Liver Function Breath Tests for Differentiation of Steatohepatitis From Simple Fatty Liver in Patients With Nonalcoholic Fatty Liver Disease

Abstract

In the NAFLD patients, decreased and delayed liver microsomal function, as assessed by C-ABT, is associated with more severe necroinflammation and fibrosis, whereas C-ABT results at 120 minutes may be helpful for the diagnosis of NASH.

Experimental nonalcoholic steatohepatitis compromises ureagenesis, an essential hepatic metabolic function

“…The reduced albumin may reflect low-grade inflammation with albumin as a negative acute-phase protein or decreased hepatic protein synthetic capacity. These findings are consistent with the few existing data on liver function in human NAFLD (8,19,42).…”

“…It has been demonstrated that NASH patients tend to have a reduced activity of liver-derived coagulation factors and lower levels of albumin than patients with pure steatosis (7). Breath tests as indirect measures of liver function suggest some degree of relation between functional impairment and the extent of fatty liver lesions (8,42). The metabolic liver function assessed more directly by the galactose elimination capacity was found to be decreased in steatosis patients (19).…”

European guideline on indications, performance and clinical impact of 13C‐breath tests in adult and pediatric patients: An EAGEN, ESNM, and ESPGHAN consensus, supported by EPC

“…13 C‐LFBT also represent dynamic tests with oral consumption or intravenous application of the marker substance and measurement of the end product of hepatic metabolism, that is exhaled 13 CO 2 . Some modifications have been shown to detect early changes in liver metabolic capacity in patients, prior to the presence of structural damage to the liver (i.e., inflammation, fibrosis), 152 though with limited sensitivities and specificities 153–160 . Still, the dynamic nature of 13 C‐LFBT, their possible versatility in terms of assessing a range of different liver functions, and the ease with which they can be repeated to follow relative changes in liver function with time, generally imply a marked potential for clinical application 40 …”

“…Some modifications have been shown to detect early changes in liver metabolic capacity in patients, prior to the presence of structural damage to the liver (i.e., inflammation, fibrosis), 152 though with limited sensitivities and specificities. [153][154][155][156][157][158][159][160] Still, the dynamic nature of 13 C-LFBT, their possible versatility in terms of assessing a range of different liver functions, and the ease with which they can be repeated to follow relative changes in liver function with time, generally imply a marked potential for clinical application. 40 When should 13 C-LFBT be utilized?…”

“…13 C-aminopyrine, [3-methyl- 13 C]-caffeine) and cytosolic ( 13 C-phenylalanine) function. 152,157,[159][160][161][162][163][164][165][166][167][168] These have been mainly used in patients with liver fibrosis and cirrhosis due to nonalcoholic fatty liver disease, 152,157,[159][160][161]163,164,169,170 chronic hepatitis C, 162,165 cirrhosis, 166,171 and hepatocellular carcinoma. 172 Additional potential fields of application are in steatohepatitis, 156,157,159 fatty liver, 160,163,169 and assessment of prognosis in chronic liver diseases, in general: In a 7-year prospective follow-up study in 132 patients with chronic HCV infection, the 4 0 -O-13 C-methacetin breath was not inferior to liver biopsy in predicting liver-related death and transplantation.…”