Ultrasound-based steatosis grading system using 2D-attenuation imaging: an individual patient data meta-analysis with external validation

BACKGROUND AND RATIONALE

Non-invasive tools assessing steatosis, such as ultrasonography-based 2D-attenuation imaging (ATI), are needed to tackle the worldwide burden of steatotic liver disease. This one-stage individual patient data (IPD) meta-analysis aimed to create an ATI-based steatosis grading system.

MAIN RESULTS

A systematic review (EMBASE+MEDLINE, 2018-2022) identified studies, including patients with histologically or MRI-PDFF-verified ATI for grading steatosis (S0 to S3). One-stage IPD meta-analyses were conducted using generalized mixed models with a random study-specific intercept. Created ATI-based steatosis grading system (aS0 to aS3) was externally validated on a prospective cohort of patients with type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD; n=174, histologically and MRI-PDFF verified steatosis). Eleven enrolled studies included 1374 patients, classified into S0, S1, S2, and S3 in 45.4%, 35.0%, 9.3%, and 10.3% of the cases. ATI was correlated with histological steatosis (r=0.60; 95%CI:0.52,0.67; p<0.001), and MRI-PDFF (r=0.70; 95%CI:0.66,0.73; p<0.001) but not with liver stiffness (r=0.03; 95%CI:-0.04,0.11, p=0.343). Steatosis grade was an independent factor associated with ATI (Coefficient: 0.24; 95%CI [0.22, 0.26]; p<0.001). ATI marginal means within S0, S1, S2, and S3 subpopulations were 0.59 (95%CI [0.58, 0.61]), 0.69 (95%CI [0.67, 0.71]), 0.78 95%CI [0.76, 0.81] and 0.85 95%CI [0.83, 0.88] dB/cm/MHz; all contrasts between grades significant (p<.0001). Three ATI thresholds were calibrated to create a new ATI-based steatosis grading system (aS0 to aS3, cut-offs: 0.66, 0.73, and 0.81 dB/cm/MHz). Its external validation showed Obuchowski measures of 0.84 ±0.02 and 0.82±0.02 with histologically- and MRI-PDFF-based references.

CONCLUSIONS

ATI is a reliable, non-invasive marker of steatosis. This validated ATI-based steatosis grading system could be valuable in assessing MASLD patients.

Two-dimensional shear wave elastography (ElastQ) accurately rules out liver fibrosis and rules in advanced chronic liver disease across liver disease etiologies: a prospective multicenter study

PURPOSE

This study evaluated ElastQ, a two-dimensional shear wave elastography (2D-SWE) technique, for the non-invasive assessment of liver fibrosis risk using liver stiffness measurement (LSM). The aim was to determine its diagnostic accuracy and establish LSM cutoffs for clinical risk stratification.

METHODS

A prospective multicenter study was conducted, employing vibration-controlled transient elastography (VCTE) as a reference standard. The statistical analysis utilized Pearson correlations and Lin concordance correlation coefficients, diagnostic areas under the curve (AUCs), and 90%-specific rule-in and 90%-sensitive rule-out ElastQ cutoffs.

RESULTS

The study included 875 patients at risk for liver disease, of whom 816 (376 women, 46.1%; median age, 57.0 years [interquartile range, 19.0]) had successful and reliable VCTE- and ElastQ-LSMs. The median LSM was 13.0 kPa (range, 2.0 to 75.0 kPa) for VCTE and 6.6 kPa (range, 2.9 to 26.5 kPa) for ElastQ. The correlation between VCTE-LSM and ElastQ-LSM was adequate for VCTE-LSM <15 kPa (Pearson r=0.63) but lower for VCTE-LSM ≥15.0 kPa (Pearson r=0.27). VCTE-LSM indicated no fibrosis risk (<5.0 kPa) in 178 cases (21.8%), gray zone (5.0-9.9 kPa) in 347 cases (42.5%), and advanced chronic liver disease (ACLD; ≥10.0 kPa) in 291 cases (35.7%). The diagnostic AUC for ElastQ-LSM was 0.82 for fibrosis risk and 0.90 for ACLD. The clinically relevant ElastQ cutoffs for ruling out fibrosis risk and ruling in compensated ACLD (cACLD) were <5.0 kPa and ≥9.0 kPa, respectively.

CONCLUSION

ElastQ 2D-SWE enables accurate, non-invasive assessments of liver fibrosis and cACLD risk. In clinical practice, ElastQ-LSM <5.0 kPa rules out fibrosis, while ElastQ-LSM ≥9.0 kPa rules in cACLD.

Liver Fat Quantification With Ultrasound: Depth Dependence of Attenuation Coefficient

OBJECTIVES

The primary aim was to estimate the influence of various depths on ultrasound attenuation coefficient (AC) of multiple vendors in the liver. The secondary aim was to evaluate the impact of region of interest (ROI) size on AC measurements in a subset of participants.

METHODS

This Institutional Review Board (IRB)-approved Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study was carried out in two centers using AC-Canon and AC-Philips algorithms and extracting AC-Siemens values from ultrasound-derived fat fraction algorithm. Measurements were performed positioning ROI upper edge (3 cm size) at 2, 3, 4, 5 cm from the liver capsule with AC-Canon and AC-Philips and at 1.5, 2, 3 cm with Siemens algorithm. In a subset of participants, measurements were obtained with 1 and 3 cm ROI size. Univariate and multivariate linear regression models and Lin's concordance correlation coefficient (CCC) were used for statistical analysis as appropriate.

RESULTS

Three different cohorts were studied. Sixty-three participants (34 females; mean age: 51 ± 14 years) were studied with AC-Canon, 60 (46 females; mean age: 57 ± 11 years) with AC-Philips, and 50 (25 females; 61 ± 13 years) with AC-Siemens. There was a decrease in AC values per 1 cm increase in depth in all. In multivariable analysis, the coefficient was -0.049 (-0.060; -0.038 P < .001) with AC-Canon, -0.058 (-0.066; -0.049 P < .001) with AC-Philips and -0.081 (-0.112; -0.050 P < .001) with AC-Siemens. AC values with 1 cm ROI were significantly higher than those obtained with 3 cm ROI at all depths (P < .001) but the agreement between AC values obtained with different ROI size was excellent (CCC 0.82 [0.77-0.88]).

CONCLUSIONS

There is depth dependence in AC measurement that affects results. A standardized protocol with fixed ROI's depth and size is needed.

Dynamic NLR and PLR in Predicting COVID-19 Severity: A Retrospective Cohort Study

INTRODUCTION

The hyperinflammation phase of severe SARS-CoV-2 is characterised by complete blood count alterations. In this context, the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) can be used as prognostic factors. We studied NLR and PLR trends at different timepoints and computed optimal cutoffs to predict four outcomes: use of continuous positive airways pressure (CPAP), intensive care unit (ICU) admission, invasive ventilation and death.

METHODS

We retrospectively included all adult patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia admitted from 23 January 2020 to 18 May 2021. Analyses included non-parametric tests to study the ability of NLR and PLR to distinguish the patients' outcomes at each timepoint. Receiver operating characteristic (ROC) curves were built for NLR and PLR at each timepoint (minus discharge) to identify cutoffs to distinguish severe and non-severe disease. Their statistical significance was assessed with the chi-square test. Collection of data under the SMACORE database was approved with protocol number 20200046877.

RESULTS

We included 2169 patients. NLR and PLR were higher in severe coronavirus disease 2019 (COVID-19). Both ratios were able to distinguish the outcomes at each timepoint. For NLR, the areas under the receiver operating characteristic curve (AUROC) ranged between 0.59 and 0.81, and for PLR between 0.53 and 0.67. From each ROC curve we computed an optimal cutoff value.

CONCLUSION

NLR and PLR cutoffs are able to distinguish severity grades and mortality at different timepoints during the course of disease, and, as such, they allow a tailored approach. Future prospects include validating our cutoffs in a prospective cohort and comparing their performance against other COVID-19 scores.

Point Shear Wave Elastography by ElastPQ for Fibrosis Screening in Patients with NAFLD: A Prospective, Multicenter Comparison to Vibration-Controlled Elastography

BACKGROUND

Since nonalcoholic fatty liver disease (NAFLD) has become the leading cause of liver disease in the Western world, clinicians need reliable noninvasive tools for the identification of NAFLD-associated fibrosis. Limited evidence on the performance of the novel shear wave elastography technique Elast-PQ (EPQ) in NAFLD is available.

METHOD

In this prospective, European multinational study we assessed the diagnostic accuracy of EPQ using vibration-controlled transient elastography (VCTE) as a reference standard.

RESULTS

Among 353 NAFLD patients, 332 (94.1%) fulfilled reliability criteria of VCTE and EPQ (defined by IQR/median ≤0.3; 41.3% female, mean age: 59 [IQR: 16.5], mean BMI: 29.0 (7.1)). 4/353 (1.1%) and 17/353 (4.8%) had unreliable VCTE and EPQ measurements, respectively. VCTE-based NAFLD fibrosis stages were F0/F1: 222(66.9%), F2: 41 (12.3%), F3: 30 (9.1%), F4: 39 (11.7%). We found a strong correlation (Pearson R=0.87; p<0.0001) and concordance (Lin's concordance correlation coefficient =0.792) of EPQ with VCTE. EPQ was able to identify NAFLD-fibrosis risk with the following EPQ cutoffs: ≥6.5 kPa for significant fibrosis (≥F2) (≥1.47 m/s; sensitivity: 78%; specificity: 95%; AUROC: 0.94), ≥6.9 kPa for advanced fibrosis (≥F3) (≥1.52 m/s; sens.: 88%, spec.: 89%; AUROC: 0.949), and ≥10.4 kPa for cirrhosis (F4) (≥1.86 m/s; sens.: 87%; spec.: 94%; AUROC: 0.949).

CONCLUSION

The point shear wave elastography technique EPQ shows excellent correlation to and concordance with VCTE. EPQ can reliably exclude NAFLD fibrosis <6.0 kPa (<1.41 m/s) and indicate a high risk of advanced fibrosis ≥10.4 kPa (≥1.86 m/s).

Is a radiological score needed to define the severity of Nontuberculous mycobacteria lung disease?

High-resolution CT-scan (HRCT) plays a major role in the diagnosis of Nontuberculous mycobacteria lung disease (NTM-LD), but its role in follow-up is controversial. Our aim was first to conceive a radiological score able to quantify the severity of pulmonary involvement by NTM infection and, second, to check its association with the NTM-LD clinical burden. We also intended, if possible, to verify the potential influence of NTM specific treatment on the radiological score. We retrospectively collected the clinical, microbiological and radiological data of all patients who were admitted to our hospital from 1 January 2012 to 1 January 2020 with a confirmed diagnosis of NTM-LD. A radiological score was applied to evaluate lung involvement on HRCT at diagnosis and at 6-18 months follow-up. Twenty-eight patients with NTM-LD performed follow-up HRCT. No association was found between radiological and clinical score (Spearman R -0.05, 95%CI -0.41 to 0.33). Repeated measures analysis showed a significant increase in radiological score over time (change 1.11, 95%CI 0.10 to 2.11; p-value 0.032), while Mann-Whitney test did not show any difference between treated and untreated patients (p value 0.922). Further studies are needed to assess the usefulness of routine radiological follow-up in patients with NTM-LD.

COVID vaccination and asthma exacerbation: might there be a link?

INTRODUCTION

There is ongoing debate regarding the role of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in asthma exacerbation, and its long-term impact on the lung function of individuals with asthma. In contrast, the potential impact of coronavirus disease 2019 (COVID-19) vaccination on asthma is entirely unexplored.

CASE STUDY

This study examined a challenging case of severe asthma exacerbation in a 28-year-old female following two doses of the mRNA-based vaccine BNT162b2 (Pfizer-BioNTech) at IRCCS Policlinico San Matteo in Pavia, Italy. The patient, a fourth-year resident at the hospital, was vaccinated in early 2021. She was an occasional smoker with a 10-year history of asthma and seasonal allergic rhinitis. She tested negative for SARS-CoV-2 on several molecular swabs and serology tests.

RESULTS

After receiving the second dose of vaccine, the patient started to experience worsening of respiratory symptoms. Following several episodes and a severe asthma attack, the patient required treatment with mepolizumab, a biologic drug (interleukin-5) antagonist monoclonal antibody.

CONCLUSION

This single case study is insufficient to draw conclusions about the association between asthma exacerbation and the COVID-19 vaccine. While the cause-effect link between vaccination against SARS-CoV-2 and worsening of asthmatic disease might only be suggested at present, this case is a valuable prompt for further investigation. This is particularly true from the perspective of mass vaccination of adolescents and children currently underway across the globe.

Performance of the Attenuation Imaging Technology in the Detection of Liver Steatosis

OBJECTIVES

The main aim was to assess the performance and cutoff value for the detection of liver steatosis (grade S > 0) with the Attenuation Imaging-Penetration (ATI-Pen) algorithm available on the Aplio i-series ultrasound systems (Canon Medical Systems, Otawara, Japan). The magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) was used as the reference standard. Secondary aims were to compare the results to those obtained with the previous ATI algorithm (Attenuation Imaging-General [ATI-Gen]) and with the controlled attenuation parameter (CAP) and to generate a regression equation between ATI-Pen and ATI-Gen values.

METHODS

Consecutive adult patients potentially at risk of liver steatosis were prospectively enrolled. Each patient underwent ultrasound quantification of liver steatosis with ATI-Pen and ATI-Gen and a CAP assessment with the FibroScan system (Echosens, Paris, France). The MRI-PDFF evaluation was performed within a week. The correlations between ATI-Pen, ATI-Gen, the CAP, and the MRI-PDFF were analyzed with the Pearson rank correlation coefficient. The diagnostic performance of ATI-Pen, ATI-Gen, and the CAP was assessed with receiver operating characteristic curves and an area under the receiver operating characteristic curve (AUROC) analysis.

RESULTS

Seventy-two individuals (31 male and 41 female) were enrolled. Correlation coefficients of ATI-Pen, ATI-Gen, and the CAP with the MRI-PDFF were 0.78, 0.83, and 0.58, respectively. The AUROCs of ATI-Pen, ATI-Gen, and the CAP for detecting steatosis (S > 0) were 0.90 (95% confidence interval, 0.81-0.96), 0.92 (0.82-0.98), and 0.85 (0.74-0.92), and the cutoffs were greater than 0.69 dB/cm/MHz, greater than 0.62 dB/cm/MHz, and greater than 273 dB/m. The regression equation between ATI-Pen and ATI-Gen was ATI-Pen = 0.88 ATI-Gen + 0.13.

CONCLUSIONS

Attenuation Imaging is a reliable tool for detecting liver steatosis, showing an excellent correlation with the MRI-PDFF and high performance with AUROCs of 0.90 or higher.

Competing-risk analysis of coronavirus disease 2019 in-hospital mortality in a Northern Italian centre from SMAtteo COvid19 REgistry (SMACORE)

An accurate prediction of the clinical outcomes of European patients requiring hospitalisation for Coronavirus Disease 2019 (COVID-19) is lacking. The aim of the study is to identify predictors of in-hospital mortality and discharge in a cohort of Lombardy patients with COVID-19. All consecutive hospitalised patients from February 21st to March 30th, 2020, with confirmed COVID-19 from the IRCCS Policlinico San Matteo, Pavia, Lombardy, Italy, were included. In-hospital mortality and discharge were evaluated by competing risk analysis. The Fine and Gray model was fitted in order to estimate the effect of covariates on the cumulative incidence functions (CIFs) for in-hospital mortality and discharge. 426 adult patients [median age 68 (IQR 56 to 77 years)] were admitted with confirmed COVID-19 over a 5-week period; 292 (69%) were male. By 21 April 2020, 141 (33%) of these patients had died, 239 (56%) patients had been discharged and 46 (11%) were still hospitalised. Among these 46 patients, updated as of 30 May, 2020, 5 (10.9%) had died, 8 (17.4%) were still in ICU, 12 (26.1%) were transferred to lower intensity care units and 21 (45.7%) were discharged. Regression on the CIFs for in-hospital mortality showed that older age, male sex, number of comorbidities and hospital admission after March 4th were independent risk factors associated with in-hospital mortality. Older age, male sex and number of comorbidities definitively predicted in-hospital mortality in hospitalised patients with COVID-19.

Clinical characteristics of coronavirus disease (COVID-19) early findings from a teaching hospital in Pavia, North Italy, 21 to 28 February 2020

We describe clinical characteristics, treatments and outcomes of 44 Caucasian patients with coronavirus disease (COVID-19) at a single hospital in Pavia, Italy, from 21-28 February 2020, at the beginning of the outbreak in Europe. Seventeen patients developed severe disease, two died. After a median of 6 days, 14 patients were discharged from hospital. Predictors of lower odds of discharge were age > 65 years, antiviral treatment and for severe disease, lactate dehydrogenase > 300 mg/dL.

Evaluation of Inter-System Variability in Liver Stiffness Measurements

AIM

 The primary aim of this study was to determine the inter-system variability of liver stiffness measurements (LSMs) in patients with varying degrees of liver stiffness. The secondary aim was to determine the inter-observer variability of measurements.

MATERIALS AND METHODS

 21 individuals affected by chronic hepatitis C and 5 healthy individuals were prospectively enrolled. The assessment of LSMs was performed using six ultrasound (US) systems, four of which with point shear wave elastography (p-SWE) and two with 2 D shear wave elastography (2D-SWE) systems. The Fibroscan (Echosens, France) was used as the reference standard. Four observers performed the measurements in pairs (A-B, C-D). The agreement between different observers or methods was calculated using Lin's concordance correlation coefficient. The Bland-Altman limits of agreement (LOA) were calculated as well.

RESULTS

 There was agreement above 0.80 for all pairs of systems. The mean difference between the values of the systems with 2D-SWE technique was 1.54 kPa, whereas the maximum mean difference between the values of three out of four systems with the pSWE technique was 0.79 kPa. The intra-patient concordance for all systems was 0.89 (95 % CI: 0.83 - 0.94). Inter-observer agreement was 0.96 (95 % CI: 0.94 - 0.98) for the pair of observers A-B and 0.93 (95 % CI: 0.89 - 0.96) for the pair of observers C-D.

CONCLUSION

 The results of this study show that the agreement between LSMs performed with different US systems is good to excellent and the overall inter-observer agreement in "ideal conditions" is above 0.90 in expert hands.

Adherence to quality criteria improves concordance between transient elastography and ElastPQ for liver stiffness assessment-A multicenter retrospective study

BACKGROUND

Assessment of liver stiffness provides important diagnostic and prognostic information in patients with chronic liver disease.

AIMS

To investigate whether the use of quality criteria (i) improves the concordance between transient elastography (TE) and a novel point shear wave elastography technique (ElastPQ^®) and (ii) impacts on the performance of ElastPQ^® for liver fibrosis staging using TE as the reference standard.

METHODS

In this multicenter retrospective study, data of patients undergoing liver stiffness measurements (LSM) in five European centers were collected. TE was performed with FibroScan^® (Echosens, France) and ElastPQ^® with EPIQ^® or Affiniti^® systems (Philips, The Netherlands). The agreement between TE and ElastPQ^® LSMs was assessed with Lin's concordance correlation coefficient (CCC). Diagnostic performance of ElastPQ^® was assessed by the area under receiver operating characteristic (AUROC) curves.

RESULTS

Overall, 664 patients were included: mean age: 54.8(13.5) years, main etiologies: viral hepatitis (83.1%) and NAFLD (7.5%). CCC increased significantly when LSMs with ElastPQ^® were obtained with IQR/M ≤ 30% (p < 0.001). The diagnostic performance of ElastPQ^® for fibrosis staging also increased if LSM values were obtained with IQR/M ≤ 30%.

CONCLUSION

Quality criteria should be followed when using ElastPQ^® for LSM, since the concordance with TE fibrosis staging was better at an ElastPQ^® IQR/M ≤ 30.

Ruling-in and Ruling-out Significant Fibrosis and Cirrhosis in Patients with Chronic Hepatitis C Using a Shear Wave Measurement Method

Aims: To prospectively assess the cutoff values of a point shear wave measurement (SWM) method for ruling-in and ruling-out significant fibrosis and cirrhosis using transient elastography (TE) as the reference standard.Method: Consecutive patients with chronic hepatitis C were enrolled. Liver stiffness was assessed with the SWM method implemented on the HI VISION Ascendus ultrasound system (Hitachi Ltd, Japan) and with the TE method of the FibroScan® device (Echosens, France). For staging significant fibrosis (F≥2) and cirrhosis (F=4) we used the TE cutoffs of 7.0 and 12.0 kiloPascal (kPa), respectively. The diagnostic performance of SWM was assessed by calculating the area under the receiver operating characteristic (AUROC) curve. Cutoffs with specificity or sensitivity > 90% were chosen to rule-in or rule-out F≥2 and F=4.Results: 445 individuals [235 males, 210 females; mean age, 61.1 (13.3) years] were studied: 190 (42.7%) individuals had F0-F1 fibrosis stage, 82 (18.4%) F2, 46 (10.3%) F3, and 127 (28.6%) F4 fibrosis stage. For ruling-in F≥2 the SWM cutoff was 6.78 kPa [sensitivity, 76.9%(70.6-82.4); specificity, 90.3% (85.0-94.3)] and for ruling-out it was 5.55 kPa [sensitivity, 90.6% (85.8-94.1); specificity, 72.2% (64.9-78.6)]. For ruling-in F=4 the SWM cutoff was 9.15 kPa [sensitivity, 83.3% (74.4-90.2); specificity, 90.1% (86.0-93.2)] and for ruling-out it was 8.41 kPa [sensitivity, 90.6% (82.9-95.6); specificity, 82.2% (77.3-86.4)]. AUROCs were 0.92 (0.89-0.94) for F≥2 and 0.94 (0.91-0.96) for F=4.Conclusions. In clinical practice, the use of a dual cutoff of SWM may increase the confidence in staging liver fibrosis with a non-invasive shear wave elastography technique.Abbreviations: ARFI: acoustic radiation force impulse; AUROC: area under the ROC curve; CCC: concordance correlation coefficient; IQR/M: interquartile range/median; LSM: liver stiffness measurement; ROC: receiver operating characteristic; pSWE: point shear wave elastography; SWM: shear wave measurement; TE: transient elastography; US: ultrasound.

Noninvasive assessment of liver steatosis in children: the clinical value of controlled attenuation parameter

Background

To assess the clinical validity of controlled attenuation parameter (CAP) in the diagnosis of hepatic steatosis in a series of overweight or obese children by using the imperfect gold standard methodology.

Methods

Consecutive children referred to our institution for auxological evaluation or obesity or minor elective surgery were prospectively enrolled. Anthropometric and biochemical parameters were recorded. Ultrasound (US) assessment of steatosis was carried out using ultrasound systems. CAP was obtained with the FibroScan 502 Touch device (Echosens, Paris, France). Pearson’s or Spearman’s rank correlation coefficient were used to test the association between two study variables. Optimal cutoff of CAP for detecting steatosis was 249 dB/m. The diagnostic performance of dichotomized CAP, US, body mass indexes (BMI), fatty liver index (FLI) and hepatic steatosis index (HSI) was analyzed using the imperfect gold standard methodology.

Results

Three hundred five pediatric patients were enrolled. The data of both US and CAP were available for 289 children. Steatosis was detected in 50/289 (17.3%) children by US and in 77/289 (26.6%) by CAP. A moderate to good correlation was detected between CAP and BMI (r = 0.53), FLI (r = 0.55) and HSI (r = 0.56). In obese children a moderate to good correlation between CAP and insulin levels (r = 0.54) and HOMA-IR (r = 0.54) was also found. Dichotomized CAP showed a performance of 0.70 (sensitivity, 0.72 [0.64–0.79]; specificity, 0.98 [0.97–0.98], which was better than that of US (performance, 0.37; sensitivity, 0.46 [0.42–0.50]; specificity, 0.91 [0.89–0.92]), BMI (performance, 0.22; sensitivity, 0.75 [0.73–0.77]; specificity, 0.57 [0.55–0.60]) and FLI or HSI.

Conclusions

For the evaluation of liver steatosis in children CAP performs better than US, which is the most widely used imaging technique for screening patients with a suspicion of liver steatosis. A cutoff value of CAP of 249 dB/m rules in liver steatosis with a very high specificity.

Accuracy of the ElastPQ Technique for the Assessment of Liver Fibrosis in Patients with Chronic Hepatitis C: a "Real Life" Single Center Study

BACKGROUND AND AIMS

Noninvasive assessment of liver stiffness has been increasingly used to evaluate fibrosis instead of liver biopsy, especially in patients with chronic viral hepatitis. The aim of this study was to assess the performance in staging liver fibrosis of the updated ElastPQ® technique (EPIQ7 ultrasound system, Philips Healthcare, Bothell, WA, USA) in the "real life" setting by using the FibroScan as the reference standard and to understand whether the use of the quality criteria improves the performance of the technique.

METHODS

This was a cross-sectional study: 278 patients affected by chronic hepatitis C referred for liver stiffness measurement with the FibroScan® 502 Touch device (Echosens, Paris, France) underwent measurements also with the ElastPQ® technique. For the assessment of significant fibrosis (F>/=2), advanced fibrosis (F>/=3) and cirrhosis (F=4), respectively, we used the cutoffs of 7.0, 9.5 and 12.0 kPa. The diagnostic performance of ElastPQ® was assessed using the area under the ROC (AUROC) curve analysis and was evaluated overall and for cases with (a) 10 measurements and IQR/M</=30%, (b) 5 measurements and IQR/M </=30%, (c) 10 measurements and IQR/M>30%, (d) 5 measurements and IQR/M>30%.

RESULTS

The optimal cutoffs of ElastPQ® for significant fibrosis, advanced fibrosis and cirrhosis were 6.43, 9.54 and 11.34 kPa, respectively. For measurements with an IQR/M</=30%, there was no statistically significant decrease in sensitivity between 10 and 5 measurements (p=0.26, p=0.09, p=0.71, for F>/=2, F>/=3, and F=4, respectively).

CONCLUSION

The ElastPQ® technique is reliable and accurate for staging liver fibrosis. The number of measurements does not affect the performance.

The clinical value of controlled attenuation parameter for the noninvasive assessment of liver steatosis

BACKGROUND & AIMS

Ultrasound is the imaging modality most widely utilized in the general population for diagnostic purposes. Controlled attenuation parameter is a novel noninvasive method for assessing steatosis. Our aim was to investigate whether the clinical value of controlled attenuation parameter in patients referred for abdominal ultrasound examinations is affected by liver fibrosis.

METHODS

Consecutive patients referred for abdominal ultrasound examinations were enrolled. Controlled attenuation parameter and liver stiffness were assessed with the FibroScan (Echosens, France). Liver fibrosis was staged according to published cutoffs of liver stiffness measurements. Pearson's or Spearman's rank correlation coefficient was used to test the association between two study variables. Optimal cutoff of controlled attenuation parameter for diagnosing liver steatosis (S≥2) was 256 dB/m. The diagnostic performance and accuracy of dichotomized controlled attenuation parameter, ultrasound and body mass index were analysed using the imperfect gold standard methodology.

RESULTS

A total of 726 subjects (464 males and 262 females) were studied. Five hundred and eight-nine (81.1%) patients were affected by chronic viral hepatitis. Correlation of controlled attenuation parameter with ultrasound score was 0.48 and 0.57 in patients with and without chronic viral hepatitis respectively. In patients with chronic viral hepatitis, ultrasound, dichotomized controlled attenuation parameter and body mass index showed performance of 58.2%, 82.3% and 46.7%, respectively, whereas in patients without chronic viral hepatitis, the performance was 86.4%, 68.6% and 48.6% respectively.

CONCLUSIONS

In patients with chronic viral hepatitis and advanced liver fibrosis, controlled attenuation parameter performs better than ultrasound for assessing liver steatosis, whereas in patients without viral hepatitis and with nonsignificant liver disease ultrasound shows the best performance.

Performance of liver stiffness measurements by transient elastography in chronic hepatitis

AIM: To compare results of liver stiffness measurements by transient elastography (TE) obtained in our patients population with that used in a recently published meta-analysis.

METHODS: This was a single center cross-sectional study. Consecutive patients with chronic viral hepatitis scheduled for liver biopsy at the outpatient ward of our Infectious Diseases Department were enrolled. TE was carried out by using FibroScan™ (Echosens, Paris, France). Liver biopsy was performed on the same day as TE, as day case procedure. Fibrosis was staged according to the Metavir scoring system. The diagnostic performance of TE was assessed by using receiver operating characteristic (ROC) curves and the area under the ROC curve analysis.

RESULTS: Two hundred and fifty-two patients met the inclusion criteria. Six (2%) patients were excluded due to unreliable TE measurements. Thus, 246 (171 men and 75 women) patients were analyzed. One hundred and ninety-five (79.3%) patients had chronic hepatitis C, 41 (16.7%) had chronic hepatitis B, and 10 (4.0%) were coinfected with human immunodeficiency virus. ROC curve analysis identified optimal cut-off value of TE as high as 6.9 kPa for F≥ 2; 7.9 kPa for F≥ 3; 9.6 kPa for F = 4 in all patients (n = 246), and as high as 6.9 kPa for F≥ 2; 7.3 kPa for F≥ 3; 9.3 kPa for F = 4 in patients with hepatitis C (n = 195). Cut-off values of TE obtained by maximizing only the specificity were as high as 6.9 kPa for F≥ 2; 9.6 kPa for F≥ 3; 12.2 kPa for F = 4 in all patients (n = 246), and as high as 7.0 kPa for F≥ 2; 9.3 kPa for F≥ 3; 12.3 kPa for F = 4 in patients with hepatitis C (n = 195).

CONCLUSION: The cut-off values of TE obtained in this single center study are comparable to that obtained in a recently published meta-analysis that included up to 40 studies.

Comparison of peginterferon pharmacokinetic and pharmacodynamic profiles

The pharmacokinetics and in dosing regimens of the currently available pegylated interferon (peginterferon) alfa molecules differ greatly, depending on the size and nature of their polyethylene glycol (PEG) moiety. Peginterferon alfa-2a has a branched 40 kDa PEG chain covalently attached to lysine residues and circulates as an intact molecule. On the other hand, peginterferon alfa-2b has a linear 12 kDa PEG chain covalently attached to interferon-a-2b via an unstable urethane bond that is hydrolysed after injection, releasing native interferon alfa-2b. The difference in pegylation between the two peginterferons has a significant impact on their pharmacokinetic properties. Data from comparative and non-comparative studies indicate that peginterferon alfa-2b has a shorter half-life in serum than peginterferon alfa-2a, and a significant proportion of patients receiving peginterferon alfa-2b may have trough concentrations below the limit of detection during the latter part of the 7-day dosing schedule. However, the pharmacodynamic parameters of the two drugs appear to be similar.

Forthcoming challenges in the management of direct-acting antiviral agents (DAAs) for hepatitis C

Agents that specifically target the replication cycle of the virus direct-acting antiviral agents (DAAs) by directly inhibiting the NS3/4A serine protease, the NS5B polymerase and NS5A are currently in clinical development. The need to achieve serum drug concentrations able to suppress viral replication is a key factor for a successful antiviral therapy and the prevention of resistance. Thus pharmacokinetics parameters became important issues for drugs used in the therapy of hepatitis C. The ratio of C(min)/IC(50) (inhibitory quotient or IQ) can provide a surrogate measure of a drug's ability to suppress HCV replication, by taking into account the relationship between plasma drug levels and viral susceptibility to the drug. Ritonavir boosting may be a useful strategy to improve pharmacokinetic parameters. Characterising resistance to DAAs in clinical trials is essential for the management of a drug regimen to reduce the development of resistance and thereby maximise SVR rate. The lesson of HIV therapy, provide a compelling case for the exploration of combinations of direct-acting antiviral agents.

Pathogenesis of liver damage in HCV-HIV patients

The coinfection of HIV and HCV has become a pathology with several distinctive characteristics. Pathogenesis of liver damage in patients with HIV and HCV coinfection is complex and multifactorial. It derives from a balance of factors which interact among themselves in a dynamic way. The reasons for the accelerated course of HIV/HCV coinfection are mainly related to two principal causes: the persistence of HCV, which depends upon alterations of cell-mediated immunity, and the activation of the immune system towards secretion of proinflammatory and profibrotic cytokines. This review will first focus on the characteristics of both these immune-mediated mechanisms, and then their implication on fibrogenesis as well as on other pathogenetic mechanisms, such as interactions between viruses and the deficit of protective mechanisms. A better knowledge of adaptive immune mechanisms, cytokine alteration, interference with host defense mechanisms, and the "cross-talk" among the viruses will improve the understanding of the pathogenetic mechanism and provide the opportunity to cure this disease.

Pharmacodynamics of peginterferon alpha-2a and peginterferon alpha-2b in interferon-naïve patients with chronic hepatitis C: a randomized, controlled study

BACKGROUND

Peginterferon alpha-2a and alpha-2b, the two commercially available pegylated interferons, have different pharmacokinetic properties that produce differing abilities to suppress replication of the hepatitis C virus.

AIM

To compare the pharmacodynamics of peginterferon alpha-2a and peginterferon alpha-2b in interferon-naive patients with chronic hepatitis C.

METHODS

Patients were randomized to receive peginterferon alpha-2a, 180 microg (n = 10) or peginterferon alpha-2b 1.0 microg/kg (n = 12) once weekly. The enzymatic activity of 2'5'-oligoadenylate synthetase and levels of neopterin and beta(2)-microglobulin were measured at baseline and at 24, 48, 120 and 168 h.

RESULTS

Oligoadenylate synthetase activity and serum neopterin and beta(2)-microglobulin concentrations did not differ significantly between the two patient groups at any time point, nor was there a significant correlation between the serum area under the concentration-time curve of either peginterferon and the area under the concentration-time curve for 2',5'-oligoadenylate synthetase, neopterin and beta(2)-microglobulin. The area under the concentration-time curves calculated for these three markers did not correlate with body mass index stratified at <25 and >or=25 kg/m(2) for either peginterferon.

CONCLUSIONS

Despite pharmacokinetic differences between peginterferon alpha-2a and peginterferon alpha-2b, the pharmacodynamic profiles of the two formulations appear to be comparable.

Hepatotoxicity and antiretroviral therapy with protease inhibitors: A review

Highly active antiretroviral therapy including protease inhibitors has led to dramatic decrease in the morbidity and mortality resulting from infection with human immunodeficiency virus-1. However, this combination regimen can be associated with the occurrence of serious toxicities, which may reduce patient compliance. In particular, human immunodeficiency virus-1 protease inhibitors and nevirapine among nonnucleoside reverse transcriptase inhibitors, have the potential for producing hepatotoxicity. We summarise current knowledge of the hepatotoxic effects associated with the commercially available human immunodeficiency virus-1 protease inhibitors based on a literature review of the major retrospective and prospective clinical studies designed to elucidate risk factors for developing hepatotoxicity among human immunodeficiency virus-1-infected patients receiving antiretroviral therapy containing protease inhibitors. Coinfection with chronic hepatitis, a common occurrence in human immunodeficiency virus-1-infected patients, is identified as an independent risk factor for developing hepatotoxicity in antiretroviral-treated human immunodeficiency virus-1-infected patients treated with antiretroviral regimens containing protease inhibitors. The importance of other risk factors for developing protease inhibitor-associated hepatotoxicity and the mechanism underlying the drug-related hepatotoxicity are discussed. The data indicate that the potential for producing hepatotoxicity is variable among the protease inhibitors and suggest that based on differences in drug-related hepatotoxicity, certain protease inhibitors may be preferred for the treatment of human immunodeficiency virus-hepatitis C virus coinfected patients.

The current role of abdominal ultrasound in the clinical management of patients with AIDS

Patients with AIDS present a wide variety of clinical manifestations through involvement of various organs. Ultrasonography (US) is easy to perform, safe, inexpensive, not invasive and repeatable. Those features are crucial for AIDS patients, who in industrialised countries are now mostly seen on an outpatient basis thanks to the introduction of Highly Active Antiretroviral Therapy. US can investigate most of the organs affected in AIDS and can guide biopsies, allowing the cyto-histological and microbiological investigations needed for a definitive diagnosis. This paper reviews the wide variety of applications of abdominal US and stresses its importance in the management of a complex and changing condition, particularly in settings where other more expensive imaging techniques are not--and will not be for a long time--available. The increasing use of portable/hand-carried scanners further adds to the value of the technique in such settings. With new treatments, prevalence and morbidity/mortality rates change, but new conditions and new side effects appear. US applications to these new conditions are discussed as well.

Hepatotoxicity and nelfinavir: a meta-analysis

BACKGROUND & AIMS

The inclusion of protease inhibitors in 3-drug highly active antiretroviral regimens for treating patients who are infected with human immunodeficiency virus-1 has had a significant impact in increasing survival and decreasing morbidity. However, the effectiveness of this class of drugs may be compromised by the occurrence of drug-related hepatotoxicity, which is problematic especially in individuals co-infected with hepatitis viruses. Based on its clinical and pharmacologic profile, especially its unique pattern of resistance, nelfinavir has been used frequently as a first-line protease-inhibitor therapy for human immunodeficiency virus-1-infected patients. The aim of this study was to identify the relative potential for developing hepatotoxicity for nelfinavir vs other protease inhibitors.

METHODS

An exploratory meta-analysis of liver enzyme level increases was conducted in a combined total of 4268 patients derived from 3 large recently conducted prospective and retrospective clinical trials and a prospective cohort study.

RESULTS

The results indicate that among 4 commercially available protease inhibitors and a 2-protease inhibitor combination, nelfinavir and indinavir are associated with the lowest rates of occurrence of severe hepatotoxicity (ie, combined estimates of liver enzyme level increases of 2.9% and 3.1%, respectively). The low rate of occurrence of severe hepatotoxicity for nelfinavir was shown even among patients co-infected with hepatitis viruses.

CONCLUSIONS

In conclusion, these data provide support for the conclusion that differences in the potential for hepatotoxicity do exist among the commercially available protease inhibitors.

Area-Under-The-Curve for Peginterferon Alpha-2A and Peginterferon Alpha-2B is Not Related to Body Weight in Treatment-Naive Patients with Chronic Hepatitis C

One reason for dosing a drug by body weight is to reduce interpatient variability in clinical response. This study evaluated the relationship between body weight and drug exposure for peginterferon alpha-2a and peginterferon alpha-2b used in combination with ribavirin for treating patients with chronic hepatitis C. These two products are dosed differently: peginterferon alpha-2a is flat-dosed at 180 μg regardless of body weight, whereas peginterferon alpha-2b is dosed by body weight at 0.5–1.5 μg/kg. Body-weight dosing of peginterferon alpha-2b is purported to overcome the adverse effect of increased body weight on sustained virological response. To test this hypothesis, we measured the area-under-the-curve (AUC) for both drugs as part of a previously reported pharmacokinetics study. In total, 22 interferon-naive patients with chronic hepatitis C were treated for 12 weeks. Patients were randomly assigned in a 1:1 ratio to receive once-weekly peginterferon alpha-2a 180 μg ( n=10) or peginterferon alpha-2b 1.0 μg/kg ( n=12). Ribavirin was dosed by body weight at 1000 mg/day (≤75 kg) or 1200 mg/day (>75 kg). We found no correlation between body weight and AUC for either peginterferon alpha-2a or peginterferon alpha-2b. Considerable interpatient variability in AUC occurred for peginterferon alpha-2a [coefficient of variation (CV): 37.5%] and, despite dosing by body weight, for peginterferon alpha-2b (CV: 36.8%). Thus, there appears to be no rationale for a body-weight dosing regimen for peginterferon alpha-2a, and such dosing does not achieve more consistent AUC measurements in patients receiving peginterferon alpha-2b.

Area-under-the-curve for peginterferon alpha-2a and peginterferon alpha-2b is not related to body weight in treatment-naive patients with chronic hepatitis C

One reason for dosing a drug by body weight is to reduce interpatient variability in clinical response. This study evaluated the relationship between body weight and drug exposure for peginterferon alpha-2a and peginterferon alpha-2b used in combination with ribavirin for treating patients with chronic hepatitis C. These two products are dosed differently: peginterferon alpha-2a is flat-dosed at 180 microg regardless of body weight, whereas peginterferon alpha-2b is dosed by body weight at 0.5-1.5 microg/kg. Bodyweight dosing of peginterferon alpha-2b is purported to overcome the adverse effect of increased body weight on sustained virological response. To test this hypothesis, we measured the area-under-the-curve (AUC) for both drugs as part of a previously reported pharmacokinetics study. In total, 22 interferon-naive patients with chronic hepatitis C were treated for 12 weeks. Patients were randomly assigned in a 1:1 ratio to receive once-weekly peginterferon alpha-2a 180 microg (n=10) or peginterferon alpha-2b 1.0 microg/kg (n=12). Ribavirin was dosed by body weight at 1000 mg/day (< or = 75kg) or 1200 mg/day (> 75 kg). We found no correlation between body weight and AUC for either peginterferon alpha-2a or peginterferon alpha-2b. Considerable interpatient variability in AUC occurred for peginterferon alpha-2a [coefficient of variation (CV): 37.5%] and, despite dosing by body weight, for peginterferon alpha-2b (CV: 36.8%). Thus, there appears to be no rationale for a body-weight dosing regimen for peginterferon alpha-2a, and such dosing does not achieve more consistent AUC measurements in patients receiving peginterferon alpha-2b.

Viral dynamics and pharmacokinetics of peginterferon alpha-2a and peginterferon alpha-2b in naive patients with chronic hepatitis c: a randomized, controlled study

The two available pegylated interferon formulations, peginterferon alpha-2a and peginterferon alpha-2b, have different pharmacokinetic profiles; as a result they may have differing abilities to suppress the hepatitis C virus. A recently reported study by Formann and colleagues assessing early viral kinetics among 20 patients receiving peginterferon alpha-2b either once or twice weekly suggests that once-weekly administration of peginterferon alpha-2b is not sufficient for continuous exposure to interferon over 160 h. Twice-weekly administration is recommended to avoid increases in viral load as interferon levels decline prior to the end of the one-week dosing period. The objective of this study was to compare viral dynamics and pharmacokinetics between peginterferon alpha-2a and peginterferon alpha-2b in interferon-naive chronic hepatitis C patients. Patients were randomized to receive peginterferon alpha-2a 180 microg (n=10) or peginterferon alpha-2b 1.0 microg/kg (n=12) once weekly. Serum peginterferon concentrations were measured at baseline, 24, 48, 120 and 168h. Hepatitis C virus (HCV) RNA was measured at baseline, 24, 48, 120 and 168 h during week 1 and then at 4 and 12 weeks. Peginterferon alpha-2b achieved maximal serum levels at 24 h, and then decreased rapidly. Of the 12 patients who received peginterferon alpha-2b, no drug was detectable in seven (58%) patients at 120 h and in 11 (92%) at 168 h. In contrast, peginterferon alpha-2a concentrations increased continuously over time, reaching maximal serum levels from 48 to 168 h. Drug was detectable in all 10 patients at 168 h. At weeks 1 and 4 no significant difference was observed in mean HCV RNA between the groups. However, at week 12, mean HCV RNA was significantly lower in the peginterferon alpha-2a group versus the peginterferon alpha-2b group (2.8126 vs 3.8726; P<0.01). The differences in mean HCV RNA values at 12 weeks may be related to the different absorption and distribution profiles of the two drugs. In conclusion, once-weekly administration of peginterferon alpha-2b (1.0 microg/kg/wk) may be insufficient for continuous interferon exposure; twice-weekly administration may help avoid increases in viral replication as interferon levels decline. Larger-scale studies assessing both viral kinetics and sustained virological responses are needed to confirm these observations.

[Overview of therapeutic options for cystic echinococcosis]

Surgical excision of echinococcal cyst has long been considered the only effective treatment for echinococcosis. However, the remarkable advances in imaging techniques, particularly ultrasound, made during the past 25 years have greatly facilitated diagnosis, treatment and follow-up. Today, chemotherapy and percutaneous treatments have become widely available. A major step forward in management of the disease came in 2001, when the WHO International Working Group on Echinococcosis (WHO-IWGE) came to a consensus by developing a standardized classification of ultrasound images in cystic echinococcosis. Thus, the most appropriate treatment for patients affected by this serious and sometimes life-threatening disease may now be chosen. An overview of the three main therapeutic options for abdominal- and particularly hepatic-cystic echinococcosis is presented, with focus on the indications and contraindications of each one. Data from long-term follow-up studies are also discussed, with emphasis on the resulting stage-specific criteria for treatment.

Viral Dynamics and Pharmacokinetics of Peginterferon Alpha-2A and Peginterferon Alpha-2B in Naive Patients with Chronic Hepatitis C: A Randomized, Controlled Study

The two available pegylated interferon formulations, peginterferon alpha-2a and peginterferon alpha-2b, have different pharmacokinetic profiles; as a result they may have differing abilities to suppress the hepatitis C virus. A recently reported study by Formann and colleagues assessing early viral kinetics among 20 patients receiving peginterferon alpha-2b either once or twice weekly suggests that once-weekly administration of peginterferon alpha-2b is not sufficient for continuous exposure to interferon over 160 h. Twice-weekly administration is recommended to avoid increases in viral load as interferon levels decline prior to the end of the one-week dosing period. The objective of this study was to compare viral dynamics and pharmacokinetics between peginterferon alpha-2a and peginterferon alpha-2b in interferon-naive chronic hepatitis C patients. Patients were randomized to receive peginterferon alpha-2a 180 μg ( n=10) or peginterferon alpha-2b 1.0 μg/kg ( n=12) once weekly. Serum peginterferon concentrations were measured at baseline, 24, 48, 120 and 168 h. Hepatitis C virus (HCV) RNA was measured at baseline, 24, 48, 120 and 168 h during week 1 and then at 4 and 12 weeks. Peginterferon alpha-2b achieved maximal serum levels at 24 h, and then decreased rapidly. Of the 12 patients who received peginterferon alpha-2b, no drug was detectable in seven (58%) patients at 120 h and in 11 (92%) at 168 h. In contrast, peginterferon alpha-2a concentrations increased continuously over time, reaching maximal serum levels from 48 to 168 h. Drug was detectable in all 10 patients at 168 h. At weeks 1 and 4 no significant difference was observed in mean HCV RNA between the groups. However, at week 12, mean HCV RNA was significantly lower in the peginterferon alpha-2a group versus the peginterferon alpha-2b group (2.8126 vs 3.8726; P<0.01). The differences in mean HCV RNA values at 12 weeks may be related to the different absorption and distribution profiles of the two drugs. In conclusion, once-weekly administration of peginterferon alpha-2b (1.0 μg/kg/wk) may be insufficient for continuous interferon exposure; twice-weekly administration may help avoid increases in viral replication as interferon levels decline. Larger-scale studies assessing both viral kinetics and sustained virological responses are needed to confirm these observations.

Host factors affecting the outcome of treatment of hepatitis C

The development of peginterferon and ribavirin combination therapy has significantly improved the sustained virologic response (SVR) rates in patients with chronic hepatitis C. However, poor patient adherence to therapy negatively influences drug levels and drug exposure, often preventing the development of an inhibitory drug level. To optimize patient adherence, the clinician must recognize factors predicting low adherence and negotiate a treatment plan that the patient understands and to which he or she commits. If adverse effects become intolerable, continuing patients on a reduced dose rather than withdrawing treatment seems to confer considerable advantage in preserving the chance for attaining an SVR. Results of a head-to-head comparison have demonstrated the possibility that, in cases of dose reduction, levels of peginterferon alfa-2a could remain above the limit of detection, whereas those of peginterferon alfa-2b might not.

Synthesis of a new class of 2,3-dihydro-2-oxo-1H-benzimidazole-1-carboxylic acid derivatives as highly potent 5-HT3 receptor antagonists

A series of 2,3-dihydro-2-oxo-1H-benzimidazole-1-carboxylic acid esters and amides containing a basic azacyclo- or azabicycloalkyl moiety has been synthesized and evaluated for 5-HT3 antagonistic activity in a radioligand binding assay ([3H]ICS 205930) and in the 5-HT-induced von Bezold-Jarisch reflex in the rat. It was found that endo-substituted azabicycloalkyl derivatives (e.g. 7a, 12a, 12b) were much more active than the corresponding exo analogues (e.g. 7b, 12h, 12i) or azacycloalkyl compounds. Amidic derivatives 12a, 12b, 12c, 12e, 13b, and 13c proved to be about 10 times more active than the corresponding ester derivatives 7a, 11a, 7c, 7d, 8a, and 8b. In particular, compound 12a (DA 6215) showed a Ki = 3.8 nM in the binding test and an ED50 = 1 nM/kg iv in the von Bezold-Jarisch reflex assay, an activity comparable to that of the reference compound 2 (ICS 205930, Ki = 2 nM, ED50 = 2.1 nM/kg). IR spectroscopy studies in the solid state and in CHCl3 solution revealed the existence of an intramolecular hydrogen bond in 13b, taken as a model compound for this class of substances. A molecular modeling study showed that 12a, in its internal hydrogen-bound conformation, well matches a recently proposed pharmacophoric model for 5-HT3 antagonist activity.