Subclinical but significant liver fibrosis in patients with ANCA-associated vasculitis

We evaluated the laboratory and radiological data on liver and investigate liver fibrosis induced by hepatic manifestation of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) using the aspartate aminotransferase to platelet ratio index (APRI) and an index of fibrosis (FIB-4) in 136 immunosuppressive drug-naïve patients.

We retrospectively reviewed the medical records of 136 patients with AAV without chronic liver diseases or autoimmune diseases. We collected the laboratory and imaging results. We assessed liver fibrosis by APRI and FIB-4. The critical cut-offs of APRI and FIB-4 for predicting liver fibrosis are 0.5 and 1.45. The optimal cut-off of five factor score (FFS) at diagnosis for FIB-4 ≥1.45 was extrapolated by the area under the receiver operator characteristic curve.

The mean age at diagnosis was 54.6 years and 32.4% of patients were male (69 MPA, 38 GPA and 29 EGPA). The percentage of patients having the normal results of liver function tests was ranging from 86.0% to 95.6%. There were no patients who exhibited the significantly abnormal findings on imaging studies. Nonetheless, twenty-nine patients with AAV (21.3%) exhibited subclinical but significant liver fibrosis at diagnosis based on FIB-4. Patients with FFS ≥1 had a significantly higher risk of having subclinical but significant liver fibrosis (FIB-4 ≥1.45) than those with FFS <1 (RR 12.486).

AAV may increase the results of liver function tests and it may provoke subclinical but significant liver fibrosis at diagnosis. Furthermore, liver fibrosis should be considered in AAV patients having FFS ≥1.