Evaluation of two carrier protein-angiotensin I conjugate vaccines to assess their future potential to control high blood pressure (hypertension) in man.

AIMS: We aim to modulate the renin-angiotensin system (RAS) by active immunization against angiotensin I hormone (AI), potentially providing a novel conjugate vaccine treatment for hypertension in man. METHODS: Immunization studies in rat and human subjects compare the effectiveness of tetanus toxoid (TT) and keyhole limpet haemocyanin (KLH) vaccines for immunotherapy following conjugation with an AI peptide analogue (AI). Cardiovascular responses were assessed in immunized rats and human subjects (two-dose trial only), following increasing i.v. infusions of either AI or angiotensin II hormone (AII). RESULTS: The AI-TT and AI-KLH conjugate vaccines induced an equivalent immune response, and inhibition of the pressor effects to exogenous AI in rats. Single-dose clinical trials with both conjugate vaccines only resulted in an immune response to the KLH carrier protein. A two-dose clinical trial of AI-KLH conjugate vaccine resulted in a significant immune response to AI. A shift in diastolic blood pressure (DBP) dose-response was demonstrated following challenge with AI and AII for the study volunteer showing the largest anti-AI IgG induction. CONCLUSION: KLH was shown to be a suitable alternative to TT as a carrier protein for AI, thus supporting continued evaluation of our AI-KLH conjugate vaccine for treatment of hypertension in man.

Active immunization with angiotensin I peptide analogue vaccines selectively reduces the pressor effects of exogenous angiotensin I in conscious rats.

1. Male, Sprague-Dawley rats were actively immunized with novel angiotensin vaccines, and their pressor responses to exogenous angiotensin I (AI) and angiotensin II (AII) were assessed in vivo. Serum antibody titres were also measured. 2. The most effective vaccine consisted of an AI analogue conjugated with a tetanus toxoid carrier protein and adjuvanted with aluminium hydroxide. When this vaccine was injected on days 0, 21 and 42, pressor responses to AI on day 63 were significantly inhibited (maximum, 8.9 fold shift), but responses to AII were unaffected. The anti-angiotensin antibody titre was increased 32,100 fold, and, uniquely, these antibodies also cross-reacted with angiotensinogen. 3. These findings indicate that active immunization against AI may be a useful approach for treating cardiovascular disorders involving the renin-angiotensin system.

Hemolytic uremic syndrome in small-bowel transplant recipients: the first two case reports.

Post-transplant hemolytic uremic syndrome (HUS) is an uncommon but well-described complication in solid organ transplant recipients. Believed to be secondary to immunosuppressive therapy, it has been reported after kidney, liver, pancreas, heart, and lung transplants. In all reported cases, the primary organ affected was the kidney (transplant or native). But until now, no cases after small-bowel transplants and no cases in which the kidney was not the primary organ affected have been reported. We report two cases of HUS in small-bowel transplant recipients. In our first case, clinical presentation was with renal failure; biopsy of the native kidney demonstrated the typical histological changes seen with HUS, namely occlusion of the microcirculation by thrombi and platelet aggregation. Immunosuppression was changed from tacrolimus to cyclosporin, but with no improvement in renal function. In our second case, the transplanted bowel was the primary organ affected. This recipient presented with ulcers in the bowel mucosa, which were believed to be ischemic in origin, secondary to occlusive vascular lesions affecting the small vessels in the transplanted bowel. Her tacrolimus dose was decreased with resolution of ulcers and no evidence of rejection. These two cases represent the first reports of HUS after small-bowel transplants; in addition, our second case represents the first report of an extrarenal graft as the primary organ affected. When caring for small-bowel transplant recipients, physicians must be alert to the possibility of HUS and its various presentations.

No evidence of hepatitis G virus in fulminant hepatic failure in children.

BACKGROUND: The cause of fulminant hepatic failure in children remains unknown, but a viral origin has been suspected in most cases. The recently discovered blood-borne virus, hepatitis G, has been suggested as a possible causative agent. METHOD: Six consecutive children who underwent liver transplantation for fulminant hepatic failure were studied. The children were tested for hepatitis G virus antibodies and hepatitis G virus RNA by polymerase chain reaction after excluding other causes of fulminant hepatic failure. RESULTS: No evidence of hepatitis G virus infection was found in these patients. CONCLUSION: Hepatitis G virus is unlikely to be a common cause of fulminant hepatic failure in pediatric patients from the upper midwestern United States.

Thrombotic microangiopathy after liver-small bowel transplant.

We herein report the first case of immunosuppression-associated thrombotic microangiopathy (TMA) in which an extrarenal graft was primarily affected by the characteristic microvascular lesions. Although TMA is a well-known complication of cyclosporine (CSA) or tacrolimus therapy in renal and extrarenal (liver, heart, lung) transplant recipients, the kidney (transplanted or native) is typically the site primarily affected. We describe a combined liver-small bowel transplant recipient who developed tacrolimus-associated TMA that affected both her transplanted small bowel and her native kidneys. Involvement of the bowel, with evidence of microvascular occlusion on biopsy, led to the development of ischemic mucosal ulcers and eventual bowel perforation. Involvement of the kidney manifested with a doubling of the recipient's baseline serum creatinine level. Significant lowering of the tacrolimus dose resulted in healing of the small bowel ulcers and return to her baseline level of renal function. Therefore, it is important to note that, in transplant recipients, TMA with microvascular occlusion may affect extrarenal sites. In small bowel transplant recipients, the result might be ischemic ulcers in the graft and eventual bowel perforation.

Endoscopic variceal ligation in pediatric patients with portal hypertension secondary to liver cirrhosis.

BACKGROUND: Endoscopic variceal ligation is the initial treatment of choice in the management of esophageal varices. Few reports include its use in the pediatric population. We review our experience with this therapeutic modality in pediatric patients with end stage liver disease and esophageal varices. METHODS: We reviewed the medical records of pediatric patients with end stage liver disease who underwent endoscopic variceal ligation from January 1994 until December 1996. RESULTS: Thirty-two endoscopic variceal ligation procedures were performed in six pediatric patients during the period of study. In all patients, the esophageal varices classification was improved at the end of treatment. Only one patient had an episode of bleeding from esophageal varices during the period of study; only one patients had a complication associated with endoscopic variceal ligation. CONCLUSIONS: Endoscopic variceal ligation is feasible, safe, and effective for the management of esophageal varices in pediatric patients with end stage liver disease.

Living-related intestinal transplantation: first report of a standardized surgical technique.

BACKGROUND: Intestinal transplants using cadaver donors have become an alternative to total parenteral nutrition (TPN) for the treatment of irreversible intestinal failure. Intestinal transplants using living-related donors have rarely been attempted, and the surgical technique has not been standardized. METHODS: We performed a living-related intestinal transplant for a paraplegic, 16-year-old boy with life-threatening TPN complications, including lack of vascular access, recurrent line infections, and intermittent liver dysfunction. RESULTS: A four antigen-matched donor (father) underwent resection of 200 cm of the ileum on a vascular pedicle comprising the ileocolic artery and vein. This resection left the donor with 300 cm of proximal small bowel, 20 cm of the most distal terminal ileum, the ileocecal valve, and all of the large intestine. The donor's ileocolic artery and vein were anastomosed to the recipient's infrarenal aorta and cava; bowel continuity was restored with an end-to-end anastomosis between the recipient's jejunum and the donor's ileum. Both donor and recipient had uneventful postoperative courses. Recipient maintenance immunosuppression has been with tacrolimus, mycophenolate mofetil, and prednisone. One year after transplant, urine methylmalonic acid indicates good vitamin B12 absorption in both the donor and recipient. The recipient has been completely off TPN since discharge (posttransplant day 21), has gained 20 kg, and has had no evidence of rejection, infection, or graft-versus-host disease. CONCLUSIONS: Intestinal transplants from living-related donors can be lifesaving for selected patients with chronic intestinal failure and can be done with minimal risk to the donor.

Phenotypical and functional characterization of intrahepatic bile duct cells from common duct ligated mice.

Bile duct cells (BDCs), especially intrahepatic cholangiocytes, are primary targets of immune-related injury in such pathologic processes as liver graft rejection, liver graft-versus-host disease, and primary sclerosing cholangitis. Cholestasis and progressive loss of intrahepatic BDCs indicate chronicity in these diseases. The present investigation characterizes the acquisition of immune markers of intrahepatic BDCs isolated from mice after bile duct ligation. Purified BDCs from cholestatic C57BL/6 (H-2b) mice express not only the major histocompatibility complex (MHC) class I and class II antigens but also the costimulatory molecules B7-1 (CD80) and B7-2 (CD86). The expression of the MHC class II molecules on BDCs before and after interferon (IFN)-gamma exposure is also demonstrated by immunohistochemistry on the cultured cells. Cytotoxicity assays indicate the vulnerability of these cells as targets for immunologic injuries. Effector cells generated from B10.BR splenocytes (H-2k) against C57BL/6 splenocytes (H-2b) show comparable killing of BDCs and EL4 cells, the latter being a lymphoma line that was established from the C57BL/6N (H-2b) mouse. An immortalized mouse BDC line (IBDC) is included in this study to validate some of the findings from BDCs isolated from bile duct-ligated mice. We suggest that cholestatic BDCs express surface antigens different from those of normal epithelial cells that result in increased susceptibility to damage by immune mechanisms.

Follow-up after liver transplantation for protoporphyric liver disease.

Protoporphyria is a genetic disorder in which patients may develop severe protoporphyrin-induced liver damage and require transplantation. Because unique problems occur in the perioperative period and because excess production of protoporphyrin by the bone marrow continues after liver transplantation, the efficacy of this procedure for protoporphyric liver disease is uncertain. We present follow-up of nine patients who underwent liver transplantation. Two patients died within 2 months of transplantation, one from complications of abdominal bleeding and the other from sepsis after bowel perforations. The remaining seven patients had follow-up at 14 months to 8 years after transplantation (mean, 3.8 years). Two of the seven had suffered skin burns from exposure to operating room lights, which healed without scarring. Three had axonal neuropathies in the postoperative period requiring prolonged mechanical ventilation, and motor defects persisted in two. Five patients had normal liver chemistries at follow-up (mean, 3.5 years), with liver biopsy results normal or showing mild portal triad abnormalities, but erythrocyte protoporphyrin levels remained significantly elevated (1,765 +/- 365 mcg/dL; normal, < 65). The other two patients, both of whom had rejection, cytomegalovirus infection, and biliary tract obstruction requiring endoscopic therapy, had a recurrence of protoporphyric liver disease as indicated by liver biopsy features. One died 5 years after transplantation from complications of the liver disease. The other was stable 3.3 years after transplantation and was being monitored for possible retransplantation. Thus, liver transplantation can be performed successfully in patients with protoporphyric liver disease, with intermediate survival rates comparable to the general transplant population. However, disease may recur in the graft, particularly if there are complications that cause cholestasis.

Mechanistics of formation and ultrastructural evaluation of hepatocyte spheroids.

Freshly harvested rat hepatocytes form spheroids on uncoated positively charged polystyrene surfaces. Time lapse microscopy revealed that cell movement and reorganization were involved in spheroid formation. Ultrastructural evaluation using scanning and transmission electron microscopy indicated polarized cellular morphology and extensive cell-cell communication within spheroids. Bile canalicular structures were observed to surround each individual hepatocyte, forming an intricate three-dimensional continuous network of channels that appeared to end as pores/holes on the surface of the spheroid. The maintenance of differentiated cellular morphology coincided with preservation of hepatocyte viability and enhanced levels of tissue specific functions in spheroids.

Pediatric gastroenterology. Update on metabolic liver disease.

Wilson's disease, genetic and neonatal hemochromatosis, protoporphyria, tyrosinemia, and alpha1-antitrypsin deficiency are updated. Cost effectiveness of screening is discussed. Current therapies are evaluated, including the role of transplantation. The molecular biologic technique PCR is covered. Gene therapy is introduced.

Cystic fibrosis-associated colitis and fibrosing colonopathy.

OBJECTIVE: To describe our experience with cystic fibrosis (CF)-associated colitis and fibrosing colonopathy, and to assess treatment strategies. STUDY DESIGN: We reviewed hospital charts and autopsy reports of all University of Minnesota patients with CF between 1975 and August 1994. We identified six patients with colonopathy and compared them with a cohort of 79 patients with CF in the same age range and seen during the same period. RESULTS: All patients with colonopathy had bloody diarrhea; five of the six had abdominal pain. Stool frequency and related symptoms distinguished the patients with colonopathy from the cohort population. All took a higher median dose of pancreatic enzymes than the cohort population during the 3 months preceding the onset of symptoms (p < 0.002). For all six patients, barium studies revealed loss of haustration, and shortening and diffuse narrowing of the colonic lumen with relative rectal sparing. The distal ileal mucosa was irregular in four patients. A histopathologic study reveal fibrosis of the submucosa or lamina propria, and focal acute cryptitis in all six patients. Other features included ascites (2/6) and nodular regenerative hyperplasia of the liver (1/6). One patient continues to have symptoms, three had subtotal colectomy, and the condition of two improved after a regimen including a low-fat diet, withholding of pancreatic enzymes, and supplemental parenteral nutrition was initiated. CONCLUSIONS: Fibrosing colonopathy represents a newly recognized gastrointestinal complication of cystic fibrosis. Affected persons have taken larger doses of pancreatic enzymes than similar patients with cystic fibrosis, and have bloody diarrhea. We developed a medical protocol that may avoid surgical resection of the colon in some of these patients.

Clinical and biochemical findings in progressive familial intrahepatic cholestasis.

The clinical findings in 33 patients with progressive familial intrahepatic cholestasis (PFIC) are presented. Symptoms developed almost invariably before 6 months of age with severe pruritus and moderate jaundice. Other clinical findings included wheezing and nosebleeds, fat-soluble vitamin deficiency states, and cholelithiasis. Lower values for gamma-glutamyl transpeptidase, averaging 15 IU/L before the administration of phenobarbital, and cholesterol, which averaged 156 mg/dl, are helpful in distinguishing PFIC from other pediatric cholestatic liver diseases. Autosomal recessive inheritance is probable. Twenty-six patients are alive at 12.9 +/- 6.7 years of age, all having had successful surgical treatment, either partial biliary diversion (n = 17) or orthotopic liver transplantation (n = 10). Seven patients died at a mean age of 3.9 +/- 2.4 years, as a result of liver failure in two, hepatocellular carcinoma in two, and complications of liver transplantation in three.

Long-term complications of arteriohepatic dysplasia.

PURPOSE: It has been stated that arteriohepatic dysplasia is a form of biliary paucity with a good prognosis. We wished to determine the long-term morbidity and mortality associated with arteriohepatic dysplasia. PATIENTS AND METHODS: The charts of all patients with arteriohepatic dysplasia followed by the pediatric gastroenterologists of the University of Minnesota into adulthood were reviewed. RESULTS: Over the last 33 years, the pediatric gastroenterologists have followed 16 children with syndromic paucity, six of whom are now beyond age 18 years. Although five of six patients responded to medical therapy with improvement in their cholestasis and appeared stable clinically through childhood, five of six patients had complications of arteriohepatic dysplasia after age 16 years that resulted in severe morbidity (three) or death (two). These complications included hepatic failure (two), renal failure (one), cerebellar herniation (one), and hepatocellular carcinoma (one). In only one patient were symptoms of the complications present prior to the age of 18 years. CONCLUSION: As more patients with arteriohepatic dysplasia reach adulthood, it appears that this syndrome may be accompanied by long-term manifestations extending beyond childhood. It is important that physicians assuming management of these patients from pediatricians be aware that new abnormalities may appear without warning and that the hepatic disease may deteriorate despite apparent stability through childhood.

Primary and secondary amenorrhea associated with spironolactone therapy in chronic liver disease.

Women with severe liver disease often have amenorrhea that resolves as liver disease abates. We describe three patients with mild to moderate chronic liver disease and amenorrhea. In each case amenorrhea resolved when spironolactone therapy was discontinued. We suggest that spironolactone, an androgen inhibitor, may also cause reversible amenorrhea.

The pathologic spectrum of the nephropathy associated with alpha 1-antitrypsin deficiency.

To further define the clinicopathologic spectrum and pathogenetic mechanism of the nephropathy associated with alpha 1-antitrypsin (A1AT) deficiency, we evaluated renal specimens from 34 patients with chronic hepatic disease, including 20 with A1AT deficiency (study patients), and correlated these findings with urinalysis evaluation. Glomerular lesions were noted in 79% (15 of 19) of A1AT patients with the PiZZ phenotype, including seven with mesangio-capillary glomerulonephritis (MPGN and focal segmental MPGN), six with mesangial proliferative glomerulonephritis (Mes GN), one with diffuse endocapillary proliferative glomerulonephritis (DPGN), and one with focal segmental mesangial proliferative glomerulonephritis with segmental necrosis (FS Nec GN). One A1AT patient with the PiMZ phenotype did not demonstrate glomerular abnormalities. Focal segmental Mes GN was found in 43% (six of 14) of patients in an age-matched group with chronic hepatic failure unrelated to A1AT deficiency. In nine study patients, glomerular pathology was noted in the presence of a normal urinalysis. Immunofluorescence studies revealed the presence of immunoproteins and the A1AT protein isoelectric forms, PiM and PiZ, in the subendothelial region of glomerular basement membranes in A1AT patients with MPGN, Mes GN, and DPGN. Our results emphasize the heterogeneity of glomerular lesions associated with A1AT deficiency and hepatic disease and the relatively high incidence of MPGN in these children. The presence of abnormal PiZ protein in the subendothelial region of the glomerular basement membrane in A1AT patients with glomerulonephritis suggests a possible role for this protein in the pathogenesis of this lesion.

Early liver transplantation is indicated for tyrosinemia type I.

Liver transplantation is now accepted as the treatment of choice for tyrosinemia type I (hereditary tyrosinemia). In an effort to determine whether any factors in these patients would aid in predicting optimal timing of the transplant procedure, we evaluated several clinical, biochemical, and radiographic parameters in five successive patients undergoing liver transplant for tyrosinemia type I at the University of Minnesota. All five patients evidenced prolonged periods of clinical and metabolic stability with dietary therapy and four of five remained stable at the time of evaluation for transplantation. Nevertheless, all five suffered significant and unexpected complications of tyrosinemia prior to the time of liver transplant. Four developed renal stones, two were in liver failure, and one developed a neurologic crisis that left him completely paralyzed. Hepatocellular carcinoma was found in one of the five at transplant. We could identify no clinical, biochemical, or radiographic study that was predictive of the likelihood of significant complications of the disorder. Survival from the transplant procedure itself was 100%. The inability to predict or prevent significant complications of tyrosinemia and the favorable outcome from transplantation lead us to recommend liver transplant for all patients with tyrosinemia type I by 12 months of age.