ACLY as a modulator of liver cell functions and its role in Metabolic Dysfunction-Associated Steatohepatitis

BACKGROUND

Non-alcoholic Fatty Liver Disease (NAFLD), now better known as Metabolic (Dysfunction)-Associated Fatty Liver Disease (MAFLD) and its progression to Nonalcoholic Steatohepatitis (NASH), more recently referred to as Metabolic (Dysfunction)-Associated Steatohepatitis (MASH) are the most common causes of liver failure and chronic liver damage. The new names emphasize the metabolic involvement both in relation to liver function and pathological features with extrahepatic manifestations. This study aims to explore the role of the immunometabolic enzyme ATP citrate lyase (ACLY), with a critical function in lipogenesis, carbohydrate metabolism, gene expression and inflammation.

METHODS

ACLY function was investigated in TNFα-triggered human hepatocytes and in PBMC-derived macrophages from MASH patients. Evaluation of expression levels was carried out by western blotting and/or RT-qPCR. In the presence or absence of ACLY inhibitors, ROS, lipid peroxidation and GSSG oxidative stress biomarkers were quantified. Chromatin immunoprecipitation (ChIP), transient transfections, immunocytochemistry, histone acetylation quantitation were used to investigate ACLY function in gene expression reprogramming. IL-6 and IL-1β were quantified by Lumit immunoassays.

RESULTS

Mechanistically, ACLY inhibition reverted lipid accumulation and oxidative damage while reduced secretion of inflammatory cytokines in TNFα-triggered human hepatocytes. These effects impacted not only on lipid metabolism but also on other crucial features of liver function such as redox status and production of inflammatory mediators. Moreover, ACLY mRNA levels together with those of malic enzyme 1 (ME1) increased in human PBMC-derived macrophages from MASH patients when compared to age-matched healthy controls. Remarkably, a combination of hydroxycitrate (HCA), the natural ACLY inhibitor, with red wine powder (RWP) significantly lowered ACLY and ME1 mRNA amount as well as IL-6 and IL-1β production in macrophages from subjects with MASH.

CONCLUSION

Collectively, our findings for the first time highlight a broad spectrum of ACLY functions in liver as well as in the pathogenesis of MASH and its diagnostic and therapeutic potential value.

Urinary metabolomics of HCV patients with severe liver fibrosis before and during the sustained virologic response achieved by direct acting antiviral treatment

Hepatitis C virus (HCV) infection induces a long-term inflammatory response and oxidative-stress in the liver microenvironment, leading to hepatic fibrosis and metabolic alterations. Direct-acting-antiviral-agents (DAAs) induce HCV-clearance, even though liver damage is only partially restored. In this context, understanding the impact of viral-eradication on liver metabolic activities could allow optimizing the metabolic care of the patient. The present prospective longitudinal study aims at characterizing the urinary metabolic profile of HCV-induced severe liver fibrosis and the metabolic changes induced by DAAs and HCV-clearance by nuclear magnetic resonance-based metabolomics. The urinary metabolic profile of 23 HCV males with severe liver fibrosis and 20 age-matched healthy-controls was analyzed by NMR-based-metabolomics before starting DAAs, at the end-of-therapy, after one and three months of follow-up. The urinary metabolic profile of patients with severe liver fibrosis was associated to pseudouridine, hypoxanthine, methylguanidine and dimethylamine, highlighting a profile related to oxidative damage, and to tyrosine and glutamine, related to a decreased breakdown of aromatic aminoacids and ammonia detoxification, respectively. 1-methylnicotinamide, a catabolic intermediate of nicotinamide-adenine-dinucleotide, was significantly increased in HCV-patients and restored after HCV-clearance, probably due to the reduced hepatic inflammation. 3-hydroxy-3-methylbutyrate, an intermediate of leucine-catabolism which was permanently restored after HCV-clearance, suggested an improvement of skeletal muscle protein synthesis. Finally, 3-hydroxyisobutyrate and 2,3-dihydroxy-2-methylbutyrate, intermediates of valine-catabolism, glycine and choline increased temporarily during therapy, resulting as potential biomarkers of DAAs systemic effects.

POS1200 IL-6 HIGHER LEVEL AFTER TOCILIZUMAB TREATMENT AS A PREDICTOR OF NOT-SURVIVAL IN COVID19 SEVERE PNEUMONIA: THE EXPERIENCE OF THE COVIBAS-STUDY

Background:

Cytokine release storm is the most fearsome complication associated with worse outcomes in COVID-19 patients with severe acute respiratory failure. In COVID-19 patients, interleukin-6 (IL-6) levels are significantly elevated. Blocking IL-6 preliminarily resulted in the improvement of this hyperinflammatory state.

Objectives:

To define if the serum level of IL-6 early tested after tocilizumab treatment could be useful to distinguish non-survivors from survivors in patients with severe respiratory failure due to COVID-19 pneumonia.

Methods:

This prospective cohort study was conducted at two referral hospitals for management of COVID-19 in Basilicata region, Italy: San Carlo Hospital, Potenza and Madonna delle Grazie Hospital, Matera. All consecutive patients with COVID-19 confirmed by RT-PCR testing of a naso-oropharyngeal swab. The enrollement period was from the 23rd of February to the 15th of August. 37 patients between all 124 underwent tocilizumab 8 mg/kg intravenously at baseline and after 24h. All patients were tested for serum IL-6, 24 hours before and 72 hours after tocilizumab infusion. Comparisons between survivors (Sv) and nonsurvivors (NSv) were performed.

Results:

21 patients were discharged, while 16 patients died. The main clinical or laboratory differences (p < 0.001) between the two groups at baseline were mean diseases duration before ward admission and serum troponine levels. IL-6 was not different at baseline (p = 0.01), while 72 hours post-tocilizumab IL-6 serum levels were significantly higher in non-survivors than in survivors [(Sv 21.1%)vs(NSv 64%) p < 0.001)]. Serum IL-6 post-tocilizumab could be considered a good predictor to discriminate Sv from NSv. At multivariate stepwise analysis including disease duration at admission, baseline serum troponine levels and IL-6 post TCZ) were independent predictors of not survival

Conclusion:

Our data confirm the results of Quartuccio et al. In fact the highest burden of inflammation may be revealed by IL-6 levels after tocilizumab. Therefore repeated measurement of the serum level of IL-6 early after tocilizumab could be useful to distinguish non-survivors from survivors and support the choice of deeper targeting IL-6 in COVID-19 pneumonia.

References:

[1]Mehta P, McAuley DF, Brown M, et al. COVID-19: consider cytokine storm syndromes and immunosuppression. Lancet. 2020; 395(10229): 1033- 1034.

[2]Toniati P, Piva S, Cattalini M, et al. Tocilizumab for the treatment of severe COVID-19 pneumonia with hyperinflammatory syndrome and acute respiratory failure: a single center study of 100 patients in Brescia, Italy. Autoimmun Rev. 2020; 19:102568

[3]McGonagle D, Sharif K, O’Regan A, Bridgewood C. The role of cytokines including interleukin 6 in COVID19 induced pneumonia and macrophage activation syndrome-like disease. Autoimmun Rev. 2020; 19(6):102537.

[4]Chakraborty C, Sharma AR, Bhattacharya M, Sharma G, Lee SS, Agoramoorthy G. COVID19: consider IL6 receptor antagonist for the therapy of cytokine storm syndrome in SARS CoV2 infected patients. J Med Virol 2020

[5]Quartuccio L, Sonaglia A, Pecori D,et al. Higher levels of IL-6 early after tocilizumab distinguish survivors from nonsurvivors in COVID-19 pneumonia: A possible indication for deeper targeting of IL-6. J Med Virol.2020;92:2852–2856

Disclosure of Interests:

None declared

AB0739 MULTISYSTEM INFLAMMATORY SYNDROME ASSOCIATED WITH SARS-COV-2 INFECTION AND E.COLI SEPSIS: THE POTENTIAL ROLE OF PROCALCITONINE AS A RAPID DIAGNOSTIC BIOMARKER TO DISTINGUISH TWO DIFFERENT PHASES OF SYSTEMIC INFLAMMATORY RESPONSE SYNDROME

Background:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is typically very mild and often asymptomatic in children. A complication is the rare multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19, presenting 4-6 weeks after infection as high fever, organ dysfunction, and strongly elevated markers of inflammation. The pathogenesis is unclear but has overlapping features with Kawasaki disease suggestive of vasculitis and a likely autoimmune etiology.

Objectives:

We report a case of multisystem inflammatory syndrome in children (MIS-C) in patient with SARS-CoV-2 infection and Enteropathogenic Escherichia coli (EPEC) sepsis due to acute enteritis, observed at end of December 2020 to a tertiary-care center (San Carlo Hospital), in Basilicata region (Italy).

Methods:

This healthy 12-year- old male patient was tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Clinical presentations was characterized by fever, abdominal pain, gastrointestinal complaints and evanescent rash. Laboratory values were remarkable for high levels of procalcitonin, C-reactive protein (CRP), D-dimers, B-type natriuretic peptide (BNP), and troponin. He also had low albumin levels. Autoantibodies tests were negative. Chest tomography showed ground-glass opacities in less than 25% of the lungs, small bilateral pleural effusion and increased cardiac area; abdominal tomography showed enlargement of the lymphnodes and ascites. Evaluation for other infectious etiologies showed molecular test positivity on fecal samples for EPEC E. coli. He received broad spectrum intravenous antibiotics (macrolids and quinolones and then carbapenems). On the seventh day the enteritis resolved and procalcitonin normalized, however he continued to have lymphopenia, thrombocytopenia, hypoalbuminemia, elevated levels of CRP, D-dimers, ferritin, troponin, and increased BNP. On the ninth day he was feverish again and developed severe cardiac and respiratory failure requiring advanced respiratory support and admission to the intensive care unit. He received IVIG (intravenous immunoglobulin at 2 g/Kg, glucocorticoids (Methylprednisolone 1mg/kg) and enoxaparin.

Results:

The patient was discharged asymptomatic at home after 28 days of hospital stay.

Conclusion:

We observed multisystem inflammatory syndrome in children (MIS-C) in a previously healthy patient with SARS-CoV-2 infection and E.coli sepsis, who became critically ill with multisystem involvement. In this case viral and bacterial infections could be considered as a double hit for the etiopathogenesis of MIS-C. The trend of procalcitonin was better than C-reactive protein for differentiating bacterial from non-bacterial phase of systemic inflammatory response syndrome (SIRS) in this critically ill child. Although the accuracy of both tests is moderate. Diagnostic accuracy could be enhanced by combining these tests with bedside clinical judgment.

References:

[1]Consiglio CR, Cotugno N, Sardh et al. The Immunology of Multisystem Inflammatory Syndrome in Children with COVID-19. Cell. 2020 Nov 12;183(4):968-981.e7. doi: 10.1016/j.cell.2020.09.016. Epub 2020 Sep 6. PMID: 32966765; PMCID: PMC7474869.

[2]Nakra NA, Blumberg DA, Herrera-Guerra A, Lakshminrusimha S. Multi-System Inflammatory Syndrome in Children (MIS-C) Following SARS-CoV-2 Infection: Review of Clinical Presentation, Hypothetical Pathogenesis, and Proposed Management. Children (Basel). 2020 Jul 1;7(7):69. doi: 10.3390/children7070069. PMID: 32630212; PMCID: PMC7401880.

[3]Simon L, Saint-Louis P, Amre DK, Lacroix J, Gauvin F. Procalcitonin and C-reactive protein as markers of bacterial infection in critically ill children at onset of systemic inflammatory response syndrome. Pediatr Crit Care Med. 2008 Jul;9(4):407-13. PMID: 18496408.

Disclosure of Interests:

None declared

Optical design of InGaN/GaN nanoLED arrays on a chip: toward: highly resolved illumination

The physical laws of diffraction limit the spatial resolution of optical systems. In contrary to most superresolution microscopy approaches used today, in our novel idea we are aiming to overcome this limit by developing a spatially resolved illumination source based on semiconductor nanoscale light emitting diode (nanoLED) arrays with individual pixel control. We present and discuss the results of optical simulations performed for such nanoLED emitter arrays and analyze the theoretical limits of this approach. As possible designs we study arrays of GaN nanofins and nanorods (obtained by etching nanofin arrays), with InGaN/GaN multi quantum wells embedded as active regions. We find that a suitable choice of the array dimensions leads to a reasonably directed light output and concentration of the optical power in the near field around an activated pixel. As a consequence, the spatial resolution for this type of microscopy should only be limited by the pixel pitch, and no longer by the optical diffraction. Realization of optimized nanoLED arrays has a potential to open new field of chip based superresolution microscopy, making super-high spatial resolution ubiquitously available.

HCV cirrhotic patients treated with direct-acting antivirals: Detection of tubular dysfunction and resolution after viral clearance

BACKGROUND/AIMS

Hepatitis C virus (HCV) has been identified in tubular epithelial cells of infected patients; however, the presence of tubular dysfunction, which is a risk factor for chronic kidney disease (CKD), has never been examined in vivo. The present prospective longitudinal study aimed to estimate the prevalence of tubular dysfunction alone or with glomerular damage and its evolution after HCV clearance in cirrhotic patients.

METHODS

One hundred and thirty-five consecutive Child-Pugh A cirrhotic patients were evaluated before antiviral treatment and 6 months after the end of therapy. Tubular dysfunction was evaluated by urinary alpha1-microglobulin to creatinine ratio (α1-MCR), and glomerular damage was assessed by urinary albumin to creatinine ratio (ACR).

RESULTS

Almost all the patients (93.3%) showed a normal or mildly decreased e-GFR (KDIGO-G1/G2-categories). Tubular dysfunction was found in 23.7% (32/135) of patients, co-occurring with glomerular damage in 37.5% (12/32) of cases, while glomerular damage was found in 16.3% (22/135) of patients. In multiple logistic regression, glomerular damage and the concomitant presence of diabetes and hypertension were the only predictors significantly associated with tubular dysfunction. After HCV clearance, patients experienced a significant reduction of α1-MCR levels (21.0 vs 10.5 μg/mg, P = .009) and tubular dysfunction resolved in 57.1% of subjects.

CONCLUSIONS

Tubular dysfunction is an unrecognized feature of HCV-related kidney disease in cirrhotic patients and its presence should be primarily investigated in subjects with glomerular damage, diabetes and hypertension, despite normal e-GFR. Tubular dysfunction resolves in the majority of cases after HCV clearance; however, it may persist after antiviral treatment and further studies should evaluate its long-term impact on kidney function.

Interleukin 18: a biomarker for differential diagnosis between adult-onset Still's disease and sepsis

OBJECTIVE

The differential diagnosis between rheumatic diseases and infectious conditions is a great challenge in clinical practice. Adult-onset Still's disease (AOSD) is a rare systemic inflammatory syndrome that shares several clinical and laboratory variables with sepsis. Interleukin (IL)-18 is overexpressed in AOSD, suggesting a possible role as a disease biomarker. The aim of our study was to detect IL-18 serum levels in a cohort of patients with AOSD and sepsis and to address its possible role as a biomarker for differential diagnosis.

METHODS

A group of unselected patients with AOSD diagnosed according to the Yamaguchi criteria and consecutive patients with sepsis diagnosed according to the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference criteria were enrolled. The clinical and laboratory data were collected. In the AOSD group, disease activity was assessed by Pouchot's and Rau's criteria. IL-18 serum levels were detected by ELISA.

RESULTS

Thirty-nine patients with AOSD and 18 patients with sepsis were enrolled. Two out of 18 patients with sepsis (11.1%) also fulfilled the Yamaguchi criteria. A significant difference was found in IL-18 serum levels between patients with active and inactive disease (p < 0.001), and it positively correlated with disease activity (p = 0.0003), ferritin serum level (p = 0.016), and erythrocyte sedimentation rate (p = 0.041). IL-18 was significantly increased in patients with AOSD when compared with sepsis (p = 0.014). For a cutoff of 148.9 pg/ml, this test had a specificity of 78.3% and a sensitivity of 88.6%.

CONCLUSION

We have demonstrated that IL-18 can be a biomarker for differential diagnosis between AOSD and sepsis.

Anti-HBs seroconversion during treatment with entecavir in a patient with chronic hepatitis B virus infection on hemodialysis

Hepatitis B (HBV) virus infection is one of the most important causes of liver disease in patients with end-stage renal failure on hemodialysis. The natural history of chronic HBV infection acquired in childhood starts with an immune tolerant phase, followed by an immune clearance phase that may lead to the inactive carrier state or the development of chronic liver disease. Information on antiviral therapy administered very early during the immune clearance phase are lacking and no data exist on the treatment of early immune activation in the hemodialysis setting. This report describes the case of a patient affected by end-stage renal failure and HBeAg-positive chronic HBV virus infection treated very early during the immune clearance phase of HBV infection with an adjusted-dose of nucleoside analogue entecavir. The patient achieved a very rapid HBV-DNA undetectability, anti-HBe, and anti-HBs seroconversion. This is the first report of antiviral therapy with entecavir started during the immune reactive phase of HBV infection in a patient on hemodialysis and it suggests that antiviral treatment can enhance the effects of host immune activation resulting in biochemical, serological, and viral response, even in end-stage renal failure patients with partial immunodeficiency. Antiviral therapy with entecavir in the setting of hemodialysis was safe and well tolerated.

IL28B gene polymorphisms and US liver fatty changes in patients who spontaneously cleared hepatitis C virus infection

BACKGROUND

Recent clinical studies have shown that the presence of CC genotype in the rs12979860 region of IL28B gene is associated with an increase in the probability of spontaneous clearance of hepatitis C virus (HCV). Moreover, IL28B polymorphism seems to influence the probability of developing liver steatosis in chronic HCV patients.

AIMS

The aims of our clinical study were 1) to verify the distribution of IL28B genotypes (CC, CT or TT) among subjects with spontaneous clearance of HCV infection and 2) to examine the correlation between IL28B polymorphism and hepatic steatosis among these subjects.

METHODS AND PATIENTS

We enrolled 41 subjects with spontaneous resolution of HCV infection (detectable serum anti-HCV but undetectable HCV-RNA) and 134 healthy controls from the same geographical area. The IL28B single-nucleotide polymorphism (SNP) rs12979860 was genotyped by using a Pyrosequencing™ technique. The presence of steatosis was assessed by liver biopsy or ultrasound examination in the 41 study subjects.

RESULTS

CC, CT and TT-genotypes of the SNP rs1979860 were found in 66%, 24% and 10% of the subjects who spontaneously cleared HCV and in 31%, 54% and 15% of controls, respectively (p = 0.0003). Among the study subjects, females with CC-genotype were significantly more represented (p = 0.02). Hepatic steatosis did not correlate with IL28B genotype (p = 0,14) but only with a high body mass index (BMI) value (p = 0.03).

CONCLUSIONS

Female subjects carrying IL28B CC-genotype are significantly more represented among Italian patients who spontaneously cleared HCV infection. In addition, among these subjects, the presence of liver steatosis does not correlate with IL28B genotype but is solely related to the occurrence of high BMI. Thus, the association between IL28B polymorphism and steatosis in chronic HCV patients requires the presence of active HCV replication to occur, while in subjects who have cleared the infection, the mechanism(s) inducing liver steatosis are independent from IL28B profile.