Wilson disease: pathophysiology, diagnosis, treatment, and screening

Ratio of aspartate aminotransferase to alanine aminotransferase and alkaline phosphatase to total bilirubin in Wilsonian acute liver failure in children

BACKGROUND

Acute liver failure (ALF) caused by Wilson disease (WD) is always fatal. Therefore, a quick diagnosis of WD is needed to start immediate management. This study aims to determine the ratio of aspartate aminotransferase to alanine aminotransferase (AST/ALT) and the ratio of alkaline phosphatase to total bilirubin (ALP/TB) in diagnosing Wilsonian acute liver failure (WALF) in children.

METHODS

Sixty children with acute liver failure were included in this study, of whom 40 had WALF and 20 had a non-Wilsonian acute liver failure (non-WALF). The serum ALT, AST, alkaline phosphatase, and total bilirubin of each blood sample were measured. We evaluated the sensitivity and specificity of AST/ALT ratio and ALP/TB ratio in WALF diagnosis.

RESULTS

Consanguinity and Kayser-Fleischer (K-F) rings were found in 32.5% and 72.5% of WALF cases, respectively. The mean hemoglobin, median ALT, median alkaline phosphatase, and mean ceruloplasmin of children with WALF were lower than those in the non-WALF group. In WALF cases, the median AST/ALT ratio was higher than in non-WALF cases. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the ratio of AST to ALT were 70%, 95%, 96.5%, 61.3% and 78.3%, respectively. However, when the cutoff value is ≥ 1.85, the maximum sensitivity produced by the AST/ALT ratio is 77.5% and the specificity is 95%. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of the ratio of ALP/TB < 4 were 32.5%, 100%, 100%, 42.5%, and 55%, respectively. The overall mortality rate was 50%, while the WALF mortality was 60%.

CONCLUSION

A positive AST/ALT and ALP/TB ratio strongly suggest WALF, but a negative result does not exclude WALF. We cannot use these ratios as a diagnostic tool for children with WALF. In WALF cases, the mortality rate is remarkably high, and the high score of the new Wilson index predicts the mortality rate without liver transplantation.

Early Diagnosis of Wilson’s Disease in Children in Southern China by Using Common Parameters

Objective: The aim of the study was to develop the early diagnostic criteria for Wilson’s disease (WD) in young children in southern China by using alanine aminotransferase (ALT) elevation as the first manifestation.

Methods: A cross-sectional retrospective analysis of the clinical data and genetic test results of children with WD in southern China in the past 4 years and the follow-up of their short-term prognosis were performed in this study.

Results: A total of 30 children (5.08 ± 2.06 years old) with elevated ALT as the first manifestation of WD in southern China were enrolled in this study, including 14 females and 16 males. Specifically, in all of the 30 cases (100%), the serum ceruloplasmin (CP) level was decreased, whereas the 24-h urinary copper level was increased. The genetic mutation test of the ATP7B gene was used to confirm the diagnosis. In particular, the two mutation sites, including p.R778L and p.I1148T, had the highest mutation frequencies, approximately 23.0 and 10.7%, respectively. Through follow-up, most of the children had good recovery.

Conclusion: Early diagnosis and treatment of WD would substantially increase the survival rate and have a better prognosis. In addition, in 5-year-old children from southern China, early diagnosis could be performed quickly by referring to the following three parameters: elevated ALT, decreased ceruloplasmin level, and increased 24-h urinary copper level. It lays a foundation for further studies with a larger sample size.

Other types of diffuse liver disease: is there a way to do it?

There are a variety of less common diffuse liver diseases that can be asymptomatic or cause severe liver dysfunction. For the majority of them, the association of clinical, laboratory, and imaging findings are needed to narrow the differential diagnosis. In this article, we will review and describe the rarer diffuse liver diseases including drug-related liver disease, inflammatory and infectious diseases, and deposition disorders such as amyloidosis, glycogen storage disease, Wilson's disease, and alpha-1 antitrypsin deficiency. Abdominal radiologists should be familiar with the imaging features of different types of diffuse liver diseases to help the multidisciplinary team involved in the treatment of these patients. The data related to some of these conditions are scarce and sometimes experimental, but we want to demonstrate to the reader the value of imaging techniques in their analysis and introduce the potential of new imaging methods.

Hepatic features of Wilson disease

In Wilson disease (WD) defective AT7B function leads to biliary copper excretion and pathologic copper accumulation, particularly in liver and brain, where it induces cellular damage. Liver disease most often precedes neurologic or psychiatric manifestations. In most patients with neurologic or psychiatric symptoms there is some degree of liver disease at the time of disease presentation. Hepatic manifestations of WD can be extremely variable. Patients with clinically asymptomatic WD are often found by family screening or identified on routine laboratory testing. Others may have a clinical picture of chronic active hepatitis or of end-stage liver disease with cirrhosis. A minority present with acute liver failure, often on the background of advanced fibrosis. Complications from liver disease may be related to portal hypertension and concomitant liver disease may accelerate the course of liver disease. Liver cancer may occur in patients with WD, most commonly when cirrhosis and inflammation are present. The prognosis of patients with WD is excellent, especially for those without cirrhosis at the time of diagnosis, but requires timely initiation of appropriate therapy specific for WD and for the patient's liver disease independent of WD.

Early gestational gene transfer with targeted ATP7B expression in the liver improves phenotype in a murine model of Wilson's disease

The ideal gene therapy for metabolical liver disorders would target hepatocytes before the onset of disease and be durable, non-toxic and non-immunogenic. Early gestational gene transfer can achieve such goals. Here, we demonstrate that prenatal gene transfer of human Atp7b reduces liver pathology and improves biochemical markers in Atp7b(-/-) mice, a murine model of Wilson's disease (WD). Following prenatal injection of lentivirus vector containing the human Atp7b gene under the transcriptional control of a liver-specific promoter, the full-length ATP7B was detectable in mouse livers for the entire duration of experiments (20 weeks after birth). In contrast to a marked pathology in non-injected animals, livers from age-matched treated mice consistently demonstrated normal gross and histological morphology. Hepatic copper content was decreased in the majority of treated mice, although remaining copper levels varied. Improvement of hepatic copper metabolism was further apparent from the presence of copper-bound ceruloplasmin in the sera and normalization of the mRNA levels for HMG CoA-reductase. With this approach, the complete loss of copper transport function can be ameliorated, as evident from phenotypical improvement in treated Atp7b(-/-) mice. This study provides proof of principle for in utero gene therapy in WD and other liver-based enzyme deficiencies.

Clinical and molecular characterization of Wilson's disease in China: identification of 14 novel mutations

BACKGROUND

Wilson's disease (WND) is a rare autosomal recessive disorder. Here we have evaluated 62 WND cases (58 probands) from the Chinese Han population to expand our knowledge of ATP7B mutations and to more completely characterize WND in China.

METHODS

the coding and promoter regions of the ATP7B gene were analyzed by direct sequencing in 62 Chinese patients (58 probands) with WND (male, n = 37; female, n = 25; age range, 2 ~ 61 years old).

RESULTS

neurologic manifestations were associated with older age at diagnosis (p < 0.0001) and longer diagnostic delay (p < 0.0001). Age at diagnosis was also correlated with urinary copper concentration (r = 0.58, p < 0.001). Forty different mutations, including 14 novel mutations, were identified in these patients. Common mutations included p.Arg778Leu (31.9%) and p.Pro992Leu (11.2%). Homozygous p.Arg778Leu and nonsense mutation/frameshift mutations were more often associated with primary hepatic manifestations (p = 0.0286 and p = 0.0383, respectively) and higher alanine transaminase levels at diagnosis (p = 0.0361 and p = 0.0047, respectively). Nonsense mutation/frameshift mutations were also associated with lower serum ceruloplasmin (p = 0.0065).

CONCLUSIONS

we identified 14 novel mutations and found that the spectrum of mutations of ATP7B in China is quite distinct from that of Western countries. The mutation type plays a role in predicting clinical manifestations. Genetic testing is a valuable tool to detect WND in young children, especially in patients younger than 8 years old. Four exons (8, 12, 13, and 16) and two mutations (p.Arg778Leu, p.Pro992Leu) should be considered high priority for cost-effective testing in China.

Clinical application of liver MR imaging in Wilson's disease

OBJECTIVE

To determine whether there is a correlation between liver MR findings and the clinical manifestations and severity of liver dysfunction in patients with Wilson's disease.

MATERIALS AND METHODS

Two radiologists retrospectively evaluated MR images of the liver in 50 patients with Wilson's disease. The Institutional Review Board approved this retrospective study and informed consent was waived. MR images were evaluated with a focus on hepatic contour abnormalities and the presence of intrahepatic nodules. By using Fisher's exact test, MR findings were compared with clinical presentations (neurological and non-neurological) and hepatic dysfunction, which was categorized by the Child-Pugh classification system (A, B and C). Follow-up MR images were available for 17 patients.

RESULTS

Contour abnormalities of the liver and intrahepatic nodules were observed in 31 patients (62%) and 25 patients (50%), respectively. Each MR finding showed a statistically significant difference (p < 0.05) among the three groups of Child-Pugh classifications (A, n = 36; B, n = 5; C, n = 9), except for splenomegaly (p = 0.243). The mean age of the patients with positive MR findings was higher than that of patients with negative MR findings. For patients with Child-Pugh class A (n = 36) with neurological presentation, intrahepatic nodules, surface nodularity, and gallbladder fossa widening were more common. Intrahepatic nodules were improved (n = 8, 47%), stationary (n = 5, 29%), or aggravated (n = 4, 24%) on follow-up MR images.

CONCLUSION

MR imaging demonstrates the contour abnormalities and parenchymal nodules of the liver in more than half of the patients with Wilson's disease, which correlates with the severity of hepatic dysfunction and clinical manifestations.

Liver transplantation for children with Wilson disease: comparison of outcomes between children and adults

Liver transplantation (LT) is lifesaving for patients with Wilson disease (WD) presenting with fulminant hepatic failure (FHF) or chronic liver disease (CLD) unresponsive to treatment.

AIM

To determine the outcome of LT in pediatric and adult patients with WD.

METHODS

United Network for Organ Sharing data on LT from 1987 to 2008 were analyzed. Outcomes were compared for patients requiring LT for FHF and CLD after 2002. Multivariate logistic regression was used to determine risk factors for death and graft loss.

RESULTS

Of 90,867 patients transplanted between 1987 and 2008, 170 children and 400 adults had WD. The one- and five-yr patient survival of children was 90.1% and 89% compared to 88.3% and 86% for adults, p = 0.53, 0.34. After 2002, 103 (41 children) were transplanted for FHF and 67 (10 children) for CLD. One- and five-yr patient survival was higher in children transplanted for CLD compared to FHF; 100%, 100% vs. 90%, 87.5% respectively, p = 0.30, 0.32. One- and five-yr patient survival was higher in adults transplanted for CLD compared to FHF; 94.7%, 90.1% vs. 90.3%, 89.7%, respectively, p = 0.36, 0.88. Encephalopathy, partial graft, and ventilator use were risk factors for death by logistic regression.

CONCLUSION

LT is an excellent treatment option for patients with WD. Patients transplanted for CLD had higher patient survival rates than patients with FHF.

Urinary copper/zinc ratio: a promising parameter for replacement of 24-hour urinary copper excretion for diagnosis of Wilson's disease in children

BACKGROUND

Although 24-hour urinary copper excretion is valuable for diagnosis of Wilson's disease, accurate, timed collection entails practical difficulties. This study aimed to investigate the feasibility of morning urinary copper/creatinine or copper/zinc ratio as replacement parameter for diagnosing Wilson's disease.

METHODS

Five random urinary samples collected during 24 hours from two inpatients were used to estimate the consistency of urinary copper/creatinine and copper/zinc ratios. The correlation of the ratios with 24-hour urinary copper excretion was studied in 15 patients with liver diseases. The diagnostic value of morning urinary copper/zinc ratio was further studied in 9 children with Wilson's disease and 22 children with other liver diseases.

RESULTS

The coefficients of variation of urinary copper/creatinine and copper/zinc ratios during 24 hours were 12.5% and 9.3% respectively. The morning urinary copper/creatinine ratio, copper/zinc ratio, and 24-hour urinary copper excretion were correlated well. The area under receiver-operating characteristic curve was comparable between the morning urinary copper/zinc ratio and 24-hour urinary copper excretion (0.983 vs. 0.977).

CONCLUSION

Morning urinary copper/zinc ratio seems to be a promising parameter in replacement of 24-hour urinary copper excretion for diagnosis of Wilson's disease.

Laser secondary neutral mass spectrometry for copper detection in micro-scale biopsies

Disease progression and clinical diagnostics of a number of hereditable metabolic diseases are determined by organ involvement in disturbed deposition of certain molecules. Current clinical imaging is unable to visualize this maldistribution with sufficient specificity and sensitivity, such as in Wilson's disease. The quest for understanding cellular Cu distribution in these patients requires element- and molecule-specific images with nanometer-scale spatial resolution. We have used a new cryo-mass spectrometric instrument with an integrated cryosectioning chamber for preparation and analysis of frozen hydrated samples of Wilson's disease tissue. With laser post-ionization secondary neutral mass spectrometry (laser-SNMS), we were able to image Cu and other intrinsic elements and molecules in less than 1 mg of frozen hydrated liver tissue from a murine model of Wilson's disease. A 40-50 times higher Cu concentration was measured in the disease tissue as compared to the control mouse. Furthermore, major histomorphological changes were observed using this advanced nano-science tool. The results showed that the combination of in-vacuum cryosectioning and cryo-laser-SNMS technologies is particularly well suited for identifying specific cell structures and imaging trace element concentrations with subcellular resolution and upper-parts-per-billion sensitivity in biological samples. This technology can provide a novel diagnostic tool for clinical applications in various diseases involving trace elements.

High frequency of the c.3207C>A (p.H1069Q) mutation in ATP7B gene of Lithuanian patients with hepatic presentation of Wilson's disease

AIM

To investigate the prevalence of the ATP7B gene mutation in patients with hepatic presentation of Wilson's disease (WD) in Lithuania.

METHODS

Eleven unrelated Lithuanian families, including 13 WD patients were tested. Clinically WD diagnosis was established in accordance to the Leipzig scoring system. Genomic DNA was extracted from whole venous blood using a salt precipitation method. Firstly, the semi-nested polymerase chain reaction (PCR) technique was used to detect the c.3207C>A (p.H1069Q) mutation. Patients not homozygous for the c.3207C>A (p.H1069Q) mutation were further analyzed. The 21 exons of the WD gene were amplified in a thermal cycler (Biometra T3 Thermocycler, Gottingen, Germany). Direct sequencing of the amplified PCR products was performed by cycle sequencing using fluorescent dye terminators in an automatic sequencer (Applied Biosystems, Darmstadt, Germany).

RESULTS

Total of 13 WD patients (mean age 26.4 years; range 17-40; male/female 3/10) presented with hepatic disorders and 16 their first degree relatives (including 12 siblings) were studied. Some of WD patients, in addition to hepatic symptoms, have had extrahepatic disorders (hemolytic anemia 3; Fanconi syndrome 1; neurophsychiatric and behavioural disorder 2). Liver biopsy specimens were available in all of 13 WD patients (8 had cirrhosis; 1-chronic hepatitis; 3-acute liver failure, 1-liver steatosis). Twelve of 13 (92.3%) WD patients had the c.3207C>A (p.H1069Q) mutation, 6 of them in both chromosomes, 6 were presented as compound heterozygotes with additional c.3472-82delGGTTTAACCAT, c.3402delC, c.3121C>T (p.R1041W) or unknown mutations. For one patient with liver cirrhosis and psychiatric disorder (Leipzig score 6), no mutations were found. Out of 16 first degree WD relatives, 11 (68.7%) were heterozygous for the c.3207C>A (p.H1069Q) mutation. Two patients with fulminant WD died from acute liver failure and 11 are in full remission under penicillamine or zinc acetate treatment. Three women with WD successfully delivered healthy babies.

CONCLUSION

The c.3207C>A (p.H1069Q) missense mutation is the most characteristic mutation for Lithuanian patients with WD. Even 92.3% of WD patients with hepatic presentation of the disease are homozygous or compound heterozygotes for the p.H1069Q mutation.

In vitro differentiation of reprogrammed murine somatic cells into hepatic precursor cells

Recently, a new approach to reprogram somatic cells into pluripotent stem cells was shown by fusion of somatic cells with embryonic stem (ES) cells, which results in a tetraploid karyotype. Normal hepatocytes are often polyploid, so we decided to investigate the differentiation potential of fusion hybrids into hepatic cells. We chose toxic milk mice (a model of Wilson's disease) and performed initial transplantation experiments using this potential cell therapy approach. Mononuclear bone marrow cells from Rosa26 mice were fused with OG2 (Oct4-GFP transgenic) ES cells. Unfused ES cells were eliminated by selection with G418 for OG2-Rosa26 hybrids and fusion-derived colonies could be subcloned. Using an endodermal differentiation protocol, hepatic precursor cells could be generated. After FACS depletion of contaminating Oct4-GFP-positive cells, the hepatic precursor cells were transplanted into immunosuppressed toxic milk mice by intrasplenic injection. However, five out of eight mice showed teratoma formation within 3-6 weeks after transplantation in the spleen and liver. In conclusion, a hepatic precursor cell type was achieved from mononuclear bone marrow cell-ES cell hybrids and preliminary transplantation experiments confirmed engraftment, but also showed teratoma formation, which needs to be excluded by using more stringent purification strategies.

Early and presymptomatic detection of Wilson's disease at the mandatory 3-year-old medical health care examination in Hokkaido Prefecture with the use of a novel automated urinary ceruloplasmin assay

Wilson's disease (WND) is an autosomal recessive disorder of copper (Cu) accumulation leading to liver and/or brain damage. Oral chelating agents and diet are effective in treating WND. However, once irreversible damage has occurred, the effect of treatment is diminished and the patient's quality of life is compromised. For these reasons an effective method for screening has been needed for early detection of presymptomatic patients. We conducted an early and presymptomatic detection of WND using a novel automated assay of ceruloplasmin (Cp) concentration in urine and selected the mandatory medical health care examination for 3-year-old children in Hokkaido Prefecture (the largest administrative division in Japan) as a sampling point. We measured urinary Cp concentrations in 11,362 children using an immunological latex agglutination assay kit developed by us. Among these children we identified a positive case with markedly reduced urinary Cp concentration. Detailed medical examination provided no clinical manifestations to support the diagnosis of WND, although serum Cp and Cu levels were remarkably low in this case. Therefore, we analyzed the WND gene in order to confirm the diagnosis. Sequence analysis revealed that the case was compound heterozygous for the WND gene mutations 2871del.C and D1296N. According to the Ferenci scoring system for WND diagnosis, the case was established as a WND patient at the presymptomatic stage. Consequently, the patient has maintained a good quality of life under medical treatment with polaprezinc administration to date. Our investigation suggests that the screening system for WND using the automated urinary assay at the mandatory medical health care examination for 3-year-old children is a noninvasive and efficient method for the early and presymptomatic diagnosis of WND.

Indications for liver transplantation

Patients should be considered for liver transplantation if they have evidence of fulminant hepatic failure, a life-threatening systemic complication of liver disease, or a liver-based metabolic defect or, more commonly, cirrhosis with complications such as hepatic encephalopathy, ascites, hepatocellular carcinoma, hepatorenal syndrome, or bleeding caused by portal hypertension. While the complications of cirrhosis can often be managed relatively effectively, they indicate a change in the natural history of the disease that should lead to consideration of liver transplantation. Referral to a liver transplant center is followed by a detailed medical evaluation to ensure that transplantation is technically feasible, medically appropriate, and in the best interest of both the patient and society. Patients approved for transplantation are placed on a national transplant list, although donor organs are allocated locally and regionally. Since 2002, priority for transplantation has been determined by the Model of End-Stage Liver Disease (MELD) score, which provides donor organs to listed patients with the highest estimated short-term mortality.

Genetics in liver diseases

In recent years, few fields in medicine have witnessed discoveries as momentous as those pertaining to the liver. Dramatic advances have been made, particularly in the areas of molecular biology and genetics. A joint EASL/AASLD Monothematic Conference was held on June 23rd-24th, 2006, in Modena, Italy, to bring the latest breakthroughs in different fields of genetics to hepatologists. This article reports the highlights of the conference and summarizes the main conclusions and implications for clinical and experimental hepatology.

The bane of a silent illness: when Wilson's disease takes its course

We present the case of a 21-year-old young lady with Wilson's disease, asymptomatic at first and consequently declining prophylaxis with chelating agents, who presented years after her diagnosis was made with multiple motor and neuropsychiatric manifestations of the disease, causing extensive morbidity and a major decrease in her quality of life. Following extensive education and supportive therapy, she showed conviction in the need for therapy. On close follow-up she continues to show compliance with appointments, the prescribed chelating agents, and psychotropic medication.

Cure of ventriculitis and central nervous system shunt infection by Staphylococcus epidermidis with vancomycin by intraventricular injection in a liver transplant recipient

A 19-year-old female underwent orthotopic liver transplantation for acute hepatic failure because of fulminant Wilson's disease. Three months post transplantation she developed systemic fungal meningoencephalitis and obstructive hydrocephalus that required cerebrospinal fluid (CSF) shunting by a ventriculo-atrial shunt. Subsequently, she contracted Staphylococcus epidermidis bacteremia, ventriculitis, and shunt infection. Treatment with vancomycin either by conventional intravenous (i.v.) or continuous i.v. injection proved ineffective because of insufficient drug concentrations in the CSF. Eradication of S. epidermidis from CSF and cure of chronic ventriculitis and shunt infection was readily achieved by delivering vancomycin by intraventricular injection (5 mg/24 h) via an extraventricular drain together with continuous i.v. infusion (4 g/24 h) over a period of 18 days. This treatment was well tolerated and free of untoward side effects despite the patient's chronic immunosuppression subsequent to liver transplantation. Intraventricular injection of vancomycin is an effective and safe procedure to eradicate S. epidermidis from the central nervous system when i.v. vancomycin treatment fails.

Clinical and molecular characterization of Wilson disease in Spanish patients

Wilson disease (WD) results when specific mutations occur at the ATP7B gene. The presence of mutations in the ATP7B gene was studied in the coding region and the intron-exon boundaries in 15 WD Spanish patients, and their first-degree relatives when possible. A total of 20 nucleotide sequence changes were detected, 18 missense and two splicing mutations. Six of these variants were classified as disease-causing mutations, five missense, and one splicing; four of them have been previously described (M645R, A1065P, H1069Q, and 3060 + 5G > T), whereas two were novel (P768L and A990P). No mutation was clearly prevalent, although the H1069Q mutation predominated, nor did a good phenotype-genotype correlation exist. The two new mutations described were manifested as an asymptomatic increase in serum transaminases. The remaining 14 changes were classified as polymorphisms and their potential effects on protein function are discussed. The identification of mutations in the ATP7B gene has allowed a conclusive diagnosis to be made of WD in patients presenting neurological phenotype or neurological of hepatic phenotype, who would otherwise not have been diagnosed using classical criteria. WD patients could start chelating treatment earlier on and possibly modify the natural progression of the disease.

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