Multicenter Validation of Association Between Decline in MRI-PDFF and Histologic Response in NASH

BACKGROUND AND AIMS

Emerging data from a single-center study suggests that a 30% relative reduction in liver fat content as assessed by magnetic resonance imaging-proton density fat fraction (MRI-PDFF) from baseline may be associated with histologic improvement in nonalcoholic steatohepatitis (NASH). There are limited multicenter data comparing an active drug versus placebo on the association between the quantity of liver fat reduction assessed by MRI-PDFF and histologic response in NASH. This study aims to examine the association between 30% relative reduction in MRI-PDFF and histologic response in obeticholic acid (OCA) versus placebo-treated patients in the FLINT (farnesoid X receptor ligand obeticholic acid in NASH trial).

APPROACH AND RESULTS

This is a secondary analysis of the FLINT trial including 78 patients with MRI-PDFF measured before and after treatment along with paired liver histology assessment. Histologic response was defined as a 2-point improvement in nonalcoholic fatty liver disease activity score without worsening of fibrosis. OCA (25 mg orally once daily) was better than placebo in improving MRI-PDFF by an absolute difference of -3.4% (95% confidence interval [CI], -6.5 to -0.2%, P value = 0.04) and relative difference of -17% (95% CI, -34 to 0%, P value = 0.05). The optimal cutoff point for relative decline in MRI-PDFF for histologic response was 30% (using Youden's index). The rate of histologic response in those who achieved less than 30% decline in MRI-PDFF versus those who achieved a 30% or greater decline in MRI-PDFF (MRI-PDFF responders) relative to baseline was 19% versus 50%, respectively. Compared with MRI-PDFF nonresponders, MRI-PDFF responders demonstrated both a statistically and clinically significant higher odds 4.86 (95% CI, 1.4-12.8, P value < 0.009) of histologic response, including significant improvements in both steatosis and ballooning.

CONCLUSION

OCA was better than placebo in reducing liver fat. This multicenter trial provides data regarding the association between 30% decline in MRI-PDFF relative to baseline and histologic response in NASH.

Heavy marijuana users show increased serum apolipoprotein C-III levels: evidence from proteomic analyses

Marijuana (MJ) is the most commonly used illicit drug in the United States. Its abuse is associated with cognitive dysfunctions and increased resistance to blood flow in the cerebral vasculature. In addition, MJ abuse is associated with increased risks of potentially serious cardiovascular disorders. In the present study, we used the protein chip platform based on surface-enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI-TOF-MS) to test the possibility that MJ abuse might be associated with changes in serum protein levels. Indeed, MJ users showed significant increases in three protein peaks, which were identified as three isoforms of apolipoprotein (apo) C-III. Immunoprecipitation using an apoC-III antibody also validated the identification of the proteins. Marijuana-induced increases in apoC-III levels might occur through chronic stimulation of hepatic cannabinoid receptors (CB1 and/or CB2) by its active ingredient, Delta(9)tetrahydrocannibol (THC). Thus, chronic MJ abuse might cause increased transcription and/or translation of apoC-III in the liver with corresponding changes reflected in the plasma of these patients. In any case, because apoC-III is a cardiovascular risk factor, the increased levels observed in MJ users might explain, in part, the cardiac and cerebral abnormalities reported in these patients.