Clinical significance and prevalence of anti-Saccharomyces cerevisiae antibody in Chinese patients with primary biliary cirrhosis

Intestinal homeostasis in autoimmune liver diseases

ABSTRACT

Intestinal homeostasis depends on complex interactions between the gut microbiota and host immune system. Emerging evidence indicates that the intestinal microbiota is a key player in autoimmune liver disease (AILD). Autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis, and IgG4-related sclerosing cholangitis have been linked to gut dysbiosis. Diverse mechanisms contribute to disturbances in intestinal homeostasis in AILD. Bacterial translocation and molecular mimicry can lead to hepatic inflammation and immune activation. Additionally, the gut and liver are continuously exposed to microbial metabolic products, mediating variable effects on liver immune pathologies. Importantly, microbiota-specific or associated immune responses, either hepatic or systemic, are abnormal in AILD. Comprehensive knowledge about host-microbiota interactions, included but not limited to this review, facilitates novel clinical practice from a microbiome-based perspective. However, many challenges and controversies remain in the microbiota field of AILD, and there is an urgent need for future investigations.

Anti-gp210 and anti-Sp100 antibodies in primary biliary cholangitis

BACKGROUND AND STUDY AIMS

To determine the sensitivity and specificity of anti-gp210 and anti-Sp100 autoantibodies in primary biliary cholangitis (PBC) PATIENTS AND METHODS: Sera of 106 PBC patients with positive anti-mitochondrial antibodies and 58 healthy blood donors were analyzed. A line immunoassay was used to evaluate the reactivity of anti-gp210 and anti-Sp100 antibodies.

RESULTS

The frequency of anti-gp210 and anti-Sp100 autoantibodies was 29.2% and 28.3%, respectively. Eight patients had both anti-gp210 and anti-Sp100 antibodies. Of 106 patients, 23 (21.7%) had anti-gp210 antibody, although not anti-Sp100 antibody, and 22 (20.7%) had anti-Sp100, although not anti-gp210 antibodies. Their combination increased the frequency of anti-gp210 and anti-Sp100 antibodies from 29.2% to 50% (P = 0.002) and 28.3% to 50% (P = 0.0012), respectively. In the control group, two subjects had anti-gp210 antibody and none had anti-Sp100 antibody. Thus, the specificity of anti-gp210 and anti-Sp100 antibodies was 96.5% and 100%, respectively. The positive predictive value (PPV) of anti-gp210 antibody was 94%; its negative predictive value (NPV) was 42.7%. The PPV and NPV of anti-Sp100 antibody were 100% and 43.3%, respectively.

CONCLUSION

It is important to combine anti-gp210 and anti-Sp100 antibodies in the immunological exploration of PBC.

Emerging therapies for PBC

Primary biliary cholangitis is an uncommon cholestatic liver disease predominantly affecting middle-aged women. Left untreated, there is a high risk of progression to end-stage liver disease. Few treatment options exist. To date, ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are the only medical therapies approved for use, other than symptomatic treatments and liver transplantation, the latter of which is reserved for those developing complications of cirrhosis or with intractable pruritus. UDCA improves outcomes, but many patients do not adequately respond. OCA therapy may improve response, but long-term data are limited. New therapies are desperately needed, but evaluation has been limited by the fact that the disease is heterogeneous, hard end points take years to develop, and there are different criteria in use for determining therapeutic response based on surrogate biomarkers. Fibrates appear to be the most promising new therapy and have beneficially affected surrogate end points and are beginning to show improvement in clinical end points.

Antimitochondrial Antibody-Negative Primary Biliary Cholangitis: Is It Really the Same Disease?

Antimitochondrial antibody (AMA)-negative primary biliary cholangitis (PBC) is a term reserved for patients with clinical and histopathological findings consistent with PBC but without positive AMA. There does not seem to be a natural progression from AMA negativity to positivity. Antinuclear and antismooth muscle antibodies are frequently found in the absence of histologic autoimmune hepatitis features. The disease course may be more severe than AMA-positive. Response to standard therapy for PBC and autoimmune hepatitis varies. Nevertheless, there is insufficient evidence to suggest AMA-negative PBC is different enough to warrant classification as a separate disease from AMA-positive PBC.