Daiki Abukawa

Clinical pictures of 75 patients with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD)

SummaryWe clarified the clinical features of NICCD (neonatal intrahepatic cholestasis caused by citrin deficiency) by retrospective review of symptoms, management and long-term outcome of 75 patients. The data were generated from questionnaires to paediatricians in charge of the patients. Thirty of the patients were referred to hospitals before 1 month of age because of positive results in newborn screening (hypergalactosaemia, hypermethioninaemia, and hyperphenylalaninaemia). The other 45, the screen-negative patients, were referred to hospitals with suspected neonatal hepatitis or biliary atresia because of jaundice or discoloured stool. Most of the screen-negative patients presented before 4 months of age, and 11 had failure to thrive. Laboratory data showed elevated serum bile acid concentrations, hypoproteinaemia, low levels of vitamin K-dependent coagulation factors and hypergalactosaemia. Hypoglycaemia was detected in 18 patients. Serum amino acid analyses showed significant elevation of citrulline and methionine concentrations. Most of the patients were given a lactose-free and/or medium-chain triglyceride-enriched formula and fat-soluble vitamins. Symptoms resolved in all but two of the patients by 12 months of age. The two patients with unresolved symptoms suffered from progressive liver failure and underwent liver transplantation before their first birthday. Another patient developed citrullinaemia type II (CTLN2) at age 16 years. It is important to recognize that NICCD is not always a benign condition.

Diagnostic accuracy of the 13C-urea breath test for childhood Helicobacter pylori infection: a multicenter Japanese study

OBJECTIVES:In adults, the 13C-urea breath test (UBT) has been widely used as a noninvasive test of Helicobacter pylori infection because of its high sensitivity and specificity. However, this test is less well established in pediatric practice. The optimum cutoff value and test protocol of the 13C-UBT remains to be established in the pediatric population. The primary purpose of this study was to evaluate diagnostic accuracy of the 13C-UBT for children and to determine its optimum cutoff value.METHODS:A total of 220 Japanese children aged 2–16 yr (mean = 11.9) who underwent upper GI endoscopy and gastric biopsies were finally studied. Endoscopic diagnoses included gastritis (n = 131), gastric ulcer (n = 15), duodenal ulcer (n = 72), and combined ulcer (n = 2). H. pylori infection status was confirmed by biopsy tests including histology, urease test, and culture. With the 13C-UBT, breath samples were obtained at baseline and at 20 min after ingestion of 13C-urea without a test meal and were analyzed by isotope ratio mass spectrometry. Based on biopsy tests, a cutoff value was determined using a receiver operating characteristic curve. In 26 children (seven children infected and 19 noninfected), paired breath samples were also measured by nondispersive infrared spectometry (NDIRS).RESULTS:Biopsy tests demonstrated that 89 children (40%) were infected with H. pylori and 131 children were not infected. There were no statistical differences in mean Δ 13C values at 20 min between male and female H. pylori-infected and noninfected patients. A receiver operating characteristic analysis defined the best cutoff value as 3.5‰. The overall sensitivity and specificity at a cutoff value of 3.5‰ were 97.8% (95% CI = 92.1–99.7%) and 98.5% (95% CI = 96.4–100%), respectively: high sensitivity and specificity were demonstrated in all three age groups (≤5, 6–10, and ≥11 yr). There was a close correlation between the values with isotope ratio mass spectrometry and NDIRS methods (r = 0.998, p < 0.001).CONCLUSIONS:The 13C-UBT with a cutoff value of 3.5‰ is an accurate diagnostic method for active H. pylori infection. The test with the NDIRS method is inexpensive and might be widely applied in clinical practice.

Helicobacter pylori reinfection rates in children after eradication therapy.

BACKGROUND There are few studies of Helicobacter pylori reinfection in childhood. In the current study the reinfection rate of H. pylori and ulcer recurrence were investigated during a follow-up period of 12 months or more in children who had undergone eradication therapy. METHODS Twenty-seven patients aged 5 to 16 years (6 with gastric ulcer, 13 with duodenal ulcer, and 8 with nodular gastritis) were studied. Biopsy-based H. pylori tests performed 1 to 2 months after eradication therapy demonstrated that eradication was successful in 23 patients (5 with gastric ulcer, 11 with duodenal ulcer, and 7 with nodular gastritis) and unsuccessful in 4 (1 with gastric ulcer, 2 with duodenal ulcer, and 1 with nodular gastritis). Twenty-three successfully treated patients were observed for a mean of 22 months (a total of 42.2 patient years of follow-up). To assess H. pylori status, all 23 patients underwent a 13C-urea breath test 1 year after eradication therapy. If the test result was negative, the patients underwent the follow-up test once every year thereafter. In successfully and unsuccessfully treated patients, endoscopy was performed if a patient reported symptoms suggesting ulcer recurrence. RESULTS The initial follow-up 13C-urea breath tests showed that all 23 patients remained free of infection at 12 to 19 months. Among 17 patients, the second test confirmed reinfection in 1 at 28 months. In two patients studied, the third test showed a negative result. The reinfection rate was 2.4% per patient year. Over the follow-up period, ulcer recurrence was found in 2 of 3 ulcer patients with eradication failure but in none of the 16 ulcer patients with successful eradication. The recurrence rate was significantly lower in successfully treated patients than in unsuccessfully treated patients (p < 0.05). CONCLUSIONS Reinfection with H. pylori is rare in children aged more than 5 years, and successful eradication significantly reduces ulcer recurrence. This study supports the benefit of eradication therapy in older children.

A novel inborn error of metabolism detected by elevated methionine and/or galactose in newborn screening: neonatal intrahepatic cholestasis caused by citrin deficiency

Adult-onset type II citrullinaemia, caused by deficiency of the citrin protein encoded by the SLC25A13 gene, is characterised by a liver-specific argininosuccinate synthetase deficiency. DNA analysis for citrin deficiency revealed that SLC25A13 mutations are the cause of a particular type of neonatal intrahepatic cholestasis. We retrospectively investigated nine infants with cholestatic jaundice of unknown origin, detected by newborn screening over a period of 17 years, to determine the role of SLC25A13 defects in children. The results of the newborn screening were varied; four neonates were positive for hypermethioninaemia, two for hyperphenylalaninaemia, one for hypergalactosaemia and two for both hypermethioninaemia and hypergalactosaemia. Clinical characteristics of the patients were severe intrahepatic cholestasis, hypercitrullinaemia, and fatty liver. The symptoms resolved in all patients by 12 months of age without special treatment other than nutritional management. Although five patients were lost to follow-up, we detected SLC25A13 mutations in the remaining four patients examined. Conclusion: the differential diagnosis of cholestatic jaundice of unknown origin in infants should therefore include citrin deficiency. In this paper, we stress the importance of newborn screening to detect infants with neonatal intrahepatic cholestasis caused by citrin deficiency.

Fine-resolution mapping by haplotype evaluation: the examples of PFIC1 and BRIC

Abstract Loci for two inherited liver diseases, benign recurrent intrahepatic cholestasis (BRIC) and progressive familial intrahepatic cholestasis type 1 (PFIC1), have previously been mapped to 18q21 by a search for shared haplotypes in patients in two isolated populations. This paper describes the use of further haplotype evaluation with a larger sample of patients for both disorders, drawn from several different populations. Our assessment places both loci in the same interval of less than 1 cM and has led to the discovery of the PFIC1/BRIC gene, FIC1; this discovery permits retrospective examination of the general utility of haplotype evaluation and highlights possible caveats regarding this method of genetic mapping.

Effects of Citrin Deficiency in the Perinatal Period: Feasibility of Newborn Mass Screening for Citrin Deficiency

Deficiency of citrin due to mutations of the SLC25A13 gene causes adult-onset type II citrullinemia (CTLN2) and one type of neonatal intrahepatic cholestasis (NICCD). About half of the NICCD patients are detected based on high galactose, phenylalanine, and/or methionine concentrations on newborn mass screening (NMS). To clarify the perinatal and neonatal effects and the inconsistent results on NMS, we examined aminograms, the levels of bile acids and galactose in dried blood spots for NMS from 20 patients with NICCD. Birth weight was low for gestational age (−1.4 ± 0.7 SD). Affected fetuses may have suffered intrauterine citrin deficiency. The first abnormality detected after birth was citrullinemia, and 19 of 20 patients had citrulline levels higher than +2 SD of controls. Tyrosine, phenylalanine, methionine, galactose, and bile acids were less affected than citrulline on d 5 after birth. Galactose and bile acids levels were increased at 1 mo in comparison with d 5 after birth due to impairment of the cytosolic NADH reducing–equivalent supply into mitochondria of hepatocytes. Patients with negative findings on NMS had low levels of total 20 amino acids. Citrulline/serine, citrulline /leucine plus isoleucine, and citrulline/total amino acids ratios, controlled for the confounding effect of low amount of total amino acids, were higher in all patients than +2 SD, +2 SD, and +3 SD of controls, respectively. NMS for citrin deficiency (frequency of homozygote with SLC25A13 mutation: 1/10,000–1/38,000 in East Asia) will be useful for clarification of the clinical course, treatment, and prevention of this disease.

Immunochemical study in three patients with cytochromec oxidase deficiency presenting leigh's encephalomyelopathy

Cytochrome c oxidase deficiency has been characterized by remarkable clinical heterogeneity because of the complexity of the enzyme. This complex enzyme consists of thirteen subunits which are the product of two separate genomes. Three larger subunits (I-III) are encoded by mitochondrial DNA and synthesized on mitochondrial ribosomes, whereas smaller subunits (IV-VII) are nuclear gene products. The clinical heterogeneity may be caused by biochemical heterogeneity. In this paper, we made immunological studies of cytochrome c oxidase (CCO; EC 1.9.3.1.) in muscle biopsies, post-mortem tissues and cultured skin fibroblasts from three patients with CCO deficiency presenting with Leighs encephalomyelopathy (McKusick 25600) in order to understand the molecular defect in this disorder.

Direct enzymatic assay of urinary sulfated bile acids to replace serum bilirubin testing for selective screening of neonatal cholestasis

Direct enzymatic assay of urinary sulfated bile acids is a sensitive, rapid, minimally invasive, and convenient method of detecting cholestasis in young infants. It may replace measurement of serum direct bilirubin for selective screening for biliary atresia and neonatal hepatitis syndrome at 1 month of age.

Histological findings in the livers of patients with neonatal intrahepatic cholestasis caused by citrin deficiency

Aim:  To characterize the histological features of the livers of patients with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), we studied specimens from 30 patients diagnosed with NICCD by genetically analyzing the SLC25A13 gene.

Pilot study of screening for Wilson disease using dried blood spots obtained from children seen at outpatient clinics

Wilson disease (WD) is an autosomal recessive disorder of copper accumulation leading to liver and/or brain damage. In this paper, we describe the results of a pilot study of screening for WD using ceruloplasmin determinations in dried blood samples. Specimens were collected from children aged 1 to 6 years who were seen at local paediatric outpatient clinics in the Miyagi Prefecture. We measured ceruloplasmin (CP) concentrations in 2789 children using an enzyme-linked immunosorbent assay. The mean value was 12.4±3.95 mg/dl blood. Among these children, we identified two (case 1, male, 2 years old; case 2, female, 3 years old) with markedly reduced CP concentrations. Apart from low serum copper concentrations, their biochemical findings were almost normal, as were growth and development. To confirm the diagnosis, we analysed the WD gene and detected A803T/2871delC mutations in case 1 and R778L/G1035V mutations in case 2. We conclude that these children were presymptomatic WD patients. The CP level in dried blood samples from children aged 1 to 6 years appears to be a reliable marker for early detection of WD.