Molecular and functional analysis of the C-terminal region of human erythroid-specific 5-aminolevulinic synthase associated with X-linked dominant protoporphyria (XLDPP).

Frameshift mutations in the last coding exon of the 5-aminolevulinate synthase (ALAS) 2 gene were described to activate the enzyme causing increased levels of zinc- and metal-free protoporphyrin in patients with X-linked dominant protoporphyria (XLDPP). Only two such so-called gain-of-function mutations have been reported since the description of XLDPP in 2008. In this study of four newly identified XLDPP families, we identified two novel ALAS2 gene mutations, a nonsense p.Q548X and a frameshift c.1651-1677del26bp, along with a known mutation (delAGTG) found in two unrelated families. Of relevance, a de novo somatic and germinal mosaicism was present in a delAGTG family. Such a phenomenon may explain the high proportion of this mutation in XLDPP worldwide. Enhancements of over 3- and 14-fold in the catalytic rate and specificity constant of purified recombinant XLDPP variants in relation to those of wild-type ALAS2 confirmed the gain of function ascribed to these enzymes. The fact that both p.Q548X and c.1651-1677del26bp are located in close proximity and upstream from the two previously described mutations led us to propose the presence of a large gain-of-function domain within the C-terminus of ALAS2. To test this hypothesis, we generated four additional nonsense mutants (p.A539X, p.G544X, p.G576X and p.V583X) surrounding the human XLDPP mutations and defined an ALAS2 gain-of-function domain with a minimal size of 33 amino acids. The identification of this gain-of-function domain provides important information on the enzymatic activity of ALAS2, which was proposed to be constitutively inhibited, either directly or indirectly, through its own C-terminus.

Distribution of interferon lambda-3 gene polymorphisms in Australian patients with previously untreated genotype 1 chronic hepatitis C: Analysis from the PREDICT and CHARIOT studies.

BACKGROUND AND AIMS: The aim of this study was to examine the distribution of interferon lambda-3 (IFN-λ3) gene polymorphisms in previously untreated Australian patients with genotype 1 (Gt1) chronic hepatitis C (CHC) and to compare the IFN-λ3 genotype frequency among the different ethnic populations. METHODS: This was a prospective, multicenter, observational study undertaken by the Australian Liver Association Clinical Research Network. Eligible subjects had Gt1 CHC and were being considered for and/or undergoing treatment. IFN-λ3 single nucleotide polymorphisms were genotyped by the Applied Biosystems's Taqman single nucleotide polymorphism genotyping assay. RESULTS: Between May 2012 and June 2012, 1132 patients were recruited from 38 treatment clinics across Australia. Also, 561 subjects from the CHARIOT (collaborative group hepatitis C study using high dose Pegasys RBV Induction dose in genotype one) study of high-dose interferon who had baseline serum available were retrospectively tested. The overall frequency of IFN-λ3 rs12979860 CC/CT/TT genotypes was 36%, 52%, and 12%, and that of rs8099917 TT/TG/GG genotypes was 54%, 41%, and 5%, respectively. The prevalence of the favorable IFN-λ3 rs12979860 CC and rs8099917 TT genotypes in Causcasians, Asians, Aboriginals, Maori/Pacific Islanders, and Mediterraneans was 32% and 52%, 80% and 86%, 33% and 63%, 77% and 88%, and 19% and 29%, respectively. Compared with Caucasians, the frequency of IFN-λ3 CC was significantly higher among Asians (P < 0.0001) and Maori/Pacific Islander subjects (P < 0.0001). CONCLUSIONS: The distribution of IFN-λ3 polymorphisms among untreated patients with Gt1 CHC in Australia appears similar to that reported from North America. The frequency of the favorable response alleles varies considerably according to ethnicity, being more common in self-reported Asians and Maori/Pacific Islanders than Caucasians, Aboriginals, and Mediterraneans.

Hepatitis C treatment outcomes in Australian clinics.

OBJECTIVE: To determine hepatitis C (HCV) treatment effectiveness and predictors of response in the "real-world" Australian clinic setting. DESIGN, SETTING AND PARTICIPANTS: Patients with chronic HCV, who were HCV-treatment-naive at enrolment, and were then treated with standard therapy (pegylated interferon-α plus ribavirin), were recruited prospectively through a national network of 24 HCV clinics between April 2008 and December 2009. Patients were interviewed and a medical record review was conducted at enrolment and at routine follow-up clinic visits. MAIN OUTCOME MEASURES: Proportion of patients achieving a sustained virological response (SVR), predictors of SVR, and impact of treatment on biochemical markers of liver disease (alanine aminotransferase levels and aspartate aminotransferase-to-platelet ratio index scores). RESULTS: The SVR by intention to treat was 60% (327/550). Infection with HCV genotype 2 or 3 (compared with genotype 1) was an independent predictor of SVR (odds ratio [OR], 2.45; 95% CI, 1.70-3.52), while HIV coinfection (OR, 0.28; 95% CI, 0.10-0.82), cirrhosis (OR, 0.38; 95% CI, 0.18-0.81), and increased body mass index for ≥ 30 kg/m(2) v ≤ 25 kg/m(2) (OR, 0.58; 95% CI, 0.35-0.96) were independently associated with lower SVR. There was a significant improvement in biochemical markers of liver disease following SVR (P< 0.001). CONCLUSIONS: Our findings are similar to those seen in clinical trials, despite the inclusion of patients with a broad range of comorbid conditions such as injecting drug and alcohol use and psychiatric illness. They suggest that, with appropriate patient and infrastructure support, expansion of treatment services to the broader HCV-infected community is warranted.

An association between non-alcoholic fatty liver disease and polycystic ovarian syndrome.

OBJECTIVES: The aim of this study was to determine if there is an association between non-alcoholic fatty liver disease (NAFLD) and polycystic ovarian syndrome (PCOS). NAFLD and PCOS are both known to be associated with metabolic syndrome/insulin resistance. METHOD: Fourteen consecutive female patients of reproductive age (20-45) either with liver biopsy proven NAFLD (50%) or abdominal ultrasound (US) consistent with steatosis together with elevated ALT levels (50%) were screened for PCOS using 2003 Rotterdam consensus meeting criteria. Other causes of hyperandrogenism were excluded. All subjects underwent relevant questionnaire and clinical exam together with hormonal assays, pelvic (1) or transvaginal US (13) and were screened for evidence of the metabolic syndrome. RESULTS: Ten out of fourteen women matched 2003 Rotterdam consensus meeting diagnostic criteria for PCOS (71%). Eight women suffered from oligo/amenorrhoea, nine women manifested presence of hyperandrogenism and six had history of infertility. Seven women had evidence of biochemical hyperandrogenism with low SHBG, raised free testosterone and elevation of serum LH concentration. Seven women fulfilled US criteria for PCOS. Three of ten patients with PCOS also had type 2 diabetes mellitus. Women with PCOS and NAFLD had higher triglyceride and cholesterol and lower HDL level than group without PCOS. Five patients with NAFLD and PCOS had documented fibrosis on liver biopsy, indicative of more advanced liver disease. IMPLICATIONS: Despite limitations of the study due to the sample size, we found evidence of PCOS in the majority of subjects with NAFLD. Women with NAFLD should be routinely screened for presence of PCOS, diabetes mellitus and metabolic risk factors for cardiovascular disease. Equally, women with PCOS should be screened for NAFLD. Evaluation for liver disease should be considered at an earlier age in some women with PCOS particularly those with an evidence of metabolic syndrome.

Results of a prospective study of acute liver failure at 17 tertiary care centers in the United States.

BACKGROUND: Because acute liver failure is rare, related data have been sparse. Studies have suggested that viral hepatitis is the most common underlying cause of this condition. OBJECTIVE: To describe the clinical features, presumed causes, and short-term outcomes of acute liver failure. DESIGN: Prospective cohort study. SETTING: 17 tertiary care centers participating in the U.S. Acute Liver Failure Study Group. PATIENTS: 308 consecutive patients with acute liver failure, admitted over a 41-month period. MEASUREMENTS: Detailed clinical and laboratory data collected during hospitalization, including outcome 3 weeks after study admission. RESULTS: 73% of patients were women; median age was 38 years. Acetaminophen overdose was the most common apparent cause of acute liver failure, accounting for 39% of cases. Idiosyncratic drug reactions were the presumptive cause in 13% of cases, viral hepatitis A and B combined were implicated in 12% of cases, and 17% of cases were of indeterminate cause. Overall patient survival at 3 weeks was 67%. Twenty-nine percent of patients had liver transplantation, and 43% survived without transplantation. Short-term transplant-free survival varied greatly, from 68% for patients with acetaminophen-related liver failure to 25% and 17% for those with other drug reactions and liver failure of indeterminate cause, respectively. Coma grade at admission appeared to be associated with outcome, but age and symptom duration did not. CONCLUSIONS: Acetaminophen overdose and idiosyncratic drug reactions have replaced viral hepatitis as the most frequent apparent causes of acute liver failure. Apparent cause and coma grade at admission were associated with outcome. Although transplantation may improve patient survival, it was unavailable or unnecessary for most patients.

Non-physician endoscopists: A systematic review.

AIM: To examine the available evidence on safety, competency and cost-effectiveness of nursing staff providing gastrointestinal (GI) endoscopy services. METHODS: The literature was searched for publications reporting nurse endoscopy using several databases and specific search terms. Studies were screened against eligibility criteria and for relevance. Initial searches yielded 74 eligible and relevant articles; 26 of these studies were primary research articles using original datasets relating to the ability of non-physician endoscopists. These publications included a total of 28883 procedures performed by non-physician endoscopists. RESULTS: The number of publications in the field of non-specialist gastrointestinal endoscopy reached a peak between 1999 and 2001 and has decreased thereafter. 17/26 studies related to flexible sigmoidoscopies, 5 to upper GI endoscopy and 6 to colonoscopy. All studies were from metropolitan centres with nurses working under strict supervision and guidance by specialist gastroenterologists. Geographic distribution of publications showed the majority of research was conducted in the United States (43%), the United Kingdom (39%) and the Netherlands (7%). Most studies conclude that after appropriate training nurse endoscopists safely perform procedures. However, in relation to endoscopic competency, safety or patient satisfaction, all studies had major methodological limitations. Patients were often not randomized (21/26 studies) and not appropriately controlled. In relation to cost-efficiency, nurse endoscopists were less cost-effective per procedure at year 1 when compared to services provided by physicians, due largely to the increased need for subsequent endoscopies, specialist follow-up and primary care consultations. CONCLUSION: Contrary to general beliefs, endoscopic services provided by nurse endoscopists are not more cost effective compared to standard service models and evidence suggests the opposite. Overall significant shortcomings and biases limit the validity and generalizability of studies that have explored safety and quality of services delivered by non-medical endoscopists.

Alpha-fetoprotein and prognosis in acute liver failure.

Serum concentrations of alpha-fetoprotein (AFP), variably elevated during liver injury, have been suggested to be of prognostic importance in acute liver failure (ALF), higher values being associated with improved outcome. Using a nephelometric assay, we measured AFP in sera obtained on admission from 206 patients prospectively enrolled in the US ALF Study, and on day 3 in 162 of these patients. The AFP ratio was defined as the day 3 AFP concentration divided by that observed on day 1. Median (range) admission serum AFP in all patients was 8.1 (1-1,811) ng/mL and increased to 17.6 (1.1-1,162) ng/mL on day 3 (P < 0.001). Higher absolute levels were not associated with improved outcome. In fact, admission AFP levels were lower in survivors not receiving transplants than in those who died or were transplanted (P < 0.001), whereas there was no difference between the 2 groups on day 3 (P = 0.34). However, a rise in AFP values between day 1 and day 3 indicated a better prognosis: the AFP ratio was 2.2 (0.11-22.1) in spontaneous survivors and 0.87 (0.11-16.4) in nonsurvivors (P < 0.001). An increasing AFP level indicated by an AFP ratio >or=1 was observed in 70 of 98 (71%) survivors, whereas a ratio <1 was observed in 51 of 64 (80%) nonsurvivors. In conclusion, AFP values change dynamically during ALF. In this large prospective study, higher absolute values of AFP did not predict a favorable outcome, but a rising level of AFP over the first 3 hospital days frequently indicated survival.

Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study.

Severe acetaminophen hepatotoxicity frequently leads to acute liver failure (ALF). We determined the incidence, risk factors, and outcomes of acetaminophen-induced ALF at 22 tertiary care centers in the United States. Detailed prospective data were gathered on 662 consecutive patients over a 6-year period fulfilling standard criteria for ALF (coagulopathy and encephalopathy), from which 275 (42%) were determined to result from acetaminophen liver injury. The annual percentage of acetaminophen-related ALF rose during the study from 28% in 1998 to 51% in 2003. Median dose ingested was 24 g (equivalent to 48 extra-strength tablets). Unintentional overdoses accounted for 131 (48%) cases, intentional (suicide attempts) 122 (44%), and 22 (8%) were of unknown intent. In the unintentional group, 38% took two or more acetaminophen preparations simultaneously, and 63% used narcotic-containing compounds. Eighty-one percent of unintentional patients reported taking acetaminophen and/or other analgesics for acute or chronic pain syndromes. Overall, 178 subjects (65%) survived, 74 (27%) died without transplantation, and 23 subjects (8%) underwent liver transplantation; 71% were alive at 3 weeks. Transplant-free survival rate and rate of liver transplantation were similar between intentional and unintentional groups. In conclusion, acetaminophen hepatotoxicity far exceeds other causes of acute liver failure in the United States. Susceptible patients have concomitant depression, chronic pain, alcohol or narcotic use, and/or take several preparations simultaneously. Education of patients, physicians, and pharmacies to limit high-risk use settings is recommended.

Investigation of SEN virus infection in patients with cryptogenic acute liver failure, hepatitis-associated aplastic anemia, or acute and chronic non-A-E hepatitis.

SEN virus (SENV) has been tentatively linked to transfusion-associated non-A-E hepatitis. We investigated SENV's role in unexplained hepatitis in other settings. Polymerase chain reaction amplification was used to detect 2 SENV variants (SENV-D and SENV-H) in 1706 patients and control subjects. SENV was detected in 54 (22%) of 248 patients with acute or chronic non-A-E hepatitis, 9 (35%) of 26 patients with hepatitis-associated aplastic anemia, and 0 of 17 patients with cryptogenic acute liver failure, compared with 150 (24%) of 621 control subjects with liver disease and 76 (10%) of 794 healthy control subjects. When controlling for geographic region, the prevalence of SENV among case and control subjects was not significantly different. The severity of acute or chronic hepatitis A, B, or C was not influenced by coexisting SENV infection. No etiological role for SENV in the cause of cryptogenic hepatitis could be demonstrated.