A Review of the Challenges Associated with the Diagnosis and Therapy of Primary Sclerosing Cholangitis

Liver transplant in patients with primary sclerosing cholangitis: A retrospective cohort from Northeastern Brazil

BACKGROUND

Primary sclerosing cholangitis (PSC) manifests within a broad ethnic and racial spectrum, reflecting different levels of access to health care.

AIM

To evaluate the clinical profile, complications and survival rates of patients with PSC undergoing liver transplantation (LTx) at a Brazilian reference center.

METHODS

All patients diagnosed with PSC before or after LTx were included. The medical records were reviewed for demographic and clinical variables, including outcomes and survival. The level of statistical significance was set at P < 0.05.

RESULTS

Our cohort represented 1.6% (n = 34) of the 2113 patients receiving liver grafts at our service over the past two decades. Most were male (n = 19; 56%). The average age (40 ± 14 years) was similar for men and women (P = 0.347). The mean follow-up time from diagnosis to LTx was 68 mo. Most patients had the classic form of PSC. Three women had PSC/autoimmune hepatitis overlap syndrome, and one patient had small-duct PSC. Alkaline phosphatase levels at diagnosis and pre-LTx model for end-stage liver disease. scores were significantly higher in males. Inflammatory bowel research (IBD) was investigated by colonoscopy in 26/34 (76%) and was present in most cases (18/26; 69%). IBD was less common in women than in men (44.4% vs. 55.6%) (P = 0.692). Cholangiocarcinoma (CCA) was diagnosed in 2/34 (5.9%) patients by histopathology of the explant (survival: 3 years 6 mo, and 4 years 11 mo). Two patients had complications requiring a second LTx (one after 7 d due to hepatic artery thrombosis and one after 17 d due to primary graft dysfunction). Five patients (14.7%) developed biliary stricture. The overall median post-LTx survival was 66 mo. Most deaths occurred in the first year (infection n = 2, primary liver graft dysfunction n = 3, unknown cause n = 1). The 1-year and 5-year survival rates of this cohort were 82.3% and 70.6%, respectively, matching the mean overall survival rates of LTx patients at our center (87.1% and 69.43%, respectively) (P = 0.83).

CONCLUSION

Survival after 1 and 5 years was similar to that of other LTx indications. The observed CCA survival rate suggests CCA may be an indication for LTx in selected cases.

Cholangiocarcinoma in Patients with Primary Sclerosing Cholangitis (PSC): a Comprehensive Review

Cholangiocarcinoma (CCA) is the most common malignancy in patients with primary sclerosing cholangitis (PSC) and carries a high rate of mortality. Although the pathogenesis of CCA in PSC is largely unknown, inflammation-driven carcinogenesis concomitant with various genetic and epigenetic abnormalities are underlying factors. The majority of CCA cases develop from a dominant stricture (DS), which is defined as a stricture with a diameter < 1.5 mm in the common bile duct or < 1.0 mm in the hepatic duct. In PSC patients presenting with an abrupt aggravation of jaundice, pain, fatigue, pruritus, weight loss, or worsening liver biochemistries, CCA should be suspected and evaluated utilizing a variety of diagnostic modalities. However, early recognition of CCA in PSC remains a major challenge. Importantly, 30-50% of CCA in PSC patients are observed within the first year following the diagnosis of PSC followed by an annual incidence ranging from 0.5 to 1.5 per 100 persons, which is nearly 10 to 1000 times higher than that in the general population. Cumulative 5-year, 10-year, and lifetime incidences are 7%, 8-11%, and 9-20%, respectively. When PSC-associated CCA is diagnosed, most tumors are unresectable, and no effective medications are available. Given the poor therapeutic outcome, the surveillance and management of PSC patients who are at an increased risk of developing CCA are of importance. Such patients include older males with large-duct PSC and possibly concurrent ulcerative colitis. Thus, more attention should be paid to patients with these clinical features, in particular within the first year after PSC diagnosis. In contrast, CCA is less frequently observed in pediatric or female PSC patients or in those with small-duct PSC or concurrent Crohn's disease. Recently, new biomarkers such as antibodies to glycoprotein 2 have been found to be associated with an increased risk of developing CCA in PSC. Herein, we review the literature on the pathogenesis, incidence, clinical features, and risk factors, with a focus on various diagnostic modalities of PSC-associated CCA.

Inhibition of microRNA-24 increases liver fibrosis by enhanced menin expression in Mdr2-/- mice

BACKGROUND

Liver transplantation remains the primary treatment for primary sclerosing cholangitis (PSC). Mdr2-/- mice provide a reliable in vivo model of PSC and develop characteristic biliary inflammation and fibrosis. We tested the hypothesis that the tumor suppressor protein menin is implicated in the progression of liver fibrosis and that menin expression can be regulated in the liver via microRNA-24 (miR-24).

MATERIALS AND METHODS

Menin expression was measured in human PSC and Mdr2-/- mice. Twelve-week-old FVB/NJ wild-type (WT) and Mdr2-/- mice were treated with miR-24 Vivo-Morpholino to knockdown miR-24 expression levels. Liver fibrosis was evaluated by Sirius Red staining and quantitative polymerase chain reaction (qPCR) for genes associated with liver fibrosis, such as fibronectin 1, collagen type 1 alpha 1, transforming growth factor-β1 (TGF-β1), and α-smooth muscle actin. Studies were also performed in vitro using immortalized murine cholangiocyte lines treated with miR-24 hairpin inhibitor and mimic.

RESULTS

Menin gene expression was increased in Mdr2-/- mice and late-stage human PSC samples. Treatment of FVB/NJ WT and Mdr2-/- mice with miR-24 Vivo-Morpholino increased menin expression, which correlated with increased expression of fibrosis genes. In vitro, inhibition of miR-24 also significantly increased the expression of fibrosis genes.

CONCLUSIONS

Inhibition of miR-24 increases menin and TGF-β1 expression, subsequently increasing hepatic fibrosis in FVB/NJ WT and Mdr2-/- mice. Modulation of the menin/miR-24 axis may provide novel targeted therapies to slow the progression of hepatic fibrosis into cirrhosis in PSC patients by altering TGF-β1 expression.