Durability of sustained response shown in paediatric patients with chronic hepatitis C who were treated with interferon alfa-2b plus ribavirin.

Long-term studies in adults indicate that sustained virologic response (SVR) after combination treatment for chronic hepatitis C (CHC) predicts long-term clearance. Although peginterferon plus ribavirin is now standard care for children with CHC, long-term follow-up studies are not yet available. This study evaluated durability of virologic response over 5 years in children previously treated with interferon alfa-2b plus ribavirin (IFN/R). Ninety-seven of 147 children with CHC, who were treated with IFN/R and completed the 6-month follow-up in two previous clinical trials, participated in this long-term follow-up study. All were assessed annually for up to 5 years; patients with SVR were assessed for durability of virologic response. Children with SVR (n = 56) and those with detectable hepatitis C virus (HCV) RNA 24-week post-treatment (n = 41) were followed for a median of 284 weeks. Overall, 70% (68/97) of patients completed the 5-year follow-up. One patient with genotype 1a CHC had SVR and relapsed at year 1 of follow-up with the same genotype. Kaplan-Meier estimate for sustained response at 5 years was 98% (95% CI: 95%, 100%). Six patients with low-positive HCV RNA levels (n = 4) or missing HCV RNA at the 24-week follow-up visit (n = 2) in the initial treatment studies had virologic response during this long-term follow-up study. Linear growth rate was impaired during treatment with rapid increases in the immediate 6 months post-treatment. Mean height percentile at the end of the 5-year follow-up was slightly less than the mean pretreatment height percentile. Five patients experienced serious adverse events; none related to study drug exposure. SVR after IFN/R predicts long-term clearance of HCV in paediatric patients; growth normalized in the majority of children during the long-term follow-up. Similar long-term results could be expected after peginterferon alfa-2b plus ribavirin treatment.

Simultaneous liver and pancreas transplantation in patients with cystic fibrosis.

BACKGROUND: Improved survival in patients with cystic fibrosis (CF) has led to an increased incidence of extrapulmonary complications of this disease. Of these, cirrhosis and pancreatic insufficiency, including CF-related diabetes (CFRD) and exocrine insufficiency, are significant causes of morbidity and mortality. Liver transplantation is the treatment of choice for cirrhosis in this setting, but the addition of an isolated simultaneous pancreas transplant in patients with CFRD has not been reported. METHODS: Two female patients with CF underwent simultaneous pancreas and liver transplantation. Both had pancreatic insufficiency, CFRD, cirrhosis, and preserved renal function. In each case, the liver and pancreas were procured from a single cadaveric donor. The liver transplant was performed first. A lower midline extension was added for improved exposure of the iliac vessels. The donor pancreas transplant was performed with systemic venous drainage and enteric exocrine drainage. Immunosuppression included rabbit anti-thymocyte globulin, tacrolimus, mycophenolate mofetil, and early steroid withdrawal. RESULTS: Both patients recovered well with normal liver function, resolution of portal hypertension, and normal blood glucoses independent of insulin. As a result of the enteric exocrine drainage of the pancreas, they are now independent of supplemental pancreatic enzymes. CONCLUSIONS: Simultaneous liver and pancreas transplantation in CF patients provides the advantages of normalization of glucose and improved nutrition for patients requiring liver transplantation and should be considered in CF patients with CFRD who require liver transplants.

Evidence that pediatric liver transplant recipients may undergo late rejection episodes in spite of donor-specific microchimerism.

Lymphocytes of donor origin can be demonstrated in the blood of many liver transplant recipients. It has been proposed that this chimerism may imply graft tolerance and permit withdrawal of immunosuppression. We report two children with liver transplants who had lymphocyte chimerism demonstrated at the time of late rejection episodes. One child was chimeric for both of his donors, although he retained the first allograft for only 3 days. Thus, the persistence of donor lymphocytes may be unrelated to the presence of the donor organ. Graft rejection can occur in spite of donor-specific microchimerism. The role of donor-specific microchimerism in graft acceptance or graft tolerance remains to be elucidated.

Alpha1-antitrypsin deficiency-associated liver disease progresses slowly in some children.

BACKGROUND: A prospective nationwide screening study initiated more than 20 years ago in Sweden has shown that clinically significant liver disease develops in only 10% to 15% of alpha1-antitrypsin (AT)-deficient children. This study provides information about 85% to 90% of those children, many of whom had elevated serum transaminases in infancy but have no evidence of liver injury by age 18 years. However, there is relatively limited information about the course of alpha1-AT-deficient children who have cirrhosis or portal hypertension. Based on several anecdotal experiences, we have been impressed by the relatively slow progression and stable course of the liver disease in some of these children. METHODS: We reviewed the course of patients with homozygous PIZZ alpha1-antitrypsin deficiency seen at this institution since establishing a patient database 16 years ago. RESULTS: Of 44 patients with alpha1-AT deficiency, 17 had cirrhosis, portal hypertension, or both. Nine of the 17 patients with cirrhosis or portal hypertension had a prolonged, relatively uneventful course for at least 4 years after the diagnosis of cirrhosis or portal hypertension. Two of these patients eventually underwent liver transplantation, but seven are leading relatively healthy lives for up to 23 years while carrying a diagnosis of severe alpha1-AT deficiency-associated liver disease. Patients with the prolonged stable course could be distinguished from those with a rapidly progressive course on the basis of overall life functioning but not on the basis of any other more conventional clinical or biochemical criteria. CONCLUSIONS: These data provide further evidence for the variable severity of liver disease associated with alpha1-AT deficiency and indicate that some patients have chronic, slowly progressing or nonprogressing cirrhosis.

Molecular conservation of the P6 outer membrane protein among strains of Haemophilus influenzae: analysis of antigenic determinants, gene sequences, and restriction fragment length polymorphisms.

Infections caused by Haemophilus influenzae are a major worldwide health problem. In particular, nontypeable strains of H. influenzae are a common cause of otitis media in infants and children. A vaccine to prevent these infections would result in the prevention of substantial morbidity and cost savings. A problem in identifying an appropriate vaccine antigen has been the enormous antigenic heterogeneity among nontypeable strains of H. influenzae. The present study was undertaken to characterize the conservation of the P6 outer membrane protein (approximately 16,000 daltons) among strains of H. influenzae. A total of 20 type b strains and 20 nontypeable strains of diverse geographic and clinical origins was studied. Three approaches were taken. (i) Antigenic determinants recognized by monoclonal and polyclonal antibodies were present on P6 in all 40 strains tested. The molecular weight of P6 was identical in all strains. (ii) Comparison of the DNA sequences of the P6 genes from three epidemiologically and serologically unrelated strains demonstrated 100% homology at the amino acid level and 97 to 99% homology at the nucleotide level. (iii) Restriction fragment length polymorphism analysis demonstrated that the P6 gene and flanking sequences were highly conserved among all strains. These three independent series of experiments indicated that the P6 protein is highly conserved among strains of H. influenzae. P6 should receive serious consideration for inclusion in a vaccine to prevent infections caused by nontypeable H. influenzae.

Colorectal adenocarcinoma as a second malignant neoplasm following Wilms' tumor and rhabdomyosarcoma.

Colorectal carcinoma is one of the most common primary malignancies in adults and occurs in older patients after pelvic radiation. It is rare in children and young adults. We report two cases of colonic adenocarcinoma which were second malignant neoplasms following treatment for early childhood malignancies. One child had Wilms' tumor at 9 months of age treated with preoperative radiation and surgery. He developed radiation colitis and multifocal intestinal adenocarcinomas 42 years later and died with abdominal carcinomatosis. The second child had retroperitoneal embryonal rhabdomyosarcoma at age 1 year and was treated with preoperative radiation, surgery, and chemotherapy. At age 2 years he had radiation colitis; at age 11 years he had rectal adenocarcinoma associated with adenomatous polyps, focal adenomatous change and radiation colitis. Immunohistochemical studies revealed p53 positivity in both adenocarcinomas and in adenomas from the second patient, suggesting that p53 mutation was involved in carcinogenesis. The history of high-dose radiation in early childhood and the multifocal lesions suggest the adenocarcinomas in both patients were second malignant neoplasms, with associated reactive and benign neoplastic and premalignant lesions well documented in one case. These two cases document the phenomenon of early onset of adult type tumors in survivors of childhood cancer and emphasize the need for continued clinical evaluation of patients at risk for second malignant neoplasms.

Liver transplantation for the treatment of urea cycle disorders.

The principal goal of therapy when liver transplantation is used for the treatment of metabolic disease is to correct the metabolic error. By doing so, liver transplantation eliminates the hepatic and peripheral consequences of the error. Inborn errors involving the urea cycle appear on theoretical grounds to be amenable to treatment using liver transplantation and, indeed, published data demonstrate that this approach to therapy can be successful. The purpose of this study is to examine the outcome of liver transplantation done for the indication of urea cycle defects in a large group of patients. The first goal of the study is to determine with certainty that liver transplantation corrects hyperammonaemia and halts the progress of disease. A second goal is to determine the extent of neurological recovery in children previously injured by hyperammonaemia. The final goal is to understand whether the quality of life is improved and medical expense is reduced by transplantation. The study involved a survey of major transplantation centres. Four centres provided data about 16 patients, 14 of whom were alive 11 months to 6 years after transplantation. The results demonstrate that liver transplantation resulted in correction of hyperammonaemia in all patients. The neurological outcome after transplantation correlated closely with the condition prior to transplantation. This population of patients has had relatively few problems in the long term related to the liver transplant itself. The quality of life seems to be much improved, but further study will be needed to confirm this. Limited data involving two patients show a reduction in the cost of care. We conclude from our experience that liver transplantation can be an effective treatment for children with urea cycle defects.