31Phosphorus magnetic resonance spectroscopy of the liver for evaluating inflammation and fibrosis in autoimmune hepatitis

Abstract

Background: Liver biopsy is the gold standard in evaluating inflammation and fibrosis in autoimmune hepatitis.Aims: In search of non-invasive follow-up tools in autoimmune hepatitis, we evaluated 31phosphorus magnetic resonance spectroscopy (31P MRS).Methods: Twelve consecutive AIH patients (mean age 42.8 years, 10 women) underwent liver biopsy, routine laboratory liver function tests, which were compared to findings in 31P MRS and transient elastography (TE).Results: Phosphoenolpuryvate (PEP) correlated with the grade of inflammation (r = 0.746, p = .005) and thromboplastin time (r = 0.592, p = .043). It also differentiated patients with active inflammation from patients without (t = 3.781, p = .009). There was no correlation between PEP and aminotransferase or immunoglobulin G levels.The phosphoethanolamine (PE)/phosphocholine (PC) ratio, PE/glyserophosphoethanolamine (GPE) ratio and PC/[total phosphomonoester (PME) + phosphodiester (PDE)] ratios correlated with immunoglobulin G (r = 0.764, p = .006; r = 0.618, p = .043; and r= −0.636, p = .035, respectively).PME/PDE and PE/GPE correlated with fibrosis (r = 0.668, p = .018 and r = 0.604, p = .037). PE/GPE also differentiated F3 from F0-2 patients (t = 3.810, p = .003).Phosphorus metabolites did not correlate with TE results and TE did not correlate with liver histology or laboratory parameters.Conclusions: 31P MRS seems to detect active inflammation and advanced fibrosis in AIH patients. TE was ineffective in fibrosis quantification.