and pulmonary-associated injury in a larger extension than genetic deletion of PARP-1. Our results support the potential therapeutic application of PARP inhibitors in the development and severity of acute pancreatitis and associated lung injury.

Immunosuppression withdrawal improves long-term metabolic parameters, cardiovascular risk factors and renal function in liver transplant patients

Abstract:  After liver transplantation, long‐term immunosuppression (IS) administration is commonly complicated by renal dysfunction and cardiovascular complications. Twenty liver transplant patients on cyclosporine (CyA)‐based IS were followed up prospectively after IS withdrawal. They consisted of 10 electively weaned patients and 10 either forcibly or incidentally weaned patients. Liver biochemical tests, blood pressure, serum creatinine, serum urea, serum uric acid, triglycerides, cholesterol and glucose were monitored after the start of weaning. Eight of the 20 patients (40%) were IS therapy free for a mean period of 61 ± 39 months (range: 10–132 months). Of the remaining 12 patients, mild or moderate acute rejection occurred in six patients (30%), and mixed inflammatory portal tract infiltrate was seen in another six patients (30%). At the end of the study, mean (SD) serum creatinine had fallen by 0.28 (0.10) mg/dL (p < 0.001) in operationally tolerant (T) patients whereas the serum creatinine level increased in IS‐dependent patients [+0.35 (0.35) mg/dL] (p = 0.005). In T patients, serum cholesterol, serum uric acid, fasting glucose and diastolic arterial pressure values significantly decreased. IS withdrawal can be achieved in selected liver transplant patients, and can improve not only kidney function, but also other CyA‐associated side effects, such as hypercholesterolemia, hyperuricemia, hypertension and diabetes.

Laparoscopic Iatrogeny of the Hepatic Hilum as an Indication for Liver Transplantation

The introduction of biliary laparoscopic surgery led to an increase in the incidence of liver hilum injuries. These types of lesions are very serious, because they can lead to secondary biliary cirrhosis or fulminant hepatic failure and the need for liver transplantion (LT). We present three cases of liver hilum injuries, which were treated with LT; one case was due to severe and persistent cholangitis, and two cases were due to fulminant hepatic failure. The world literature is also reviewed, and published cases of iatrogenic lesions of the liver hilum caused by laparoscopic surgery and requiring LT are presented. These iatrogenic lesions of the hepatic hilum are complex and technically demanding, due to their high morbidity and mortality and even the need for LT. In conclusion, these lesions must be always managed in centers with experience in hepatobiliary surgery. (Liver Transpl 2004;10:147–152.)

Effects of cold ischemia time on the graft after orthotopic liver transplantation : a bile cytological study

We conducted a daily analysis of bile cellularity in 16 orthotopic liver transplant patients fitted with a T-tube, and correlated the cytological parameters (number of cells per slide, and percentage of difference cell types) with the duration of cold ischemia time (CIT). Two groups were established: one comprised patients whose CIT was less than 7 hr (CIT averaged 345 min) and the other comprised patients with a CIT of more than 7 hr (CIT averaged 505 min). The control group consisted of 15 patients who had received cholecystectomy for biliary lithiasis and were fitted with a T-tube. All 3 groups showed the highest cell density on the 1st postoperative day (control: 53.3 +/- 15.5 cells/slide; short ischemia: 70 +/0 21.4 cells/slide; long ischemia: 158.8 +/- 53.2 cells/slide), which steadily ischemia group showed a higher cell density than did the control group for the first 2 days, although this was not significant. The long ischemia group showed the highest cell density, although only significantly for the first 2 days when compared with the controls, and basically at the expense of a increase in ductal epithelial cells. Our results show that prolonged cold ischemia causes an increase in bile cell density at the expense of ductal epithelial cells: the longer the preservation time, the greater the increase.

Therapeutic treatment with poly(ADP-ribose) polymerase inhibitors attenuates the severity of acute pancreatitis and associated liver and lung injury

The mortality associated with acute pancreatitis (AP) is largely attributable to abnormalities that occur in distant organs and supportive care remains the only treatment for patients with these complications. Recently, prophylactic pharmacological blockade of poly(ADP‐ribose) polymerase (PARP) enzymes has been shown to attenuate the severity of the disease. However, the clinical relevance of PARP inhibitors administered after the onset of AP remains uncertain. The aim of the present study was to investigate the therapeutic effects of PARP inhibitors in established AP.

CD28/CTLA-4 and CD80/CD86 costimulatory molecules are mainly involved in acceptance or rejection of human liver transplant

CD28/CTLA-4 interactions with their specific B7-ligands (CD80 and CD86) have decisive roles in antigenic and allogenic responses. Recently, experimental transplant studies demonstrated that donor-specific tolerance is achieved by blocking these interactions. The present study analyzes the expression of these co-stimulatory molecules in peripheral blood cells from 74 liver recipients and in 16 liver biopsies, which were classified into acute-rejection (AR, n = 27) and nonacute-rejection (NAR, n = 47) groups, as well as their influence on the in vitro response of in vivo allosensitized cells. The results clearly indicate that in human liver transplant too, B7 and CD28/CTLA-4 expression on B and CD4(+) peripheral lymphocytes respectively, contributes to graft acceptance or rejection, and appears to be of crucial importance in modulating the host alloresponse and specific-CTL generation. In the NAR-group, costimulatory molecule expression remained at basal levels after transplant, whereas in the AR-group these molecules were significantly upregulated on days of AR. CTLA-4 was observed in the infiltrating lymphocytes in most of the biopsies, but CD80 or CD86 were not. Moreover, specific cytotoxicity from the in vivo primed cells was clearly suppressed in the NAR-patients with low co-stimulatory molecule expression, whereas this activity was not modified but rather stimulated in the AR-group. Together, these findings indicate that intervention of CD28/CTLA-4/B7 signaling could be therapeutically useful in clinical transplantation.

HLA-C matching and liver transplants: donor-recipient genotypes influence early outcome and CD8+KIR2D+ T-cells recuperation.

Background. Fully human leukocyte antigens (HLA)-mismatched liver grafts are well accepted, but the HLA influence on acceptance or rejection is unclear and much less so the impact of HLA-C, which may be conditioned by the fact that HLA-C-encode molecules are the major ligands for killer cell immunoglobulin-like receptors (KIR). Methods. The HLA-C allele compatibility and the effect of donor and recipient HLA-C genotype on early liver graft acceptance and on CD8+KIR+ T-cells recuperation were analyzed in a series of 431 primary liver transplants. Standard polymerase chain reaction PCR-SSO was used for HLA-C typing and flow cytometry to identify T cells KIR positives. Transplants were classified into two groups: acute rejection and nonacute rejection, and individual HLA-C genotypes as C1/C1, C2/C2, and C1/C2. Results. A favorable effect of HLA-C allelic compatibility on early liver graft acceptance was found because acute rejection significantly increased in transplants performed with 2 HLA-C allele mismatches (P=0.02). Considering the HLA-C groups, it was observed that C1/C2 heterozygous donors were best accepted in C1/C1 patients than in C2/C2 recipients, who experienced a high rate of acute rejection (P<0.004 and P<0.005, respectively). In addition, after transplantation CD3+CD8+KIR2D+ T-cells repertoires significantly increased in C1/C1 and C1/C2, but not in C2/C2 patients. Conclusions. This study confirms the benefit of HLA-C allele matching on early liver transplant outcome and shows that donor HLA-C heterozygosis influences the alloresponse of C1 and C2 homozygous patients and the recuperation of CD3+CD8+KIR2D+ T cells, suggesting an involvement in liver graft tolerance.

Influence of human leukocyte antigen mismatching on rejection development and allograft survival in liver transplantation: is the relevance of HLA-A locus matching being underestimated?

The influence of HLA matching on liver transplant is still controversial, as studies have failed to demonstrate an adverse effect of HLA mismatching on transplant outcome. We examined the effect of HLA mismatching on transplant outcome in a series of 342 consecutive liver transplants (224 finally analyzed). HLA typing was performed by serological and molecular methods. HLA-A matching was associated with an increased chronic rejection incidence (P=0.04). Indeed, HLA-A match also demonstrated a significant impact on allograft survival (P=0.03), confirming previous observation concerning to rejection, as complete HLA-A mismatching favored a better liver transplant outcome. Analysis of HLA-A+B+DR matching also demonstrated a significant impact on graft survival (P<0.05). Multivariate Cox regression analysis confirmed the effect of HLA-A and DPB1 matching as independent risk factors for graft loss. Another independent factor was a positive pre-transplant crossmatch. In conclusion, liver transplant outcome has not been found to be improved by HLA matching, however a poorer HLA compatibility favored a better graft survival and decreased rejection incidence, with a special relevance for HLA-A matching.

Liver transplantation for hilar cholangiocarcinoma

The most appropriate treatment for Klatskin tumor (KT) with a curative intention is multimodal therapy based on achieving resection with tumour-free margins (R0 resections) combined with other types of neoadjuvant or adjuvant treatment (the most important factor affecting KT survival is the possibility of R0 resections, achieving 5-year survival rate of 40%-50%). Thirty to forty percent of patients with KT are inoperable and present a 5-year survival rate of 0%. In irresectable non-disseminated KT patients, using liver transplantation without neoadjuvant treatment, the 5-year survival rate increase to 38%, reaching 50% survival in early stage. In selected cases, with liver transplantation and neoadjuvant treatment (chemotherapy and radiotherapy), the actuarial survival rate is 65% at 5 years and 59% at 10 years. In conclusion, correct staging, neoadjuvant treatment, living donor and priority on the liver transplant waiting list may lead to improved results.