Decreased serum DNase1-activity in patients with autoimmune liver diseases

Abstract

Deoxyribonuclease1 (DNase1) is involved in chromatin degradation of apoptotic cells. Its deficiency results in accumulation of self-DNA, which in turn may induce inflammation and autoimmunity. We assessed for the first time serum DNase1-activity in a large consecutive cohort of treatment-naïve patients with autoimmune liver diseases (ALD). DNase1-activity was determined by single radial enzyme-diffusion (SRED) at diagnosis of 224 patients with autoimmune hepatitis (AIH), 249 with primary biliary cirrhosis (PBC) and 36 with primary sclerosing cholangitis (PSC). Sera from 146 patients with chronic hepatitis B or C, 140 with nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) and 114 healthy individuals served as disease and healthy controls. Available serum samples during remission from 50 AIH and 39 PBC patients were also investigated by paired analyzes. DNase1-activity was significantly lower in AIH, PBC and PSC compared to viral hepatitis (p < 0.02, p < 0.001, p = 0.03), NAFLD/NASH (p < 0.001) and healthy (p < 0.001). No significant difference was found in between each specific ALD. In AIH, DNAse1-activity was positively correlated with aspartate aminotransferase (AST) (p < 0.02), bilirubin (p < 0.01) and increased IgG (>1400 mg/dl; p < 0.05); in PBC, with AST (p < 0.01), alanine aminotransferase (ALT) (p < 0.03) and anti-mitochondrial antibodies (AMA) (p = 0.008). In PSC, DNase1-activity was inversely associated with alkaline phosphatase (ALP) (p < 0.05). In AIH, complete responders were characterized by increased baseline DNase1-activity compared to partial responders, relapsers and non-responders (p < 0.02), whereas it was significantly increased after achievement of remission (p < 0.001). Serum DNase1-activity is significantly decreased in ALD patients, indicating its potential implication in their pathogenesis. Furthermore, DNase1-activity could be used as a new surrogate biomarker for predicting response to AIH treatment.

Prompt initiation of high‐dose i.v. corticosteroids seems to prevent progression to liver failure in patients with original acute severe autoimmune hepatitis

“…Antinuclear antibodies (ANA), smooth muscle antibodies (SMA), antibodies against liver kidney microsomal type‐1 (anti‐LKM1), and against liver cytosol type‐1 (anti‐LC1) were initially detected by indirect immunofluorescence on 5‐μm fresh frozen sections of in‐house rodent kidney, liver, and stomach tissue substrates as we described previously . Anti‐LKM1, anti‐LC1, and antibodies against soluble liver antigen/liver pancreas (anti‐SLA/LP) were also evaluated by immunoblotting using rat liver microsomal or cytosolic extracts .…”

“…Antinuclear antibodies (ANA), smooth muscle antibodies (SMA), antibodies against liver kidney microsomal type-1 (anti-LKM1), and against liver cytosol type-1 (anti-LC1) were initially detected by indirect immunofluorescence on 5-μm fresh frozen sections of in-house rodent kidney, liver, and stomach tissue substrates as we described previously. 1,11,[27][28][29][30] Anti-LKM1, anti-LC1, and antibodies against soluble liver antigen/liver pancreas (anti-SLA/LP) were also evaluated by immunoblotting using rat liver microsomal or cytosolic extracts. 1,11,29 Commercially available enzyme-linked immunosorbent assay kits using recombinant SLA/LP/tRNP (Ser) Sec (Inova Diagnostics, San Diego, CA, USA) and formiminotransferase cyclodeaminase (Euroimmun Medizinische Labordiagnostika, Lubeck, Germany) were also used for anti-SLA/ LP and anti-LC1 determination respectively, according to the manufacturer's instructions.…”

“…All biopsies were assessed using the Knodell histologic/activity index score. 31 According to previous publications of our group, [27][28][29][30] patients were divided into two groups according to inflammation (minimal-mild [score, 0-8] and moderate-severe [score, [9][10][11][12][13][14][15][16][17][18]) and fibrosis (minimal/mild-moderate [score, 0-2] and severe fibrosis-cirrhosis [score, [3][4]. Detailed description of biopsies from original AS-AIH patients was included in the analysis.…”

Autoimmune hepatitis in patients aged 70 years or older: Disease characteristics, treatment response and outcome

“…Antinuclear antibodies, smooth muscle antibodies, anti‐liver/kidney microsome type‐1 (anti‐LKM1) and anti‐liver cytosol type‐1 (anti‐LC1) were initially detected by indirect immunofluorescence as we have described 1,2,7,17‐22 . Anti‐LKM1, anti‐LC1 and anti‐soluble liver antigen/liver pancreas (anti‐SLA/LP) were also evaluated by Western immunoblotting using rat liver microsomal or cytosolic extracts 1,2,19,20 .…”

“…All biopsies were assessed by one experienced liver immunopathologist who was unaware of the clinical diagnosis of patients, using the Knodell histologic/activity index score 23 . According to our previous publications, 17‐22 patients were divided into two groups according to inflammation: minimal‐mild (score: 0‐8) and moderate‐severe (score: 9‐18) and according to fibrosis: minimal/mild‐moderate (score: 0‐2) and severe fibrosis‐cirrhosis (score: 3‐4). For patients without available biopsy, diagnosis of cirrhosis was based on ultrasonography (coarse echo pattern of the liver parenchyma along with irregular hepatic margins, spleen >12cm, portal vein >16mm), and/or endoscopic findings of portal hypertension, and/or clinical findings of decompensation as we have reported recently 24 …”