Osteoporosis in primary biliary cholangitis

Pemigatinib suppresses liver fibrosis and subsequent osteodystrophy in mice

BACKGROUND

Liver fibrosis could lead to serious secondary diseases, including osteodystrophy. The interaction between liver and bone has not been fully elucidated, thus existing therapies for osteodystrophy secondary to liver fibrosis are often ineffective. FGF23 was initially found as an endocrine regulator of phosphate homeostasis, but recently, its involvement in fibrosis has been suggested. In this study, we hypothesized that the FGF23 level increases with liver injury, which in turn induces liver fibrosis and osteodystrophy.

METHODS

Liver fibrosis model mice were generated via carbon tetrachloride administration and bile duct ligation. Fibrosis was assessed using Masson trichrome staining and hydroxyproline assay. The bone structure was evaluated using dual-energy x-ray absorptiometry and microcomputed tomography. Human HSC lines LX-2 and primary rat HSCs were used for in vitro analyses.

RESULTS

Carbon tetrachloride-induced and bile duct ligation-induced liver injury increased the serum FGF23 level compared with that in control mice. RNA sequencing analysis of FGF23-treated LX-2 showed that FGF23 promotes the production of matrisome, which helps in forming the extracellular matrix. The FGF receptor antagonist pemigatinib alleviated carbon tetrachloride-induced and bile duct ligation-induced liver fibrosis and the deleterious alterations in bone density and microstructure in mice.

CONCLUSIONS

The serum FGF23 level increased with liver injury, and FGF23 promoted liver fibrosis. Moreover, pemigatinib alleviated liver fibrosis and hepatic osteodystrophy. These findings suggest that FGF23 mediates the communication between the liver and bone and that FGF23 may be a new therapeutic target for liver fibrosis and subsequent osteodystrophy.

Up-to-Date Snapshot of Current and Emerging Medical Therapies in Primary Biliary Cholangitis

Background/Objectives: Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic disease of the liver that symptomatically can present with pruritus and fatigue. Its established first- and second-line therapies are ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) although they provide limited symptom management. Liver transplantation offers a potentially curative therapeutic option in refractory cases progressing to cirrhosis. Novel research published after the current guidelines highlights the importance of providing an up-to-date analysis of treatment options available. Methods: In this study, we conducted a literature search using Pubmed, Ovid Medline, and SCOPUS to provide a narrative review of first-line, second-line, and emerging therapies in PBC. Results: UDCA has been well established as a long-term, safe therapy within the literature although it is possible that treatment dosage can be further optimised in refractory patients. It has a favourable side effect profile. Despite improving biochemical markers, histopathological profile, and overall outcomes, up to 30-40% of patients are refractory to it. Age and sex are highlighted as independent indicators of non-responsiveness. This necessitates effective second-line therapies. Future trials could aim to investigate UDCA as a co-first-line therapy. Further supporting results for OCA were found in the interim extension trial of the seminal POISE study. The long-term phase 4 COBOLT trial is still awaiting results to further assess the complications, adherence, and potential adverse effects. It is a viable option in UDCA-refractory patients. The high incidence rate of dose-related pruritis indicates that alternative second-line options are needed. Bezafibrate is an off-label antilipemic agent that shows promise as a prospective second-line therapy option. The landmark BEZURSO trial alleviated some efficacy and safety concerns, but it remains associated with elevated serum creatinine; thus, it should be considered with caution. Other prospective second-line therapies are budesonide, triple therapy, and novel agents such as seladelpar and elafibranor. Conclusions: UDCA should remain the treatment of choice for PBC, though perhaps not as monotherapy. With further investigation, BF shows promise as a new second-line therapy alongside OCA, which it may outperform.

Primary biliary cholangitis

Primary biliary cholangitis is a chronic, autoimmune, cholestatic disease that mainly affects women aged 40-70 years. Recent epidemiological studies have shown an increasing incidence worldwide despite geographical heterogeneity and a decrease in the female-to-male ratio of those the disease affects. Similar to other autoimmune diseases, primary biliary cholangitis occurs in genetically predisposed individuals upon exposure to environmental triggers, specifically xenobiotics, smoking, and the gut microbiome. Notably, the diversity of the intestinal microbiome is diminished in individuals with primary biliary cholangitis. The intricate interplay among immune cells, cytokines, chemokines, and biliary epithelial cells is postulated as the underlying pathogenic mechanism involved in the development and progression of primary biliary cholangitis, and extensive research has been dedicated to comprehending these complex interactions. Following the official approval of obeticholic acid as second-line treatment for patients with an incomplete response or intolerance to ursodeoxycholic acid, clinical trials have indicated that peroxisome proliferator activator receptor agonists are promising additional second-line drugs. Future dual or triple drug regimens might reach a new treatment goal of normalisation of alkaline phosphatase levels, rather than a decrease to less than 1·67 times the upper limit of normal levels, and potentially improve long-term outcomes. Improvement of health-related quality of life with better recognition and care of subjective symptoms, such as pruritus and fatigue, is also an important treatment goal. Promising clinical investigations are underway to alleviate these symptoms. Efforts to facilitate better access to medical care and dissemination of current knowledge should enable diagnosis at an earlier stage of primary biliary cholangitis and ensure access to treatments based on risk stratification for all patients.

Epidemiologic and genetic associations between primary biliary cholangitis and extrahepatic rheumatic diseases

Patients with primary biliary cholangitis (PBC) commonly experience extrahepatic rheumatic diseases. However, the epidemiologic and genetic associations as well as causal relationship between PBC and these extrahepatic conditions remain undetermined. In this study, we first conducted systematic review and meta-analyses by analyzing 73 studies comprising 334,963 participants across 17 countries and found strong phenotypic associations between PBC and rheumatic diseases. Next, we utilized large-scale genome-wide association study summary data to define the shared genetic architecture between PBC and rheumatic diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and Sjögren's syndrome (SS). We observed significant genetic correlations between PBC and each of the four rheumatic diseases. Pleiotropy and heritability enrichment analysis suggested the involvement of humoral immunity and interferon-associated processes for the comorbidity. Of note, we identified four variants shared between PBC and RA (rs80200208), SLE (rs9843053), and SSc (rs27524, rs3873182) using cross-trait meta-analysis. Additionally, several pleotropic loci for PBC and rheumatic diseases were found to share causal variants with gut microbes possessing immunoregulatory functions. Finally, Mendelian randomization revealed consistent evidence for a causal effect of PBC on RA, SLE, SSc, and SS, but no or inconsistent evidence for a causal effect of extrahepatic rheumatic diseases on PBC. Our study reveals a profound genetic overlap and causal relationships between PBC and extrahepatic rheumatic diseases, thus providing insights into shared biological mechanisms and novel therapeutic interventions.

Increased risk of fragility fractures in patients with primary biliary cholangitis

Large-scale studies on the risk of fragility fractures in patients with primary biliary cholangitis (PBC) are limited due to low incidence. We aimed to investigate whether PBC is associated with fragility fractures using real-world nationwide data. The Korean National Health Insurance Service claims data from 2007 to 2020 were analyzed in this population-based cohort study. Patients with PBC (n = 4951) were matched with controls (n = 19 793) using a 1:4 ratio based on age, sex, and follow-up duration. The primary outcome was fragility fracture, which comprised fractures of the vertebra, hip, distal radius, and proximal humerus. The incidence rates (IRs) and hazard ratios (HRs) were determined to assess the impact of PBC on fragility fractures. During the median follow-up period of 5.37 years, 524 patients in the PBC group had fragility fractures (IR, 18.59/1000 person-years [PYs]). After adjusting for covariates, PBC increased the risk of fragility fractures by 1.63-fold (95% confidence interval, 1.20-2.22; P = .002). The vertebra and hip were particularly susceptible to fracture in patients with PBC, with adjusted HRs of 1.77 and 2.23, respectively. In the subgroup analysis, the risk of fragility fracture was 2.53-fold higher in men and 1.59-fold higher in women with PBC than that in the respective matched control groups. Considering the morbidity and mortality related to fragility fractures, increasing awareness of fragility fracture risk and implementing appropriate preventive measures in patients with PBC are imperative.

High C-reactive protein-to-albumin ratio levels are associated with osteoporosis in patients with primary biliary cholangitis

Objective

Inflammation contributes to the development of metabolic bone diseases. The C-reactive protein-to-albumin ratio (CAR) is an inflammation-based marker with a prognostic value for several metabolic diseases. This study investigated the relationship between the CAR and osteoporosis (OP) in patients with primary biliary cholangitis (PBC).

Methods

Patients with PBC treated at Beijing Ditan Hospital between January 2018 and June 2023 were enrolled. Logistic regression analysis was performed to investigate the factors influencing OP. The predictive value of CAR for OP was evaluated using receiver operating characteristic (ROC) curves. Moreover, a restricted cubic spline (RCS) fitted with a logistic regression model was used to analyze the relationship between CAR and OP.

Results

The prevalence of OP among the patients with PBC was 26.9% (n = 82). CAR levels were higher in the OP group than in the non-OP group (0.33 (0.09, 0.61) vs. 0.08 (0.04, 0.18), P < 0.001). Logistic regression analysis showed that CAR was an independent predictor of OP in patients with PBC (odds ratio = 2.642, 95% confidence interval = 1.537-4.540, P < 0.001). CAR exhibited a good predictive ability for OP, with an areas under the curve (AUC) of 0.741. We found that individuals with CAR values > 0.1 have higher odds of OP. In addition, high CAR levels were associated with an increased prevalence of fragility fractures and high 10-year fracture risk.

Conclusion

High CAR levels were associated with greater odds of developing OP, and the CAR could serve as an independent predictor of OP in patients with PBC.

Pruritus, Fatigue, Osteoporosis and Dyslipoproteinemia in Pbc Patients: A Clinician’s Perspective

In this review article, we summarize the most common clinical manifestations of Primary biliary cholangitis (PBC): pruritus, fatigue, osteoporosis, and dyslipoproteinemia and discuss their impact of the patients’ quality of life. More than half of PBC patients suffer from pruritus or fatigue at the time of diagnosis. We discuss the pathophysiological aspects of the PBC clinical manifestations and treatment options. The pathophysiology of pruritus and fatigue is not adequately elucidated, but IL-31 is associated with the severity of pruritus and could be used to objectify the subjective reporting by questionnaires. Although PBC patients suffer from atherogenic dyslipidemia, they do not seem to have a higher cardiovascular risk; however, this observation needs to be clarified by further clinical studies. The second-line of PBC treatment affects pruritus severity: Obeticholic acid (OCA) worsens pruritus while fibrates improve it. Itching can be alleviated by both non-pharmacological and pharmacological approach, however the are multiple barriers to pharmacological treatment. There is no adequate treatment for fatigue today. Treatment of osteoporosis and dyslipidemia is similar for non-PBC patients; stage of liver disease should be considered in treatment. Further research to clarify the pathophysiology and to eventually discover an effective treatment to improve survival and quality of life (especially pruritus and fatigue) in PBC patients is needed.

Genetic association and causal relationship between multiple modifiable risk factors and autoimmune liver disease: a two-sample mendelian randomization study

BACKGROUND

The intricate etiology of autoimmune liver disease (AILD) involves genetic, environmental, and other factors that yet to be completely elucidated. This study comprehensively assessed the causal association between genetically predicted modifiable risk factors and AILD by employing Mendelian randomization.

METHODS

Genetic variants associated with 29 exposure factors were obtained from genome-wide association studies (GWAS). Genetic association data with autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) were also obtained from publicly available GWAS. Univariate and multivariate Mendelian randomization analyses were performed to identify potential risk factors for AILD.

RESULTS

Genetically predicted rheumatoid arthritis (RA) (OR = 1.620, 95%CI 1.423-1.843, P = 2.506 × 10- 13) was significantly associated with an increased risk of AIH. Genetically predicted smoking initiation (OR = 1.637, 95%CI 1.055-2.540, P = 0.028), lower coffee intake (OR = 0.359, 95%CI 0.131-0.985, P = 0.047), cholelithiasis (OR = 1.134, 95%CI 1.023-1.257, P = 0.017) and higher C-reactive protein (CRP) (OR = 1.397, 95%CI 1.094-1.784, P = 0.007) were suggestively associated with an increased risk of AIH. Genetically predicted inflammatory bowel disease (IBD) (OR = 1.212, 95%CI 1.127-1.303, P = 2.015 × 10- 7) and RA (OR = 1.417, 95%CI 1.193-1.683, P = 7.193 × 10- 5) were significantly associated with increased risk of PBC. Genetically predicted smoking initiation (OR = 1.167, 95%CI 1.005-1.355, P = 0.043), systemic lupus erythematosus (SLE) (OR = 1.086, 95%CI 1.017-1.160, P = 0.014) and higher CRP (OR = 1.199, 95%CI 1.019-1.410, P = 0.028) were suggestively associated with an increased risk of PBC. Higher vitamin D3 (OR = 0.741, 95%CI 0.560-0.980, P = 0.036) and calcium (OR = 0.834, 95%CI 0.699-0.995, P = 0.044) levels were suggestive protective factors for PBC. Genetically predicted smoking initiation (OR = 0.630, 95%CI 0.462-0.860, P = 0.004) was suggestively associated with a decreased risk of PSC. Genetically predicted IBD (OR = 1.252, 95%CI 1.164-1.346, P = 1.394 × 10- 9), RA (OR = 1.543, 95%CI 1.279-1.861, P = 5.728 × 10- 6) and lower glycosylated hemoglobin (HbA1c) (OR = 0.268, 95%CI 0.141-0.510, P = 6.172 × 10- 5) were positively associated with an increased risk of PSC.

CONCLUSIONS

Evidence on the causal relationship between 29 genetically predicted modifiable risk factors and the risk of AIH, PBC, and PSC is provided by this study. These findings provide fresh perspectives on the management and prevention strategies for AILD.

Influence of socioeconomic factors on liver transplant survival outcomes in patients with autoimmune liver disease in the United States

INTRODUCTION AND OBJECTIVES

Autoimmune liver diseases (AILDs): autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) have different survival outcomes after liver transplant (LT). Outcomes are influenced by factors including disease burden, medical comorbidities, and socioeconomic variables.

MATERIALS AND METHODS

Using the United Network for Organ Sharing database (UNOS), we identified 13,702 patients with AILDs listed for LT between 2002 and 2021. Outcomes of interest were waitlist removal, post-LT patient survival, and post- LT graft survival. A stepwise multivariate analysis was performed adjusting for transplant recipient gender, race, diabetes mellitus, model for end-stage liver disease (MELD) score, and additional social determinants including the presence of education, reliance on public insurance, working for income, and U.S. citizenship status.

RESULTS

Lack of college education and having public insurance increased the risk of waitlist removal (HR, 1.13; 95 % CI, 1.05-1.23, and HR, 1.09; 95 % CI, 1.00-1.18; respectively), and negatively influenced post-LT patient survival (HR, 1.16; 95 % CI, 1.06-1.26, and HR, 1.15; 95 % CI, 1.06-1.25; respectively) and graft survival (HR, 1.13; 95 % CI, 1.05-1.23, and HR, 1.15; 95 % CI, 1.06-1.25; respectively). Not working for income proved to have the greatest detrimental impact on both patient survival (HR, 1.41; 95 % CI, 1.24-1.6) and graft survival (HR, 1.21; 95 % CI, 1.09-1.35).

CONCLUSIONS

Our study highlights that lack of college education and public insurance have a detrimental impact on waitlist mortality, patient survival, and graft survival. Not working for income negatively affects post-LT survival outcomes. Not having U.S. citizenship does not affect survival outcomes in AILDs patients.

The Impact of Non-alcohol Fatty Liver Disease on Bone Mineral Density is Mediated by Sclerostin by Mendelian Randomization Study

Non-alcoholic fatty liver disease (NAFLD) has been found to be associated with osteoporosis (OP) in observational studies. However, the precise causal relationship between NAFLD and OP remains unclear. Here, we used Mendelian randomization (MR) to explore the causal relationship. We selected NAFLD-related single-nucleotide polymorphisms from a genome-wide meta-analysis (8434 cases and 434,770 controls) as instrumental variants. We used inverse variance weighted analysis for the primary MR analysis. Furthermore, we used similar methodologies in parallel investigations of other chronic liver diseases (CLDs). We performed sensitivity analyses to ensure the reliability of the results. We observed a causality between NAFLD and forearm bone mineral density (FABMD) (beta-estimate [β]: - 0.212; p-value: 0.034). We also found that sclerostin can act as a mediator to influence the NAFLD and FABMD pathways to form a mediated MR network (mediated proportion = 8.8%). We also identified indications of causal relationships between other CLDs and OP. However, we were unable to establish any associated mediators. Notably, our analyses did not yield any evidence of pleiotropy. Our findings have implications in the development of preventive and interventional measures aimed at managing low bone mineral density in patients with NAFLD.

Letter: Prioritising osteosarcopenia assessment in the ongoing care of patients with cholestatic liver diseases

This article is linked to Thomson et al papers. To view these articles, visit https://doi.org/10.1111/apt.17823 and https://doi.org/10.1111/apt.17877

Treatment of Primary Biliary Cholangitis including Transplantation

Ursodeoxycholic acid (UDCA) is the first-line treatment of primary biliary cholangitis (PBC). Long-term UDCA use significantly reduces progression to cirrhosis. UDCA improves liver enzymes and transplant-free survival rates. Despite the association between PBC and hyperlipidemia, treatment is indicated under specific circumstances with statins and fibrates being safe options. Osteoporosis, which is frequently seen, is usually managed based on data from postmenopausal women. Sicca syndrome is treated similarly to its standalone condition with the use of hydroxypropyl methylcellulose eye drops and anticholinergic drugs.

Micro-scale vertebral features in postmenopausal women with alcohol-associated and metabolic-associated fatty liver disease: ex vivo bone quality analyses

PURPOSE

Although epidemiological studies indicate increased fracture risk in women with alcohol-associated liver disease (AALD) and metabolic-associated fatty liver disease (MAFLD), data about their micro-scale bone features are still limited. We aimed to characterize bone quality changes in the anterior mid-transverse part of the first lumbar vertebral body collected from 32 adult postmenopausal females. Based on pathohistological assessment of the liver tissue, individuals were divided into AALD (n = 13), MAFLD (n = 9), and control group (n = 10).

METHODS

We analyzed trabecular and cortical micro-architecture (using micro-computed tomography), bone mechanical properties (using Vickers microhardness tester), osteocyte lacunar network and bone marrow adiposity morphology (using optic microscopy). Data were adjusted to elude the covariant effects of advanced age and body mass index on our results.

RESULTS

Our data indicated a minor trend toward deteriorated bone quality in MAFLD women, presented in impaired trabecular and cortical micro-architectural integrity, which could be associated with bone marrow adiposity alterations noted in these women. Additionally, we observed a significant decline in micro-architectural, mechanical, and osteocyte lacunar features in lumbar vertebrae collected from the AALD group. Lastly, our data indicated that vertebral bone deterioration was more prominent in the AALD group than in the MAFLD group.

CONCLUSION

Our data suggested that MAFLD and AALD are factors that could play a part in compromised vertebral strength of postmenopausal women. Also, our data contribute to understanding the multifactorial nature of bone fragility in these patients and highlight the necessity for developing more effective patient-specific diagnostic, preventive, and therapeutic strategies.

Bioinformatic analysis identified novel candidate genes with the potentials for diagnostic blood testing of primary biliary cholangitis

Primary biliary cholangitis (PBC) is an autoimmune disorder characterized by intrahepatic bile duct destruction and cholestatic liver injury. Diagnosis of PBC is generally based on the existence of anti-mitochondrial antibody (AMA) in blood samples; however, some PBC patients are negative for serum AMA tests, and invasive liver histological testing is required in rare PBC cases. The current study seeks novel candidate genes that are associated with PBC status and have potentials for blood diagnostic testing. Human transcriptomic profiling data of liver and blood samples were obtained from Gene Expression Omnibus (GEO). Three GEO data series (GSE79850, GSE159676, and GSE119600) were downloaded, and bioinformatic analyses were performed. Various differentially expressed genes were identified in three data series by comparing PBC patients and control individuals. Twelve candidate genes were identified, which were upregulated in both liver tissues and blood samples of PBC patients in all three data series. The enrichment analysis demonstrated that 8 out of 12 candidate genes were associated with biological functions, which were closely related to autoimmune diseases including PBC. Candidate genes, especially ITGAL showed good potentials to distinguish PBC with other diseases. These candidate genes could be useful for diagnostic blood testing of PBC, although further clinical studies are required to evaluate their potentials as diagnostic biomarkers.

Prevalence and risk factors of osteoporosis detected by dual-energy X-ray absorptiometry among Chinese patients with primary biliary cholangitis

BACKGROUND

Osteoporosis is an extrahepatic complication of primary biliary cholangitis (PBC) that increases the risk of fractures and mortality. However, Epidemiological studies of osteoporosis in patients with PBC in China and the Asia-Pacific region is lack.

AIM

To assess the prevalence and clinical characteristics of osteoporosis in Chinese patients with PBC.

METHODS

This retrospective analysis included consecutive patients with PBC from a tertiary care center in China who underwent bone mineral density (BMD) assessment using dual-energy X-ray absorptiometry between January 2013 and December 2021. We defined subjects with T-scores ≤ -2.5 in any sites (L1 to L4, femoral neck, or total hip) as having osteoporosis. Demographic, serological, clinical, and histological data were collected. Independent risk factors for osteoporosis were identified by multivariate logistic regression analysis.

RESULTS

A total of 268 patients with PBC [236 women (88.1%); mean age, 56.7 ± 10.6 years; 163 liver biopsies (60.8%)] were included. The overall prevalence of osteoporosis in patients with PBC was 45.5% (122/268), with the prevalence of osteoporosis in women and men being 47.0% and 34.4%, respectively. The prevalence of osteoporosis in postmenopausal women was significantly higher than that in premenopausal women (56.3% vs 21.0%, P < 0.001). Osteoporosis in patients with PBC is associated with age, fatigue, menopausal status, previous steroid therapy, body mass index (BMI), splenomegaly, gastroesophageal varices, ascites, Mayo risk score, histological stage, alanine aminotransferase, albumin, bilirubin, platelet and prothrombin activity. Multivariate regression analysis identified that older age, lower BMI, previous steroid therapy, higher Mayo risk score, and advanced histological stage as the main independent risk factors for osteoporosis in PBC.

CONCLUSION

Osteoporosis is very common in Chinese patients with PBC, allowing for prior screening of BMD in those PBC patients with older age, lower BMI, previous steroid therapy and advanced liver disease.

Risk of fractures and postfracture mortality in 3980 people with primary biliary cholangitis: A population-based cohort study

BACKGROUND

Morbidity in primary biliary cholangitis (PBC) is multifactorial. Osteoporosis related to cholestasis is an extrahepatic complication of PBC. It is not fully established to what extent people with PBC have an increased risk for fractures, and if mortality after a fracture is increased, compared to the general population.

METHODS

All Swedish people with PBC diagnosed between 2001 and 2016 were identified from the National Swedish Patient Register using ICD-10 codes. Incident fractures were ascertained in the same register and compared to matched controls from the Swedish general population (1:10 for age, sex, and municipality). Cox regression was used to investigate the rates of fractures and postfracture mortality. The cumulative incidence of fractures was calculated while accounting for competing risks (death or liver transplantation).

RESULTS

People with PBC (n = 3980) showed a higher risk of fractures at all-time points during follow-up compared to matched controls (n = 37,196), which was seen both in men and women. At 5 years of follow-up, the cumulative incidence of any fracture in people with PBC was 16.8% (95% confidence interval [CI] = 15.6-18.1), compared to 11.6% (95%CI = 11.3-12.0) in controls. The rate of osteoporotic fractures was particularly high (adjusted Hazard ratio [aHR] = 1.9; 95% = CI 1.7-2.0). The 30-day as well as the 1-year mortality after a fracture was significantly higher in people with PBC compared to controls that also experienced a fracture (aHR = 2.2; 95%CI = 1.5-3.2; aHR = 2.0; 95%CI 1.7-2.4).

CONCLUSION

People with PBC have a significantly higher risk of fractures and postfracture mortality compared to matched controls from the general population.

Bone loss in chronic liver diseases: Could healthy liver be a requirement for good bone health?

Given that the liver is involved in many metabolic mechanisms, it is not surprising that chronic liver disease (CLD) could have numerous complications. Secondary osteoporosis and increased bone fragility are frequently overlooked complications in CLD patients. Previous studies implied that up to one-third of these individuals meet diagnostic criteria for osteopenia or osteoporosis. Recent publications indicated that CLD-induced bone fragility depends on the etiology, duration, and stage of liver disease. Therefore, the increased fracture risk in CLD patients puts a severe socioeconomic burden on the health system and urgently requires more effective prevention, diagnosis, and treatment measures. The pathogenesis of CLD-induced bone loss is multifactorial and still insufficiently understood, especially considering the relative impact of increased bone resorption and reduced bone formation in these individuals. It is essential to note that inconsistent findings regarding bone mineral density measurement were previously reported in these individuals. Bone mineral density is widely used as the “golden standard” in the clinical assessment of bone fragility although it is not adequate to predict individual fracture risk. Therefore, microscale bone alterations (bone microstructure, mechanical properties, and cellular indices) were analyzed in CLD individuals. These studies further support the thesis that bone strength could be compromised in CLD individuals, implying that an individualized approach to fracture risk assessment and subsequent therapy is necessary for CLD patients. However, more well-designed studies are required to solve the bone fragility puzzle in CLD patients.

Pretransplant Evaluation and Liver Transplantation Outcome in PBC Patients

Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic liver disease characterized by progressive cholangiocyte and bile duct destruction leading to fibrosis and finally to liver cirrhosis. The presence of disease-specific serological antimitochondrial antibody (AMA) together with elevated alkaline phosphatase (ALP) as a biomarker of cholestasis is sufficient for diagnosis. Ursodeoxycholic acid (UDCA) is the first treatment option for PBC. Up to 40% of patients have an incomplete response to therapy, and over time disease progresses to liver cirrhosis. Several risk scores are proposed for better evaluation of patients before and during treatment to stratify patients at increased risk of disease progression. GLOBE score and UK PBC risk score are used for the evaluation of UDCA treatment and Mayo risk score for transplant-free survival. Liver transplantation (LT) is the only treatment option for end-stage liver disease. More than 10 years after LT, 40% of patients experience recurrence of the disease. A liver biopsy is required to establish rPBC (recurrent primary biliary cholangitis). The only treatment option for rPBC is UDCA, and data show biochemical and clinical improvement, plus potential beneficial effects for use after transplantation for the prevention of rPBC development. Additional studies are required to assess the full impact of rPBC on graft and recipient survival and for treatment options for rPBC.

Mechanism for development of malnutrition in primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that is associated with impaired biliary excretion processes. Along with the development of cholestasis, there is a deficient flow of bile acids into the intestinal lumen causing malnutrition (MN) that is manifested in deficiencies of both macro- and micronutrients. The mechanism for development of trophological insufficiency is multifactorial. However, the trigger of MN in PBC is impaired enterohepatic circulation of bile acids. The ingress of bile acids with a detergent effect into the general bloodstream, followed by elimination via the kidneys and skin, triggers a cascade of metabolic disturbances, which leads to the gradual development and progression of calorie MN. The latter gradually transforms into protein-calorie MN (PСM) (as marasmus) due to the insufficient entry of bile acids into the duodenum, which is accompanied by a decrease in the emulsification, hydrolysis, and absorption of fats and fat-soluble vitamins, as well as disturbance of intestinal motility and bacterial overgrowth. Fat-soluble vitamin deficiencies complement PСM with vitamin and mineral MN. The development of hepatocellular failure enhances the progression of PСM due to the impaired protein synthetic function of hepatocytes in the advanced stage of PBC, which results in deficiency of not only the somatic but also the visceral pool of proteins. A mixed PСM form of marasmus and kwashiorkor develops. Early recognition of energy, protein, micronutrient, and macronutrient deficiencies is of great importance because timely nutritional support can improve liver function and quality of life in patients with PBC. In this case, it is important to know what type (energy, protein-calorie, vitamin, and vitamin-mineral) and form (marasmus, marasmus-kwashiorkor) of MN is present in the patient and how it is associated with the stage of the disease. Therefore, it is recommended to screen all patients with PBC for MN, from the early asymptomatic stage of the disease in order to identify and avoid preventable complications, such as fatigue, malaise, performance decrement, sarcopenia, osteoporosis, and hepatic encephalopathy, which will be able to provide appropriate nutritional support for correction of the trophological status.

Decreasing Rates of Fracture-Related Hospitalization With Primary Biliary Cholangitis: Insights From the Nationwide Inpatient Sample

Introduction

Primary biliary cholangitis (PBC) is associated with an increased risk of developing fractures. Current guidelines recommend measures that can help prevent the development of fractures in these patients. The purpose of this study was to trend the rates of hospitalizations related to fractures and their burden on healthcare.

Methods

We performed a retrospective, cohort study of adults hospitalized in the United States with PBC between 2010 and 2014. Patients were identified using the Nationwide Inpatient Sample (NIS). Temporal analysis of PBC patients with a co-diagnosis of hip, vertebral, or wrist fractures (the study group) was performed with regards to the total number of inpatient admissions, inpatient mortality, length of stay, and total charges associated with hospitalization. Descriptive analyses were performed using the t-test for continuous data and the chi-square test for categorical data.

Results

During the five-year study period, there were 308,753 hospitalizations for PBC. There has been a downward trend (p=0.02) in fracture-related admissions among patients with PBC during this study period. Length of stay was higher in the PBC-fracture group (10.85 days vs 7.36 days; p<0.001). Total hospitalization charges were higher among the PBC-fracture patients when compared to the control group ($98,444 vs $72,964; p=0.004).

Conclusion

There has been a gradual reduction in the rate of fracture-related hospitalizations in patients with PBC. However, patients with PBC who have fractures have increased the utilization of health care resources as compared to their cohort admitted for reasons other than for a fracture.

Osteosarcopenia in autoimmune cholestatic liver diseases: Causes, management, and challenges

Primary biliary cholangitis and primary sclerosing cholangitis (PSC) are the most common cholestatic liver diseases (CLD) in adults and are both characterized by an immune pathogenesis. While primary biliary cholangitis is a model autoimmune disease, with over 90% of patients presenting very specific autoantibodies against mitochondrial antigens, PSC is considered an immune mediated disease. Osteoporosis is the most common bone disease in CLD, resulting in frequent fractures and leading to significant morbidity. Further, sarcopenia is emerging as a frequent complication of chronic liver diseases with a significant prognostic impact and severe implications on the quality of life of patients. The mechanisms underlying osteoporosis and sarcopenia in CLD are still largely unknown and the association between these clinical conditions remains to be dissected. Although timely diagnosis, prevention, and management of osteosarcopenia are crucial to limit the consequences, there are no specific guidelines for management of osteoporosis and sarcopenia in patients with CLD. International guidelines recommend screening for bone disease at the time of diagnosis of CLD. However, the optimal monitoring strategies and treatments have not been defined yet and vary among centers. We herein aim to comprehensively outline the pathogenic mechanisms and clinical implications of osteosarcopenia in CLD, and to summarize expert recommendations for appropriate diagnostic and therapeutic approaches.

RISK FACTORS ASSOCIATED WITH FRACTURE OF THE LUMBOSACRAL SPINE AND ITS COMPROMISE IN THE QUALITY OF LIFE OF CIRRHOTICS

ABSTRACT Background Chronic hepatic disease is associated with osteoporosis, osteopenia or osteomalacia. Osteoporosis and fractures due to bone fragility present high prevalences and are more frequent in patients with liver cirrhosis than in the general population. The search for a diagnosis of osteopenia and osteoporosis in this population may allow early intervention and modify unfavorable outcomes. Objective To know the prevalence of osteopenia or osteoporosis and of fracture due to bone fragility in individuals with liver cirrhosis, the associated risk factors, and its compromise in their quality of life (QoL). Methods Observational, transversal study performed with 71 liver cirrhosis patients of the Hepatology Service of the Hospital de Base do Distrito Federal, Brasília, DF, Brazil, between July 2017 and December 2018. The patients were submitted to bone densitometry (DXA) of the lumbar spine and of the femoral neck, to x-ray of the lumbosacral spine and to the Chronic Liver Disease Questionnaire (CLDQ) for the evaluation of quality of life (QoL). The Fracture Risk Assessment (FRAX) major was calculated for patients >50 years old. The analyses were performed for the evaluation of the risk factors associated with lumbosacral spine fracture. Results The majority (62%) of the 71 evaluated patients was diagnosed with osteoporosis or osteopenia on DXA. Of the 44 patients with osteopenia or osteoporosis, 52.3% were female, with a mean age of 62.6±9.51 years old, with the majority (72.7%) being Child A, cirrhotics of alcoholic etiology (36.4%), and with an intermediate QoL according to the CLDQ (3.3). Regarding the patients with lumbosacral spine fracture, the mean age was 61.6±11.1 years old, 60% were female, most of them Child A (66.7%), of alcoholic etiology (46.7%), and with an intermediary QoL according to the CLDQ (3.5). The presence of osteopenia and/or osteoporosis was associated with lumbosacral fracture (P<0.001), without correlation with the other analyzed variables: age, body mass index, gender, presence and absence of ascites, Child-Pugh classification, vitamin D, calcium, and phosphorus serum concentration, cirrhosis etiology and FRAX major. Conclusion The prevalence of hepatic osteodystrophy was high, and the occurrence of lumbosacral spine fracture was more associated with osteoporosis and/or osteopenia among the cirrhotic patients studied. The QoL was intermediate and with no differences between cirrhotics with and without fracture.

Clinical Management of Primary Biliary Cholangitis-Strategies and Evolving Trends

PBC is a chronic progressive autoimmune disorder involving the destruction of intrahepatic small bile ducts, cholestasis, fibrosis, and ultimately cirrhosis if left untreated. It is largely driven by the autoimmune response, but bile acids and the intestinal microbiota are implicated in disease progression as well. The only drugs licensed for PBC are UDCA and OCA. UDCA as a first-line and OCA as a second-line therapy are safe and effective, but the lack of response in a significant portion of patients and inadequate control of symptoms such as fatigue and pruritus remain as concerns. Liver transplantation is an end-stage therapy for many patients refractory to UDCA, which gives excellent survival rates but also moderate to high recurrence rates. The limited options for FDA-approved PBC therapies necessitate the development of alternative approaches. Currently, a wide variety of experimental drugs exist targeting immunological and physiological aspects of PBC to suppress inflammation. Immunological therapies include drugs targeting immune molecules in the B cell and T cell response, and specific cytokines and chemokines implicated in inflammation. Drugs targeting bile acids are also noteworthy as bile acids can perpetuate hepatic inflammation and lead to fibrosis over time. These include FXR agonists, ASBT inhibitors, and PPAR agonists such as bezafibrate and fenofibrate. Nonetheless, many of these drugs can only delay disease progression and fail to enhance patients' quality of life. Nanomedicine shows great potential for treatment of autoimmune diseases, as it provides a new approach that focuses on tolerance induction rather than immunosuppression. Tolerogenic nanoparticles carrying immune-modifying agents can be engineered to safely and effectively target the antigen-specific immune response in autoimmune diseases. These may work well with PBC especially, given the anatomical features and immunological specificity of the disease. Nanobiological therapy is thus an area of highly promising research for future treatment of PBC.

Management of Autoimmune Liver Diseases after Liver Transplantation

Autoimmune liver diseases are characterized by immune-mediated inflammation and eventual destruction of the hepatocytes and the biliary epithelial cells. They can progress to irreversible liver damage requiring liver transplantation. The post-liver transplant goals of treatment include improving the recipient’s survival, preventing liver graft-failure, and decreasing the recurrence of the disease. The keystone in post-liver transplant management for autoimmune liver diseases relies on identifying which would be the most appropriate immunosuppressive maintenance therapy. The combination of a steroid and a calcineurin inhibitor is the current immunosuppressive regimen of choice for autoimmune hepatitis. A gradual withdrawal of glucocorticoids is also recommended. On the other hand, ursodeoxycholic acid should be initiated soon after liver transplant to prevent recurrence and improve graft and patient survival in primary biliary cholangitis recipients. Unlike the previously mentioned autoimmune diseases, there are not immunosuppressive or disease-modifying agents available for patients with primary sclerosing cholangitis. However, colectomy and annual colonoscopy are key components during the post-liver transplant period.

Relationship between osteoporosis, sarcopenia, vertebral fracture, and osteosarcopenia in patients with primary biliary cholangitis

AIM

Bone disorders are serious complications in patients with primary biliary cholangitis (PBC), especially in postmenopausal female patients. Given that osteoporosis interrelates closely with sarcopenia, the concept of osteosarcopenia (coexistence of the two complications) has been established. This study aimed to investigate the relationship between osteoporosis, sarcopenia, vertebral fracture, and osteosarcopenia in PBC patients.

METHODS

This study involved 117 consecutive PBC patients (21 males and 96 females). Bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry. Sarcopenia was diagnosed according to the Japan Society of Hepatology assessment criteria.

RESULTS

Of the 117 patients, 33 (28.2%), 27 (23.1%), 21 (17.9%), and 18 (15.4%) had osteoporosis, sarcopenia, vertebral fracture, and osteosarcopenia, respectively. Multivariate analysis identified sarcopenia as a significant, independent risk factor associated with osteoporosis in all and female patients [odds ratio (OR) = 4.126, P = 0.018; OR = 6.510, P = 0.001, respectively], and vice versa (OR = 3.420, P = 0.040; OR = 4.012, P = 0.026, respectively). The skeletal muscle mass index and handgrip strength were significantly correlated with the BMD of the lumbar spine, femoral neck, and total hip (r = 0.46-0.59, P < 0.001). Patients with osteosarcopenia had significantly higher prevalence of vertebral fracture (10/18; 55.6%) than those without both osteoporosis and sarcopenia (5/75; 6.7%).

CONCLUSION

We demonstrated the prevalence of osteoporosis, sarcopenia, vertebral fracture, and osteosarcopenia in PBC, and noted that these complications interrelated closely with each other. Comprehensive assessment and treatment strategies for bone and muscle disorders are essential for PBC patients.

An Overview of the Molecular Mechanisms Contributing to Musculoskeletal Disorders in Chronic Liver Disease: Osteoporosis, Sarcopenia, and Osteoporotic Sarcopenia

The prevalence of osteoporosis and sarcopenia is significantly higher in patients with liver disease than in those without liver disease and osteoporosis and sarcopenia negatively influence morbidity and mortality in liver disease, yet these musculoskeletal disorders are frequently overlooked in clinical practice for patients with chronic liver disease. The objective of this review is to provide a comprehensive understanding of the molecular mechanisms of musculoskeletal disorders accompanying the pathogenesis of liver disease. The increased bone resorption through the receptor activator of nuclear factor kappa (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) system and upregulation of inflammatory cytokines and decreased bone formation through increased bilirubin and sclerostin and lower insulin-like growth factor-1 are important mechanisms for osteoporosis in patients with liver disease. Sarcopenia is associated with insulin resistance and obesity in non-alcoholic fatty liver disease, whereas hyperammonemia, low amount of branched chain amino acids, and hypogonadism contributes to sarcopenia in liver cirrhosis. The bidirectional crosstalk between muscle and bone through myostatin, irisin, β-aminoisobutyric acid (BAIBA), osteocalcin, as well as the activation of the RANK and the Wnt/β-catenin pathways are associated with osteosarcopenia. The increased understandings for these musculoskeletal disorders would be contributes to the development of effective therapies targeting the pathophysiological mechanism involved.

A Clinical Review of Primary Biliary Cholangitis

Primary biliary cholangitis is a slowly progressive immune-mediated cholestatic disease that causes a destruction of the intrahepatic bile ducts and may lead to cirrhosis of the liver, end-stage liver disease, and the need for liver transplantation. The disease is among the most common reasons why adults require liver transplantation. The primary signs of the disease include the presence of antimitochondrial and antinuclear antibodies, elevated alkaline phosphatase, hyperbilirubinemia, hypercholesterolemia, and histologic features, such as intense inflammation with a florid duct lesion and hepatic fibrosis. The patient's quality of life is impacted by fatigue, pruritus, malabsorption syndrome, sicca syndrome, osteoporosis, and challenges coping with chronic illness. Advanced practice registered nurses need to understand the pathophysiology, clinical presentation, diagnostic approaches, disease and symptom management, and priority nursing assessment and care in patients with this rare disease to differentiate it from primary sclerosing cholangitis, autoimmune hepatitis, obstructed bile duct lesions, drug-induced cholestasis, cholestasis in pregnancy, cholangiocarcinoma, hepatic malignancy, and peptic ulcer disease.

The Pharmacologic Management of Osteoporosis in Primary Biliary Cholangitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Osteoporosis is a common complication of primary biliary cholangitis (PBC) yet evidence for effective therapy is lacking. We sought to review all randomized controlled trials evaluating pharmacotherapy against placebo or no intervention for treatment of osteoporosis in PBC.

METHODOLOGY

A comprehensive database search was conducted from inception through 29 March 2017. The primary outcome was incidence of fractures; secondary outcomes were change in bone mineral density (BMD) and adverse events. We assessed studies for risk of bias, graded quality of evidence, and used meta-analysis to obtain overall effect by pooling studies of the same drug class.

RESULTS

We identified 11 randomized controlled trials evaluating bisphosphonates (3), hormone replacement therapy (2), ursodeoxycholic acid (1), obeticholic acid (1), cyclosporin A (1), vitamin K (1), calcitriol (1), and sodium fluoride (1). No intervention significantly reduced fractures compared to control. Although significant improvement in BMD was seen in one study with alendronate, a third-generation bisphosphonate, no significant improvement was seen on pooled analysis of all bisphosphonates including first-generation bisphosphonates (standard mean difference 0.41, p = 0.68). On pooled analysis, hormone replacement therapy modestly improved lumbar BMD (standard mean difference 0.69, p = 0.02), but with significantly increased adverse events (odds ratio 8.82, p = 0.01).

CONCLUSIONS

There is a lack of high-quality evidence supporting the efficacy of any treatment of osteoporosis in PBC. This may be explained by lack of power in the included studies. However, our current understanding of PBC-related osteoporosis indicates that it results from decreased bone formation, which may explain the attenuated effect of traditional antiresorptive agents. Future studies should investigate newer anabolic bone agents.

Bone Health in Patients With Liver Diseases

Osteoporosis is the most common bone disease in chronic liver disease (CLD) resulting in frequent fractures and leading to significant morbidity in this population. In addition to patients with cirrhosis and chronic cholestasis, patients with CLD from other etiologies may be affected in the absence of cirrhosis. The mechanism of osteoporosis in CLD varies according to etiology, but in cirrhosis and cholestatic liver disease it is driven primarily by decreased bone formation, which differs from the increased bone resorption seen in postmenopausal osteoporosis. Direct toxic effects from iron and alcohol play a role in hemochromatosis and alcoholic liver disease, respectively. Chronic inflammation also has been proposed to mediate bone disease in viral hepatitis and nonalcoholic fatty liver disease. Treatment trials specific to osteoporosis in CLD are small, confined to primary biliary cholangitis and post-transplant patients, and have not consistently demonstrated a benefit in this population. As it stands, prevention of osteoporosis in CLD relies on the mitigation of risk factors such as smoking and alcohol use, treatment of underlying hypogonadism, and encouraging a healthy diet and weight-bearing exercise. The primary medical intervention for the treatment of osteoporosis in CLD remains bisphosphonates though a benefit in terms of fracture reduction has never been shown. This review outlines what is known regarding the pathogenesis of bone disease in CLD and summarizes current and emerging therapies.

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.

Bone Diseases in Patients with Chronic Liver Disease

Osteoporosis is a frequently observed complication in patients with chronic liver disease, particularly liver cirrhosis and cholestatic liver diseases. In addition, osteoporosis is critical in patients receiving a liver transplant. Nevertheless, few studies have evaluated bone diseases in patients with more frequently observed chronic liver disease, such as chronic viral hepatitis, nonalcoholic fatty liver disease and alcoholic liver disease. Osteoporosis is a disease caused by an imbalance in the activities of osteoblasts and osteoclasts. Over the last few decades, many advances have improved our knowledge of the pathogenesis of osteoporosis. Importantly, activated immune cells affect the progression of osteoporosis, and chronic inflammation may exert an additional effect on the existing pathophysiology of osteoporosis. The microbiota of the intestinal tract may also affect the progression of bone loss in patients with chronic liver disease. Recently, studies regarding the effects of chronic inflammation on dysbiosis in bone diseases have been conducted. However, mechanisms underlying osteoporosis in patients with chronic liver disease are complex and precise mechanisms remain unknown. The following special considerations in patients with chronic liver disease are reviewed: bone diseases in patients who underwent a liver transplant, the association between chronic hepatitis B virus infection treatment and bone diseases, the association between sarcopenia and bone diseases in patients with chronic liver disease, and the association between chronic liver disease and avascular necrosis of the hip. Few guidelines are currently available for the management of low bone mineral density or bone diseases in patients with chronic liver disease. Due to increased life expectancy and therapeutic advances in chronic liver disease, the importance of managing osteoporosis and other bone diseases in patients with chronic liver disease is expected to increase. Consequently, specific guidelines need to be established in the near future.

Hepatic Osteodystrophy-Molecular Mechanisms Proposed to Favor Its Development

Almost all patients with chronic liver diseases (CLD) show altered bone metabolism. Depending on the etiology, this manifests in a severe osteoporosis in up to 75% of the affected patients. Due to high prevalence, the generic term hepatic osteodystrophy (HOD) evolved, describing altered bone metabolism, decreased bone mineral density, and deterioration of bone structure in patients with CLD. Once developed, HOD is difficult to treat and increases the risk of fragility fractures. Existing fractures affect the quality of life and, more importantly, long-term prognosis of these patients, which presents with increased mortality. Thus, special care is required to support the healing process. However, for early diagnosis (reduce fracture risk) and development of adequate treatment strategies (support healing of existing fractures), it is essential to understand the underlying mechanisms that link disturbed liver function with this bone phenotype. In the present review, we summarize proposed molecular mechanisms favoring the development of HOD and compromising the healing of associated fractures, including alterations in vitamin D metabolism and action, disbalances in transforming growth factor beta (TGF-β) and bone morphogenetic protein (BMP) signaling with histone deacetylases (HDACs) as secondary regulators, as well as alterations in the receptor activator of nuclear factor kappa B ligand (RANKL)–osteoprotegerin (OPG) system mediated by sclerostin. Based on these mechanisms, we give an overview on the limitations of early diagnosis of HOD with established serum markers.

A Practical Review of Primary Biliary Cholangitis for the Gastroenterologist

Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic liver disease characterized by biliary destruction and progressive intrahepatic cholestasis. PBC primarily affects women in their fifth or sixth decade of life. Although many patients are asymptomatic at presentation, fatigue, pruritus, sicca syndrome, and upper abdominal discomfort are common symptom manifestations. The etiology of PBC is thought to be related to interactions between underlying genetic predisposition and microbial and xenobiotic environmental triggers. The diagnosis is established in the setting of biochemical cholestasis and antimitochondrial or disease-specific antinuclear antibodies, with histologic evidence of nonsuppurative granulomatous cholangitis being supportive, but not required, to confirm disease. Care of patients with PBC encompasses therapies to slow disease progression, manage symptoms associated with cholestasis, and treat complications of advanced liver disease. Risk stratification based on simple clinical and laboratory parameters, either as binary response criteria and/or continuous models, helps identify the patients at greatest risk of poor outcome. First-line therapy to slow disease progression is ursodeoxycholic acid (UDCA), which is the mainstay of pharmacologic therapy for all patients with PBC. The only currently approved second-line option for patients who do not achieve adequate biochemical response or are intolerant to UDCA is the novel farnesoid X receptor agonist obeticholic acid. Off-label use of peroxisome proliferator-activated receptor agonists, including the fibrate class of drugs where available, is also recognized as an option for patients.

Understanding and managing secondary osteoporosis

INTRODUCTION

The term secondary osteoporosis (SO) identifies a reduction of bone mass related to a well-established disease or pharmacological agent. The identification of the underlying disease often represents a challenging situation in clinical practice.

AREAS COVERED

The prevalence of SO in the real world may vary, ranging from 17% to 80%; therefore, search for a form of SO represents a pillar when evaluating patients with osteoporosis. Guidelines for treatment of specific secondary forms of osteoporosis, such as glucocorticoid-induced osteoporosis, have been published even though often neglected in clinical practice. For the majority of SO, there are currently no specific guidelines concerning treatment with only few trials showing the effect of bone-active drugs on fracture risk reduction.

EXPERT OPINION

Healthcare professionals should be aware of the secondary forms of osteoporosis, in particular when the reason for reduced skeletal resistance is uncertain or when bone mineral density results are unsatisfactory in a patient compliant to therapy. In a few cases (such as, for example: no response to therapy, better classification of bone involvement in patients with kidney failure, suspicion of rare metabolic bone disease) bone biopsy is needed to investigate the patient. This review highlights recent advances in understanding and managing SO.