Objective Most patients with erythropoietic protoporphyria have deficient ferrochelatase (FECH) activity due to changes in FECH DNA. We evaluated seven patients with erythropoietic protoporphyria ...phenotype in whom abnormalities of FECH DNA were not found by conventional analysis. The major focus was mitoferrin-1 (MFRN1), the mitochondrial transporter of Fe used for heme formation by FECH and for 2Fe2S cluster synthesis, which is critical to FECH activity/stability. Materials and Methods Four patients had a deletion in ALAS2 that causes enzyme gain-of-function, resulting in increased formation of protoporphyrin; one had a heterozygous major deletion in FECH DNA. All had an abnormal transcript of MFRN1 in messenger RNA extracted from blood leukocytes and/or liver tissue. The abnormal transcript contained an insert of intron 2 that had a stop codon. The consequences of abnormal MFRN1 expression were examined using zebrafish and yeast MFRN -deficient strains and cultured lymphoblasts from the patients. Results Abnormal human MFRN1 complementary DNA showed loss-of-function in zebrafish and yeast mutants, whereas normal human MFRN1 complementary DNA rescued both. Using cultured lymphoblasts, quantitative reverse transcription polymerase chain reaction showed increased formation of abnormal transcript that was accompanied by decreased formation of normal transcript and reduced FECH activity in patients compared to normal lines. A positive correlation coefficient (0.75) was found between FECH activity and normal MFRN1 messenger RNA in lymphoblasts. However, no obvious cause for increased formation of abnormal transcript was identified in MFRN1 exons and splice junctions. Conclusions Abnormal MFRN1 expression can contribute to erythropoietic protoporphyria phenotype in some patients, probably by causing a reduction in FECH activity.
AbstractBackground and objective. Steatohepatitis is a common cause of liver disease due to alcohol (ALD) or non-alcoholic fatty liver disease (NAFLD). We performed this study to compare natural ...history of ALD and NAFLD. Material and methods. Retrospective analysis of ALD or NAFLD patients managed at our center (2007-2011). ALD diagnosed by excluding other liver diseases (except HCV) and alcohol abuse of > 40 g/d in women and > 60 g/d in men for > 5 years. NAFLD diagnosed by excluding other liver diseases and a history of alcohol use of < 10 g/d. Cirrhosis was diagnosed using biopsy for uncertain clinical diagnosis. Results. Compared to patients with NAFLD (n = 365; mean age 50 yrs; 43% males; 53% diabetic), ALD patients (n = 206; mean age 51 yrs; 68% males; 24% diabetic) presented more often with cirrhosis or complications(46 vs. 12%; P< 0.0001) with a higher MELD score (13 ± 7 vs. 8 ± 8; P<0.0001). On logistic regression, ALD diagnosis was associated with presence of cirrhosis by over 4-fold (4.1 1.8-9.1) even after excluding 23 patients with concomitant HCV. Over median follow up of about 3 and 4 yrs among ALD and NAFLD patients respectively, ALD patients more frequently developed cirrhosis or its complications including HCC with worse transplant free survival (90 vs. 95%; P = 0.038). Conclusions. Compared to NAFLD, ALD patients present at an advanced stage of liver disease with a faster progression on follow-up. Prospective multicenter studies are needed to identify potential barriers to early referral of ALD patients as basis for development of strategies to improve outcome of patients with ALD.
Porphyria is a group of metabolic disorders due to altered enzyme activities within the heme biosynthetic pathway. It is a systemic disease with multiple potential contributions to mitochondrial ...dysfunction and oxidative stress. Recently, it has become possible to measure mitochondrial function from cells isolated from peripheral blood (cellular bioenergetics) using the XF96 analyzer (Seahorse Bioscience). Mitochondrial respiration in these cells is measured with the addition of activators and inhibitors of respiration. The output is measured as the O2 consumption rate (OCR) at basal conditions, ATP linked, proton leak, maximal, reserve capacity, non-mitochondrial, and oxidative burst. We performed cellular bioenergetics on 22 porphyria (12 porphyria cutanea tarda (PCT), seven acute hepatic porphyria (AHP), and three erythropoietic protoporphyria (EPP)) patients and 18 age and gender matched healthy controls. Of porphyria cases, eight were active (2 PCT, 1 EPP, and 5 AHP) and 14 in biochemical remission. The OCR were decreased in patients compared to healthy controls. The bioenergetic profile was significantly lower when measuring proton leak and the non-mitochondrial associated OCR in the eight active porphyria patients when compared to 18 healthy controls. In conclusion, we demonstrate that the bioenergetic profile and mitochondrial activities assessed in porphyria patients and is different than in healthy control individuals. Further, our novel preliminary findings suggest the existence of a mitochondrial dysfunction in porphyria and this may be used as potential non-invasive biomarker for disease activity. This needs to be assessed with a systematic examination in a larger patient cohort. Studies are also suggested to examine mitochondrial metabolism as basis to understand mechanisms of these findings and deriving mitochondrial based therapies for porphyria.
Black Americans are disproportionally infected with hepatitis C virus (HCV) and are less likely than whites to respond to treatment with peginterferon (PEG‐IFN) plus ribavirin (RBV). The impact of ...race on HCV treatment eligibility is unknown. We therefore performed a retrospective analysis of a phase 3B multicenter clinical trial conducted at 118 United States community and academic medical centers to evaluate the rates of and reasons for HCV treatment ineligibility according to self‐reported race. In all, 4,469 patients were screened, of whom 1,038 (23.2%) were treatment ineligible. Although blacks represented 19% of treated patients, they were more likely not to be treated due to ineligibility and/or failure to complete required evaluations (40.2%) than were nonblack patients (28.5%; P < 0.001). After the exclusion of persons not treated due to undetectable HCV RNA or nongenotype 1 infection, blacks were 65% less likely than nonblacks to be eligible for treatment (28.1% > 17.0%; relative risk, 1.65; 95% confidence interval, 1.46‐1.87; P < 0.001). Blacks were more likely to be ineligible due to neutropenia (14% versus 3%, P < 0.001), anemia (7% versus 4%, P = 0.02), elevated glucose (8% versus 3%, P < 0.001), and elevated creatinine (5% versus 1%, P < 0.001). Conclusion: Largely due to a higher prevalence of neutropenia and uncontrolled medical conditions, blacks were significantly less likely to be eligible for HCV treatment. Increased access to treatment may be facilitated by less conservative neutrophil requirements and more effective care for chronic diseases, namely, diabetes and renal insufficiency. (HEPATOLOGY 2011;)
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