Absence of liver steatosis in HIV-HCV co-infected patients receiving regimens containing tenofovir or abacavir

Identification of hepatic steatosis among persons with and without HIV using natural language processing

BACKGROUND

Steatotic liver disease (SLD) is a growing phenomenon, and our understanding of its determinants has been limited by our ability to identify it clinically. Natural language processing (NLP) can potentially identify hepatic steatosis systematically within large clinical repositories of imaging reports. We validated the performance of an NLP algorithm for the identification of SLD in clinical imaging reports and applied this tool to a large population of people with and without HIV.

METHODS

Patients were included in the analysis if they enrolled in the Veterans Aging Cohort Study between 2001 and 2017, had an imaging report inclusive of the liver, and had ≥2 years of observation before the imaging study. SLD was considered present when reports contained the terms "fatty," "steatosis," "steatotic," or "steatohepatitis." The performance of the SLD NLP algorithm was compared to a clinical review of 800 reports. We then applied the NLP algorithm to the first eligible imaging study and compared patient characteristics by SLD and HIV status.

RESULTS

NLP achieved 100% sensitivity and 88.5% positive predictive value for the identification of SLD. When applied to 26,706 eligible Veterans Aging Cohort Study patient imaging reports, SLD was identified in 72.2% and did not significantly differ by HIV status. SLD was associated with a higher prevalence of metabolic comorbidities, alcohol use disorder, and hepatitis B and C, but not HIV infection.

CONCLUSIONS

While limited to those undergoing radiologic study, the NLP algorithm accurately identified SLD in people with and without HIV and offers a valuable tool to evaluate the determinants and consequences of hepatic steatosis.

Comparison of the prevalence, severity, and risk factors for hepatic steatosis in HIV-infected and uninfected people

Background

Hepatic steatosis is prevalent in Western countries, but few studies have evaluated whether the frequency and severity of steatosis are greater in the setting of HIV infection. We compared the prevalence and severity of hepatic steatosis between HIV-infected (HIV+) and uninfected persons and identified factors associated with greater steatosis severity within both groups.

Methods

We performed a cross-sectional study among participants without cardiovascular disease who participated in a substudy of the Veterans Aging Cohort Study. Hepatic steatosis was defined by noncontrast computed tomography (CT) liver-to-spleen (L/S) attenuation ratio < 1.0. Multivariable linear regression was used to: 1) evaluate the association between HIV infection and severity of hepatic steatosis, as measured by absolute liver attenuation, and 2) identify factors associated with greater severity of steatosis, by HIV status.

Results

Among 268 participants (median age, 55 years; 99% male; 79% black; 23% obese; 64% HIV+ [91% on antiretroviral therapy]), the overall prevalence of steatosis was 7.8% and was similar between HIV+ and uninfected individuals (13 [7.6%] versus 8 [8.2%], respectively; p = 0.85). Participants with HIV, the majority of whom received antiretroviral therapy, had a higher mean absolute liver attenuation (mean difference, 5.68 Hounsfield units; p < 0.001), correlating with lesser hepatic steatosis severity, compared to uninfected participants. After adjusting for covariates, only advanced hepatic fibrosis was associated with greater severity of steatosis in HIV+ persons (p = 0.03) and uninfected individuals (p < 0.001).

Conclusions

In this sample of participants without cardiovascular disease, the prevalence of hepatic steatosis by noncontrast abdominal CT was not different by HIV status. Increasing severity of steatosis was independently associated with advanced hepatic fibrosis in both groups.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-0969-1) contains supplementary material, which is available to authorized users.

Hepatic steatosis in HCV-infected persons in the direct-acting antiviral era

Hepatitis C virus (HCV) infects 130-170 million people worldwide. Recently, direct-acting antivirals have been shown to eradicate HCV infection in 90-95 % of non-cirrhotic patients depending on genotype, treatment experience, and regimen used. Similar rates are achieved among compensated cirrhotics, although longer treatment duration and/or ribavirin may be required. HCV uses host lipid metabolism for its lifecycle and can cause hepatic steatosis and insulin resistance. Hepatic steatosis, defined as excessive triglyceride deposition in hepatocytes, affects approximately half of HCV-infected individuals. Genetic factors and co-morbidities can drive further steatosis, which in turn can instigate fibrosis and progression to cirrhosis and hepatocellular carcinoma. Polymorphisms in genes that modulate lipid deposition in hepatocytes such as patatin-like phospholipase domain-containing protein 3 (PNPLA3) and transmembrane six superfamily member 2 (TM6SF2) predispose people to steatosis. Metabolic syndrome, obesity, and insulin resistance are increasing worldwide and further contribute to hepatic steatosis, and alcohol has long been recognized as a cause of lipid deposition in the liver. HIV and antiretroviral drugs, but not HBV, may further drive hepatic steatosis. While many of these factors limit response to interferon-based regimens for treating HCV, responses to direct-acting antivirals appear not to be impaired. The effect of HCV eradication on hepatic steatosis and progression to fibrosis, cirrhosis, and hepatocellular carcinoma warrants further study in the era of direct-acting antivirals.