Primary biliary cholangitis: new treatments for an old disease

Efficacy of ursodeoxycholic acid for primary biliary cholangitis: Experience from a tertiary care centre in Saudi Arabia

BACKGROUND

Primary biliary cholangitis (PBC) is a progressive autoimmune cholestatic liver disease that primarily affects females more than males and may lead to end-stage liver disease. We studied baseline characteristics, and the biochemical and clinical response to ursodeoxycholic acid (UDCA), a first-line treatment option for patients with PBC, in a cohort of patients diagnosed with PBC from Saudi Arabia.

METHODS

A total of 30 patients meeting the diagnostic criteria of PBC who were being followed in the King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia, between January 1, 2008, and December 31, 2017, were enrolled in the study. The patients with autoimmune hepatitis, primary sclerosing cholangitis, and overlap syndromes were excluded. The baseline characteristics of the patients were recorded. The response to UDCA treatment was assessed according to the Barcelona, Paris I, Paris II, and Toronto criteria, and clinical outcomes, and biochemical changes were ascertained.

RESULTS

The mean age was 46 years ± 11.7 with a female gender predominance of 93% (n = 28). Pruritus was the predominant symptom reported by 90% (n = 27) of the patients. A total of 23 (77.7%) patients underwent liver biopsy and all of them showed histological features suggestive of PBC. Cirrhosis was documented in 30% (n = 9) of the patients at baseline. Overall, 86.7% (n = 26) of the patients were positive for antimitochondrial antibodies. The biochemical response rates to UDCA based on Paris I, Paris II, Barcelona, and Toronto criteria were 73.3, 40, 56.7, and 53.3%, respectively.

CONCLUSION

Over 10 years, 30 patients with PBC were diagnosed at a large referral center in Saudi Arabia. The response to UDCA treatment was inadequate.

Osteoporosis in Primary Biliary Cholangitis: Prevalence, Impact and Management Challenges

Primary biliary cholangitis (PBC) is a chronic, cholestatic condition associated with symptoms that directly impact the quality of life in those afflicted with the disease. In addition to pruritus and fatigue, patients with PBC may develop metabolic bone disease from reduced bone density, such as osteopenia and osteoporosis. Osteoporosis increases the risk of fractures, as well as morbidity and mortality. The prevalence of osteoporosis in PBC is expected to increase in conjunction with the rising prevalence of PBC as a whole. Timely diagnosis, prevention and management of osteoporosis are crucial in order to optimize the quality of life. There is a paucity of data evaluating the management of osteoporosis in PBC. The optimal timing for diagnosis and monitoring is not yet established and is guided by expert opinion. National guidelines recommend screening for osteoporosis at the time of diagnosis of PBC. Monitoring strategies are based on results of initial screening and individual risk factors for bone disease. Identifying reduced bone density is imperative to institute timely preventive and treatment strategies. However, treatment remains challenging as efficacious therapies are currently lacking. The data on treatment of osteoporosis in PBC are mostly extrapolated from postmenopausal osteoporosis literature. However, this data has not directly translated to useful treatment strategies for PBC-related osteoporosis, partly because of the different pathophysiological mechanisms of the two diseases. The lack of useful preventive measures and efficacious treatment strategies remains the largest pitfall that challenges the management of patients with PBC. In this review, we comprehensively outline the epidemiology, clinical implications and challenges, as well as management strategies of PBC-related osteoporosis.

Factors Associated With Potential Progressive Course of Primary Biliary Cholangitis: Data From Real-world US Database

BACKGROUND AND AIMS

Although relatively, primary biliary cholangitis (PBC) is an important cause of nonalcoholic chronic liver disease which may lead to liver transplantation. PBC patients with alkaline phosphatase (ALP) ≥1.5× the upper limit of normal (ULN) tend to have a more aggressive course. The study was designed to identify factors associated with ALP≥1.5×ULN or cirrhosis in PBC and to evaluate concomitant health care resource utilization.

METHODS

We used a large real-world database that contained comprehensive and continuous electronic medical recored/claims data from over 500 health care practices or systems from the United States.

RESULTS

Of 195 million patients included in the database, 36,317 were adults with PBC. After applying exclusion criteria, 15,875 patients comprised the final PBC cohort (63.0±13.5 y, 78% female, 71% privately insured, 5% covered by Medicaid, 57% with other autoimmune diseases, 46% with cirrhosis); 6083 (38%) had ALP≥1.5×ULN. Patients with ALP≥1.5×ULN were more frequently female, less covered by Medicaid, had more pruritus, cirrhosis, and other autoimmune diseases (P<0.05). In multivariate analysis, older age, female gender, the presence of other autoimmune diseases, and having compensated or decompensated cirrhosis were independently associated with having ALP≥1.5×ULN in PBC (P<0.05). In contrast, being male was associated with higher risk of cirrhosis in PBC [odds ratio 2.3 (95% confidence interval, 2.1-2.5)]. Patients with ALP≥1.5×ULN and/or with cirrhosis also incurred substantially more health care resource utilization (P<0.05).

CONCLUSIONS

Many clinical, sociodemographic, and economic factors are associated with a potentially more aggressive profile of PBC with elevated ALP. These data may inform clinicians to implement management strategies to optimize care of these patients.

A comprehensive autoantigen-ome of autoimmune liver diseases identified from dermatan sulfate affinity enrichment of liver tissue proteins

BACKGROUND

Autoimmune diseases result from aberrant immune attacks by the body itself. It is mysterious how autoantigens, a large cohort of seemingly unconnected molecules expressed in different parts of the body, can induce similar autoimmune responses. We have previously found that dermatan sulfate (DS) can form complexes with molecules of apoptotic cells and stimulate autoreactive CD5+ B cells to produce autoantibodies. Hence, autoantigenic molecules share a unique biochemical property in their affinity to DS. This study sought to further test this uniform principle of autoantigenicity.

RESULTS

Proteomes were extracted from freshly collected mouse livers. They were loaded onto columns packed with DS-Sepharose resins. Proteins were eluted with step gradients of increasing salt strength. Proteins that bound to DS with weak, moderate, or strong affinity were eluted with 0.4, 0.6, and 1.0 M NaCl, respectively. After desalting, trypsin digestion, and gel electrophoresis, proteins were sequenced by mass spectrometry. To validate whether these proteins have been previously identified as autoantigens, an extensive literature search was conducted using the protein name or its alternative names as keywords. Of the 41 proteins identified from the strong DS-affinity fraction, 33 (80%) were verified autoantigens. Of the 46 proteins with moderate DS-affinity, 27 (59%) were verified autoantigens. Of the 125 proteins with weak DS-affinity, 44 (35%) were known autoantigens. Strikingly, these autoantigens fell into the classical autoantibody categories of autoimmune liver diseases: ANA (anti-nuclear autoantibodies), SMA (anti-smooth muscle autoantibodies), AMA (anti-mitochondrial autoantibodies), and LKM (liver-kidney microsomal autoantigens).

CONCLUSIONS

This study of DS-affinity enrichment of liver proteins establishes a comprehensive autoantigen-ome for autoimmune liver diseases, yielding 104 verified and 108 potential autoantigens. The liver autoantigen-ome sheds light on the molecular origins of autoimmune liver diseases and further supports the notion of a unifying biochemical principle of autoantigenicity.

Primary Biliary Cholangitis in Medicare Population: The Impact on Mortality and Resource Use

Primary biliary cholangitis (PBC) is a disease of small bile ducts, which can lead to morbidity and mortality. Our aim was to assess recent trends in mortality and healthcare use of PBC patients in the Medicare program. Data from Medicare beneficiaries between 2005 and 2015 (5% random samples) were used. The diagnosis of PBC was established with International Classification of Diseases-9 code 571.6 used for both primary and secondary diagnoses. Mortality was assessed by Medicare-linked death registry. Healthcare use included episodes of care, length of stay, and total charges/payments. Independent predictors of outcomes were evaluated in multiple generalized linear or logistic regression models. The study cohort included a total of 6,375 inpatient/outpatient Medicare beneficiaries (mean age 69.8 years, 17% male, 88% white, and 18% with disability). Over the study period, 1-year mortality remained stable (9.1% to 14.3%, P = 0.11). Independent predictors of 1-year mortality were older age, male gender, black race, the presence of ascites, encephalopathy, hepatocellular carcinoma, and higher Charlson score. Outpatient total yearly charges and payments per beneficiary with PBC increased from $3,065 and $777 (2005) to $5,773 and $967 (2014), respectively. Similarly, inpatient total yearly charges and payments per beneficiary with PBC increased from $59,765 and $19,406 (2007), to $98,941 and $27,948 (2013), respectively (P < 0.05). The presence of ascites, portal hypertension, and higher Charlson score were independent predictors of higher payments for both inpatient and outpatient resource use, and the presence of hepatic encephalopathy was an additional predictor of higher inpatient resource use (all P < 0.02). Conclusion: The prevalence of PBC among the Medicare beneficiaries has increased. Despite stable mortality rates, resource use for Medicare patients with PBC continues to rise.

Dysregulation of antioxidant responses in patients diagnosed with concomitant Primary Sclerosing Cholangitis/Inflammatory Bowel Disease

OBJECTIVE

Primary Sclerosing Cholangitis (PSC) is a chronic cholestatic liver disease that is characterized by severe peri-biliary tract inflammation and fibrosis, elevated oxidative stress and hepatocellular injury. A hallmark of PSC patients is the concurrent diagnosis of Inflammatory Bowel Disease occurring in approximately 70%-80% of PSC patients (PSC/IBD). The objective of this study was to determine the impact of end stage PSC/IBD on cellular antioxidant responses and the formation of protein carbonylation.

METHODS

Using hepatic tissue and whole cell extracts isolated from age-matched healthy humans and patients diagnosed with end stage PSC/IBD, overall inflammation, oxidative stress, and protein carbonylation were assessed by Western blotting, and immunohistochemistry.

RESULTS

Increased immunohistochemical staining for CD3+ (lymphocyte), CD68 (Kupffer cell) and myeloperoxidase (neutrophil) colocalized with the extensive Picrosirius red stained fibrosis confirming the inflammatory aspect of PSC. Importantly, the increased inflammation also colocalized with elevated periportal post-translational modification by the reactive aldehydes 4-HNE, MDA and acrolein. 4-HNE, MDA and acrolein IHC all displayed a significant component in hepatocytes adjacent to fibrotic regions. Furthermore, acrolein was also elevated within the nuclei of periportal inflammatory cells whereas MDA staining was increased in hepatocytes across the lobule. Prussian Blue staining, when compared to the positive controls (ALD, NASH), did not display any evidence of iron accumulation in PSC/IBD livers. Western analysis of PSC/IBD anti-oxidant responses revealed elevated expression of SOD2, GSTπ as well as upregulation of Akt Ser473 phosphorylation. In contrast, expression of GSTμ, GSTA4, catalase, Gpx1 and Hsp70 were suppressed. These data were further supported by a significant decrease in measured GST activity. Dysregulation of anti-oxidant responses in the periportal region of the liver was supported by elevated SOD2 and GSTπ IHC signals in periportal hepatocytes and cholangiocytes. Expression of the Nrf2-regulated proteins HO-1, NAD(P)H quinone reductase (NQO1) and Gpx1 was primarily localized to macrophages. In contrast, catalase staining decreased within periportal hepatocytes and was not evident within cholangiocytes.

CONCLUSIONS

Results herein provide additional evidence that cholestasis induces significant increases in periportal oxidative stress and suggest that there are significant differences in the cellular and subcellular generation of reactive aldehydes formed during cholestatic liver injury. Furthermore, these data suggest that anti-oxidant responses are dysregulated during end-stage PSC/IBD supporting pathological data. This work was funded by NIH5R37AA009300-22 D.R.P.