Vibration-controlled transient elastography outperformed aspartate aminotransferase to platelet ratio index and Fibrosis-4 index as a noninvasive biomarker for advanced fibrosis in patients with hepatitis B and HIV coinfection, according to a study published in Hepatology.
While several studies have examined single noninvasive markers of fibrosis in HBV/HIV coinfection, Richard K. Sterling, MD, MSc, from Virginia Commonwealth University, and colleagues sought to further investigate the relative discriminatory capacity of these tests.
“Given the risks and low rate of acceptance [to undergo biopsy] by patients, there has been extensive research into non-invasive markers for hepatic fibrosis or cirrhosis,” they wrote. “Comparing the performance of three common noninvasive markers of liver fibrosis used in North America, we found that VCTE out-performed the serum-based non-invasive markers.”
The study comprised 108 patients who were currently receiving combined anti-retroviral therapy (cART). Of those, 106 patients had results from APRI and FIB-4, while 63 patients had liver stiffness measurements from VCTE, 61 of whom also had APRI and FIB-4.
The AUROCs for differentiation of advanced fibrosis by biomarkers was 0.615 for APRI, 0.665 for FIB-4, and 0.865 for VCTE.
The optimal cut-off for VCTE was 7.8 kPa or higher (0.1 different from the established cut-off of more than 7.6 kPa), with a combined sensitivity and specificity rate of 155.5, a positive predictive value (PPV) of 72.7% and negative predictive value (NPV) of 90.5%.
In comparison, the optimal APRI cut-off of 0.42 kPa or higher had a sensitivity and specificity rate of 135.7, PPV of 40.5% and NPV of 87%; and the optimal FIB-4 cut-off of 1.76 kPa or higher had a sensitivity and specificity rate of 126.8, PPV of 38.7% and NPV of 84%.
Classification and regression tree analysis also identified VCTE as the primary predictor of advanced fibrosis in this population. Addition of APRI or FIB-4 in the analysis did not improve misclassification rates.
Sterling and colleagues recommend a low VCTE cut-off of 5 kPa or less to exclude advanced fibrosis and a cut-off of 8.8 kPa or higher to confirm advanced fibrosis.
“Given the poor performance of APRI and FIB-4, we do not recommend their use in HBV-HIV patients on cART,” they wrote. “VCTE exclusionary and confirmatory cutoffs can be used to reduce the number of patients who need biopsy to determine advanced fibrosis by over one half in this understudied population.”
By Talitha Bennett