Corron Sanders

Unrecognized acetaminophen toxicity as a cause of indeterminate acute liver failure

Despite extensive investigations, the cause of liver injury in 14% of patients with acute liver failure remains unknown (indeterminate). In a pilot study using a novel assay, highly specific acetaminophen‐cysteine adducts were detected in 7 of 36 indeterminate patients (19%). To extend these observations, sera from 110 subjects enrolled in the Acute Liver Failure Study Group registry with indeterminate acute liver failure were analyzed with a similar but more efficient and sensitive adduct assay. As positive controls, another 199 patients with known or presumed acetaminophen‐induced liver failure were assessed for the presence and quantity of adducts. Clinical, laboratory, and outcome data were compared for the two groups. On the basis of previous data for known therapeutic exposures and acetaminophen overdoses, an adduct concentration ≥1.0 nmol/mL of serum indicated a definite acetaminophen overdose. Among the 110 indeterminate cases, 18% had assay values ≥1.0 with a median level of 9.2 nmol/mL; 94.5% of the positive controls (known acetaminophen cases) had values ≥1.0 nmol/mL. Regardless of the initial diagnosis, subjects with elevated adduct levels demonstrated the clinical profile and hyperacute biochemical injury pattern associated with acetaminophen overdose: a predominance of female gender, very high aminotransferase levels, and low bilirubin levels. Conclusion: These data confirm and extend previous observations regarding the high (18%) prevalence of unrecognized or uncertain acetaminophen toxicity among subjects with indeterminate acute liver failure. N‐Acetylcysteine use was limited in this group, presumably because of the lack of a specific diagnosis of acetaminophen toxicity. (HEPATOLOGY 2011;53:567‐576.)

Steroid use in acute liver failure

Drug‐induced and indeterminate acute liver failure (ALF) might be due to an autoimmune‐like hepatitis that is responsive to corticosteroid therapy. The aim of this study was to evaluate whether corticosteroids improve survival in fulminant autoimmune hepatitis, drug‐induced, or indeterminate ALF, and whether this benefit varies according to the severity of illness. We conducted a retrospective analysis of autoimmune, indeterminate, and drug‐induced ALF patients in the Acute Liver Failure Study Group from 1998‐2007. The primary endpoints were overall and spontaneous survival (SS, survival without transplant). In all, 361 ALF patients were studied, 66 with autoimmune (25 steroids, 41 no steroids), 164 with indeterminate (21 steroids, 143 no steroids), and 131 with drug‐induced (16 steroids, 115 no steroids) ALF. Steroid use was not associated with improved overall survival (61% versus 66%, P = 0.41), nor with improved survival in any diagnosis category. Steroid use was associated with diminished survival in certain subgroups of patients, including those with the highest quartile of the Model for Endstage Liver Disease (MELD) (>40, survival 30% versus 57%, P = 0.03). In multivariate analysis controlling for steroid use and diagnosis, age (odds ratio [OR] 1.37 per decade), coma grade (OR 2.02 grade 2, 2.65 grade 3, 5.29 grade 4), MELD (OR 1.07), and pH < 7.4 (OR 3.09) were significantly associated with mortality. Although steroid use was associated with a marginal benefit in SS overall (35% versus 23%, P = 0.047), this benefit did not persistent in multivariate analysis; mechanical ventilation (OR 0.24), MELD (OR 0.93), and alanine aminotransferase (1.02) were the only significant predictors of SS. Conclusion: Corticosteroids did not improve overall survival or SS in drug‐induced, indeterminate, or autoimmune ALF and were associated with lower survival in patients with the highest MELD scores. (Hepatology 2014;59:612–621)

Detection of anti‐isoniazid and anti–cytochrome P450 antibodies in patients with isoniazid‐induced liver failure

Isoniazid (INH)‐induced hepatotoxicity remains one of the most common causes of drug‐induced idiosyncratic liver injury and liver failure. This form of liver injury is not believed to be immune‐mediated because it is not usually associated with fever or rash, does not recur more rapidly on rechallenge, and previous studies have failed to identify anti‐INH antibodies (Abs). In this study, we found Abs present in sera of 15 of 19 cases of INH‐induced liver failure. Anti‐INH Abs were present in 8 sera; 11 had anti–cytochrome P450 (CYP)2E1 Abs, 14 had Abs against CYP2E1 modified by INH, 14 had anti‐CYP3A4 antibodies, and 10 had anti‐CYP2C9 Abs. INH was found to form covalent adducts with CYP2E1, CYP3A4, and CYP2C9. None of these Abs were detected in sera from INH‐treated controls without significant liver injury. The presence of a range of antidrug and autoAbs has been observed in other drug‐induced liver injury that is presumed to be immune mediated. Conclusion: These data provide strong evidence that INH induces an immune response that causes INH‐induced liver injury. (Hepatology 2014;59:1084–1093)

Outcomes and complications of intracranial pressure monitoring in acute liver failure: a retrospective cohort study.

Objective:To determine if intracranial pressure monitor placement in patients with acute liver failure is associated with significant clinical outcomes. Design:Retrospective multicenter cohort study. Setting:Academic liver transplant centers comprising the U.S. Acute Liver Failure Study Group. Patients:Adult critically ill patients with acute liver failure presenting with grade III/IV hepatic encephalopathy (n = 629) prospectively enrolled between March 2004 and August 2011. Intervention:Intracranial pressure monitored (n = 140) versus nonmonitored controls (n = 489). Measurements and Main Results:Intracranial pressure monitored patients were younger than controls (35 vs 43 yr, p < 0.001) and more likely to be on renal replacement therapy (52% vs 38%, p = 0.003). Of 87 intracranial pressure monitored patients with detailed information, 44 (51%) had evidence of intracranial hypertension (intracranial pressure > 25 mm Hg) and overall 21-day mortality was higher in patients with intracranial hypertension (43% vs 23%, p = 0.05). During the first 7 days, intracranial pressure monitored patients received more intracranial hypertension–directed therapies (mannitol, 56% vs 21%; hypertonic saline, 14% vs 7%; hypothermia, 24% vs 10%; p < 0.03 for each). Forty-one percent of intracranial pressure monitored patients received liver transplant (vs 18% controls; p < 0.001). Overall 21-day mortality was similar (intracranial pressure monitored 33% vs controls 38%, p = 0.24). Where data were available, hemorrhagic complications were rare in intracranial pressure monitored patients (4 of 56 [7%]; three died). When stratifying by acetaminophen status and adjusting for confounders, intracranial pressure monitor placement did not impact 21-day mortality in acetaminophen patients (p = 0.89). However, intracranial pressure monitor was associated with increased 21-day mortality in nonacetaminophen patients (odds ratio, ~ 3.04; p = 0.014). Conclusions:In intracranial pressure monitored patients with acute liver failure, intracranial hypertension is commonly observed. The use of intracranial pressure monitor in acetaminophen acute liver failure did not confer a significant 21-day mortality benefit, whereas in nonacetaminophen acute liver failure, it may be associated with worse outcomes. Hemorrhagic complications from intracranial pressure monitor placement were uncommon and cannot account for mortality trends. Although our results cannot conclusively confirm or refute the utility of intracranial pressure monitoring in patients with acute liver failure, patient selection and ancillary assessments of cerebral blood flow likely have a significant role. Prospective studies would be required to conclusively account for confounding by illness severity and transplant.

Cytokine and autoantibody patterns in acute liver failure

The mechanisms of idiosyncratic drug-induced liver injury (IDILI) are still a matter of dispute. Some of the characteristics of reactions that have been classed as metabolic idiosyncrasy could also be those of an immune-mediated reaction with an autoimmune component. Many auto-immune reactions appear to be mediated by TH17 cells, which are in part characterized by the production of interleukin (IL)-17. To test the involvement of TH17 cells in IDILI, we quantified a number of cytokines, chemokines, and autoantibodies in the serum of 39 patients with acute liver failure (ALF) due to IDILI and compared the values with those from 21 patients with acetaminophen-induced ALF and 10 patients with viral hepatitis-induced ALF. The IL-17 levels were elevated in 60% of patients with IDILI, but also in a similar number of patients with acetaminophen-induced ALF and occasionally in patients with viral hepatitis. Levels of other cytokines, such as IL-21, that are also produced by TH17 cells were higher in patients with IDILI, but again, there was overlap with acetaminophen DILI. Autoantibodies were more frequent in patients in the IDILI group but were absent in most patients. These data provide a picture of the cytokine/chemokine profile in patients with various types of ALF. The pattern varies from patient to patient and not specifically by etiology. This suggests that different underlying disease mechanisms may be at play in different individuals, even among those demonstrating injury from the same drug. Since cytokines may originate from more than one type of cell, interpretation of results of cytokine assays remains difficult in complex disease settings.

Two‐year outcomes in initial survivors with acute liver failure: results from a prospective, multicentre study

The long‐term clinical outcomes in initial survivors with acute liver failure (ALF) are not well known. The aim of this study was to provide an overview of the 2‐year clinical outcomes among initial survivors and liver transplant (LT) recipients that were alive 3 weeks after enrolment in the Acute Liver Failure Study Group (ALFSG).

Two distinct subtypes of hepatitis B virus–related acute liver failure are separable by quantitative serum immunoglobulin M anti‐hepatitis B core antibody and hepatitis B virus DNA levels

Hepatitis B virus (HBV)‐related acute liver failure (HBV‐ALF) may occur after acute HBV infection (AHBV‐ALF) or during an exacerbation of chronic HBV infection (CHBV‐ALF). Clinical differentiation of the two is often difficult if a previous history of HBV is not available. Quantitative measurements of immunoglobulin M (IgM) anti–hepatitis B core antibody (anti‐HBc) titers and of HBV viral loads (VLs) might allow the separation of AHBV‐ALF from CHBV‐ALF. Of 1,602 patients with ALF, 60 met clinical criteria for AHBV‐ALF and 27 for CHBV‐ALF. Sera were available on 47 and 23 patients, respectively. A quantitative immunoassay was used to determine IgM anti‐HBc levels, and real‐time polymerase chain reaction (rtPCR) was used to determine HBV VLs. AHBV‐ALFs had much higher IgM anti‐HBc titers than CHBV‐ALFs (signal‐to‐noise [S/N] ratio median: 88.5; range, 0‐1,120 versus 1.3, 0‐750; P < 0.001); a cut point for a S/N ratio of 5.0 correctly identified 44 of 46 (96%) AHBV‐ALFs and 16 of 23 (70%) CHBV‐ALFs; the area under the receiver operator characteristic curve was 0.86 (P < 0.001). AHBV‐ALF median admission VL was 3.9 (0‐8.1) log10 IU/mL versus 5.2 (2.0‐8.7) log10 IU/mL for CHBV‐ALF (P < 0.025). Twenty percent (12 of 60) of the AHBV‐ALF group had no hepatitis B surface antigen (HBsAg) detectable on admission to study, wheras no CHBV‐ALF patients experienced HBsAg clearance. Rates of transplant‐free survival were 33% (20 of 60) for AHBV‐ALF versus 11% (3 of 27) for CHBV‐ALF (P = 0.030). Conclusions: AHBV‐ALF and CHBV‐ALF differ markedly in IgM anti‐HBc titers, in HBV VLs, and in prognosis, suggesting that the two forms are, indeed, different entities that might each have a unique pathogenesis. (HEPATOLOGY 2011)

Malignant infiltration of the liver presenting as acute liver failure.

There have been few reports of acute liver failure (ALF), with encephalopathy and coagulopathy, caused by infiltration of the liver by malignant cells. We describe a case series of 27 patients with ALF caused by malignancy. We examined a large, multicenter ALF registry (1910 patients; mean age, 47.1 ± 13.9 y) and found only 27 cases (1.4%) of ALF attributed to malignancy. Twenty cases (74%) presented with abdominal pain and 11 presented with ascites. The most common malignancies included lymphoma or leukemia (33%), breast cancer, (30%), and colon cancer (7%); 90% of the patients with lymphoma or leukemia had no history of cancer, compared with 25% of patients with breast cancer. Overall, 44% of the patients had evidence of liver masses on imaging. Diagnosis was confirmed by biopsy in 15 cases (55%) and by autopsy for 6 cases. Twenty-four patients (89%) died within 3 weeks of ALF.

Plasma osteopontin in acute liver failure.

BACKGROUND Osteopontin (OPN) is a novel phosphoglycoprotein expressed in Kupffer cells that plays a pivotal role in activating natural killer cells, neutrophils and macrophages. Measuring plasma OPN levels in patients with acute liver failure (ALF) might provide insights into OPN function in the setting of massive hepatocyte injury. METHODS OPN levels were measured using a Quantikine® ELISA assay on plasma from 105 consecutive ALF patients enrolled by the US Acute Liver Failure Study Group, as well as controls including 40 with rheumatoid arthritis (RA) and 35 healthy subjects both before, and 1 and 3 days after undergoing spine fusion (SF) surgery as a model for acute inflammation. RESULTS Median plasma OPN levels across all etiologies of ALF patients were elevated 10- to 30-fold: overall median 1055ng/mL; range: 33-19,127), when compared to healthy controls (median in pre-SF patients: 41ng/mL; range 2.6-86.4). RA and SF post op patients had elevated OPN levels (37ng/mL and 198ng/mL respectively), well below those of the ALF patients. Median OPN levels were highest in acetaminophen (3603ng/mL) and ischemia-related ALF (4102ng/mL) as opposed to viral hepatitis (706ng/mL), drug-induced liver injury (353ng/mL) or autoimmune hepatitis (436ng/mL), correlating with the degree of hepatocellular damage, as reflected by aminotransferase values (R value: 0.47 for AST, p<0.001). CONCLUSIONS OPN levels appeared to correlate with degree of liver necrosis in ALF. Very high levels were associated with hyperacute injury and good outcomes. Whether OPN exerts a protective effect in limiting disease progression in this setting remains uncertain.

Racial and ethnic differences in presentation, etiology, and outcomes of acute liver failure in the United States.

BACKGROUND & AIMS In patients with chronic liver disease, race plays a role in the rate of survival after transplantation. It is not known how race and ethnicity influence the presentation, etiology, and outcomes in patients with acute liver failure (ALF). METHODS A retrospective cohort study was conducted using the ALF Study Group database to assess differences between racial and ethnic groups in subjects with ALF. RESULTS In the cohort of 927 subjects (81.8% white, 12.8% black, and 5.4% Asian), enrolled between January 1998 and March 2006, age, sex, and level of education were comparable among the groups. Differences were found in the prevalence of psychiatric illness and the use of medications. Racial groups also differed with respect to etiology of ALF. Whites presented more frequently with acetaminophen toxicity (51% vs 27%; P < .001). By day 21, 228 (30%) whites, 46 (39%) blacks, and 11 (22%) Asians had died. There were no significant differences found in the overall mortality rate after adjustment for potential confounders including etiology of ALF, encephalopathy, age, sex, admission laboratory values, and region. The odds of liver transplantation were higher among Asians and Hispanics; however, this finding was attenuated after adjustment for the previously-described confounders (adjusted odds ratio, 1.50; 95% confidence interval, 0.72-3.13; and adjusted odds ratio, 1.89; 95% confidence interval, 1.08-3.30, respectively). CONCLUSIONS In patients with ALF, there were no significant differences in survival or rate of liver transplantation among racial and ethnic groups except for transplantation in Hispanics.