ABSTRACT
BACKGROUND: We aimed at determination of the usefulness of elastography [acoustic radiation force impulse (ARFI) and FibroScan] for evaluation of nonalcoholic fatty liver disease (NAFLD) patients. PATIENTS AND METHODS: A prospective cross-sectional study included 60 biopsy-proven NAFLD patients (mean age: 45 years) was carried out. All patients were subjected to lab works, liver biopsy, and measurement of liver stiffness by ARFI and FibroScan and steatosis by controlled attenuation parameter (CAP). CAP measurements were adjusted for the presence of NAFLD and presence or absence of diabetes and according to BMI. RESULTS: Linear regression analysis showed that CAP is an independent predictor for significant hepatic steatosis (P<0.001). No significant difference was found in diagnostic accuracy between adjusted and nonadjusted CAP values for diagnosis of mild (>S1) or significant (>S2) hepatic steatosis (P=0.17 and 0.29 respectively). The median ARFI velocities for F1, F2, F3, and F4 were 0.92, 1.08, 1.07, and 2.58 m/s, respectively. Although there was an overall significant increase in ARFI values across the fibrosis grades (P<0.04), the difference in ARFI values was only significant between fibrosis grades F1 and F4 (P=0.02). CONCLUSION: Elastography is a promising noninvasive tool for diagnosis and grading of hepatic steatosis and fibrosis in patients with NAFLD/nonalcoholic steatohepatitis with good sensitivity and specificity, especially in moderate to marked grades.
Subject(s)
Biopsy/methods , Elasticity Imaging Techniques/methods , Liver/diagnostic imaging , Non-alcoholic Fatty Liver Disease/diagnosis , Cross-Sectional Studies , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , ROC Curve , Reproducibility of Results , Severity of Illness IndexABSTRACT
BACKGROUND AND AIMS: Various genetic polymorphisms play a key-role in the pathogenesis of NAFLD and progression to NASH with fibrosis to cirrhosis. We aimed to study the association between single-nucleotide polymorphisms (SNPs) in NNMT gene, namely rs694539 and the development of different stages of NAFLD diagnosed by controlled attenuation parameter (CAP) of FibroScan Echosens®. METHODS: Transient elastography (FibroScan®) with controlled attenuation parameter (CAP) measurement was performed in 81 NAFLD patients (35 of them with liver biopsy) and 80 non-NAFLD controls. The accuracy of CAP and FibroScan for the detection and quantification of hepatic steatosis/fibrosis, respectively, was assessed based on liver biopsy aspect. Genetic variants of NNMT gene rs694539 were analyzed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: According to BMI (kg/m2), among the patients, 17 (21%) were overweight, 56 (69.1%) obese, and 8 (9.9%) morbidly obese. CAP and FibroScan diagnosed steatosis/fibrosis correlated significantly with liver biopsy. There was a significant association between polymorphisms of rs694539-NNMT gene and NAFLD presence and stages. The mutant type (AA-genotype) was found in 33% NAFLD patients versus 1.2% controls (P<0.001), whereas the wild type (GG-genotype) was present in 21% versus 63.8% controls (P<0.001). Moreover, the AA-genotype significantly correlated with the steatosis degree by CAP but not the fibrosis degree by FibroScan. Multivariate regression analysis of all the independent risk factors showed non-significant correlations with the degree of steatosis on CAP. However, by using a stepwise approach, waist circumference showed significance as an independent predictor of NAFLD. CONCLUSIONS: Polymorphisms in rs694539-NNMT gene (mutant AA-genotype) could be a genetic risk factor for developing NAFLD and NASH (indicating susceptibility for progression and complications). Individuals with wild type (GG-genotype) are at less risk of NAFLD development. CAP and FibroScan efficiently diagnosed steatosis and fibrosis.
