Author Correction: Predicting hepatic complications of allogeneic hematopoietic stem cell transplantation using liver stiffness measurement.

In the original article, the affiliations were presented incorrectly. David Petroff is in fact the only author at affiliation 2. All other authors listed as being at affiliation 2 (Tina Weiße, Sebastian Beer, Franziska Gnatzy, Joachim Mössner, Michael Tröltzsch, Johannes Wiegand and Volker Keim) are in fact just at affiliation 1. These have now been corrected in the original article.

Predicting hepatic complications of allogeneic hematopoietic stem cell transplantation using liver stiffness measurement.

Allogeneic hematopoietic stem cell transplantation is the only curative option for a variety of diseases. Despite advances, it is associated with considerable morbidity and mortality, often involving liver complications. Liver disease can be characterized using ultrasound-based liver stiffness measurement. To assess its prognostic value, consecutive patients undergoing allogeneic hematopoietic stem cell transplantation were prospectively evaluated in a single-center study. Endpoints included liver event-free survival and all-cause mortality at 1 year. Competing risk and Cox-regression were used for analysis. We evaluated 106 patients (42 female, age 57) and observed 33 life-threatening events (14 died) including 16 liver complications at 100 days. At 1 year, 36 patients had died, 20 with disease relapse. The hazard ratios for liver-related complications at 100 days were 3.2 (95% CI: 1.8-14.6, p = 0.0022) and 4.4 (95% CI: 1.6-11.9, p = 0.0042) for elevated transient elastography (n = 11) and shear-wave velocity (n = 31), respectively. Results were analogous for all-cause mortality at 1 year. Prior stem cell therapy and elevated gamma glutamyltransferase were also associated with outcome. This demonstrates that elastography is a promising and viable tool for risk prediction and should be included in upcoming multi-center trials to establish new means of guiding treatment and prophylaxis.

Predictive value of liver and spleen stiffness in advanced alcoholic cirrhosis with refractory ascites.

BACKGROUND: Recurrent ascitic decompensation is a frequent complication of advanced alcoholic liver disease. Ascites can be controlled by transjugular intrahepatic portosystemic shunt (TIPS) implantation, but specific pre-procedural outcome predictors are not well established. Liver and spleen stiffness measurement (LSM, SSM) correlate with outcome of compensated liver disease, but data for decompensated cirrhosis disease are scarce. Therefore, the predictive value of LSM and SSM was evaluated in patients with refractory ascites treated with TIPS insertion or receiving conservative therapy. MATERIAL AND METHODS: Patients with alcoholic liver cirrhosis and recurrent or refractory ascites were stratified according to TIPS eligibility. LSM was prospectively assessed by transient elastography (TE, XL probe) and point shear wave elastography (pSWE). pSWE was also used for SSM. The primary study endpoint was transplant-free survival after 12 months. In addition, correlation of LSM and SSM with TIPS complications was analyzed. RESULTS: 43 patients (16 % female, age 55.5 [28.6 - 79.6] years) were recruited, n = 20 underwent TIPS and n = 23 were treated with repeated paracenteses only. 15 patients died and five underwent liver transplantation during follow-up. LSM and SSM at baseline did not predict the patients' outcome in the TIPS cohort and in patients with conservative therapy. SSM was increased in two cases with spontaneous TIPS occlusion and declined after revision. CONCLUSION: LSM and SSM cannot be recommended for risk stratification in cirrhotic patients with refractory ascites. SSM may be useful in monitoring TIPS function during follow-up.

Evaluation of Transient Elastography, Acoustic Radiation Force Impulse Imaging (ARFI), and Enhanced Liver Function (ELF) Score for Detection of Fibrosis in Morbidly Obese Patients.

BACKGROUND: Liver fibrosis induced by non-alcoholic fatty liver disease causes peri-interventional complications in morbidly obese patients. We determined the performance of transient elastography (TE), acoustic radiation force impulse (ARFI) imaging, and enhanced liver fibrosis (ELF) score for fibrosis detection in bariatric patients. PATIENTS AND METHODS: 41 patients (median BMI 47 kg/m2) underwent 14-day low-energy diets to improve conditions prior to bariatric surgery (day 0). TE (M and XL probe), ARFI, and ELF score were performed on days -15 and -1 and compared with intraoperative liver biopsies (NAS staging). RESULTS: Valid TE and ARFI results at day -15 and -1 were obtained in 49%/88% and 51%/90% of cases, respectively. High skin-to-liver-capsule distances correlated with invalid TE measurements. Fibrosis of liver biopsies was staged as F1 and F3 in n = 40 and n = 1 individuals. However, variations (median/range at d-15/-1) of TE (4.6/2.6-75 and 6.7/2.9-21.3 kPa) and ARFI (2.1/0.7-3.7 and 2.0/0.7-3.8 m/s) were high and associated with overestimation of fibrosis. The ELF score correctly classified 87.5% of patients. CONCLUSION: In bariatric patients, performance of TE and ARFI was poor and did not improve after weight loss. The ELF score correctly classified the majority of cases and should be further evaluated.

Estimating steatosis and fibrosis: Comparison of acoustic structure quantification with established techniques.

AIM: To compare ultrasound-based acoustic structure quantification (ASQ) with established non-invasive techniques for grading and staging fatty liver disease. METHODS: Type 2 diabetic patients at risk of non-alcoholic fatty liver disease (n = 50) and healthy volunteers (n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography (TE), controlled attenuation parameter (CAP), proton magnetic resonance spectroscopy ((1)H-MRS; only available for the diabetic cohort), and ASQ. ASQ parameters mode, average and focal disturbance (FD) ratio were compared with: (1) the extent of liver fibrosis estimated from TE and non-alcoholic fatty liver disease (NAFLD) fibrosis scores; and (2) the amount of steatosis, which was classified according to CAP values. RESULTS: Forty-seven diabetic patients (age 67.0 ± 8.6 years; body mass index 29.4 ± 4.5 kg/m²) with reliable CAP measurements and all controls (age 26.5 ± 3.2 years; body mass index 22.0 ± 2.7 kg/m²) were included in the analysis. All ASQ parameters showed differences between healthy controls and diabetic patients (P < 0.001, respectively). The ASQ FD ratio (logarithmic) correlated with the CAP (r = -0.81, P < 0.001) and (1)H-MRS (r = -0.43, P = 0.004) results. The FD ratio [CAP < 250 dB/m: 107 (102-109), CAP between 250 and 300 dB/m: 106 (102-114); CAP between 300 and 350 dB/m: 105 (100-112), CAP ≥ 350 dB/m: 102 (99-108)] as well as mode and average parameters, were reduced in cases with advanced steatosis (ANOVA P < 0.05). However, none of the ASQ parameters showed a significant difference in patients with advanced fibrosis, as determined by TE and the NAFLD fibrosis score (P > 0.08, respectively). CONCLUSION: ASQ parameters correlate with steatosis, but not with fibrosis in fatty liver disease. Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies.

Noninvasive characterization of graft steatosis after liver transplantation.

OBJECTIVE: Liver graft steatosis has not been noninvasively evaluated yet. We therefore characterized liver transplant recipients by transient elastography (TE) and controlled attenuation parameter (CAP) and correlated the results with clinical and genetic risk factors. METHODS: A total of 204 patients (pretransplant disease: n = 102 nonalcoholic etiology, nonalcoholic liver cirrhosis (non-ALC); n = 102 alcoholic liver disease, ALC; 42% female; median age 57.8 years; median time since transplantation 66 months) underwent ultrasound, TE, CAP, and nonalcoholic fatty liver disease (NAFLD) fibrosis score. Recipient DNA samples were genotyped for patatin-like phospholipase domain-containing protein 3 (PNPLA3) (rs738409) and IL28B (rs8099917, rs12979860) polymorphisms. RESULTS: Increased hepatic echogenicity at ultrasound was observed in 36% of patients, CAP values >252 and >300 dB/m indicated steatosis and advanced steatosis in 44% and 24% of individuals. Advanced fibrosis (TE >7.9 kPa) was associated with increased CAP results (266 vs. 229 dB/m, p = 0.012). PNPLA3 G-allele carriers had increased CAP values (257 vs. 222 dB/m, p = 0.032), higher liver stiffness (TE 6.4 vs. 5.5 kPa, p = 0.005), and prevalence of diabetes mellitus (40% vs. 22%, p = 0.016). No such association was observed for IL28B polymorphisms. ALC compared to non-ALC patients had higher body mass index (28.1 vs. 25.5 kg/m², p < 0.001), higher prevalence of diabetes mellitus (41% vs. 25%, p = 0.017), and PNPLA3 CG + GG genotype (73% vs. 47%, p = 0.006), and had elevated TE (6.3 vs. 5.4 kPa, p = 0.022), CAP (266 vs. 221 dB/m, p = 0.001), and NAFLD fibrosis score (score -0.5 vs. -1.3, p < 0.001). CONCLUSION: Modern noninvasive liver graft assessment frequently detects hepatic steatosis, which is associated with graft fibrosis, components of the metabolic syndrome and recipient PNPLA3 rs738409 genotype, especially in ALC patients.

Non-invasive assessment of hepatic steatosis in patients with NAFLD using controlled attenuation parameter and 1H-MR spectroscopy.

INTRODUCTION: Non-invasive assessment of steatosis and fibrosis is of growing relevance in non-alcoholic fatty liver disease (NAFLD). 1H-Magnetic resonance spectroscopy (1H-MRS) and the ultrasound-based controlled attenuation parameter (CAP) correlate with biopsy proven steatosis, but have not been correlated with each other so far. We therefore performed a head-to-head comparison between both methods. METHODS: Fifty patients with biopsy-proven NAFLD and 15 healthy volunteers were evaluated with 1H-MRS and transient elastography (TE) including CAP. Steatosis was defined according to the percentage of affected hepatocytes: S1 5-33%, S2 34-66%, S3 ≥67%. RESULTS: Steatosis grade in patients with NAFLD was S1 36%, S2 40% and S3 24%. CAP and 1H-MRS significantly correlated with histopathology and showed comparable accuracy for the detection of hepatic steatosis: areas under the receiver-operating characteristics curves were 0.93 vs. 0.88 for steatosis ≥S1 and 0.94 vs. 0.88 for ≥S2, respectively. Boot-strapping analysis revealed a CAP cut-off of 300 dB/m for detection of S2-3 steatosis, while retaining the lower cut-off of 215 dB/m for the definition of healthy individuals. Direct comparison between CAP and 1H-MRS revealed only modest correlation (total cohort: r = 0.63 [0.44, 0.76]; NAFLD cases: r = 0.56 [0.32, 0.74]). For detection of F2-4 fibrosis TE had sensitivity and specificity of 100% and 98.1% at a cut-off value of 8.85 kPa. CONCLUSION: Our data suggest a comparable diagnostic value of CAP and 1H-MRS for hepatic steatosis quantification. Combined with the simultaneous TE fibrosis assessment, CAP represents an efficient method for non-invasive characterization of NAFLD. Limited correlation between CAP and 1H-MRS may be explained by different technical aspects, anthropometry, and presence of advanced liver fibrosis.

Non-invasive evaluation of hepatic manifestation in Wilson disease with transient elastography, ARFI, and different fibrosis scores.

OBJECTIVE: Noninvasive investigation of liver fibrosis with ultrasound-based elastography and laboratory-based fibrosis indices have been established in various chronic liver diseases within the last years. We aimed to evaluate feasibility and diagnostic value of transient elastography (TE), acoustic radiation force impulse imaging (ARFI), and different serologic fibrosis indices in Wilson's disease (WD). MATERIALS AND METHODS: TE and ARFI were performed in 50 Wilson patients. In addition, AST/Platelet Ratio Index (APRI), FIB-4, and Forns score were calculated. Hepatic fibrosis was classified by a clinical score. RESULTS: Of the 50 Wilson patients 41 had hepatic manifestation of WD. TE results were significantly increased in advanced hepatic fibrosis (7.0 ± 2.2 kPa; p < 0.05) and cirrhosis (10.1 ± 6.73 kPa; p < 0.05) compared to individuals without hepatic manifestation (5.0 ± 1.4 kPa). Right liver lobe ARFI (R-ARFI) values were only increased in cirrhotic patients (1.43 ± 0.28 vs. 1.19 ± 0.14 m/s; p < 0.05). The cutoff values to best discriminate cirrhosis were 6.1 kPa for TE and 1.29 m/s for R-ARFI. Left lobe ARFI failed to provide additional diagnostic benefit. Elastography methods displayed a significant correlation with APRI, FIB-4, and Forns indices (Pearson's rho > 0.33; p < 0.03). CONCLUSIONS: TE displayed a gradual increase between different stages of hepatic manifestation in WD and could significantly discriminate cirrhosis. The TE cutoff for cirrhosis may be clinically more relevant than the R-ARFI value.

Non-invasive evaluation of cystic fibrosis related liver disease in adults with ARFI, transient elastography and different fibrosis scores.

BACKGROUND: Cystic fibrosis-related liver disease (CFLD) is present in up to 30% of cystic fibrosis patients and can result in progressive liver failure. Diagnosis of CFLD is challenging. Non-invasive methods for staging of liver fibrosis display an interesting diagnostic approach for CFLD detection. AIM: We evaluated transient elastography (TE), acoustic radiation force impulse imaging (ARFI), and fibrosis indices for CFLD detection. METHODS: TE and ARFI were performed in 55 adult CF patients. In addition, AST/Platelets-Ratio-Index (APRI), and Forns' score were calculated. Healthy probands and patients with alcoholic liver cirrhosis served as controls. RESULTS: Fourteen CF patients met CFLD criteria, six had liver cirrhosis. Elastography acquisition was successful in >89% of cases. Non-cirrhotic CFLD individuals showed elastography values similar to CF patients without liver involvement. Cases with liver cirrhosis differed significantly from other CFLD patients (ARFI: 1.49 vs. 1.13 m/s; p = 0.031; TE: 7.95 vs. 4.16 kPa; p = 0.020) and had significantly lower results than individuals with alcoholic liver cirrhosis (ARFI: 1.49 vs. 2.99 m/s; p = 0.002). APRI showed the best diagnostic performance for CFLD detection (AUROC 0.815; sensitivity 85.7%, specificity 70.7%). CONCLUSIONS: ARFI, TE, and laboratory based fibrosis indices correlate with each other and reliably detect CFLD related liver cirrhosis in adult CF patients. CF specific cut-off values for cirrhosis in adults are lower than in alcoholic cirrhosis.

Acoustic radiation force impulse imaging (ARFI) for non-invasive detection of liver fibrosis: examination standards and evaluation of interlobe differences in healthy subjects and chronic liver disease.

OBJECTIVE: Acoustic radiation force impulse imaging (ARFI) is a non-invasive method for the quantification of liver stiffness. We aimed to develop standards for the measuring procedure and studied the impact of different measuring sites. MATERIALS AND METHODS: ARFI was tested in a tissue phantom and in 50 healthy volunteers. In addition, 116 patients with chronic liver disease underwent ARFI. The results were compared with histological staging (non-viral liver disease) and transient elastography (hepatitis C). ARFI diagnostic performance was evaluated with receiver operating characteristic curves. RESULTS: ARFI results were not normally distributed in >20% of cases. Deep inspiration significantly increased ARFI values by 13% (p < 0.05). The mean shear-wave velocity in healthy individuals was 1.28 ± 0.19 m/s in the left liver lobe and 1.15 ± 0.17 m/s in the right liver lobe (p < 0.001). Similarly, in 79/116 patients with chronic liver disease a significant difference of shear-wave velocity between both liver lobes was detected. The histological staging correlated with ARFI results of the biopsy site (r = 0.661, p < 0.001) in non-viral liver disease (n = 47). The mean shear-wave velocity in cases with F1 and F2 fibrosis was increased in the left compared with the right liver lobe (2.1 ± 0.73 m/s vs. 1.75 ± 0.89 m/s, p = 0.041). Similar results were obtained in patients with hepatitis C (n = 69). CONCLUSION: Our study strengthens the necessity for definition of examination standards and demonstrates the usefulness of ARFI in non-viral liver disease. Interlobe variations of liver stiffness demand further investigation.

Pitfall alveolar echinococcosis in non-endemic areas. Alveolar echinococcosis migrating northward.

Alveolar echinococcosis of the liver can be mistaken as a liver tumor. The occurrence of the fox tapeworm echinococcus multilocularis is increasing in formerly unaffected European regions. As a consequence, alveolar echinococcosis is becoming an important differential diagnosis in Eastern and Northern Europe.

The inverse starving test is not a suitable provocation test for Gilbert's syndrome.

INTRODUCTION: The aim of this study was to evaluate a simple diagnostic test for Gilbert's syndrome (GS), which avoids hospitalization and exposure to toxic test substrates. GS is the most frequent cause of isolated unconjugated hyperbilirubinemia. The nicotinic acid test and the starving test are established approaches to diagnose GS. However, these tests cause considerable side effects or require hospital admission. In single GS patients, we observed rapid serum bilirubin normalization after a standard European lunch (the "inverse starving test"). FINDINGS: At two consecutive days, 18 profoundly characterized GS patients (7 females, 11 males, median age 34.5 years, range 21-58 years) were investigated with the nicotinic acid test and the inverse starving test. Unconjugated serum bilirubin (UCB) levels were measured before and hourly up to four hours after lunch (median 645 kcal), and after the ingestion of 170 milligrams nicotinic acid, respectively. Patients who consulted their physicians with jaundice were significantly more likely to undergo invasive diagnostic procedures than patients with an incidental finding of elevated UCB, despite UCB levels were indifferent in both groups. Two hours after nicotinic acid ingestion, relative UCB exceeded 1.7 fold the fasting levels (median, range 0.9-2.4 fold, sensitivity 83%). In the inverse starving test, UCB remained almost unchanged three hours after lunch (median 1.0; range: 0.8-1.2 fold). Molecular analysis established the genotype of the TATAA box of the UGT1A1 gene; all patients carried an UGT1A1 promotor polymorphism. CONCLUSION: The inverse starving test is not an appropriate provocation test for patients with suspected GS. The 100% prevalence of the UGT1A1 polymorphism in our cohort underlines that the diagnosis of GS may be substantiated with this simple molecular test in patients with an uncertain diagnosis of GS.