N-Acetyl Cysteine Overdose Inducing Hepatic Steatosis and Systemic Inflammation in Both Propacetamol-Induced Hepatotoxic and Normal Mice

Acetaminophen (APAP) overdose induces acute liver damage and even death. The standard therapeutic dose of N-acetyl cysteine (NAC) cannot be applied to every patient, especially those with high-dose APAP poisoning. There is insufficient evidence to prove that increasing NAC dose can treat patients who failed in standard treatment. This study explores the toxicity of NAC overdose in both APAP poisoning and normal mice. Two inbred mouse strains with different sensitivities to propacetamol-induced hepatotoxicity (PIH) were treated with different NAC doses. NAC therapy decreased PIH by reducing lipid oxidation, protein nitration and inflammation, and increasing glutathione (GSH) levels and antioxidative enzyme activities. However, the therapeutic effects of NAC on PIH were dose-dependent from 125 (N125) to 275 mg/kg (N275). Elevated doses of NAC (400 and 800 mg/kg, N400 and N800) caused additional deaths in both propacetamol-treated and normal mice. N800 treatments significantly decreased hepatic GSH levels and induced inflammatory cytokines and hepatic microvesicular steatosis in both propacetamol-treated and normal mice. Furthermore, both N275 and N400 treatments decreased serum triglyceride (TG) and induced hepatic TG, whereas N800 treatment significantly increased interleukin-6, hepatic TG, and total cholesterol levels. In conclusion, NAC overdose induces hepatic and systemic inflammations and interferes with fatty acid metabolism.

Microvesicular steatosis: a missed item in the management of nonalcoholic fatty liver disease?

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is among the most common causes of chronic liver disease and cirrhosis. In NAFLD, histological course of steatosis is usually macrovesicular (MacroS), but it may be accompanied by varying degrees of microvesicular steatosis (MicroS). Thus, in this study, we aimed to evaluate the prevalence and significance of MicroS in subjects with NAFLD.

METHODS

A retrospective analysis of clinical and laboratory data of patients with histologically proven NAFLD was performed. The liver biopsy specimens which stained with hematoxylin eosin, reticulin, and Masson's Trichrome stains were evaluated by single expert liver pathologist. Scoring and semiquantitative assessment of steatosis and NAFLD severity was done according to Kleiner scale known as NAFLD activity score (NAS). Grading for steatosis, steatosis type, zonal distribution of steatosis and other histological findings were also determined.

RESULTS

The prevalence of MicroS among the study population (n= 191) was 30.4%. There was no difference regarding the demographic and biochemical parameters between patients with or without MicroS. On the other hand, the prevalence of ballooning injury and megamitochondria were higher in patients with MicroS (p= 0.019 and p= 0.036, respectively). There was a significant association of MicroS with ballooning injury (OR 2.65, 95% CI= 1.26-5.55 ; p= 0.005) and the presence of megamitochondria (OR 3.72, 95% CI= 1.00-13.72 ; p= 0.037).

CONCLUSION

MicroS is common in patients with NAFLD and is associated with early histological findings in this clinically relevant condition. Further longitudinal studies are needed to characterize the role of MicroS in the natural history of NAFLD.

Autopsy of a child with Spinal muscular atrophy Type I (Werdnig-Hoffmann disease)

Spinal muscular atrophy (SMA) is a heritable neuromuscular disorder which encompasses a large group of genetic disorders characterized by slowly progressive degeneration of lower motor neurons. The mutation is seen in the SMN1 gene mapped on chromosome 5. Depending on the age of the onset and the degree of severity, SMA has three subtypes. We discuss the autopsy findings in a case of Type 1 SMA also known by the name Werdnig-Hoffmann disease, to highlight the primary changes in the spinal cord, and skeletal muscle with association changes in the liver and terminal respiratory complications.

Clinicopathological features of hepatocellular carcinoma with fatty change: Tumors with macrovesicular steatosis have better prognosis and aberrant expression patterns of perilipin and adipophilin

The clinicopathological characteristics of steatosis in hepatocellular carcinoma (HCC) remain unclear. Here, we elucidate the features of macrovesicular steatosis (MaS) and microvesicular steatosis (MiS) in HCC and their relationships with background liver steatosis. A total of 165 HCC lesions were classified as MaS-HCC, MiS-HCC, or conventional HCC (cHCC) according to the cutoff value of 30% MaS or MiS in tumor cells. We analyzed the clinicopathological differences among these groups. MaS-HCC had less portal vein invasion, a higher proportion of HCC with intratumoral fibrosis, and a lower cumulative risk of recurrence than MiS-HCC or cHCC. Moreover, both MaS-HCC and MiS-HCC had lower incidences of hepatitis virus infection and higher levels of HbA1c than cHCC. Background liver steatosis was also higher in MaS-HCC than in cHCC. Immunohistochemical expression of perilipin (Plin1) and adipophilin (ADRP), major proteins expressed on lipid droplet membranes, revealed that almost all lipid droplets in HCC were Plin1 negative, whereas those in background liver were positive. In contrast, ADRP was expressed on lipid droplets in both HCC and background liver. We concluded that MaS-HCC and MiS-HCC were associated with metabolic abnormalities but exhibited different biologic behaviors. Furthermore, lipid droplets in HCC were pathophysiologically different from those in background liver.

Lysosomal acid lipase deficiency - early diagnosis is the key

Lysosomal acid lipase deficiency (LAL-D) is an ultra-rare lysosomal storage disease that may present from infancy to late adulthood depending on residual enzyme activity. While the severe form manifests as a rapidly progressive disease with near universal mortality within the first 6 months of life, milder forms frequently go undiagnosed for prolonged periods and typically present with progressive fatty liver disease, enlarged spleen, atherogenic dyslipidemia and premature atherosclerosis. The adult variant of LAL-D is typically diagnosed late or even overlooked due to the unspecific nature of the presenting symptoms, which are similar to common changes observed in the context of the metabolic syndrome. This review is aimed at delineating clinically useful scenarios in which pediatric or adult medicine clinicians should be aware of LAL-D as a differential diagnosis for selected patients. This is particularly relevant as a potentially life-saving enzyme replacement therapy has become available and the diagnosis can easily be ruled out or confirmed using a dried blood spot test.

Grade of donor liver microvesicular steatosis does not affect the postoperative outcome after liver transplantation

BACKGROUND

The potential effect of graft steatosis on the postoperative liver function is discussed controversially. The present study aimed to evaluate the effect of the donor liver microvesicular steatosis on the postoperative outcome after liver transplantation.

METHODS

Ninety-four patients undergoing liver transplantation at the University Hospital Aachen were included in this study. The patient cohort was divided into three groups according to the grade of microvesicular steatosis (MiS): MiS <30% (n=27), MiS 30%-60% (n=41) and MiS >60% (n=26). The outcomes after liver transplantation were evaluated, including the 30-day and 1-year patient and graft survival rates and the incidences of early allograft dysfunction (EAD) and primary nonfunction (PNF).

RESULTS

The incidences of EAD and PNF did not differ significantly between the groups. We observed 5 cases of PNF, one occurred in the MiS <30% group and 4 in the MiS 30%-60% group. The 30-day and 1-year graft survivals did not differ significantly between groups. The 30-day patient survival rates were 100% in all groups. The 1-year patient survival rates were 94.4% in the MiS <30% group, 87.9% in the MiS 30%-60% group and 90.9% in the MiS >60% group.

CONCLUSION

Microvesicular steatosis of donor livers has no negative effect on the postoperative outcome after liver transplantation.

Presence and significance of microvesicular steatosis in nonalcoholic fatty liver disease

BACKGROUND & AIMS

Liver biopsies from patients with nonalcoholic fatty liver disease (NAFLD) sometimes exhibit non-zonal aggregates of hepatocytes with microvesicular steatosis, but its prevalence and significance are unclear. In this study, we have evaluated the frequency of microvesicular steatosis and assessed its association with histological markers of disease severity in a large sample of NAFLD liver biopsies.

METHODS

Liver biopsies from a large cohort of adults who participated in two studies conducted by the NASH Clinical Research Network (NASH CRN) were included in this cross-sectional study. Liver histology was assessed centrally and various histological features scored in a systematic fashion. The relationship between microvesicular steatosis and various histological features that characterize NAFLD was tested by multiple logistic regression, after controlling for age, gender, race, body mass index, and diabetes.

RESULTS

Among 1022 liver biopsies included, 102 (10%) had microvesicular steatosis. No demographic differences were noted between patients with or without microvesicular steatosis. The presence of microvesicular steatosis was associated with higher grades of steatosis (p<0.001), ballooning cell injury (p<0.001), presence of Mallory-Denk bodies (p<0.007), presence of megamitochondria (p<0.0001), higher NAS scores (p<0.0001), more advanced fibrosis (p<0.0001), and diagnosis of borderline or definite NASH (p<0.0001).

CONCLUSIONS

Microvesicular steatosis correlates with more advanced histology of NAFLD. Longitudinal studies are needed to address the role of microvesicular steatosis in mediating cellular injury and disease progression in NAFLD.

Severe drug-induced liver injury associated with prolonged use of linezolid

This study aims to describe a patient developing concomitant severe liver failure and lactic acidosis after long-term treatment with linezolid. A 55-year-old Caucasian woman developed concomitant severe liver failure and lactic acidosis after a treatment with linezolid for 50 days because of infected hip prosthesis. Other causes of liver failure and lactic acidosis were excluded by extensive diagnostic workup. A liver biopsy showed microvesicular steatosis. As linezolid toxicity was considered to be the cause of the lactic acidosis and the severe hepatic failure, the antibiotic was withdrawn. After 4 days of supportive therapy and hemodialysis, the serum lactate level returned within normal limits. The prothrombin time ratio and thrombocytes recovered within 2 weeks. Bilirubin levels normalized within 14 weeks. Since no other cause could be identified, liver injury was considered to be drug-related. Resolution of the hepatotoxicity occurred after discontinuation of linezolid, supportive treatment measures, and hemodialysis. Both lactic acidosis and microvesicular steatosis after the use of linezolid are related to mitochondrial dysfunction. The Council for International Organizations of Medical Sciences/Roussel Ucalf Causality Assessment Method scale revealed that the adverse drug event was probable. Prolonged exposure to linezolid may induce severe hepatotoxicity. Clinicians should be aware of this possible adverse effect especially in case of long-term treatment.