Dataset Information

Optimal Threshold of Controlled Attenuation Parameter for Detection of HIV-Associated NAFLD With Magnetic Resonance Imaging as the Reference Standard.

ABSTRACT:

Background

Controlled attenuation parameter (CAP) is an ultrasound-based point-of-care method to quantify liver fat; however, the optimal threshold for CAP to detect pathologic liver fat among persons living with human immunodeficiency virus (HIV; PLWH) is unknown. Therefore, we aimed to identify the diagnostic accuracy and optimal threshold of CAP for the detection of liver-fat among PLWH with magnetic resonance imaging proton-density fat fraction (MRI-PDFF) as the reference standard.

Methods

Patients from a prospective single-center cohort of PLWH at risk for HIV-associated nonalcoholic fatty liver disease (NAFLD) who underwent contemporaneous MRI-PDFF and CAP assessment were included. Subjects with other forms of liver disease including viral hepatitis and excessive alcohol intake were excluded. Receiver operatic characteristic (ROC) curve analysis were performed to identify the optimal threshold for the detection of HIV-associated NAFLD (liver fat ≥ 5%).

Results

Seventy PLWH (90% men) at risk for NAFLD were included. The mean (± standard deviation) age and body mass index were 48.6 (±10.2) years and 30 (± 5.3) kg/m2, respectively. The prevalence of HIV-associated NAFLD (MRI-PDFF ≥ 5%) was 80%. The M and XL probes were used for 56% and 44% of patients, respectively. The area under the ROC curve of CAP for the detection of MRI-PDFF ≥ 5% was 0.82 (0.69-0.95) at the cut-point of 285 dB/m. The positive predictive value of CAP ≥ 285 dB/m was 93.2% in this cohort with sensitivity of 73% and specificity of 78.6%.

Conclusions

The optimal cut-point of CAP to correctly identify HIV-associated NAFLD was 285 dB/m, is similar to previously published cut-point for primary NAFLD and may be incorporated into routine care to identify patients at risk of HIV-associated NAFLD.

SUBMITTER: Ajmera VH

PROVIDER: S-EPMC8204791 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Background MRI-derived proton density fat fraction (PDFF) is an accurate, reliable, and safe biologic marker for use in the noninvasive diagnosis of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD). Because of the cost and limited availability of MRI, it is necessary to develop an accurate method to diagnose NAFLD with potential point-of-care access. Purpose To compare the diagnostic accuracy of the quantitative US (QUS) fat fraction (FF) estimator with that of the controlled attenuation parameter (CAP) in the diagnosis of NAFLD using contemporaneous MRI-derived PDFF as the reference standard. Materials and Methods Participants with or suspected of having NAFLD were prospectively recruited at the NAFLD Research Center between July 2015 and July 2019. All participants underwent MRI-derived PDFF measurement, transient elastography with CAP measurement, and QUS. QUS FF was derived using computed QUS parameters from the acquired radiofrequency US data using a calibrated reference phantom. The area under the receiver operating characteristic curve (AUC) was calculated to assess the accuracy of QUS FF and CAP in the diagnosis of hepatic steatosis (defined as MRI-derived PDFF ≥ 5%). AUCs were compared using the DeLong test. Results A total of 123 participants were included (mean age, 52 years ± 13 [SD]; 67 [54%] women). Of these participants, 100 (81%) had MRI-derived PDFF of 5% or more. QUS FF had a significantly higher AUC for diagnosis of NAFLD than did CAP (0.92 [95% CI: 0.87, 0.98] vs 0.79 [95% CI: 0.67, 0.90], P = .03). QUS FF had a sensitivity of 98% (98 of 100) and a specificity of 48% (11 of 23). CAP had a sensitivity of 87% (87 of 100) and a specificity of 57% (13 of 23). Conclusion The quantitative US fat fraction estimator is more accurate than the controlled attenuation parameter in the diagnosis of hepatic steatosis in patients with or suspected of having nonalcoholic fatty liver disease. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Ito in this issue.

Project description:OBJECTIVE:Hepatic steatosis is common in HIV-infected individuals. Magnetic resonance spectroscopy (MRS) is the preferred noninvasive method for hepatic steatosis measurement but is expensive. Controlled attenuation parameter (CAP) also assesses hepatic steatosis and is conveniently performed concomitantly with transient elastography. We aimed to assess the accuracy of CAP in the setting of HIV infection. DESIGN:Cross-sectional study. METHODS:CAP and MRS were performed in 82 study participants (39 HIV monoinfected; seven hepatitis C virus (HCV) monoinfected; 21?HIV/HCV coinfected; 15 with neither infection). We used concordance correlation coefficients to compare log-transformed and standardized CAP and MRS values and linear regression to examine factors associated with CAP and MRS-measured hepatic steatosis (MRS-HS). The accuracy of CAP to detect at least mild hepatic steatosis, defined as MRS-liver fat fraction more than 0.05, and the factors associated with discordance between CAP and MRS were evaluated. RESULTS:Overall, CAP-measured hepatic steatosis and MRS-HS correlated moderately well (rc?=?0.63; P?<?0.001), and correlation was strongest in the HIV-monoinfected group (rc?=?0.67; P?<?0.001). Body composition factors (higher BMI, waist circumference, visceral and abdominal subcutaneous adipose tissue) and insulin resistance were significantly associated with both greater CAP-measured hepatic steatosis and MRS-HS. Using a validated CAP cut-off of at least 238?dB/m, sensitivity and specificity for at least mild hepatic steatosis were 84% and 75% in the entire cohort; 89% and 80% in the HIV-monoinfected group. Participants with higher body composition parameters were more likely to be misclassified as having hepatic steatosis by CAP. CONCLUSION:Our findings suggest CAP is an acceptable noninvasive surrogate for hepatic steatosis in HIV-infected individuals but may overestimate hepatic steatosis prevalence, especially in individuals with high BMI. Evaluation of factors that improve CAP accuracy and determination of optimal cut-offs are warranted.