Acute liver failure.

Acute liver failure (ALF) is a life-threatening disorder characterised by rapid deterioration of liver function, coagulopathy, and hepatic encephalopathy in the absence of pre-existing liver disease. The cause of ALF varies across the world. Common causes of ALF in adults include drug toxicity, hepatotropic and non-hepatotropic viruses, herbal and dietary supplements, antituberculosis drugs, and autoimmune hepatitis. The cause of liver failure affects the management and prognosis, and therefore extensive investigation for cause is strongly suggested. Sepsis with multiorgan failure and cerebral oedema remain the leading causes of death in patients with ALF and early identification and appropriate management can alter the course of ALF. Liver transplantation is the best current therapy, although the role of artificial liver support systems, particularly therapeutic plasma exchange, can be useful for patients with ALF, especially in non-transplant centres. In this Seminar, we discuss the cause, prognostic models, and management of ALF.

Development and external validation of a model to predict multidrug-resistant bacterial infections in patients with cirrhosis.

With the increasing rate of infections caused by multidrug-resistant organisms (MDRO), selecting appropriate empiric antibiotics has become challenging. We aimed to develop and externally validate a model for predicting the risk of MDRO infections in patients with cirrhosis. METHODS: We included patients with cirrhosis and bacterial infections from two prospective studies: a transcontinental study was used for model development and internal validation (n = 1302), and a study from Argentina and Uruguay was used for external validation (n = 472). All predictors were measured at the time of infection. Both culture-positive and culture-negative infections were included. The model was developed using logistic regression with backward stepwise predictor selection. We externally validated the optimism-adjusted model using calibration and discrimination statistics and evaluated its clinical utility. RESULTS: The prevalence of MDRO infections was 19% and 22% in the development and external validation datasets, respectively. The model's predictors were sex, prior antibiotic use, type and site of infection, MELD-Na, use of vasopressors, acute-on-chronic liver failure, and interaction terms. Upon external validation, the calibration slope was 77 (95% CI .48-1.05), and the area under the ROC curve was .68 (95% CI .61-.73). The application of the model significantly changed the post-test probability of having an MDRO infection, identifying patients with nosocomial infection at very low risk (8%) and patients with community-acquired infections at significant risk (36%). CONCLUSION: This model achieved adequate performance and could be used to improve the selection of empiric antibiotics, aligning with other antibiotic stewardship program strategies.

Frailty and sarcopenia in patients with cirrhosis awaiting liver transplantation: evidence from a single-centre, prospective cohort study.

Sarcopenia and frailty are common complications in patients with cirrhosis evaluated for liver transplantation (LT). Although the negative impact of sarcopenia on patient's outcome has been well studied, the prognostic role of frailty is not as clear. We assessed the prevalence of sarcopenia and frailty and the clinical impact of frailty in a prospective cohort of cirrhosis patients with and without hepatocellular carcinoma (HCC) listed for LT. Patients with cirrhosis were prospectively recruited at the time of admission into the waiting list. Clinical and lab values were collected. Physical frailty was assessed by liver frailty index (LFI) and patients were categorized into robust (< 3.2); pre-frail (between 3.2 and 4.5), and frail (> 4.5). Skeletal muscle mass was evaluated via skeletal muscle index (SMI) obtained from last CT scan before LT; sarcopenia was defined by SMI < 50 cm2/m2 in males and < 39 cm2/m2 in females. 105 patients were included, of which 42 (40%) had hepatocellular carcinoma (HCC). In patients without HCC (63.5% males, median age 61 years), 36.5% were frail, 50.8% were pre-frail and 12.7% were robust. Frail patients were older than non-frail patients (63 vs. 56; p = 0.008) and had more severe liver disease (Child C: 65% vs. 37.5%; p = 0.02). Prevalence of sarcopenia in patients without HCC was 63%, with similar value of median SMI between frail and not frail patients (p = 0.454). Patients with HCC (78.6% males, 65 years old) were 21.4% frail, 61.9% pre-frail, and 16.7% robust. Frail patients had more severe liver disease (Child C: 77% vs. 18.2%; p = 0.004), whereas age was comparable to non-frail patients; among patients without HCC, during a median follow-up of 263 days, 17% died (of which 72% were frail) and 10 patients were delisted due to clinical improvement (none of whom were frail). Among those with HCC, during a median follow-up of 289 days, 4 (9%) patients died of which 50% were frail. Frailty and sarcopenia are common complications in patients with cirrhosis awaiting LT. Frailty appears to be associated with an increased risk of mortality during wait-list time especially in those with decompensated cirrhosis. At univariate analysis Meld score, Child score and presence of frailty were found to be associated with shorter survival, however, at multivariate analysis presence of frailty and Child C vs. A/B were the only independent predictor of death. Larger cohorts are required to confirm these results.

Long-term albumin improves the outcomes of patients with decompensated cirrhosis and diabetes mellitus: Post hoc analysis of the ANSWER trial.

Type-2 diabetes mellitus is a frequent comorbidity of cirrhosis independently associated with cirrhosis-related complications and mortality. This post hoc analysis of the ANSWER trial database assessed the effects of long-term human albumin (HA) administration on top of the standard medical treatment (SMT) on the clinical outcomes of a subgroup of 85 outpatients with liver cirrhosis, uncomplicated ascites and insulin-treated diabetes mellitus type 2 (ITDM). Compared to patients in the SMT arm, the SMT + HA group showed a better overall survival (86% vs. 57%, p = .016) and lower incidence rates of paracenteses, overt hepatic encephalopathy, bacterial infections, renal dysfunction and electrolyte disorders. Hospital admissions did not differ between the two arms, but the number of days spent in hospital was lower in the SMT + HA group. In conclusion, in a subgroup of ITDM outpatients with decompensated cirrhosis and ascites, long-term HA administration was associated with better survival and a lower incidence of cirrhosis-related complications.

Recompensation of cirrhosis in candidates of transplant: Tips and tricks for delisting.

Liver transplantation (LT) is the most successful treatment for patients with decompensated cirrhosis. The availability of effective and safe etiological treatments has altered the natural history of decompensated cirrhosis. Recently, the concept of recompensation has been defined. Patients who achieve recompensation may be removed from the waiting list for LT. Therefore, achieving an etiological cure is the cornerstone in the treatment of patients with decompensated cirrhosis. However, most patients improve their liver function after an etiologic cure, and only a proportion of patients achieve true recompensation after an etiological cure. Some patients maintain a condition of "MELD purgatory," that is, an improvement in the Model for End-Stage Liver Disease score without relevant clinical improvement that prevents delisting and may be even detrimental because lower Model for End-Stage Liver Disease score delays LT. Herein, we review the available evidence regarding recompensation and the management of recompensated patients on the waiting list for LT.

Infectious Complications of Portal Hypertension.

Patients with cirrhosis and clinically significant portal hypertension are at high risk of developing bacterial infections (BIs) that are the most common trigger of acute decompensation and acute-on-chronic liver failure. Furthermore, after decompensation, the risk of developing BIs further increases in an ominous vicious circle. BIs may be subtle, and they should be ruled out in all patients at admission and in case of deterioration. Timely administration of adequate empirical antibiotics is the cornerstone of treatment. Herein, we reviewed current evidences about pathogenesis, clinical implications and management of BIs in patients with cirrhosis and portal hypertension.

Infections in cirrhosis.

Cirrhosis is an immune dysfunction state, and as such, patients with cirrhosis are susceptible to bacterial, fungal, and viral infections. Because of infection, these patients have a propensity to develop multiorgan failure, which is associated with high mortality. Bacterial infections are the most prevalent type of infection in patients with cirrhosis, with the prevalence of bacterial infections in patients admitted for an acute decompensating event ranging from 24% to 29%. Together with invasive fungal infections, bacterial infections are the most severe. Multidrug-resistant organisms have been evolving at a rapid and alarming rate around the world, which presents enormous challenges. The development of effective measures for the prevention, early detection, and treatment of infections in patients with cirrhosis is challenging, given the rising incidence of infections in this patient population.

Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting.

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.

Controversies in terlipressin and transplantation in the United States: How do we MELD the two?

Hepatorenal syndrome-acute kidney injury (HRS-AKI) is a severe complication of cirrhosis that carries a poor prognosis. The recent Food and Drug Administration approval of terlipressin has substantial implications for managing HRS-AKI and liver allocation in the United States. Terlipressin has been available in Europe for over a decade, and several countries have adapted policy changes such as Model for End-Stage Liver Disease (MELD) score "lock" for HRS-AKI. In this article, we outline the European experience with terlipressin use and explore the question of whether terlipressin treatment for HRS-AKI should qualify for the MELD score "lock" in the United States in those who respond to therapy. Arguments for the MELD lock include protecting waitlist priority for terlipressin responders or partial responders who may miss offers due to MELD reduction in the terlipressin treatment window. Arguments against MELD lock include the fact that terlipressin may produce a durable response and improve overall survival and that equitable access to terlipressin is not guaranteed due to cost and availability. We subsequently discuss the proposed next steps for studying terlipressin implementation in the United States. A successful approach will require the involvement of all major stakeholders and the mobilization of our transplant community to spearhead research in this area.

Hepatorenal Syndrome in Cirrhosis.

Hepatorenal syndrome (HRS) is a form of kidney dysfunction that characteristically occurs in liver cirrhosis. It is characterized by a marked impairment of kidney function in response to circulatory and hemodynamic alterations that occur in advanced stages of liver cirrhosis, aggravated by systemic inflammation and bacterial translocation. The classical definitions of the types of HRS have been recently revisited and 2 forms of HRS have been redefined: the acute form, referred to as acute kidney injury (HRS-AKI), and the chronic form, referred to as chronic kidney disease. HRS-AKI is one of the most severe forms of AKI in patients with cirrhosis and it consists of an abrupt impairment of kidney function, frequently triggered by an infection, appearing in the setting of advanced decompensated cirrhosis. Differential diagnosis with other causes of AKI is crucial because HRS-AKI requires a specific treatment. Differential diagnosis with AKI-acute tubular necrosis may be challenging and kidney biomarkers may be useful in this setting. Treatment of HRS-AKI is based on the administration of vasoconstrictor drugs in combination with volume expansion with albumin. Prognosis of HRS-AKI is poor, and the ideal definitive treatment consists of liver transplantation or simultaneous liver-kidney transplantation. HRS-AKI has a big impact on patients' quality of life. Management of HRS-AKI remains challenging in specific situations such as alcohol-associated hepatitis or metabolic-associated steatotic liver disease cirrhosis. Developing preventive measures for HRS-AKI, improving its early identification, discovering new biomarkers for differential diagnosis, and improving the response to therapy are some of the unmet needs in the field of HRS-AKI.

Prognostic significance of acute kidney injury stage 1B in hospitalized patients with cirrhosis: A US nationwide study.

Understanding the prognostic significance of acute kidney injury (AKI) stage 1B [serum creatinine (sCr) ≥1.5 mg/dL] compared with stage 1A (sCr < 1.5 mg/dL) in a US population is important as it can impact initial management decisions for AKI in hospitalized cirrhosis patients. Therefore, we aimed to define outcomes associated with stage 1B in a nationwide US cohort of hospitalized cirrhosis patients with AKI. Hospitalized cirrhosis patients with AKI in the Cerner-Health-Facts database from January 2009 to September 2017 (n = 6250) were assessed for AKI stage 1 (≥1.5-2-fold increase in sCr from baseline) and were followed for 90 days for outcomes. The primary outcome was 90-day mortality; secondary outcomes were in-hospital AKI progression and AKI recovery. Competing-risk multivariable analysis was performed to determine the independent association between stage 1B, 90-day mortality (liver transplant as a competing risk), and AKI recovery (death/liver transplant as a competing risk). Multivariable logistic regression analysis was performed to determine the independent association between stage 1B and AKI progression. In all, 4654 patients with stage 1 were analyzed: 1A (44.3%) and 1B (55.7%). Stage 1B patients had a significantly higher cumulative incidence of 90-day mortality compared with stage 1A patients, 27.2% versus 19.7% ( p < 0.001). In multivariable competing-risk analysis, patients with stage 1B (vs. 1A) had a higher risk for mortality at 90 days [sHR 1.52 (95% CI 1.20-1.92), p = 0.001] and decreased probability for AKI recovery [sHR 0.76 (95% CI 0.69-0.83), p < 0.001]. Furthermore, in multivariable logistic regression analysis, AKI stage 1B (vs. 1A) was independently associated with AKI progression, OR 1.42 (95% CI 1.14-1.72) ( p < 0.001). AKI stage 1B patients have a significantly higher risk for 90-day mortality, AKI progression, and reduced probability of AKI recovery compared with AKI stage 1A patients. These results could guide initial management decisions for AKI in hospitalized patients with cirrhosis.

Determinants of clinical response to empirical antibiotic treatment in patients with cirrhosis and bacterial and fungal infections-Results from the ICA "Global Study" (EABCIR-Global Study).

BACKGROUND: The administration of an appropriate empirical antibiotic treatment is essential in cirrhosis and severe bacterial infections. We aimed to investigate the predictors of clinical response of empirical antibiotic treatment in a prospective cohort of patients with cirrhosis and bacterial and fungal infections included in the International Club of Ascites "Global Study." METHODS: Patients hospitalized with cirrhosis and bacterial/fungal infection were prospectively enrolled at 46 centers. Clinical response to antibiotic treatment was defined according to changes in markers of infection/inflammation, vital signs, improvement of organ failure, and results of cultures. RESULTS: From October 2015 to September 2016, 1302 patients were included at 46 centers. A clinical response was achieved in only 61% of cases. Independent predictors of lack of clinical response to empirical treatment were C-reactive protein (OR = 1.16; 95% CI = 1.02-1.31), blood leukocyte count (OR = 1.39;95% CI = 1.09-1.77), serum albumin (OR = 0.70; 95% CI = 0.55-0.88), nosocomial infections (OR = 1.96; 95% CI = 1.20-2.38), pneumonia (OR = 1.75; 95% CI = 1.22-2.53), and ineffective treatment according to antibiotic susceptibility test (OR = 5.32; 95% CI = 3.47-8.57). Patients with a lack of clinical response to first-line antibiotic treatment had a significantly lower resolution rate of infections (55% vs. 96%; p < 0.001), a higher incidence of second infections (29% vs. 15%; p < 0.001), shock (35% vs. 7%; p < 0.001) and new organ failures (52% vs. 19 %; p < 0.001) than responders. Clinical response to empirical treatment was an independent predictor of 28-day survival ( subdistribution = 0.20; 95% CI = 0.14-0.27). CONCLUSIONS: Four out of 10 patients with cirrhosis do not respond to the first-line antibiotic therapy, leading to lower resolution of infections and higher mortality. Broader-spectrum antibiotics and strategies targeting systemic inflammation may improve prognosis in patients with a high degree of inflammation, low serum albumin levels, and severe liver impairment.

The polymorphic variant of SerpinB3 (SerpinB3-PD) is associated with faster cirrhosis decompensation.

BACKGROUND: SerpinB3 is a cysteine protease inhibitor involved in liver disease progression due to its proinflammatory and profibrogenic properties. The polymorphic variant SerpinB3-PD (SB3-PD), presents a substitution in its reactive centre loop, determining the gain of function. AIMS: To disclose the clinical characteristics of a cohort of patients with cirrhosis in relation to the presence of SB3-PD and to assess the effect of this genetic variant on fibrogenic and inflammatory cytokines in vitro. METHODS: We assessed SB3 polymorphism in 90 patients with cirrhosis, prospectively followed up in our referral centre. We used HepG2 and HuH-7 cells transfected to overexpress either wild-type SB3 (SB3-WT) or SB3-PD to assess their endogenous effect, while LX2 and THP-1 cells were treated with exogenous SB3-WT or SB3-PD proteins. RESULTS: Patients carrying SB3-PD had more severe portal hypertension and higher MELD scores, than patients carrying SB3-WT. In multivariate analysis, SB3-PD was an independent predictor of cirrhosis complications. Patients with SB3-PD polymorphism presented with more severe liver fibrosis and inflammatory features. Hepatoma cells overexpressing SB3-PD showed higher TGF-ß1 expression than controls. The addition of recombinant SB3-PD induced an up-regulation of TGF-ß1 in LX2 cells and a more prominent inflammatory profile in THP-1 cells, compared to the effect of SB3-WT protein. CONCLUSIONS: The polymorphic variant SB3-PD is highly effective in determining activation of TGF-ß1 and inflammation in vitro. Patients with cirrhosis who carry SB3-PD polymorphism may be more prone to develop severe liver disease progression. However, further validation studies are warranted to support the in vivo relevance of this polymorphism.

A new clinical and prognostic characterization of the patterns of decompensation of cirrhosis.

BACKGROUND & AIMS: The prognostic impact of acute decompensation (AD), i.e. the development of complications that require hospitalization, has recently been assessed. However, complications of cirrhosis do not necessarily require hospitalization and can develop progressively, as in the recently defined non-acute decompensation (NAD). Nevertheless, there is no data regarding the incidence and prognostic impact of NAD. The aim of the study was to evaluate the incidence and the prognostic impact of NAD and AD in outpatients with cirrhosis. METHODS: A total of 617 outpatients with cirrhosis from two Italian tertiary centers (Padua and Milan) were enrolled from January 2003 to June 2021 and followed prospectively until the end of the study, death or liver transplantation. The complications registered during follow-up were considered as AD if they required hospitalization, or NAD if managed at the outpatient clinic. RESULTS: During follow-up, 154 patients (25.0% of total patients) developed complications, 69 patients (44.8%) developed NAD and 85 (55.2%) developed AD, while 29 patients with NAD (42.0%) developed a further episode of AD during follow-up. Sixty-month survival was significantly higher in patients with no decompensation than in patients with NAD or AD. On multivariable analysis, AD (hazard ratio [HR] 21.07, p <0.001), NAD (HR 7.13, p <0.001), the etiological cure of cirrhosis (HR 0.38, p <0.001) and model for end-stage liver disease score (HR 1.12, p = 0.003) were found to be independent predictors of mortality. CONCLUSIONS: The first decompensation is non-acute in almost 50% of outpatients, though such events are still associated with decreased survival compared to no decompensation. Patients who develop NAD must be treated with extreme care and monitored closely to prevent the development of AD. IMPACT AND IMPLICATIONS: This multicenter study is the first to investigate the role of non-acute decompensation (NAD) in patients with cirrhosis. In fact, while the unfavorable impact of acute decompensation is well known, there is currently a dearth of evidence on NAD, despite it being a common occurrence in clinical practice. Our data show that almost half of decompensations in patients with cirrhosis can be considered NAD and that such events are associated with a higher risk of mortality than no decompensation. This study has important clinical implications because it highlights the need to carefully consider patients who develop NAD, in order to prevent further decompensation and reduce mortality.

Novel prognostic biomarkers in decompensated cirrhosis: a systematic review and meta-analysis.

BACKGROUND: Patients with decompensated cirrhosis experience high mortality rates. Current prognostic scores, including the model for end-stage liver disease (MELD), may underperform in settings other than in those they were initially developed. Novel biomarkers have been proposed to improve prognostication accuracy and even to predict development of complications. METHODS: We performed a systematic review and meta-analysis on novel urine and blood biomarkers and their ability to predict 90-day mortality in patients with decompensated cirrhosis. Secondary outcomes included 28-day and 1-year mortality, and development of acute-on-chronic liver failure, acute kidney injury and other complications. To overcome differences in units, temporal changes in assays and reporting heterogeneity, we used the ratio of means (RoM) as measure of association for assessing strength in predicting outcomes. An RoM>1 implies that the mean biomarker level is higher in those that develop the outcome than in those that do not. RESULTS: Of 6629 unique references, 103 were included, reporting on 29 different biomarkers, with a total of 31 362 biomarker patients. Most studies were prospective cohorts of hospitalised patients (median Child-Pugh-Turcotte score of 9 and MELD score of 18). The pooled 90-day mortality rate was 0.27 (95% CI 0.24 to 0.29). The RoM for predicting 90-day mortality was highest for interleukin 6 (IL-6) (2.56, 95% CI 2.39 to 2.74), followed by urinary neutrophil gelatinase-associated lipocalin (uNGAL) (2.42, 95% CI 2.20 to 2.66) and copeptin (2.33, 95% CI 2.17 to 2.50). These RoMs were all higher than for MELD (1.44, 95% CI 1.42 to 1.46). CONCLUSION: Novel biomarkers, including IL-6, uNGAL and copeptin, can probably improve prognostication of patients with decompensated cirrhosis compared with MELD alone.

Mechanisms and treatment approaches for ACLF.

Acute-on-chronic liver failure (ACLF) is a life-threatening syndrome characterized by decompensation of cirrhosis, severe systemic inflammation and organ failures. ACLF is frequently triggered by intra- and/or extrahepatic insults, such as bacterial infections, alcohol-related hepatitis or flares of hepatic viruses. The imbalance between systemic inflammation and immune tolerance causes organ failures through the following mechanisms: (i) direct damage of immune cells/mediators; (ii) worsening of circulatory dysfunction resulting in organ hypoperfusion and (iii) metabolic alterations with prioritization of energetic substrates for inflammation and peripheral organ 'energetic crisis'. Currently, the management of ACLF includes the support of organ failures, the identification and treatment of precipitating factors and expedited assessment for liver transplantation (LT). Early LT should be considered in patients with ACLF grade 3, who are unlikely to recover with the available treatments and have a mortality rate > 70% at 28 days. However, the selection of transplant candidates and their prioritization on the LT waiting list need standardization. Future challenges in the ACLF field include a better understanding of pathophysiological mechanisms leading to inflammation and organ failures, the development of specific treatments for the disease and personalized treatment approaches. Herein, we reviewed the current knowledge and future perspectives on mechanisms and treatment of ACLF.

Development, validation, and prognostic evaluation of a risk score for long-term liver-related outcomes in the general population: a multicohort study.

BACKGROUND: Liver cirrhosis is a major cause of death worldwide. Cirrhosis develops after a long asymptomatic period of fibrosis progression, with the diagnosis frequently occurring late, when major complications or cancer develop. Few reliable tools exist for timely identification of individuals at risk of cirrhosis to allow for early intervention. We aimed to develop a novel score to identify individuals at risk for future liver-related outcomes. METHODS: We derived the LiverRisk score from an international prospective cohort of individuals from six countries without known liver disease from the general population, who underwent liver fibrosis assessment by transient elastography. The score included age, sex, and six standard laboratory variables. We created four groups: minimal risk, low risk, medium risk, and high risk according to selected cutoff values of the LiverRisk score (6, 10, and 15). The model's discriminatory accuracy and calibration were externally validated in two prospective cohorts from the general population. Moreover, we ascertained the prognostic value of the score in the prediction of liver-related outcomes in participants without known liver disease with median follow-up of 12 years (UK Biobank cohort). FINDINGS: We included 14 726 participants: 6357 (43·2%) in the derivation cohort, 4370 (29·7%) in the first external validation cohort, and 3999 (27·2%) in the second external validation cohort. The score accurately predicted liver stiffness in the development and external validation cohorts, and was superior to conventional serum biomarkers of fibrosis, as measured by area under the receiver-operating characteristics curve (AUC; 0·83 [95% CI [0·78-0·89]) versus the fibrosis-4 index (FIB-4; 0·68 [0·61-0·75] at 10 kPa). The score was effective in identifying individuals at risk of liver-related mortality, liver-related hospitalisation, and liver cancer, thereby allowing stratification to different risk groups for liver-related outcomes. The hazard ratio for liver-related mortality in the high-risk group was 471 (95% CI 347-641) compared with the minimal risk group, and the overall AUC of the score in predicting 10-year liver-related mortality was 0·90 (0·88-0·91) versus 0.84 (0·82-0·86) for FIB-4. INTERPRETATION: The LiverRisk score, based on simple parameters, predicted liver fibrosis and future development of liver-related outcomes in the general population. The score might allow for stratification of individuals according to liver risk and thus guide preventive care. FUNDING: European Commission under the H20/20 programme; Fondo de Investigación Sanitaria de Salud; Instituto de Salud Carlos III; Spanish Ministry of Economy, Industry, and Competitiveness; the European Regional Development Fund; and the German Ministry of Education and Research (BMBF).