Acute on Chronic Liver Failure-What is in a 'Definition'?

Acute on chronic liver failure (ACLF) is a recently recognized syndrome and its definition has been evolving over last two decades. Currently, there is no universal consensus about the definition as kind of cases being seen in the Western world appear to be somewhat different from those that are seen in Asia Pacific region. But every one agrees that definition of ACLF should include following components. (a) The status of pre-existing liver disease, (b) defining the acute insult that leads to rapid deterioration of liver status, (c) time frame during which the acute insult can lead to rapid deterioration, (d) the quantification and definition of liver failure status after deterioration, which will determine the severity of ACLF, and (e) prediction of prognosis after analyzing first four components in the short and long terms. There is some consensus that number of organ failures may be the main determinant of prognosis. Whatever the definition is being used, the central role that superadded infections play in ACLF cannot be denied and need to be tackled aggressively. Apart from that, recovery may be possible if the acute insult or the baseline disease is curable, i.e. with the use of nucleoside analogs for hepatitis B, and corticosteroids for severe autoimmune hepatitis. Development of dynamic criteria with observations in Hospital may improve our understanding of prognosis as well as our approach to the management of ACLF.

Prognostication of critically ill patients with acute-on-chronic liver failure using the Chronic Liver Failure-Sequential Organ Failure Assessment: A Canadian retrospective study

PURPOSE

We evaluated the Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA) score to predict survival in a Canadian critically ill cohort with acute-on-chronic liver failure.

METHODS

We retrospectively examined 274 acute-on-chronic liver failure patients admitted to a quaternary level intensive care unit (ICU) between April 1, 2000, and April 30, 2011. We evaluated severity of illness scores, including the Acute Physiology and Chronic Health Evaluation (APACHE) II, model for end-stage liver disease (MELD), Child-Turcotte-Pugh (CTP), SOFA, and CLIF-SOFA.

RESULTS

On ICU admission, patients had the following median (interquartile range): APACHE II, 23 (19-28); MELD, 26 (19-35); CTP, 12 (10-13); SOFA, 15 (11-18); and CLIF-SOFA, 17 (13-21). In-hospital survival was 40%. There were no significant differences in survival for cirrhosis etiology, reason, or year of admission. The CLIF-SOFA score had the greatest area under receiver operating curve of 0.865 (95% confidence interval, 0.820-0.909) and outperformed the CTP, MELD, SOFA, and APACHE II scores. Sequential Organ Failure Assessment score performance improved on the third day of ICU admission (area under receiver operating curve, 0.935; 95% confidence interval, 0.895-0.975).

CONCLUSIONS

The CLIF-SOFA and SOFA scores during the first 3 days of ICU admission appear to be highly predictive of in-hospital mortality.

Child-Pugh, MELD, and ALBI scores for predicting the in-hospital mortality in cirrhotic patients with acute-on-chronic liver failure

OBJECTIVES

Our study aimed to evaluate the discriminative abilities of Child-Pugh, model for end-stage liver disease (MELD), and albumin-bilirubin (ALBI) scores in predicting the in-hospital mortality in cirrhotic patients with acute-on-chronic liver failure (ACLF).

METHODS

Cirrhotic patients with ACLF admitted between 2010 January and 2014 June were retrospectively reviewed. Areas under the receiver operating characteristic curves (AUROCs) with 95% confidence intervals (CIs) were calculated.

RESULTS

One hundred patients were eligible for the Asia-Pacific Association for the Study of the Liver (APASL) criteria. AUROCs of Child-Pugh, MELD, and ALBI scores in predicting the in-hospital mortality was 0.63 (95%CI: 0.52-0.72, P = 0.05), 0.75 (95%CI: 0.65-0.83, P < 0.0001), and 0.53 (95%CI: 0.42-0.63, P = 0.69), respectively. Eighty-eight patients were eligible for the EASL/AASLD criteria. AUROCs of Child-Pugh, MELD, and ALBI scores in predicting the in-hospital mortality were 0.59 (95%CI: 0.48-0.69, P = 0.14), 0.57 (95%CI: 0.46-0.68, P = 0.26), and 0.57 (95%CI: 0.46-0.67, P = 0.29), respectively. There was no significant difference among them.

CONCLUSION

Child-Pugh, MELD, and ALBI scores might be ineffective in predicting the in-hospital mortality of cirrhosis with ACLF.

Acute-on-chronic liver failure in cirrhosis

The definition of acute-on-chronic liver failure (ACLF) remains contested. In Europe and North America, the term is generally applied according to the European Association for the Study of the Liver-Chronic Liver Failure (EASL-CLIF) Consortium guidelines, which defines this condition as a syndrome that develops in patients with cirrhosis and is characterized by acute decompensation, organ failure and high short-term mortality. One-third of patients who are hospitalized for acute decompensation present with ACLF at admission or develop the syndrome during hospitalization. ACLF frequently occurs in a closed temporal relationship to a precipitating event, such as bacterial infection or acute alcoholic, drug-induced or viral hepatitis. However, no precipitating event can be identified in approximately 40% of patients. The mechanisms of ACLF involve systemic inflammation due to infections, acute liver damage and, in cases without precipitating events, probably intestinal translocation of bacteria or bacterial products. ACLF is graded into three stages (ACLF grades 1-3) on the basis of the number of organ failures, with higher grades associated with increased mortality. Liver and renal failures are the most common organ failures, followed by coagulation, brain, circulatory and respiratory failure. The 28-day mortality rate associated with ACLF is 30%. Depending on the grade, ACLF can be reversed using standard therapy in only 16-51% of patients, leaving a considerable proportion of patients with ACLF that remains steady or progresses. Liver transplantation in selected patients with ACLF grade 2 and ACLF grade 3 increases the 6-month survival from 10% to 80%.

Characteristics, Diagnosis and Prognosis of Acute-on-Chronic Liver Failure in Cirrhosis Associated to Hepatitis B

The diagnostic and prognostic criteria of acute-on-chronic liver failure (ACLF) were developed in patients with no Hepatitis B virus (HBV) cirrhosis (CANONIC study). The aims of this study were to evaluate whether the diagnostic (CLIF-C organ failure score; CLIF-C OFs) criteria can be used to classify patients; and the prognostic score (CLIF-C ACLF score) could be used to provide prognostic information in HBV cirrhotic patients with ACLF. 890 HBV associated cirrhotic patients with acute decompensation (AD) were enrolled. Using the CLIF-C OFs, 33.7% (300 patients) were diagnosed as ACLF. ACLF was more common in the younger patients and in those with no previous history of decompensation. The most common organ failures were ‘hepatic’ and ‘coagulation’. As in the CANONIC study, 90-day mortality was extremely low in the non-ACLF patients compared with ACLF patients (4.6% vs 50%, p < 0.0001). ACLF grade and white cell count, were independent predictors of mortality. CLIF-C ACLFs accurately predicted short-term mortality, significantly better than the MELDs and a disease specific score generated for the HBV patients. Current study indicates that ACLF is a clinically and pathophysiology distinct even in HBV patients. Consequently, diagnostic criteria, prognostic scores and probably the management of ACLF should base on similar principles.

Evaluation of neutrophil/leukocyte ratio and organ failure score as predictors of reversibility and survival following an acute-on-chronic liver failure event

AIM

Acute-on-chronic liver failure (ACLF) is defined as an acute deterioration of liver disease with high mortality in patients with cirrhosis. The early mortality in ACLF is associated with organ failure and high leukocyte count. The time needed to reverse this condition and the factors affecting mortality after the early 30-day-period were evaluated.

METHODS

One hundred and ninety-seven consecutive patients with cirrhosis were included. Patients were prospectively followed up for 180 days.

RESULTS

ACLF was diagnosed in 54.8% of the patients. Infection was the most common precipitating event in patients with ACLF. On multivariate analysis, only the neutrophil/leukocyte ratio and Chronic Liver Failure Consortium Organ Failure (CLIF-C OF) score were associated with mortality. Hazard ratios for mortality of patients with ACLF compared with those without at different time end-points post-enrollment revealed that the relative risk of death in the ACLF group was 8.54 during the first 30-day period and declined to 1.94 during the second period of observation. The time varying effect of neutrophil/leukocyte ratio and CLIF-C score was negative (1% and 18% decline in the hazard ratio per month) while that of Model for End-Stage Liver Disease (MELD) was positive (3% increase in the hazard ratio per month).

CONCLUSION

The condition of ACLF was reversible in patients who survived. During the 30-180-day period following the acute event, the probability of death in ACLF became gradually similar to the non-ACLF group. The impact of inflammatory response and organ failure on survival is powerful during the first 30-day period and weakens thereafter while that of MELD increases.

Effects of Minocycline on Urine Albumin, Interleukin-6, and Osteoprotegerin in Patients with Diabetic Nephropathy: A Randomized Controlled Pilot Trial

Background

We tested minocycline as an anti-proteinuric adjunct to renin-angiotensin-aldosterone system inhibitors (RAASi) in diabetic nephropathy (DN) and measured urinary biomarkers to evaluate minocycline’s biological effects.

Methods

Design: Prospective, single center, randomized, placebo-controlled, intention-to-treat pilot trial. Inclusion. Type 2 diabetes/DN; Baseline creatinine clearance > 30 mL/min; proteinuria ≥ 1.0 g/day; Age ≥30 years; BP <150/95 mm Hg; intolerant of/at maximum RAASi dose. Protocol. 3-wk screening; Baseline randomization; Urine and blood measures at months 1, 2, 4, and Month 6 study completion. Urine interleukin-6 (IL-6) and osteoprotegerin were measured in a subset. Primary outcome. Natural log of urine protein/creatinine (ln U P:Cr) ratio at Month 6 vs Baseline.

Results

30 patients completed the study. The 15% decline in U P: Cr in minocycline patients (6 month P:Cr ÷ Baseline P:Cr, 0.85 vs. 0.92) was not significant (p = 0.27). Creatinine clearance did not differ in the 2 groups. Urine IL-6:Cr (p = 0.03) and osteoprotegerin/Cr (p = 0.046) decrements were significant. Minocycline modified the relationship between urine IL-6 and proteinuria, suggesting a protective biological effect.

Conclusions

Although the decline in U P:Cr in minocycline patients was not statistically significant, the significant differences in urine IL-6 and osteoprotegerin suggest that minocycline may confer cytoprotection in patients with DN, providing a rationale for further study.

Trial Registration

Clinicaltrials.gov NCT01779089

Acute-on-Chronic Liver Failure (ACLF) in Coastal Eastern India: "A Single-Center Experience"

BACKGROUND AND OBJECTIVES

Acute-On-Chronic liver failure (ACLF) is an emerging entity. The present study was undertaken to analyze the clinical profile and natural course of ACLF patients.

PATIENTS AND METHODS

ACLF was defined as per Asia Pacific Association for the Study of Liver consensus criteria 2009. Patients fulfilling these criteria with some deviations were included and prospectively evaluated for clinical profile, etiologies of acute decompensation (AD) and underlying chronic liver disease, and short-term natural course [3 months].

RESULTS

Out of 123 patients with ACLF (mean age: 45.83 ± 12.05 years; male:female 109:14), 45.53% cases had prior history of AD, and 54.47% presented for the first time as ACLF. Etiologies of cirrhosis were alcohol, cryptogenic, and chronic hepatitis B virus infection in 65.04%, 23.57%, and 11.38% cases, respectively. Recent history of alcohol intake (within 4 weeks) [42.27%] followed by bacterial infections [36.58%] were the common etiologic precipitants for AD. Only 87 (70.73%) out of 123 cases could be followed up for a duration of 3 months; 62 (71.26%) cases died by 3 months. Most deaths occurred in the alcoholics compared to nonalcoholics [(43/53) 81.13% vs. (19/34) 55.88%; P = 0.01]. No significant difference in mortality rate was observed between ACLF cases with history of prior AD compared to newly diagnosed ACLF cases [30/40 (75%) vs. 32/47 (68.09%); P = 0.477]. The prognostic markers [MELD, MELD-Na, CTP] were not significantly different between survivors and nonsurvivors.

CONCLUSION

ACLF patients in our population had high short-term mortality rates with majority of deaths in alcoholics. Alcohol intake and bacterial infections were mainly responsible for AD in our study.

Acute-on-chronic liver failure: terminology, mechanisms and management

Acute-on-chronic liver failure (ACLF) is a distinct clinical entity and differs from acute liver failure and decompensated cirrhosis in timing, presence of acute precipitant, course of disease and potential for unaided recovery. The definition involves outlining the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific timeframe. The pathophysiology of ACLF relates to persistent inflammation, immune dysregulation with initial wide-spread immune activation, a state of systematic inflammatory response syndrome and subsequent sepsis due to immune paresis. The disease severity and outcome can be predicted by both hepatic and extrahepatic organ failure(s). Clinical recovery is expected with the use of nucleoside analogues for hepatitis B, and steroids for severe alcoholic hepatitis and, possibly, severe autoimmune hepatitis. Artificial liver support systems help remove toxins and metabolites and serve as a bridge therapy before liver transplantation. Hepatic regeneration during ongoing liver failure, although challenging, is possible through the use of growth factors. Liver transplantation remains the definitive treatment with a good outcome. Pre-emptive antiviral agents for hepatitis B before chemotherapy to prevent viral reactivation and caution in using potentially hepatotoxic drugs can prevent the development of ACLF.

Overview on acute-on-chronic liver failure

Liver failure (LF) is defined as severe dysfunction in hepatic synthesis, detoxification, and metabolism induced by various etiologies. Clinical presentation of LF typically includes severe jaundice, coagulation disorder, hepatic encephalopathy, and ascites. LF can be classified into acute LF, acute-on-chronic LF (ACLF), and chronic LF. ACLF has been demonstrated as a distinct syndrome with unique clinical presentation and outcomes. The severity, curability, and reversibility of ACLF have attracted considerable attention. Remarkable developments in ACLF-related conception, diagnostic criteria, pathogenesis, and therapy have been achieved. However, this disease, especially its diagnostic criteria, remains controversial. In this paper, we systemically reviewed the current understanding of ACLF from its definition, etiology, pathophysiology, pathology, and clinical presentation to management by thoroughly comparing important findings between east and west countries, as well as those from other regions. We also discussed the controversies, challenges, and needs for future studies to promote the standardization and optimization of the diagnosis and treatment for ACLF.

Child-Pugh Versus MELD Score for the Assessment of Prognosis in Liver Cirrhosis: A Systematic Review and Meta-Analysis of Observational Studies

Child-Pugh and MELD scores have been widely used for the assessment of prognosis in liver cirrhosis. A systematic review and meta-analysis aimed to compare the discriminative ability of Child-Pugh versus MELD score to assess the prognosis of cirrhotic patients.PubMed and EMBASE databases were searched. The statistical results were summarized from every individual study. The summary areas under receiver operating characteristic curves, sensitivities, specificities, positive and negative likelihood ratios, and diagnostic odds ratios were also calculated.Of the 1095 papers initially identified, 119 were eligible for the systematic review. Study population was heterogeneous among studies. They included 269 comparisons, of which 44 favored MELD score, 16 favored Child-Pugh score, 99 did not find any significant difference between them, and 110 did not report the statistical significance. Forty-two papers were further included in the meta-analysis. In patients with acute-on-chronic liver failure, Child-Pugh score had a higher sensitivity and a lower specificity than MELD score. In patients admitted to ICU, MELD score had a smaller negative likelihood ratio and a higher sensitivity than Child-Pugh score. In patients undergoing surgery, Child-Pugh score had a higher specificity than MELD score. In other subgroup analyses, Child-Pugh and MELD scores had statistically similar discriminative abilities or could not be compared due to the presence of significant diagnostic threshold effects.Although Child-Pugh and MELD scores had similar prognostic values in most of cases, their benefits might be heterogeneous in some specific conditions. The indications for Child-Pugh and MELD scores should be further identified.

Characteristics and Discrepancies in Acute-on-Chronic Liver Failure: Need for a Unified Definition

BACKGROUND & AIM

To investigate the prevalence, mortalities, and patient characteristics of Acute-on-chronic liver failure (ACLF) according to the AARC (Asian Pacific Association for the Study of the Liver ACLF Research Consortium) and European Association for the Study of the Liver CLIF-C (Chronic Liver Failure Consortium) definitions.

METHODS

We collected retrospective data for 1470 hospitalized patients with chronic liver disease (CLD) and acute deterioration between January 2013 and December 2013 from 21 university hospitals in Korea.

RESULTS

Of the patients assessed, the prevalence of ACLF based on the AARC and CLIF-C definitions was 9.5% and 18.6%, respectively. The 28-day and 90-day mortality rates were higher in patients with ACLF than in those without ACLF. Patients who only met the CLIF-C definition had significantly lower 28-day and 90-day survival rates than those who only met the AARC definition (68.0% vs. 93.9%, P<0.001; 55.1% vs. 92.4%, P<0.001). Among the patients who had non-cirrhotic CLD, the 90-day mortality of the patients with ACLF was higher than of those without ACLF, although not significant (33.3% vs. 6.0%, P = 0.192). Patients with previous acute decompensation (AD) within 1- year had a lower 90-day survival rate than those with AD more than 1 year prior or without previous AD (81.0% vs. 91.9% or 89.4%, respectively, all P<0.001). Patients who had extra-hepatic organ failure without liver failure had a similar 90-day survival rate to those who had liver failure as a prerequisite (57.0% vs. 60.6%, P = 0.391).

CONCLUSIONS

The two ACLF definitions result in differences in mortality and patient characteristics among ACLF patients. We suggest that non-cirrhotic CLD, previous AD within 1 year, and extra-hepatic organ failure should be included in the ACLF diagnostic criteria. In addition, further studies are necessary to develop a universal definition of ACLF.

Acute-on-chronic liver failure: Pathogenesis, prognostic factors and management

Acute-on-chronic liver failure (ACLF) is increasingly recognized as a complex syndrome that is reversible in many cases. It is characterized by an acute deterioration of liver function in the background of a pre-existing chronic liver disease often associated with a high short-term mortality rate. Organ failure (OF) is always associated, and plays a key role in determining the course, and the outcome of the disease. The definition of ACLF remains controversial due to its overall ambiguity, with several disparate criteria among various associations dedicated to the study of liver diseases. Although the precise pathogenesis needs to be clarified, it appears that an altered host response to injury might be a contributing factor caused by immune dysfunction, ultimately leading to a pro-inflammatory status, and eventually to OF. The PIRO concept (Predisposition, Insult, Response and Organ Failure) has been proposed to better approach the underlying mechanisms. It is accepted that ACLF is a different and specific form of liver failure, where a precipitating event is always involved, even though it cannot always be ascertained. According to several studies, infections and active alcoholism often trigger ACLF. Viral hepatitis, gastrointestinal haemorrhage, or drug induced liver injury, which can also provoke the syndrome. This review mainly focuses on the physiopathology and prognostic aspects. We believe these features are essential to further understanding and providing the rationale for improveddisease management strategies.

Defining acute-on-chronic liver failure: East, West or Middle ground?

Acute-on-chronic liver failure (ACLF), a newly recognized clinical entity seen in hospitalized patients with chronic liver disease including cirrhosis, is associated with high short- and medium term morbidity and mortality. None of the definitions of ACLF proposed so far have been universally accepted, the two most commonly used being those proposed by the Asia-Pacific Association for the Study of Liver (APASL) and the European Association for the Study of Liver - Chronic Liver Failure (EASL-CLIF) consortium. On paper both definitions and diagnostic criteria appear to be different from each other, reflecting the differences in cut-off values for individual parameters used in diagnosis, the acute insult or precipitating event and the underlying chronic liver disease. Data directly comparing these two criteria are limited, and available studies reveal different outcomes when the two are applied to the same set of patients. However a review of the literature suggests that both definitions do not seem to identify the same set of patients. The definition given by the APASL consortium is easier to apply in day-to-day practice but the EASL-CLIF criteria appear to better predict mortality in ACLF. The World Gastroenterology Organization working party have proposed a working definition of ACLF which will identify patients from whom relevant data can be collected so that the similarities and the differences between the two regions, if any, can be clearly defined.

Role of non-hepatotropic viruses in acute sporadic viral hepatitis and acute-on-chronic liver failure in adults

BACKGROUND

Acute viral hepatitis (AVH) is mostly caused by hepatitis E (HEV) and hepatitis A (HAV) viruses in India. This study was undertaken to find out the incidence of various hepatotropic and non-hepatotropic viruses in AVH and acute-on-chronic liver failure (ACLF) patients.

METHODS

Six-hundred and seventy-three adult patients of AVH and ACLF were screened for acute serological markers of hepatotropic (A, B, C, D, and E) and the non-hepatotropic cytomegalovirus (CMV) and Epstein-Barr virus (EBV).

RESULTS

Viral etiology profile in 295 samples with confirmed etiology were HEV in 155 (52.5 %); HAV in 43 (14.5 %); HBV in 35 (11.8 %); HCV in 1 (0.3 %); mixed viral etiology in 30 (10.1 %); and non-hepatotropic viruses, cytomegalovirus, and Epstein-Barr virus in 31 (10.5 %). Two-hundred and six patients (69.8 %) were AVH and 89 (30.1 %) ACLF. HEV was the commonest cause of infection in both the groups AVH (n = 95, 46.1 %) and ACLF (n = 60, 67.4 %). Twenty-nine (9.8 %) patients died on follow up; mortality was higher in ACLF (25/89, 28 %) than AVH group (4/206, 1.94 %; p < 0.001). The mortality was higher when HEV was the cause of acute event (20/29, 68.9 %). In AVH, mixed infection was more common as compared to ACLF (27 vs. 3, p < 0.001). Non-hepatotropic viruses contributed significantly higher infections in AVH as compared to ACLF (29 vs. 2, p = 0.002) patients.

CONCLUSIONS

HEV was an important cause of symptomatic hepatitis in both AVH and ACLF patients. Non-hepatotropic viruses like CMV and EBV were identified in a significant number of patients with AVH and much less frequently in ACLF.

Acute-on-chronic liver failure

Acute-on-chronic liver failure combines an acute deterioration in liver function in an individual with pre-existing chronic liver disease and hepatic and extrahepatic organ failures, and is associated with substantial short-term mortality. Common precipitants include bacterial and viral infections, alcoholic hepatitis, and surgery, but in more than 40% of patients, no precipitating event is identified. Systemic inflammation and susceptibility to infection are characteristic pathophysiological features. A new diagnostic score, the Chronic Liver Failure Consortium (CLIF-C) organ failure score, has been developed for classification and prognostic assessment of patients with acute-on-chronic liver failure. Disease can be reversed in many patients, and thus clinical management focuses upon the identification and treatment of the precipitant while providing multiorgan-supportive care that addresses the complex pattern of physiological disturbance in critically ill patients with liver disease. Liver transplantation is a highly effective intervention in some specific cases, but recipient identification, organ availability, timing of transplantation, and high resource use are barriers to more widespread application. Recognition of acute-on-chronic liver failure as a clinically and pathophysiologically distinct syndrome with defined diagnostic and prognostic criteria will help to encourage the development of new management pathways and interventions to address the unacceptably high mortality.

Diabetic nephropathy: What does the future hold?

The consensus management of diabetic nephropathy (DN) in 2015 involves good control of glycaemia, dyslipidaemia and blood pressure (BP). Blockade of the renin-angiotensin-aldosterone system using angiotensin-converting enzyme inhibitors, angiotensin-2 receptor blockers or mineralocorticoid inhibitors are key therapeutic approaches, shown to be beneficial once overt nephropathy is manifest, as either, or both, of albuminuria and loss of glomerular filtration rate. Some significant additional clinical benefits in slowing the progression of DN was reported from the Remission clinic experience, where simultaneous intensive control of BP, tight glycaemic control, weight loss, exercise and smoking cessation were prioritised in the management of DN. This has not proved possible to translate to more conventional clinical settings. This review briefly looks over the history and limitations of current therapy from landmark papers and expert reviews, and following an extensive PubMed search identifies the most promising clinical biomarkers (both established and proposed). Many challenges need to be addressed urgently as in order to obtain novel therapies in the clinic; we also need to examine what we mean by remission, stability and progression of DN in the modern era.

Acute-on-chronic liver failure precipitated by hepatic injury is distinct from that precipitated by extrahepatic insults

Patients with acute-on-chronic liver failure (ACLF) represent a heterogeneous population. The aim of the study is to identify distinct groups according to the etiologies of precipitating events. A total of 405 ACLF patients were identified from 1,361 patients with cirrhosis with acute decompensation and categorized according to the types of acute insults. Clinical characteristics and prognosis between the hepatic group and extrahepatic group were compared, and the performance of prognostic models was tested in different groups. Two distinct groups (hepatic-ACLF and extrahepatic-ACLF) were identified among the ACLF population. Hepatic-ACLF was precipitated by hepatic insults and had relatively well-compensated cirrhosis with frequent liver and coagulation failure. In contrast, extrahepatic-ACLF was exclusively precipitated by extrahepatic insults, characterized by more severe underlying cirrhosis and high occurrence of extrahepatic organ failures (kidney, cerebral, circulation, and respiratory systems). Both groups had comparably high short-term mortality (28-day transplant-free mortality: 48.3% vs. 50.7%; P = 0.22); however, the extra-hepatic-ACLF group had significantly higher 90-day and 1-year mortality (90-day: 58.9% vs. 68.3%, P = 0.035; 1-year: 63.9% vs. 74.6%, P = 0.019). In hepatic-ACLF group, the integrated Model for End-Stage Liver Disease (iMELD) score had the highest area under the receiver operating characteristic curve (auROC = 0.787) among various prognostic models in predicting 28-day mortality, whereas CLIF-Consortium scores for ACLF patients (CLIF-C-ACLF) had the highest predictive value in the other group (auROC = 0.779).

CONCLUSIONS

ACLF precipitated by hepatic insults is distinct from ACLF precipitated by extrahepatic insults in clinical presentation and prognosis. The iMELD score may be a better predictor for hepatic-ACLF short-term prognosis, whereas CLIF-C-ACLF may be better for extrahepatic-ACLF patients.

Pattern and profile of chronic liver disease in acute on chronic liver failure

The etiology of the chronic liver disease (CLD) in patients with acute on chronic liver failure (ACLF) may vary from region to region. The major cause of underlying CLD is viral (hepatitis B and C) in the East, while it is alcohol related in the West and in some parts of the Indian subcontinent. Autoimmune liver disease and Wilson's disease are the major underlying etiologies in the pediatric age group. The patients with CLD without cirrhosis should be included when defining ACLF. Non-alcoholic fatty liver disease related chronic liver insult in patients with known risk factors for progressive disease should be taken as a chronic liver disease in the setting of ACLF, whereas fatty liver with normal aminotransferases in low risk patients should not. The patients with CLD and previous decompensation should be excluded. Diagnosis of chronic liver disease in the setting of ACLF is made by history, physical examination and previously available or recent laboratory, endoscopic or radiological investigations. A liver biopsy through the transjugular route may help in cases where the presence of underlying CLD or its cause is not clear. The need of liver biopsy in ACLF should, however, be individualized. Standardization of liver biopsy assessment is essential for a uniform approach to the diagnosis and treatment of CLD and acute insult. Tools to measure liver stiffness may aid in identifying patients with advanced fibrosis. Studies are needed to validate the performance of these tests in the setting of ACLF.

Present and future in the treatment of diabetic kidney disease

Diabetic kidney disease is the leading cause of end-stage renal disease. Albuminuria is recognized as the most important prognostic factor for chronic kidney disease progression. For this reason, blockade of renin-angiotensin system remains the main recommended strategy, with either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. However, other antiproteinuric treatments have begun to be studied, such as direct renin inhibitors or aldosterone blockers. Beyond antiproteinuric treatments, other drugs such as pentoxifylline or bardoxolone have yielded conflicting results. Finally, alternative pathogenic pathways are being explored, and emerging therapies including antifibrotic agents, endothelin receptor antagonists, or transcription factors show promising results. The aim of this review is to explain the advances in newer agents to treat diabetic kidney disease, along with the background of the renin-angiotensin system blockade.

A glimpse of matrix metalloproteinases in diabetic nephropathy

Matrix metalloproteinases (MMPs) are proteolytic enzymes belonging to the family of zinc-dependent endopeptidases that are capable of degrading almost all the proteinaceous components of the extracellular matrix (ECM). It is known that MMPs play a role in a number of renal diseases, such as, various forms of glomerulonephritis and tubular diseases, including some of the inherited kidney diseases. In this regard, ECM accumulation is considered to be a hallmark morphologic finding of diabetic nephropathy, which not only is related to the excessive synthesis of matrix proteins, but also to their decreased degradation by the MMPs. In recent years, increasing evidence suggest that there is a good correlation between the activity or expression of MMPs and progression of renal disease in patients with diabetic nephropathy and in various experimental animal models. In such a diabetic milieu, the expression of MMPs is modulated by high glucose, advanced glycation end products (AGEs), TGF-β, reactive oxygen species (ROS), transcription factors and some of the microRNAs. In this review, we focused on the structure and functions of MMPs, and their role in the pathogenesis of diabetic nephropathy.

Therapeutic approaches to diabetic nephropathy--beyond the RAS

Despite improvements in glycaemic and blood pressure control, and the efficacy of renin-angiotensin system (RAS) blockade for proteinuria reduction, diabetic nephropathy is the most frequent cause of end-stage renal disease in developed countries. This finding is consistent with the hypothesis that key pathogenetic mechanisms leading to progression of renal disease are not modified or inactivated by current therapeutic approaches. Although extensive research has elucidated molecular signalling mechanisms that are involved in progression of diabetic kidney disease, a number of high-profile clinical trials of potentially nephroprotective agents have failed, highlighting an insufficient understanding of pathogenic pathways. These include trials of paricalcitol in early diabetic kidney disease and bardoxolone methyl in advanced-stage disease. Various strategies based on encouraging data from preclinical studies that showed renoprotective effects of receptor antagonists, neutralizing antibodies, kinase inhibitors, small compounds and peptide-based technologies are currently been tested in randomized controlled trials. Phase II clinical trials are investigating approaches targeting inflammation, fibrosis and signalling pathways. However, only one trial that aims to provide evidence for marketing approval of a potentially renoprotective drug (atrasentan) is underway-further research into the potential nephroprotective effects of novel glucose-lowering agents is required.

Overexpression of MMP-7 Increases Collagen 1A2 in the Aging Kidney

The percentage of the U.S. population over 65 is rapidly increasing, as is the incidence of chronic kidney disease (CKD). The kidney is susceptible to age-dependent alterations in structure, specifically tubulointerstitial fibrosis that leads to CKD. Matrix metalloproteinases (MMPs) were initially characterized as extracellular matrix (ECM) proteinases; however, it is clear that their biological role is much larger. We have observed increased gene expression of several MMPs in the aging kidney, including MMP-7. MMP-7 overexpression was observed starting at 16 months, with over a 500-fold upregulation in 2-year-old animals. Overexpression of MMP-7 is not observed in age-matched, calorically restricted controls that do not develop fibrosis and renal dysfunction, suggesting a role in the pathogenesis. In order to delineate the contributions of MMP-7 to renal dysfunction, we overexpressed MMP-7 in NRK-52E cells. High-throughput sequencing of the cells revealed that two collagen genes, Col1a2 and Col3a1, were elevated in the MMP-7 overexpressing cells. These two collagen genes were also elevated in aging rat kidneys and temporally correlated with increased MMP-7 expression. Addition of exogenous MMP-7, or conditioned media from MMP-7 overexpressing cells also increased Col1A2 expression. Inhibition of protein kinase A (PKA), src, and MAPK signaling at p38 and ERK was able to attenuate the MMP-7 upregulation of Col1a2. Consistent with this finding, increased phosphorylation of PKA, src, and ERK was seen in MMP-7 overexpressing cells and upon exogenous MMP-7 treatment of NRK-52E cells. These data suggest a novel mechanism by which MMP-7 contributes to the development of fibrosis leading to CKD.

An update on the pathomechanisms and future therapies of Alport syndrome

Alport Syndrome (AS) is an inherited progressive disease that is caused by mutations of the genes encoding the key collagen chains, α3, α4, and α5, which are necessary for the composition of collagen type IV to form a robust glomerular basement membrane (GBM), capable of withstanding the significant biomechanical strain to which the glomerulus is subjected. Progressive loss of the filtration barrier allows excessive proteinuria, which ultimately leads to end-stage kidney disease (ESKD). The evidence for a beneficial renoprotective effect of renin-angiotensin-aldosterone system (RAAS) blockade by angiotensin-converting enzyme (ACE) inhibition and/or angiotensin receptor blockers (ARBs) is well established in AS and recent evidence has shown that it can significantly delay the time to onset of renal replacement therapy and ESKD. Future potential treatments of AS disease progression are evaluated in this review.

Emerging drugs for managing kidney disease in patients with diabetes

INTRODUCTION

The need for new approaches to manage the increasing numbers of patients with diabetes and their burden of complications is urgent. Of these, chronic kidney disease imposes some of the highest costs, both in dollars and in terms of human suffering. In individuals with diabetes, the presence and severity of kidney disease adversely affects their well-being, contributes to disease morbidity and increases their risk of a premature death.

AREAS COVERED

To collect information for the strategies previously or currently under investigation for managing kidney disease in patients with diabetes, a literature search was performed through the search engines PubMed and ClinicalTrials.gov.

EXPERT OPINION

Despite advancing knowledge on the pathogenesis of diabetic kidney disease, and promising effects in experimental models, at present there are no new drugs that come close to providing the solutions we desire for our patients. Even when used in combination with standard care, renal complications are at best only modestly reduced, at the considerable expense of additional pill burden and exposure to serious off-target effects. Some of the most exciting advances over the last decade, including thiazolidinediones, direct renin inhibitors, endothelin antagonists and most recently bardoxolone methyl have all fallen at this last hurdle. Better targeted ('smarter') drugs appear to be the best hope for renoprotective therapy.

Potential new treatments for diabetic kidney disease

Antifibrotic agents, antioxidant agents, ET-a receptor antagonists, and a few other agents with nonspecific or multifaceted mechanisms of action have been evaluated and progressed to small clinical studies in human subjects. Although there are limited data at the present time, these early evaluations have produced some favorable results that at least warrant further investigation. There is certainly not enough compelling evidence to justify the routine use of any of these products specifically for DKD at the moment; however, more well-controlled and adequately powered studies in several hundred patients will help determine which of these may have a place in the DKD treatment armamentarium of the future.

Doxycycline impairs neutrophil migration to the airspaces of the lung in mice exposed to intratracheal lipopolysaccharide

Background

Tetracyclines are broad-spectrum antibiotics that are also used to induce gene expression using the reverse tetracycline transactivator / tetracycline operator system (rtTA/tetO system). The system assumes that tetracyclines have no effects on mammals. However, a number of studies suggest that tetracyclines may have powerful anti-inflammatory effects. We report that the tetracycline, doxycycline, inhibits neutrophil (PMN) influx into the lungs of mice treated with bacterial endotoxin (LPS).

Methods

Mice were challenged with intratracheal LPS in the presence or absence of doxycyline. bronchoalveolar lavage cell counts and differential, total bronchoalveolar lavage protein, lung homogenate caspase-3 and tissue imaging were used to assess lung injury. In addition, PMN chemotaxis was measured in vitro and syndecan-1 was measured in bronchoalveolar lavage fluid.

Results

The administration of doxycycline resulted in a significant decrease in the number of bronchoalveolar lavage PMNs in LPS-treated mice. Doxycycline had no effect on other markers of lung injury such as total bronchoalveolar lavage protein and whole lung caspase-3 activity. However, doxycycline resulted in a decrease in shed syndecan-1 in bronchoalveolar lavage fluid.

Conclusion

We conclude that doxycycline has an important anti-inflammatory effect that can potentially confound the experiments in which the rtTA/tetO system is being used to study the immune response.

Matrix metalloproteinases in kidney homeostasis and diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have been increasingly linked to both normal physiology and abnormal pathology in the kidney. Collectively able to degrade all components of the extracellular matrix, MMPs were originally thought to antagonize the development of fibrotic diseases solely through digestion of excessive matrix. However, increasing evidence has shown that MMPs play a wide variety of roles in regulating inflammation, epithelial-mesenchymal transition, cell proliferation, angiogenesis, and apoptosis. We now have robust evidence for MMP dysregulation in a multitude of renal diseases including acute kidney injury, diabetic nephropathy, glomerulonephritis, inherited kidney disease, and chronic allograft nephropathy. The goal of this review is to summarize current findings regarding the role of MMPs in kidney diseases as well as the mechanisms of action of this family of proteases.

Imbalanced matrix metalloproteinases in cardiovascular complications of end-stage kidney disease: a potential pharmacological target

End-stage kidney disease (ESKD) is a major health problem associated with very high morbidity and mortality secondary to cardiovascular complications, especially in ESKD patients on dialysis. Therefore, exploring key mechanisms underlying cardiovascular alterations associated with ESKD may offer reasonable pharmacological targets that may benefit these patients. Imbalanced matrix metalloproteinases (MMP) activities have been implicated in many cardiovascular diseases, and growing evidence now indicates that excessive MMP activities contribute to cardiovascular complications in ESKD patients. However, there is no study on the effects of MMP inhibitors (MMPIs) in such patients. MMPIs may prevent against the vascular and cardiac changes associated with ESKD. In this MiniReview, we aimed at reviewing current evidence supporting the idea that pharmacological inhibition of imbalanced MMP activities in ESKD may decrease the morbidity and mortality associated with cardiovascular complications in ESKD patients. However, MMPs have variable effects during different phases of kidney disease, and therefore optimal timing for MMP inhibition during a disease process may vary significantly and is largely undetermined. While current research shows that MMPs play a role in the pathogenesis of the cardiovascular alterations found in ESKD patients, clinical studies are required to validate the idea of using MMPIs in ESKD.