3. Chow DK, Sung JJ. Is the prevalence of idiopathic ulcers reallyon the increase? Nat Clin Pract Gastroenterol Hepatol 2007; 4:176–7.
4. McColl KE. Helicobacter pylori-negative nonsteroidal anti-inflammatory drug-negative ulcer. Gastroenterol Clin North Am2009; 38: 353–61.
Commentary: new tools to assess hepaticsteatosis – what do we want to measure?Z. Yu*,†,‡ & V. W.-S. Wong*,†
*Department of Medicine and Therapeutics, The Chinese University ofHong Kong, Hong Kong, China.†Institute of Digestive Disease, The Chinese University of Hong Kong,Hong Kong, China.‡Department of Liver Disease, Shuguang Hospital Affiliated toShanghai University of Traditional Chinese Medicine, Shanghai, China.E-mail: [email protected]
doi:10.1111/j.1365-2036.2012.05168.x
We read with great interest the article by Permutt et al. thatdemonstrated the use of proton density-fat fraction (PDFF)by magnetic resonance imaging to measure hepatic steato-sis in patients with non-alcoholic fatty liver disease(NAFLD).1 In addition, patients with cirrhosis had less steato-sis than noncirrhotic patients by both PDFF and histology.
The latter finding has major clinical implications. AsNAFLD progresses towards cirrhosis and end-stage liverdisease, hepatic steatosis often decreases or disappears.2
In fact, NAFLD is believed to be the most common causeof cryptogenic cirrhosis.3 Decrease in hepatic steatosisthus cannot be taken as evidence of disease improvement.
How should we interpret steatosis results then? At theclinic setting, one may look for other risk factors of diseaseprogression. For example, if a patient is nondiabetic andachieves weight reduction, a reduction in hepatic steatosismost likely represents genuine improvement.2, 4 On theother hand, for future clinical research using non-invasivetests only, steatosis results should be supplemented bymarkers of necroinflammation and fibrosis.5, 6
Moreover, this study did not include a control groupwithout NAFLD. Future studies are required to evaluatethe accuracy of PDFF in diagnosing NAFLD. It would alsobe important to compare PDFF with other state-of-the-artnon-invasive tests of steatosis like proton-magnetic reso-nance spectroscopy and dual gradient echo magneticresonance imaging.7, 8
In conclusion, new and promising tools for the mea-surement of hepatic steatosis have been developed in thepast few years. These tests will likely have a majorimpact on future research and practice. At the end ofthe day, the ultimate test would be whether these investi-gations predict clinical outcomes such as cirrhosis, hepa-tocellular carcinoma and cardiovascular complications.9
ACKNOWLEDGEMENTDeclaration of personal interests: Vincent Wong hasserved in the advisory boards of Novartis, Roche, Gileadand Otsuka, and received paid lecture fees from AbbottDiagnostics, Novartis, Roche and Echosens. Declarationof funding interests: None.
REFERENCES
1. Permutt Z, Le T-A, Peterson MR, et al. Correlation between liverhistology and novel magnetic resonance imaging in adult patientswith non-alcoholic fatty liver disease - MRI accurately quantifieshepatic steatosis in NAFLD. Aliment Pharmacol Ther 2012; 36:22–9.
2. Wong VW, Wong GL, Choi PC, et al. Disease progression ofnon-alcoholic fatty liver disease: a prospective study with pairedliver biopsies at 3 years. Gut 2010; 59: 969–74.
3. Caldwell SH, Oelsner DH, Iezzoni JC, et al. Cryptogenic cirrhosis:clinical characterization and risk factors for underlying disease.Hepatology 1999; 29: 664–9.
4. Wong VW, Hui AY, Tsang SW, et al. Prevalence of undiagnoseddiabetes and postchallenge hyperglycaemia in Chinese patientswith non-alcoholic fatty liver disease. Aliment Pharmacol Ther2006; 24: 1215–22.
5. Shen J, Chan HL, Wong GL, et al. Non-invasive diagnosis ofnon-alcoholic steatohepatitis by combined serum biomarkers.J Hepatol 2012; 56: 1363–70.
6. Wong VW, Vergniol J, Wong GL, et al. Diagnosis of fibrosis andcirrhosis using liver stiffness measurement in nonalcoholic fattyliver disease. Hepatology 2010; 51: 454–62.
7. Lee SS, Park SH, Kim HJ, et al. Non-invasive assessment ofhepatic steatosis: prospective comparison of the accuracy ofimaging examinations. J Hepatol 2010; 52: 579–85.
8. Wong VW, Wong GL, Tsang SW, et al. High prevalence ofcolorectal neoplasm in patients with non-alcoholic steatohepatitis.Gut 2011; 60: 829–36.
9. Younossi ZM, Stepanova M, Rafiq N, et al. Pathologic criteria fornonalcoholic steatohepatitis: interprotocol agreement and abilityto predict liver-related mortality. Hepatology 2011; 53: 1874–82.
Aliment Pharmacol Ther 2012; 36: 290-295 293
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