Safety and efficacy of N-acetylcysteine in children with non-acetaminophen-induced acute liver failure.

Acute liver failure (ALF) carries a high mortality in children. N-acetylcysteine (NAC), an antioxidant agent that replenishes mitochondrial and cytosolic glutathione stores, has been used in the treatment of late acetaminophen-induced ALF and non-acetaminophen-induced ALF. In our unit, NAC was introduced as additional treatment for non-acetaminophen-induced ALF in 1995. The aim of this study was to evaluate the safety and efficacy of NAC in children with ALF not caused by acetaminophen poisoning. A retrospective review of medical records of 170 children presenting with nonacetaminophen-induced ALF between 1989 and 2004 was undertaken. ALF was defined as either international normalized ratio of prothrombin time (INR) > 2 and abnormal liver function or INR >1.5 with encephalopathy and abnormal liver function. Children were divided into the following groups: Group 1 (1989-1994), standard care (n = 59; 34 [58%] male; median age 2.03 yr, range 0.003-15.8 yr); and Group 2 (1995-2004), standard care and NAC administration (n = 111; 57 [51%] male; median age 3.51 yr, range 0.005-17.4 yr). NAC was administered as a continuous infusion (100 mg/kg/24 hours) until INR < 1.4, death, or liver transplantation (LT). The median duration of NAC administration in Group 2 was 5 (range, 1-77) days. Complications were noted in 8 (10.8%) children: rash in 3, arrhythmia in 3, and dizziness and peripheral edema in 1. One child had an allergic reaction (bronchospasm) and NAC was stopped. A total of 41 (71%) children in Group 1 vs. 85 (77%) in Group 2 required admission to intensive care, P = not significant (ns). The length of intensive care stay was 6 (range, 1-58) days in Group 1 vs. 5 (range, 1-68) days in Group 2, P = ns and length of hospital stay was 25 (range, 1-264) days vs. 19 (range, 1-201) days, P = 0.05. The 10-yr actuarial survival was 50% in Group 1 compared to 75% in Group 2, P = 0.009. Survival with native liver occurred in 13 (22%) in Group 1 vs. 48 (43%) in Group 2, P = 0.005; 15 (25%) in Group 1 died without transplant vs. 21 (19%) in Group 2, P = ns; and LT was performed in 32 (54%) vs. 42 (38%), P = ns. Death after transplantation occurred in 15 (39%) in Group 1 vs. 8 (16%) in Group 2, P = 0.02. In conclusion, NAC is safe in non-acetaminophen-induced ALF. In this retrospective study NAC was associated with a shorter length of hospital stay, higher incidence of native liver recovery without transplantation, and better survival after transplantation.

Polyclonal T-cell responses to cytochrome P450IID6 are associated with disease activity in autoimmune hepatitis type 2.

BACKGROUND & AIMS: Autoimmune hepatitis type 2 (AIH-2), a severe juvenile liver disorder of unknown etiology and pathogenesis, is characterized by liver-kidney microsomal antibody type 1 targeting cytochrome P450IID6 (CYP2D6) and is associated to HLA DRB1*07. Although CYP2D6 B-cell reactivity has been extensively characterized, little is known about CYP2D6-specific T-cell responses. The aim of the present study was to characterize anti-CYP2D6 cellular immune responses and their possible pathogenic role in patients with AIH-2. METHODS: We investigated T-cell reactivity against 61 overlapping peptides spanning the full CYP2D6 protein using ex vivo cultures obtained at diagnosis, remission, and relapse. Moreover, CYP2D6-specific T-cell reactivity was investigated in the context of HLA restriction, peptide-binding affinity to HLA DRB1*07, cytokine profile, disease specificity, and clinical course. RESULTS: Proliferative responses to CYP2D6 cluster to 7 antigenic regions in DRB1*07 and to 4 regions in non-DRB1*07 patients. Whereas distinct peptides induce production of interferon gamma, interleukin-4, or interleukin-10, peptides inducing interferon-gamma and proliferation overlap. There is also an overlap between sequences inducing T- and B-cell responses. The breadth (number of epitopes) and intensity (quantity of cytokine produced) of the T-cell response are directly correlated to disease activity (biochemical and histologic markers). CONCLUSIONS: These data imply that the T-cell response to CYP2D6 in AIH-2 is polyclonal, involves multiple effector types targeting different epitopes, and is associated with hepatocyte damage, knowledge that should form the basis for a more refined therapeutic approach.

Neonatal hemochromatosis--medical treatment vs. transplantation: the king's experience.

The aim of our study was to compare the outcome of medical treatment vs. liver transplantation in infants with neonatal hemochromatosis (NH) referred to King's College Hospital from 1990-2002. We conducted a retrospective review of 19 children from 14 families. Fifteen children presented at birth and 4 during the first week of life. One child was diagnosed by cordocentesis at 30 weeks of gestation. NH recurred in 7 of 9 families with further children. In one family, 2 children from different fathers were affected. All patients had elevated ferritin levels, hypoalbuminemia, and coagulopathy. Liver histology showed parenchymal collapse, diffuse fibrosis, and moderate to severe hepatocyte hemosiderin deposition. Extrahepatic siderosis was demonstrated by magnetic resonance in 2 patients, lip biopsy in 3, and autopsy in 10. Ten patients received a chelation-antioxidant cocktail: 1 survived, 4 died, and 5 required liver transplantation, of whom 2 died. One of the 9 infants who did not receive the cocktail survived with medical support, 3 died, and 5 required transplantation, of whom 3 died. Seven children are alive, 5 after transplantation, at a median follow-up of 5.6 years, with excellent quality of life and no recurrence of the disease. In conclusion, chelation-antioxidant treatment does not appear to modify the prognosis of NH, at least in severe cases. Liver transplantation, with 50% long-term survival, remains the treatment of choice and should be promptly offered to those infants who do not improve with supportive medical treatment.

Effect of CD4+ CD25+ regulatory T-cells on CD8 T-cell function in patients with autoimmune hepatitis.

BACKGROUND AND AIMS: CD4 T lymphocytes constitutively expressing the IL-2-receptor alpha-chain (CD25) (T-regs) are central to self-tolerance maintenance, preventing the proliferation and effector function of autoreactive T-cells. In autoimmune hepatitis T-regs are defective in number but maintain the ability to suppress IFNgamma production by CD4+CD25- T-cells. We have studied the ability of CD4+CD25+ (T-regs) to regulate proliferation and cytokine production by CD8 T-cells in patients with autoimmune hepatitis at diagnosis and during remission. METHODS: Twenty-five patients were studied. T-regs were purified from PBMCs by CD4 negative selection followed by CD25 positive selection, using immunomagnetic beads. The ability of T-regs to suppress CD8 T-cell proliferation was assessed by 3H-thymidine incorporation; their ability to regulate cytokine production by intracellular cytokine staining. RESULTS: We found that T-regs are unable to regulate CD8 T-cell proliferation and cytokine production in patients studied at diagnosis, while they suppress CD8 T-cell proliferation and induce an elevation of IL-4 producing CD8 T-cells in patients during drug-induced remission. CONCLUSION: Inability of T-regs to regulate CD8 T-cell function at diagnosis may contribute to the initiation of autoimmune liver damage. The ability of T-regs to regulate CD8 proliferation and IL-4 production during drug-induced remission suggests a role for immunosuppressive treatment at reconstituting T-regs function.

Wilson's disease in children: 37-year experience and revised King's score for liver transplantation.

Wilson's disease (WD) is a rare liver-based disorder of copper metabolism. Prognostic criteria described by our group in 1986 to predict death without transplantation have not been universally validated. The clinical features of 88 children were reviewed, retrospectively in 74 and prospectively in 14. Data from the retrospectively recruited patients that died or survived on long-term chelation were used to evaluate the validity of our old scoring system and to devise a new prognostic index, then assessed in the 14 prospectively recruited patients. Using the old scoring system, 5 children scoring > or = 7, the cutoff value for death without transplantation, survived, whereas 4 scoring < or = 7 died (sensitivity 87% and specificity 90%). A new index based on serum bilirubin, international normalized ratio, aspartate aminotransferase (AST), and white cell count (WCC) at presentation identified a cutoff score of 11 for death and proved to be 93% sensitive and 98% specific, with a positive predictive value of 88%. When the new index was evaluated prospectively in 14 patients, it predicted the need for transplantation in only the 4 who required it, although 1 child with a score of 11 survived on medical treatment. In conclusion, the new Wilson Index is more sensitive and specific in predicting mortality without transplantation than the old scoring system, but needs to be validated in a larger number of patients.

Risk factors for fungal infection in paediatric liver transplant recipients.

Fungal infection (FI) is a major and potentially fatal complication in liver transplantation (LT). Published experience of FI in paediatric LT is limited. We therefore reviewed case records of 79 children, aged between 0.16 and 16 yr, who underwent LT between 1997 and 1998 to document the incidence of, and identify risk factors for, FI. Sixty-eight pre-, peri- and post-LT variables were assessed in relation to FI by univariate and multivariate analyses. The major indications for LT were biliary atresia in 26 (33%) patients, fulminant hepatic failure in 16 (20%) and intrahepatic cholestasis in 11 (14%); eight patients required re-LT. Thirty-two (40.5%) children developed a FI within 1 yr of LT. The median time to FI was 42 days (range 1-342 days). Candida spp. caused 29 (90.7%) FIs; 21 (66%) of these were Candida albicans. Although FI was associated with increased mortality, most patients responded well to antifungal treatment. The variables independently associated with FI were pre-LT fungal colonization and pyrexia and, post-LT, bacterial infection, Epstein-Barr virus (EBV) infection and tacrolimus administration. Identifying risk factors for FI should contribute to the development of strategies for prophylaxis or preemptive therapy.

Cystatin C, an easy and reliable marker for assessment of renal dysfunction in children with liver disease and after liver transplantation.

Renal dysfunction of variable severity is being increasingly recognized as a major complication of calcineurin inhibitors (CI), in some patients even necessitating renal transplantation. Close and effective monitoring of the renal function is indicated. Current methods for this monitoring are calculation of the glomerular filtration rate (GFR) based on creatinine or exogenous substances like 51Cr-EDTA. The first method is unreliable in children and the second is expensive and cumbersome. Cystatin C has been shown to be an accurate marker of glomerular filtration but has not been evaluated in a large cohort of pediatric patients before and after liver transplantation (LT). We evaluated the accuracy of cystatin C in 62 children (30 male) with LT, who had their 51Cr-EDTA measured on 40 occasions prior to LT and on 47 occasions after LT. The reciprocal of cystatin C correlated better with 51Cr-EDTA GFR (r = .78) than the reciprocal of creatinine (r = .40). Diagnostic accuracy in the identification of reduced GFR was assessed by ROC analysis. Cystatin C yielded the highest area under the ROC curve (AUC) in all groups assessed. From these data a cutoff level of cystatin C predicting 51Cr-EDTA GFR < 80 ml/min/1.73 m2 was calculated. A level of 1.06 mg/L was found to have a sensitivity of 91% and a specificity of 81%. Applying this cutoff level in our patient group would have avoided 51Cr-EDTA GFR estimation in 43 of the 87 estimations. In conclusion, the use of this simple test could be recommended as screening of renal dysfunction in children with liver disease and after LT.

Approaches to acute liver failure in children.

Acute liver failure (ALF) is a rare but often fatal disorder in childhood. Its aetiology includes infections, toxins, metabolic disorders, infiltrative diseases, autoimmune hepatitis, ischaemia, irradiation damage, but in a high proportion of cases it remains unknown. In contrast to adults, in children with ALF hepatic encephalopathy can be a late event, and may not develop at all, despite a lethal outcome, particularly in infants. Children with ALF should be managed in experienced centres with facilities for liver transplantation. Transplantation should be offered only if the underlying disease is treatable by liver replacement and if the prognosis of transplant is better than that of the underlying disease, as in many cases of ALF the liver has the potential to recover with supportive treatment, if the child is kept alive and stable long enough. Universally accepted criteria for listing for transplantation have not been defined as yet. In our centre, maximum INR, bilirubin level, and white cell count, together with age have proven to be reliable predictors of outcome. Future efforts in the management of ALF should concentrate on designing efficient supportive therapy and specific treatments to provide effective non-transplant therapeutic options.

The mortality index for neonatal transportation score: a new mortality prediction model for retrieved neonates.

OBJECTIVE: To develop a mortality prediction score for retrieved neonates based on the information given at the first telephone contact with a retrieval service. METHODS: Data from the New South Wales Newborn and Pediatric Emergency Transport Service database were examined. Analysis was performed with the results for 2504 infants (median gestational age: 36 weeks; range: 24-43 weeks) who were <72 hours of age at the time of referral and whose outcome (neonatal death or survival) was known. The study population was divided randomly into 2 halves, the derivation and validation cohorts. Univariate analysis was performed to identify variables in the derivation cohort related to neonatal death. The variables were entered into a multivariate logistic regression analysis with neonatal death as the outcome. Receiver operator characteristic (ROC) curves were constructed with the regression model and data from the derivation cohort and then the validation cohort. The results were used to generate an integer-based score, the Mortality Index for Neonatal Transportation (MINT) score. ROC curves were constructed to assess the ability of the MINT score to predict perinatal and neonatal death. RESULTS: A 7-variable (Apgar score at 1 minute, birth weight, presence of a congenital anomaly, and infant's age, pH, arterial partial pressure of oxygen, and heart rate at the time of the call) model was constructed that generated areas under ROC curves of 0.82 and 0.83 for the derivation and validation cohorts, respectively. The 7 variables were then used to generate the MINT score, which gave areas under ROC curves of 0.80 for both neonatal and perinatal death. CONCLUSION: Data collected at the first telephone contact by the referring hospital with a regionalized transport service can identify neonates at the greatest risk of dying.

Impairment of CD4(+)CD25(+) regulatory T-cells in autoimmune liver disease.

BACKGROUND/AIMS: CD4(+) lymphocytes constitutively expressing the IL-2-receptor alpha-chain (CD25) regulate the activation of CD4 and CD8 autoreactive T-cells by suppressing their proliferation and effector function. The aim of this study is to: (1) measure the percentage of CD4(+)CD25(+) T-cells (T-regs) in patients with autoimmune liver disease at presentation and during remission, (2) correlate their frequency with disease activity, (3) determine their ability to expand and (4) to inhibit interferon-gamma (IFNgamma) production by CD4(+)CD25- T-cells. METHODS: 41 patients were studied. Percentage of T-regs was determined on peripheral blood mononuclear cells (PBMCs) by triple-colour flow cytometry; their ability to expand by exposing PBMCs to a T-cell expander (CD3/CD28 Dynabeads); their immunoregulatory function by measuring their ability to suppress IFNgamma production by CD4(+)CD25(-) T-cells. RESULTS: T-regs were significantly less in patients than in controls, and at diagnosis than during remission. Their percentage was inversely correlated with titres of anti-liver kidney microsomal and soluble liver antigen autoantibodies. T-regs ability to expand was significantly lower in patients than in controls, but that to suppress IFNgamma production by CD4(+)CD25(-) T-cells was maintained. CONCLUSIONS: Decreased T-regs numbers and ability to expand may favour the emergence of liver-targeted autoimmunity, despite preserved suppressor function. Treatment should aim at increasing T-regs number.

Exhaled nitric oxide levels in infants with chronic lung disease.

UNLABELLED: Chronic lung disease (CLD) is an inflammatory disorder; in patients with other inflammatory disorders exhaled nitric oxide (NO) levels are elevated. The aim of this study was to test the hypothesis that prematurely born infants with CLD would have elevated exhaled NO levels compared to those without CLD and healthy term-born infants. Ten infants with CLD (median gestational age 26 weeks; CLD group), ten infants without CLD (median gestational age 32 weeks; non-CLD group) and ten term-born infants (term group) were examined at post-conceptional ages between 36 and 45 weeks. NO levels were measured during spontaneous tidal breathing. A facemask was positioned over the infant's nose and mouth and a sampling catheter was inserted through a small leak-free valve into the facemask. To measure nasal NO, the tip of the sampling catheter was placed in the nasal space and to measure facemask NO, the catheter tip was positioned inside the facemask at the infant's lips. Nasal compared to facemask NO levels were higher in all three groups (CLD; non-CLD; term: P=0.017, P=0.012 and P=0.017, respectively). The CLD group had higher peak nasal and facemask NO levels than the non-CLD ( P=0.011 and P=0.034 respectively) and the term ( P=0.005 and P=0.01 respectively) infants. Regression analysis demonstrated that facemask NO levels were significantly related to CLD, independent of gestational, post-natal and post-conceptional age ( P=0.006). CONCLUSION: our results suggest that exhaled nitric oxide levels are elevated in chronic lung disease infants. Facemask measurement of nitric oxide levels might be a potentially useful method to monitor infants with chronic lung disease.

An illness severity score and neonatal mortality in retrieved neonates.

UNLABELLED: The Clinical Risk Index for Babies (CRIB) score is a simple tool to measure clinical risk and illness severity in very low birth weight infants. The aim of this study was to determine if a modified CRIB score (MCRIB) used at first telephone contact with a transport service differentiated between retrieved infants who did or did not die in the neonatal period and hence might be a useful triage tool. A retrospective cohort study of 2504 infants, median gestational age 36 weeks and birth weight 2782 g, transported by the New South Wales Newborn and Paediatric Emergency Transport Service (NETS) was performed. MCRIB was calculated at four time points during the retrieval process. The MCRIB score at the time of the first call and the change in the MCRIB score over the retrieval process were related to outcome (neonatal death or survival). The mean MCRIB score at the time of first call was higher in those infants who died during the neonatal period (4.37) than in those who survived (2.63), (P < 0.0001). MCRIB performed better (area under the receiver operator characteristic curves of 0.72) with regard to predicting mortality than gestational age (0.56) or birth weight (0.52). The mean MCRIB score fell progressively from the time of first call to admission at the accepting NICU (P < 0.0001); infants whose MCRIB score increased were more likely to die (P < 0.0001). CONCLUSION: these results suggest an illness severity score, applied at the time of first call to a transport service would be helpful in setting priorities for retrievals.

Can energy expenditure be predicted in critically ill children?.

OBJECTIVE: To determine whether critically ill children are hypermetabolic and to calculate whether predictive equations are appropriate for critically ill children. DESIGN: Prospective, clinical study. SETTING: Pediatric intensive care unit. PATIENTS: A total of 57 children (39 boys) aged 9 months to 15.8 yrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The median resting energy expenditure measurement measured by indirect calorimetry was 37.2 (range, 11.9-66.6) kcal x kg(-1) x day(-1). This was significantly lower than would be predicted using either the Schofield (42.7 [26.9-65.4] kcal x kg(-1) x day(-1)) or Fleisch equations (42.8 [20.9-66.2] kcalx kg(-1)-1 x day(-1), p < .001) but significantly higher than the White equation developed specifically for pediatric intensive care units (26.2 [8.5-70.1] kcal x kg(-1),day(-1), p < .0001). Methods comparison analysis showed the limits of agreement were -484 to 300, -461 to 319, and -3.2 to 854 kcal/day, respectively. Multivariate analysis indicated the following factors contribute to hypometabolism and hypermetabolism: age (p = .006), sex (p = .034), time spent in the pediatric intensive care unit (p = .001), diagnosis (p = .015), weight (p = .009), temperature (p = .04), continuous infusion for sedation (p = .04), and neuromuscular blockade (p = .03). CONCLUSION: Children do not become hypermetabolic during critical illness. These data suggest that agreement between resting energy expenditure and the predictive equations are so broad that they are inappropriate for use in critically ill children.

Bone mineral density and height gain in children with chronic cholestatic liver disease undergoing transplantation.

BACKGROUND: Osteodystrophy is a well-described complication of chronic liver disease. Previous reports in adults and children undergoing liver transplantation (LT) were discordant, with the former showing no improvement of bone disease in the first year after transplantation and the latter demonstrating remarkable benefit from it. Our aim was to perform a pilot study on osteodystrophy in children undergoing LT and evaluate the contribution of growth on bone mineral density (BMD) changes. METHODS: We studied six patients (two male), with a median age at transplantation of 8.8 (range 3.8-16.6) years. Indications for transplantation were biliary atresia and progressive familial intrahepatic cholestasis (three patients each). BMD was studied with dual-energy x-ray absorptiometry and biochemical markers of liver and bone function in patients before and at 3, 6, and 12 months after LT. RESULTS: Median L2-L4 spinal BMD was 0.54 g/cm2 (range 0.29-0.87) before LT, and 0.58 g/cm2 (0.27-0.86) at 3 months, 0.66 g/cm2 (0.36-1.00) at 6 months, and 0.76 g/cm2 (0.44-1.02) at 12 months after LT (P=0.005). Median height was 133 (range 93-167) cm before LT, and 134 (93-167) at 3 months, 136 (97-167) at 6 months, and 139 (102-167) at 12 months after LT. There was direct correlation between height gain and total body BMD improvement (r=0.929, P=0.007). CONCLUSION: BMD in children with chronic cholestatic liver disease improves remarkably by 12 months after LT. Catch-up growth in children can account for the different effect of LT on bone density between adult and pediatric populations in the first year after surgery.

Colloid infusion in the perinatal period and abnormal neurodevelopmental outcome in very low birth weight infants.

UNLABELLED: In very low birth weight (VLBW) infants, colloid infusion is associated with impaired perinatal lung function and increased oxygen dependency duration. The aim of this study was to determine whether perinatal colloid infusion was associated with abnormal neurodevelopmental outcome. All perinatal fluid input (crystalloid and colloid) given to VLBW infants entered into a randomised trial was recorded. At 1 and/or 2 years, the neurodevelopmental status of VLBW infants was routinely assessed. Of 131 survivors, median gestational age 27 weeks (range 23-33 weeks), 95 were seen at follow-up. Nineteen had abnormal neurodevelopmental outcome and differed significantly from the rest of the cohort with regard to their birth weight, magnitude of colloid infusion received and the proportions who had received postnatal steroids, suffered prolonged oxygen dependency or having had intracerebral haemorrhage/periventricular leucomalacia development. Regression analysis demonstrated that only colloid infusion related significantly to abnormal neurodevelopmental outcome independent of other variables. CONCLUSION: These data suggest that colloid infusion should be used with caution in the perinatal period.