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.