Category Archives: Hepatology

Revising the Textbooks on Isoniazid Hepatotoxicity

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Previously, isoniazid (INH) hepatoxicity has generally been described as “idiosyncratic.”  New research shows that INH-induced hepatotoxicity is often associated with anti-INH and anti-cytochrome P450 antibodies (Hepatology 2014; 59: 1084-93, editorial 746-48).

Background: INH is a crucial treatment for tuberculosis.  About 10% of patients receiving monotherapy may develop mild elevations (<3-fold the upper limit of normal) of alanine aminotransferase.  However, 0.5-1% develop overt hepatitis and some develop acute liver failure (ALF).  Risk factors for ALF include female gender, age >35 years, cotreatment with other tuberculosis medications, INH dose >50 mg/kg, ethanol use, and slower metabolic pathways (slow acetylator N-acetyltransferase 2 or cytochrome (CYP) P450 2E1 genotype).

The authors utilized two patient groups: 19 from the ALF study group registry who had >50% likelihood of IHN toxicity and 20 control patients who were receiving INH prophylaxis.  In this control group, 15 had no liver injury and 5 had mild hepatitis. The authors utilized several immunoassays.

Key findings:

  • 15 of 19 cases of INH-associated ALF had detectable antibodies: 8 anti-INH and 11 had antiCYP2E1 Abs.
  • None of these antibodies were detected from INH-treated controls

Bottomline: from the authors of the study “Although the presence of these antibodies only in INH-induced liver failure suggests that INH-induced liver injury is immune mediated, there is no evidence that these Abs are actually responsible for the liver injury.”

In this same issue is a lengthy guideline on the “Evaluation for Liver Transplantation in Adults”: http://t.co/AnnJHHVNh0

Related blog post:

Liver toxicity -where to look online | gutsandgrowth

Curing Iron Overload with Liver Transplantation

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The role of hepcidin in iron metabolism has been described in detail.  Yet, a new study provides another line of evidence that the liver has a primary role in regulating iron absorption (Hepatology 2014; 59: 839-47, editorial 749-50).

Background: Hereditary hemochomatosis (HH) is mainly due to defects in the gene encoding the human hemochromatosis protein (HFE), particularly the C282Y mutation.  Initially, HH was thought to be related to the role of HFE in regulation iron absorption at the intestinal crypt.  However, the discovery of hepcidin, which is mainly secreted by the liver, was shown to regulate iron absorption through its interaction with ferroportin, the cellular iron exporter. With HH, inappropriately low hepcidin was associated with excessive iron absorption.

Despite this understanding, many questions remain, especially regarding the fact that some C282Y homozygotes have a normal serum ferritin and transferrin saturation.  In addition, whether liver transplantation prevents further iron overload in patients transplanted for HH is not entirely certain.

Methods: This study evaluated 18 liver transplant (LT) patients with HH and who were homozygous for C282Y mutations.  16 of these patients had HCC.  All patients underwent iron evaluations (iron, hepcidin, hepatic iron concentrations) prior to LT and most (n=11) had evaluations following LT with a median followup of 57 months.

Key findings:

  • After LT, no patients received iron depletion therapy (eg. phlebotomy).  9 of 11 had no iron overload based on bloodwork (normal transferrin saturation) and MRI without iron overload.
  • One patient with hereditary spherocytosis continued to have iron overload, and one patient with metabolic syndrome had mild iron overload.
  • Hepcidin was normal (11.12 nmol/L) in 10 patients at the end of followup and low in one patient with iron deficiency anemia; prior to LT, serum hepcidin levels were low in all patients (mean 0.54 nmol/L)

Bottomline: This study shows that LT corrects hepcidin dysregulation caused by the HFE mutation and that post-LT HH patients do not require phlebotomy.  Thus, HH is clearly a liver disease and not an intestinal disease.

Related blog post: Help with hepcidin | gutsandgrowth (with annotated references)

“More to It Than Meets the BMI”

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This blog post title is quoted from a clever editorial which reviews the use of BMI and the effect of obesity with outcomes after liver transplantation (Liver Transpl 2014; 20: 253-54, related article pages 281-90.)

Key points from editorial and study:

  • Study enrolled 202 consecutive adult (mean 51 years) patients (200-2010) as part of cohort study.  Data was obtained at time of transplantation and reviewed with retrospective analysis. NAFLD was transplant indication in 7%.
  • “Use of BMI as a marker of obesity is flawed.” Authors showed only 86% agreement between calculated BMI and percent body fat as measured with DXA.
  • Patients with high BMI due to greater lean muscle mass may have improved outcomes.  Sarcopenia (loss of muscle mass) likely has greater effect on outcomes.
  • The study shows that the combination of diabetes and obesity increases the risk of complications and prolongs hospital stays (5.81 days, P<0.01).
  • Metabolic risk factors had no effect on 30-day, 1-year, or 5-year patient survival.

Another article in same issue: Liver Transpl 2014; 20: 311-22. This study retrospectively examined 148 normal-weight, 148 overweight, and 74 obese patients who underwent living donor liver transplantation. Key finding: “there were no differences in graft survival [hazard ratio (HR) =0.955] or recipient survival [HR = 0.90]” between these groups.  Obese patients do require larger grafts which can delay identifying suitable donor.

Bottomline from editorial: “this study shows us that the combination of diabetes and obesity dramatically increases the risk of complications” but not survival.  “If there comes a day when the cost of a human life is less than the cost of a 6- to 7-day hospital stay, that is the day to reckon. None of us may survive.”

Related blog post:

Sarcopenia, fatigue, and nutrition in chronic liver … – gutsandgrowth

HCV Website -No “Cat on The Roof”

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A joke I heard a long time ago:

A guy asks his friend to check up on his cat while he is away on a trip.  He calls to see how kitty is doing.  His friend says, “Sorry but she died.”  In response, he tells his friend, “you should have broken me the news a lot more gently.  Maybe you could have said she was up on the roof and the next time I called it would have been easier to accept the news.”  A few years pass and he again asks his friend for a favor, this time to check up on his grandmother while he is away on a trip.  He calls to see how granny is doing.  His friend says, “Oh, she is up on the roof.”

The AASLD and “the Infectious Diseases Society of America (IDSA), in collaboration with the International Antiviral Society-USA (IAS-USA), announced the launch of a new website,HCVguidelines.org, that offers up-to-date recommendations for testing, managing, and treating hepatitis C virus (HCV) infection.”

The website clearly dismisses the previous established breakthrough treatments of telaprevir and boceprevir “because they are markedly inferior.”

For anyone who has been confused with the onslaught of new work on HCV, the website spells out in clear detail the best regimens for HCV treatment now that both sofusbuvir and simeprevir are available.

Bottomline: The website makes it clear that both telaprevir and boceprevir are up on the roof.

Related blog posts:

Population-Based Outcomes for Primary Sclerosing Cholangitis

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A study from the Netherlands examined the outcomes for Primary Sclerosing Cholangitis (PSC) (Hepatology 2013; 2045-55). Using four independent hospital databases with 44 hospitals, allowed the investigators to identify 590 PSC patients from a population of almost 8 million. Median followup was 92 months. Mean age at diagnosis was 38.9 years.  A second comparison cohort of 450 patients was identified from three Dutch transplantation centers outside the study area.  134 (30%) of this cohort were present in the population-based cohort.  An IBD comparison group of 722 cases was identified as well from a population of 271,000 patients.

Results:

  • Prevalence: 6 per 100,000.  This is significantly lower than previous estimates.  The authors emphasize the problem with previous epidemiology studies and the need for population-based studies with rigorous case-finding.
  • Survival, estimated at 21.3 years for the entire cohort following diagnosis, was better than previous studies and this may indicate less selection bias than tertiary referral center studies.  It could also reflect diagnosis of milder cases with newer imaging techniques.
  • 402 (68%) of PSC patients were diagnosed with inflammatory bowel disease.
  • 23 (4%) had autoimmune hepatitis overlap.
  • Colorectal cancer was 10-fold increased compared to ulcerative colitis controls and developed at a younger age (39 years compared with 59 years).
  • Cholangiocarcinoma (CCA) was nearly 400-fold increased risk.  The cumulative risk of CCA was estimated at 20% after 30 years following PSC diagnosis.
  • During followup, there were 97 deaths; 73 (75%) were PSC-related.

Related blog posts:

Liver fibrosis in determining treatment for Hepatitis B

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A recent editorial reviews current guidelines and makes the point that while patients with advanced fibrosis should receive antiviral treatment, treatment is also recommended for patients with high levels of HBV DNA and active liver disease (Clin Gastroenterol Hepatol 2013; 11: 1500-02).  The related study (Clin Gastroenterol Hepatol 2013; 11: 1493-99) indicated that guidelines do not predict accurately which patients have ≥F2 fibrosis.  The editorial argues that the study’s conclusions are “misguided” because ALT and HBV DNA are not used solely for identifying patients with fibrosis.

Key points:

  • 18-47% of HBV-related HCC occurs in the absence of cirrhosis.
  • Guidelines “agree that treatment should be initiated in non-cirrhotic patients with serum HBV DNA >20,000 IU/mL and alanine aminotransferase (ALT) levels higher than 2 times upper limit of normal (ULN) or histologic evidence of moderate-to-severe inflammation or fibrosis.”
  • For HBeAg-negative patients, AASLD guidelines suggest a lower threshold for HBV DNA (>2000 IU/mL) along with ALT >2 times ULN or ALT 1-2 times ULN with concerning liver biopsy (particularly in age >40 years).
  • “Since treatment does not eradicate the virus…and in many instances [is] lifelong treatment, we agree with Sanai et al that criteria for initiating hepatitis B treatment in guidelines must be carefully weight to avoid unnecessary treatment.”

Related blog posts:

It is a Question of Fairness

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One of my professors in medical school frequently described ethical issues in terms of some things being unfair and some things being unfortunate.  A report in this month’s Liver Transplantation (2013: 19: 1330-42; editorial 1287-88) indicates that sometimes an individual does not receive a liver transplant due to an unfair allocation policy.  One potential problem with the current UNOS distribution is the use of exception points.  Because the Model for End-Stage Liver Disease (MELD) score does not work well for all patients, there are both recognized exceptional diagnoses (REDs) (eg. hepatocellular carcinoma) and non-REDs (eg. cholangitis).  The purpose of these exception points is to account for some conditions that may increase the risk of dying on the transplant list in which the MELD score is not an adequate predictor.

In this study of adult liver transplant candidates between 2002-2011, the authors examined non-REDs; among a cohort of 58,641, 7.4% applied for a non-RED.  The number of non-REDs increased over the course of the study.  In addition, approval rates which were <50% in 2002 increased to nearly 75% in 2010. Candidates with approved exceptions were more likely to undergo transplantation (68.3% vs. 53.4%, P <0.001).

There was significant variability among transplant centers with regard to requesting exception points. Centers with higher median MELD score at transplantation were more likely to have candidates with non-RED applications. The net result was that women, African-Americans, Hispanics, and patients with Medicaid insurance were statistically less likely to have an exception application.

In pediatrics, non-RED applications are more common. Thus, the problem of equitable distribution could be even greater among pediatric patients.

Bottomline: While physicians have a duty to their patients, it is vital to make sure that every effort is made to allocate organs in a fair manner.  Since the use of non-RED applications is inconsistent, it suggests that some transplant centers are utilizing this tool inappropriately (?too often, ?too few).  This report indicates that more work is needed to have a fair transplant allocation system.

Related blog posts:

Electronic Order Sets Can Improve Care

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It is recognized that checklists can improve medical care as well as help you remember to pick up butter when you go shopping.  So, it is not surprising that a standardized electronic order set can improve patient care.  A recent prospective observational study has shown that implementation of an electronic order set improved the care of 123 patients with cirrhosis who presented with upper gastrointestinal hemorrhage (Clin Gastroenterol Hepatol 2013; 11: 1342-1348).

This study was conducted from 2011 to 2012.

Key findings:

  • Administration of antibiotics increased in patients in whom the order set was used: 100% compared with 89%. A previous Cochrane meta-analysis has noted a mortality risk reduction of nearly 20% in patients who received prophylactic antibiotics in this setting.
  • Order set usage was associated with quicker administration of antibiotics: 3h28min compared with 10h4min.
  • Time for octreotide administration was reduced in patients with the order set: 2h16min vs 6h21min.
  • Mortality was not reduced in this study by using an order set.  In fact, in those who used an order set there were 7 mortalities (out of 61) compared with only 2 mortalities (out of 62) who did not use order sets.

Order set use was at the discretion of the treating physician.  This could have led to selection bias.

Bottomline: Use of a standardized order set improved adherence and timeliness of recommended therapies.

Related blog posts:

Wiping out Hepatitis C

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Here’s the view of the NY Times (nyti.ms/1b7nTbl ) about the new therapies for Hepatitis C:

Medicine may be on the brink of an enormous public health achievement: turning the tide against hepatitis C, a silent plague that kills more Americans annually than AIDSand is the leading cause of liver transplants. If the effort succeeds, it will be an unusual conquest of a viral epidemic without using a vaccine.

“There is no doubt we are on the verge of wiping out hepatitis C,” said Dr. Mitchell L. Shiffman, the director of the Bon Secours Liver Institute of Virginia and a consultant to many drug companies.

Over the next three years, starting within the next few weeks, new drugs are expected to come to market that will cure most patients with the virus, in some cases with a once-a-day pill taken for as little as eight weeks, and with only minimal side effects.

That would be a vast improvement over current therapies, which cure about 70 percent of newly treated patients but require six to 12 months of injections that can bring horrible side effects.

The latest data on the experimental drugs is being presented at The Liver Meeting in Washington, which ends Tuesday [11/5/13]

But the new drugs are expected to cost from $60,000 to more than $100,000 for a course of treatment.

Related blog posts:

PSC 2013 Review

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A recent review of PSC was published (Gastroenterology 2013; 145: 521-36).  This review is a little more detailed than a previous review noted in this blog less than 6 months ago (Staying current with PSC | gutsandgrowth).

A couple of useful comments from the review:

  • “An increased serum level of alkaline phosphatase is the most common biochemical abnormality detected in patients with PSC.  In some cases, it is the only biochemical alteration observed, such as in patients with intrahepatic involvement.”
  • “Typically, a liver biopsy is not required to diagnose PSC unless small duct PSC is suspected or if there are concerns that a patient also has AIH.”  Cholangiography is the best way to identify PSC.
  • “Patients diagnosed with PSC should undergo colonoscopy… to determine if they have IBD, even when there are no symptoms.”
  • Autoimmune hepatitis-PSC overlap is thought to occur in ≤6% of cases.  AIH-PSC should be suspected if there are biochemical features of AIH (positive serology, increased transaminases), histology suggestive of AIH, or in AIH patients that become refractory to treatment.
  • No controlled trials have identified effective medical treatments.  Studied medications have included corticosteroids, etanercept, tacrolimus, cyclosporine, azathioprine, methotrexate, infliximab, and ursodeoxycholic acid.  The latter may increase disease progression, particularly at higher doses.

Also noted:

Hepatology 2013; 58: 1392-1400. “Primary Sclerosing Cholangitis, Autoimmune Hepatitis, and Overlap in Utah Children: Epidemiology and Natural History”

In this study the authors identified 607 cases of IBD, 29 cases of PSC, 12 cases of ASC (overlap), and 44 cases of AIH.  “Cholangiocarcinoma developed in 2 of the 29 PSC patients (6.9%).  PSC occurred in 9.9% of patients with ulcerative colitis (UC) and 0.6% of patients with Crohn’s disease.”

Related blog posts:

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) and specific medical management interventions should be confirmed by prescribing physician.  Application of the information in a particular situation remains the professional responsibility of the practitioner.