Optimization of Laboratory Diagnostics of Primary Biliary Cholangitis: When Solid-Phase Assays and Immunofluorescence Combine

Abstract

The laboratory diagnostics of primary biliary cholangitis (PBC) have substantially improved, thanks to innovative analytical opportunities, such as enzyme-linked immunosorbent assays (ELISA) and multiple immunodot liver profile tests, based on recombinant or purified antigens. This study aimed to identify the best diagnostic test combination to optimize PBC diagnosis. Between January 2014 and March 2017, 164 PBC patients were recruited at the hospitals of Parma, Modena, Reggio-Emilia, and Piacenza. Antinuclear antibodies (ANA) and anti-mitochondrial antibodies (AMA) were assayed by indirect immunofluorescence (IIF), ELISA, and immunodot assays (PBC Screen, MIT3, M2, gp210, and sp100). AMA-IIF resulted in 89.6% positive cases. Using multiple immunodot liver profiles, AMA-M2 sensitivity was 94.5%, while anti-gp210 and anti-sp100 antibodies were positive in 16.5% and 17.7% of patients, respectively. PBC screening yielded positive results in 94.5% of cases; MIT3, sp100, and gp210 were detected by individual ELISA test in 89.0%, 17.1%, and 18.9% of patients, respectively. The association of PBC screening with IIF-AMA improved the diagnostic sensitivity from 89.6% to 98.2% (p < 0.01). When multiple immunodot liver profile testing was integrated with AMA-IIF, the diagnostic sensitivity increased from 89.1% to 98.8% (p < 0.01). The combination of IIF with solid-phase methods significantly improved diagnostic efficacy in PBC patients.

Clinical performance of AMA‐M2, anti‐gp210 and anti‐sp100 antibody levels in primary biliary cholangitis: When detected by multiplex bead‐based flow fluorescent immunoassay

“…7,8 Some studies have shown that nearly 30% to 50% of PBC patients are positive for anti-gp210 and anti-sp100 antibodies. 9,10 At present, immunoblotting assay (IBT) is widely used method to detect autoantibodies in China. IBT has some disadvantages of being cumbersome and timeconsuming.…”

“…Besides, antinuclear antibodies (ANA) are present in part of PBC patients, especially nuclear envelope antibody (anti‐gp210 antibody) and multiple nuclear dots (anti‐sp100 antibody) 7,8 . Some studies have shown that nearly 30% to 50% of PBC patients are positive for anti‐gp210 and anti‐sp100 antibodies 9,10 …”

Detection of M2-Type Anti-Mitochondrial Autoantibodies against Specific Subunits in the Diagnosis of Primary Biliary Cholangitis in Patients with Discordant Results

“…Primary biliary cholangitis (PBC) is a chronic autoimmune liver disorder characterized by inflammation of intrahepatic biliary ducts, which leads to fibrosis and consequently may produce cirrhosis and liver failure [1][2][3][4][5]. Its prevalence is low and it mostly affects middle-aged women [1,6].…”

“…Its prevalence is low and it mostly affects middle-aged women [1,6]. The etiology is unclear, but many data suggest that a genetic predisposition along with environmental risk factors such as infections or smoking may be a crucial responsible [1,4]. Clinical presentation is variable, and patients range from asymptomatic and stable or slowly progressive to symptomatic and rapidly progressive [3].…”

“…Diagnosis of PBC can be established if two out of the three following criteria are met: sustained elevated levels of alkaline phosphatase (ALP), evidence of antimitochondrial autoantibodies (AMA) or specific antinuclear autoantibodies (ANA) and diagnostic liver histology [4]. Therefore, a biopsy can be avoided in case of high ALP levels and detection of autoantibodies [2].…”