D. Galmarini

Patterns of hepatitis delta virus reinfection and disease in liver transplantation.

Twenty-seven carriers of the hepatitis B surface antigen who underwent liver transplantation in Italy and Belgium for terminal Hepatitis delta virus (HDV) cirrhosis were investigated. In 22 of the patients, HDV infection recurred. Two patients died of coexisting HDV and hepatitis B virus (HBV) reactivation. Four patients who died of unrelated causes were found to have HDV without signs of HBV reactivation. Five patients (18%) cleared both HBV and HDV after transplantation with no evidence of hepatitis (mean follow-up, 29 months). In many surviving patients. HDV infection recurred early without signs of HBV reactivation. Disease returned in the 11 HDV-infected patients in whom HBV also recurred. Histological hepatitis did not recur during an interim of 12-33 months in the 5 HDV-infected patients in whom HBV did not return. The overall medium-term survival in patients with HDV who underwent transplantation was 77.7%. Liver transplantation offers patients with HDV a hope of cure from disease despite a high risk of reinfection. In the transplantation setting. HDV can cause subclinical infections without any apparent assistance from HBV; these infections become symptomatic only if and when HBV reactivates. Thus, HDV may not be in itself pathogenic but requires cooperation from HBV to cause the appearance of the disease.

LIVER TRANSPLANTATION IN HEPATITIS DELTA VIRUS DISEASE

Seven patients with hepatitis delta virus (HDV) cirrhosis underwent liver transplantation. In every case the HDV infection was florid but accompanied by an inactive hepatitis B virus (HBV) infection. The patients were given anti-HB surface antigen (HBsAg) serum globulins and HBV vaccine. Two patients cleared the HBsAg and the HDV, and are alive and well 14 and 15 months, respectively, after transplantation. HDV infection recurred in the other five patients: hepatitis developed in three, another died, and the fifth was re-transplanted for causes unrelated to viral hepatitis (reinfection was shown by the presence of HD antigen in the graft). Liver transplantation is feasible in patients with HDV disease but involves a high risk of HDV reinfection that cannot be predicted by the virological pattern of the native HBV infection or prevented by conventional HBV prophylaxis.

Prognostic value of hemostatic parameters after liver transplantation

The prognostic value of hemostatic parameters after orthotopic liver transplantation was evaluated in 37 consecutive patients. Six simple hemostatic parameters (prothrombin time, activated partial thromboplastin time, thrombin time, thrombin coagulase time, plasma fibrinogen and platelet count) were obtained for each patient pre-transplantation and daily post-transplantation for at least 8 days. Using the results of these tests, the degree of hemostatic impairment was arbitrarily scored from 0 to 6. Starting from the first day post-transplantation, hemostatic parameters improved progressively, reaching plateau values on day 7 post-transplantation. On day 8 there were significant differences in the activated partial thromboplastin time, prothrombin time, and in the overall hemostatic scores between patients who survived at least 6 months and those who died. Comparing these hemostasis parameters with such liver function tests as AST, ALT and serum bilirubin, univariate analysis showed that activated partial thromboplastin time, coagulation score and AST were significant predictors of 6-month survival, but by multivariate analysis (Cox proportional hazard rate model) only the activated partial thromboplastin time was an independent predictor. Hence, a simple coagulation test is useful for predicting the survival of patients undergoing liver transplantation.

Rescue FK506 early conversion for refractory rejection after pediatric liver transplantation: experience in 20 children

Abstract Tacrolimus (FK506) is an effective and relatively safe novel immunosuppressant able to revert refractory rejection after pediatric liver transplantation (LTx). Between April 1993 and October 1996, 20 pediatric patients were converted to tacrolimus for biopsy‐proven, steroiD‐resistant liver rejection. The mean follow‐up was 18 months. The median time from LTx to switch was 20 days. Tacrolimus was administered per os at a mean dosage of 0.23 mg/kg per day to maintain median blood levels of 10.8 ng/ml at 1 week and 9.2 ng/ml at 1 year from the switch. Of the 20 patients, 15 are alive and they all recovered from rejection without the need of OKT3 after conversion. The major causes of death were: one multiorgan failure, two infections (cytomegalovirus Aspergillus), one bowel perforation, and one posttransplant lymphoproliferative disease. One patient experienced late side effects and was reconverted to cyclosporine when she was already rescued from hepatic allograft rejection. The results confirm that an earlier conversion to tacrolimus should be recommended after pediatric liver transplantation in order to revert hepatic allograft rejection with the best safety profile.

Small bowel transplantation under oral immunosuppression: experimental study in the pig.

Abstract Despite recent improvements, clinical intestinal transplantation remains an experimental procedure for the treatment of irreversible failure of the intestine. Depending on the extent of additional failures, the transplant of the bowel can also be performed as a part of a multivisceral graft. Although these procedures have been performed preclinically for many years and have also been reported to have a successful outcome in the clinical setting, they have not yet become routine, unlike the transplant of other organs. With the aim of improving clinical results, many groups are studying on experimental models. Experimental studies are predominantly performed in rats, with fewer studies conducted in large animals. In 1992, the authors began an experimental program of orthotopic liver-small bowel transplantation (OLSBTx) and surgical technique. Results in the pig have been described for the first time by our group. Despite an acceptable control of rejection, results of intestinal function were poor. The OLSBTx is a high-risk procedure, and in animals an aggressive postoperative treatment is impossible. We therefore decided to continue with the transplant of the small bowel alone (SBTx) because it is a less demanding procedure.

Serotonin (5-HT): An enteroendocrine marker of reperfusion injury after liver-small bowel allotransplantation in the pig

Abstract HISTOMORPHOLOGIC and functional aspects of preservation/reperfusion injury, after small bowel transplantation, have been well investigated after different modalities and types of perfusion solutions. Experimental and clinical studies on bowel preservation damage have well defined the modifications of enteric and Goblet cells, vascular structures, myoenteric nerves, and ganglia. The enteroendocrine system is not so well studied. In recent studies of Lai et al, 1 on auxiliary small bowel allotransplantation in the dog without immunosuppression, biopsies of the small bowel were done daily and at time of death; specimens were stained with immunohistochemical methods for chromogranin A and somatostatin. Also, in animals with severe rejection, this type of enteroendocrine cell did not present any evident modification. Kaihara et al 2 suggested serotonin as a good marker of ischemia/reperfusion injury after allotransplantation of the small bowel in the rat. In their experience, the release of serotonin in the lumen bowel after reperfusion inversely correlated with the number and quality of serotonin cells. Our previous experiences with normothermic preservation in Ringer lactate solution, up to 20 hours in the pig, showed good preservation of argentaffin and serotonin cells up to 6 hours with a progressive marked reduction in the following hours. 3 The bowel perfused and preserved ipothermically with 4°C Wisconsin solution up to 36 hours, showed normal argentaffin cells up to 20 hours, after which time these cells were numerically reduced and degranulated. On the basis of these previous observations, we decided to analyze the modifications of enteroendocrine cells in a pig model of orthotopic liver-small bowel allotransplantation with different preservation/reperfusion times.

Serotonin (5-HT): An enteroendocrine marker of rejection after small bowel allotransplantation in the pig

Abstract The histopathologic findings of mucosal epithelial cell injury in acute and chronic rejection in small bowel transplantation are well known. Several studies have been done on the pig either as autotransplantation, allotrans-plantation, orthotopic, or enterotopic transplantation, with or without immunosuppression. Very few investigations on the enteroendocrine system have been done. In particular, none have been done on rejection in pigs after intestinal transplantation. On the other hand, changes in the enteroendocrine markers (somatostatin and chromogranin A) have been examined in detail after auxiliary small bowel transplantation in dogs without immunosuppression, showing no apparent changes on the 7th postoperative day, even if in a severe rejection status. Recent studies on rats have evaluated the presence of serotonin after small bowel allotransplantation with different times of preservation, and after reperfusion. The authors concluded that the number of serotonin-positive cells decreased with a preservation time of more than 1 hour in Ringer lactate at 4°C. We too have examined the modifications of argentaffin as well as serotonin-positive cells in the harvested small bowel of pigs perfused with Belzer solution (4°C) and preserved in Ringer lactate at 4°C, after preservation and reperfusion in the combined liver-small bowel allotransplantation. We noticed that the argentaffin and serotonin cells were preserved up to 20 hours and that after reperfusion the most important injury was due to the disappearance of these cells from the crypts. In this study, we studied the modifications of the intestinal enterochromaffin cells after combined liver-small bowel and small bowel alone allotransplantation in pigs, with the aim of evaluating a correlation with rejection.

An easy high-performance liquid chromatography quantification of monosaccharides from heal mucosal tissue glycoproteins in pigs

Abstract THE carbohydrate units of glycoproteins modulate significantly the physicochemical and biological properties of the parent proteins. 1 Since the glycosylation machinery 2 depends on the type, as well as on the physiological state, of the organism, tissue, or cell in which the glycoprotein is made, it is now well clearly understood that many pathologic states are characterized by changes in the carbohydrate structure of cellular glycoproteins. Glycosylation changes are therefore becoming widely used as markers for many pathologic situations, including inflammation and cancer. Our interest is focused on small bowel transplantation in pigs in which, despite good control of rejection, the bowel does not seem to work well and a lot of complications prevent good function and long survival. So, the study of the mucosal carbohydrate moieties should help to understand the difficulties associated with an intestinal transplantation. In general, the analysis of the monosaccharide composition of oligosaccharides is performed by several techniques such as gas chromatography (GC), gas chromatographymass spectrometry (GC-MS), 3,4 and nuclear magnetic resonance (NMR). 5 However, there is still a growing demand for easy and sensitive methods of analysis and quantification of samples of biological origin, as the improved sensitive methods recently described in the literature generally concern the compositional analysis of monosaccharides derived from glycoproteins of commercial origin. Here we describe an easy approach to the quantification of the neutral monosaccharides originated from the ileal mucosal glycoprotein content through high-performance liquid chromatography (HPLC).