Pathogenesis of steatorrhea in primary biliary cirrhosis

Features of Lipid Metabolism Disorders in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune liver disease that mostly affects women. A progressive disorder in the processes of bile secretion and enterohepatic bile salts circulation in patients with PBC already in its early stages, leading to an insufficient release of bile acids into the bowel and their entry into the systemic circulation. Insufficient bile acids released into the duodenum contributes to the development of malabsorption, energy malnutrition, and slowly progressive weight loss. The pathophysiological mechanisms of weight loss and its slow progression are associated with the deterioration of the fat emulsification processes and with the reduced absorption of hydrolyzed products, such as fatty acids and monoglycerides, with steatorrhea in patients with PBC, as well as in those with gut dysbiosis. Just in the early stages of the disease, this results in accelerated fatty acid β-oxidation that is aimed at compensating for progressive energy malnutrition. The entry of bile acids into the systemic circulation in PBC is accompanied by dyslipidemia. The mechanism of hyperlipidemia in patients with PBC differs from that in other conditions because along with an increase in total cholesterol (TC), there are elevated high-density lipoprotein levels and the appearance of unusual lipoprotein X (Lp-X). The appearance of Lp-X is most likely to be the body's protective reaction to inactivate the detergent effect of bile acids on the membrane structures of blood corpuscles and vascular endothelial cells. It is bile acids, rather than TC levels, that correlate with the content of Lp-X and determine its formation. Concomitant hypercholesterolemia in patients with PBC is also aimed at neutralizing the detergent effect of bile acids that have entered the systemic circulation and is most likely a compensatory reaction of the body. "Anomalous" hypercholesterolemia in PBC can serve as a model system for the search and development of new methods for the treatment of dyslipidemia since it occurs without an increase in the incidence of cardiovascular events.

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.

Characteristics and Inpatient Outcomes of Primary Biliary Cholangitis and Autoimmune Hepatitis Overlap Syndrome

BACKGROUND AND AIMS

Primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) are hepatobiliary diseases of presumed immune-mediated origin that have been shown to overlap. The aim of this retrospective trial was to use national data to examine the characteristics and outcomes of patients hospitalized with overlapping PBC and AIH (PBC/AIH).

METHODS

The National Inpatient Sample was used to identify hospitalized adult patients with PBC, AIH, and PBC/AIH from 2010 to 2014 by International Classification of Diseases-Ninth Edition Revision codes; patients with hepatitis B virus and hepatitis C virus infection were excluded. Primary outcomes measures were in-hospital outcomes that included mortality, respiratory failure, septic shock, length of stay, and total hospital charges. Secondary outcomes were the clinical characteristics of PBC/AIH, including the comorbid extrahepatic autoimmune disease pattern and complications of cirrhosis.

RESULTS

A total of 3,478 patients with PBC/AIH were included in the study. PBC/AIH was associated with higher rates of Sjögren's syndrome (p<0.001; p<0.001), lower rates of Crohn's disease (p<0.05; p<0.05), and higher rates of cirrhosis-related complications when compared to PBC or AIH alone. There were similar rates of mortality between the PBC/AIH, PBC, and AIH groups. The PBC/AIH group had higher rates of septic shock when compared to the PBC group (p<0.05) and AIH group (p<0.05) after adjusting for possible confounders.

CONCLUSIONS

PBC/AIH is associated with a lower rate of Crohn's disease, a higher rate of Sjögren's syndrome, higher rates of cirrhosis-related complications, and significantly increased risk of septic shock compared to PBC and AIH individually.

Malnutrition in Patients with Liver Cirrhosis

Liver cirrhosis is an increasing public health threat worldwide. Malnutrition is a serious complication of cirrhosis and is associated with worse outcomes. With this review, we aim to describe the prevalence of malnutrition, pathophysiological mechanisms, diagnostic tools and therapeutic targets to treat malnutrition. Malnutrition is frequently underdiagnosed and occurs-depending on the screening methods used and patient populations studied-in 5-92% of patients. Decreased energy and protein intake, inflammation, malabsorption, altered nutrient metabolism, hypermetabolism, hormonal disturbances and gut microbiome dysbiosis can contribute to malnutrition. The stepwise diagnostic approach includes a rapid prescreen, the use of a specific screening tool, such as the Royal Free Hospital Nutritional Prioritizing Tool and a nutritional assessment by dieticians. General dietary measures-especially the timing of meals-oral nutritional supplements, micronutrient supplementation and the role of amino acids are discussed. In summary malnutrition in cirrhosis is common and needs more attention by health care professionals involved in the care of patients with cirrhosis. Screening and assessment for malnutrition should be carried out regularly in cirrhotic patients, ideally by a multidisciplinary team. Further research is needed to better clarify pathogenic mechanisms such as the role of the gut-liver-axis and to develop targeted therapeutic strategies.

Fermentable fibers induce rapid macro- and micronutrient depletion in Toll-like receptor 5-deficient mice

Functional fermentable fibers are considered essential for a healthy diet. Recently, we demonstrated that gut microbiota dysbiotic mice fed an inulin-containing diet (ICD) developed hepatocellular carcinoma (HCC) within 6 mo. In particular, a subset of Toll-like receptor 5-deficient (T5KO) mice prone to HCC exhibited rapid onset of hyperbilirubinemia (HB) and cholemia; these symptoms provide rationale that ICD induces cholestasis. Our objective in the present study was to determine whether inulin-fed T5KO-HB mice exhibit other known consequences of cholestasis, including essential fatty acid and fat-soluble vitamin deficiencies. Here, we measured hepatic fatty acids and serum vitamin A and D levels from wild-type (WT), T5KO low bilirubin (LB) and T5KO-HB mice fed ICD for 4 wk. Additionally, hepatic RNAseq and proteomics were performed to ascertain other metabolic alterations. Compared with WT and T5KO-LB, T5KO-HB mice exhibited steatorrhea, i.e., ~50% increase in fecal lipids. This could contribute to the significant reduction of linoleate in hepatic neutral lipids in T5KO-HB mice. Additionally, serum vitamins A and D were ~50% reduced in T5KO-HB mice, which was associated with metabolic compromises. Overall, our study highlights that fermentable fiber-induced cholestasis is further characterized by depletion of macro-and micronutrients.NEW & NOTEWORTHY Feeding a dietary, fermentable fiber diet to a subset of Toll-like receptor 5 deficient (T5KO) mice induces early onset hyperbilirubinemia and cholemia that later manifests to hepatocellular carcinoma (HCC). Our study highlights that fermentable fiber-induced cholestasis is characterized with modest macro- and micronutrient deficiencies that may further contribute to hepatic biliary disease. Compared with chemical induction, immunization, surgery, or genetic manipulation, these findings provide a novel approach to study the cholestatic subtype of HCC.

Metabolite variations between acute-on-chronic liver failure and chronic liver failure caused by hepatitis B virus based on ultra-performance liquid chromatography mass spectrometry

OBJECTIVE

The present study aims to compare serum metabolite alterations between acute-on-chronic liver failure (ACLF) and chronic liver failure (CLF), and find the specific biomarkers associated with the diseases.

METHODS

Serum samples were collected from patients with ACLF (n=76) and CLF (n=56) as well as healthy individuals (n=20) and assayed by ultra-performance liquid chromatography mass spectrometry (UPLC-MS). The acquired data was analyzed using principal components analysis (PCA) and partial least squares discriminate analysis (PLS-DA).

RESULTS

The PLS-DA model with satisfactory explanatory and predictive ability (R2=0.979, Q2=0.918) is capable of discriminate ACLF patients from CLF patients. Significant difference in the metabolomics among the three groups was observed, metabolites that decreased significantly in the serum of ACLF and CLF included phosphatidylcholines (PCs) and lysophosphatidylcholines (LPCs), whereas conjugated bile acids (GCDCA, GUDCA) increased significantly, these metabolites considered as common biomarkers of liver failure. Linoleyl carnitine showed significant increase in CLF compared with controls while no significant change was observed in ACLF, it could be special biomarkers of ACLF and CLF.

CONCLUSION

Metabolomics based on ultra-performance liquid chromatography mass spectrometry provide a new way to diagnose and reveal the pathogenesis of ACLF and CLF.

Primary biliary cirrhosis: Clinical and laboratory criteria for its diagnosis

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic granulomatous, and destructive inflammatory lesion of small intralobular and septal bile ducts, which is likely to be caused by an autoimmune mechanism with a the presence of serum antimitochondrial antibodies and a potential tendency to progress to cirrhosis. Despite the fact that the etiology of this disease has been unknown so far, there has been a considerable body of scientific evidence that can reveal the clinical and laboratory signs of PBC and the individual components of its pathogenesis and elaborate diagnostic criteria for the disease and its symptomatic therapy. Deficiencies in autoimmune tolerance are critical factors for the initiation and perpetuation of the disease. The purpose of this review is to summarize the data available in the literature and the author’s findings on clinical and laboratory criteria for the diagnosis of PBC. This review describes the major clinical manifestations of the disease and the mechanisms of its development. It presents the immunological, biochemical, and morphological signs of PBC and their significance for its diagnosis. A great deal of novel scientific evidence for the problem of PBC has been accumulated. However, the inadequate efficiency of therapy for the disease lends impetus to the quest for its etiological factors and to further investigations of its pathogenetic mechanisms and, on this basis, to searches for new methods for its early diagnosis.

Metabolomic analyses of faeces reveals malabsorption in cirrhotic patients

BACKGROUND

The study of faeces offers a unique opportunity to observe cooperation between the microbiome and the metabolism of mammalian hosts, an essential element in the study of the human metabolome. In the present study, a global metabolomics approach was used to identify metabolites differentially excreted in the faeces of cirrhotic patients compared to controls.

METHODS

Seventeen cirrhotic patients and 24 healthy individuals were recruited. Faecal metabolites were detected through non-targeted reversed-phase ultra-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry.

RESULTS

A total of 9215 peaks were detected. Using unequal variance t-tests, 2393 peaks were observed with P≤0.05, approximately 74.0% of which were due to decreased faecal metabolite concentrations in liver cirrhosis vs. healthy controls. Integrating multivariate data analyses, we identified six major groups of metabolites. Relative levels of identified metabolites were as follows: strong increase in lysophosphatidylcholines, aromatic amino acids, fatty acids, and acylcarnitines, and a dramatic decrease in bile acids and bile pigments.

CONCLUSION

With severe hepatic injury in patients with liver cirrhosis, malabsorption occurs along with disorders of fatty acid metabolism, potentially due to changes in gut microflora.

Primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9–10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC.

Management of autoimmune and cholestatic liver disorders

The management of autoimmune and cholestatic liver disorders is a challenging area of hepatology. Autoimmune and cholestatic liver diseases represent a comparatively small proportion of hepatobiliary disorders, yet their appropriate management is of critical importance for patient survival. In this article, management strategies are discussed, including the indications and expectations of pharmacologic therapy, endoscopic approaches, and the role of liver transplantation.

Clinical features and management of primary biliary cirrhosis

Primary biliary cirrhosis (PBC), which is characterized by progressive destruction of intrahepatic bile ducts, is not a rare disease since both prevalence and incidence are increasing during the last years mainly due to the improvement of case finding strategies. The prognosis of the disease has improved due to both the recognition of earlier and indolent cases, and to the wide use of ursodeoxycholic acid (UDCA). New indicators of prognosis are available that will be useful especially for the growing number of patients with less severe disease. Most patients are asymptomatic at presentation. Pruritus may represent the most distressing symptom and, when UDCA is ineffective, cholestyramine represents the mainstay of treatment. Complications of long-standing cholestasis may be clinically relevant only in very advanced stages. Available data on the effects of UDCA on clinically relevant end points clearly indicate that the drug is able to slow but not to halt the progression of the disease while, in advanced stages, the only therapeutic option remains liver transplantation.

Decreased Serum Leptin Levels in Primary Biliary Cirrhosis: A Link between Metabolism and Autoimmunity?

Primary biliary cirrhosis (PBC) is an autoimmune liver disease of unknown etiology resulting in the progressive destruction of the intrahepatic bile ducts and leading to chronic cholestasis and ultimately liver cirrhosis and failure. The immune response in PBC seems to be mediated by autoantibodies as well as autoreactive T lymphocytes directed against mitochondrial antigens in biliary epithelial cells, primarily PDC-E2. Experimental evidence suggests a role of the hormone/cytokine leptin in autoimmune diseases. Leptin is an adipocyte-derived molecule that acts as a hormone influencing food intake and energy metabolism as well as a cytokine with pro-inflammatory, immune-regulatory functions. To study serum leptin in PBC and its association with disease severity, we evaluated serum levels in 37 patients with PBC (27 with no signs of fibrosis or cirrhosis at histologic examination) and 37 age- and sex-matched healthy controls using a validated ELISA method. We found that patients with PBC had significantly lower leptin serum levels compared with healthy controls (13.6 +/- 13.8 vs. 17.6 +/- 11.6; P < 0.05). No correlation between disease severity and serum leptin levels was found. This study has demonstrated that leptin levels are decreased in the serum of patients with PBC but do not seem to be associated with disease severity. Data do not seem to indicate a direct role of leptin in the perpetuation of the autoimmune response in PBC. However, further studies are warranted to further characterize the functions of leptin during the natural history of autoimmunity.

Different tumor necrosis factor-alpha-associated leptin expression in rats with dimethylnitrosamine and bile duct ligation-induced liver cirrhosis

Although serum leptin concentrations are reported by several studies to increase in patients with liver cirrhosis, the mechanisms underpinning this increase remain unclear. Circulating tumor necrosis factor alpha (TNF-alpha) concentrations are also recognized to increase in liver cirrhosis. Furthermore, TNF-alpha administration to rodents results in increased expression and secretion of leptin from adipose tissue in a manner dependent on type 1 TNF-alpha receptor (TNF-RI). The present study was undertaken to examine adipose leptin expression and to explore potential relationships between leptin expression and TNF-alpha in subjects with liver cirrhosis. Liver cirrhosis was induced in male Sprague-Dawley rats by dimethylnitrosamine (DMN) administration or by common bile duct ligation (BDL). Ad libitum and pair-fed animals constituted controls. Serum leptin and TNF-alpha concentrations were determined by immunoassay. Gene expression was determined by the reverse transcription-polymerase chain reaction, and protein levels were measured by Western blotting. Serum leptin values after adjustment of body fat mass in DMN-treated rats were significantly higher than in pair-fed or ad libitum groups. Leptin mRNA and protein levels in epididymal fat in DMN rats increased by 1.8-fold and 2.3-fold, respectively, as compared with ad libitum controls, and by 4-fold and 6-fold, respectively, as compared with the pair-fed group. Epididymal TNF-alpha and membranous TNF-RI (mTNF-RI) concentrations were both 2.3 times higher in DMN rats than in ad libitum controls but did not differ between ad libitum and pair-fed groups. Adipose leptin protein levels correlated directly with TNF-alpha and mTNF-RI concentrations in combined DMN, ad libitum, and pair-fed rats (r=0.64 and r=0.49, respectively; P<.05). In BDL-treated rats, however, serum and adipose leptin concentrations were identical to those in ad libitum controls despite 2.1-fold and 2.4-fold increase in epididymal TNF-alpha and mTNF-RI, respectively. TNF-alpha administration to fasting control animals increased serum and adipose leptin concentrations significantly. The observed TNF-alpha-associated leptin up-regulation in DMN-induced, but not in BDL-induced, cirrhotic rats is consistent with distinctly different roles for TNF-alpha in rats with nonbiliary, as opposed to biliary, cirrhosis.

Treatment of pancreatic exocrine deficiency

In treating pancreatic exocrine insufficiency the diagnosis of a cause, wherever possible, is a first step. If there is an obstructing lesion, then its relief may be curative. Adequate management depends on dietary manipulation and enzyme replacement. A reduction in fat intake, with accentuation of protein and carbohydrate consumption, is recommended. For enzyme replacement, enteric-coated microspheres are required, taken with adequate acid-suppression with a proton-pump inhibitor. The enzyme supplements, using standard preparations of pancreatin, usually of porcine source, may be as much as 4 to 8 tablets per meal and should be taken with food. Endocrine insufficiency usually requires insulin.

Treatment with ursodeoxycholic acid is associated with weight gain in patients with primary biliary cirrhosis

BACKGROUND

Ursodeoxycholic acid (UDCA) is the established treatment of primary biliary cirrhosis (PBC) and is a safe and well-tolerated medication. Nevertheless, patients often anecdotally complain of weight gain while on this drug.

GOALS

We compared weight changes in patients treated with UDCA and those on placebo to characterize this potential side effect.

STUDY

One-hundred eighty patients with PBC who were enrolled into a randomized, controlled trial received either UDCA (13-15 mg/kg/d) or an identical placebo. Changes from baseline weight were calculated at 12, 24, 36, and 48 months. Other markers of disease activity, including liver biochemistries, serum lipids, histologic stage, and Mayo Risk Score were evaluated in both groups.

RESULTS

The proportion of patients who gained weight during the first 12 months of therapy was significantly greater in the UDCA than placebo group (67/86 [78%] versus 43/73 [57%] respectively, P = 0.005). Patients in the UDCA group gained an average of 3.6 +/- 6.5% kg (2.2 +/- 5.1 kg) which was significantly greater than the average of 0.6 +/- 6.9% kg (0.6 +/- 4.9 kg) gained in the placebo group (P = 0.04). The biggest change in weight occurred in the first 12 months of treatment (P < 0.001); after this, weight was maintained for the 4-year duration of treatment. There was no significant correlation between initial body mass index (BMI) and weight change or changes in disease activity and weight.

CONCLUSION

UDCA treatment in patients with PBC is associated with a significant weight gain that occurs in the first 12 months of treatment, persists for the duration of treatment, and occurs independent of baseline BMI. Discussions with PBC patients beginning UDCA treatment should include the beneficial effects this medication has on disease outcome, but should also mention weight gain as a possible side effect.

Primary biliary cirrhosis

Primary biliary cirrhosis is a chronic cholestatic liver disease of adults. This disorder is characterised histologically by chronic non-suppurative destruction of interlobular bile ducts leading to advanced fibrosis, cirrhosis, and liver failure. The precise aetiopathogenesis of primary biliary cirrhosis remains unknown, although dysregulation of the immune system and genetic susceptibility both seem to be important. Affected patients are typically middle-aged women with abnormal serum concentrations of alkaline phosphatase. Presence of antimitochondrial antibody in serum is almost diagnostic of the disorder. Identification of primary biliary cirrhosis is important, because effective treatment with ursodeoxycholic acid has been shown to halt disease progression and improve survival without need for liver transplantation. However, therapeutic options for disease-related complications-including fatigue and metabolic bone disease-remain unavailable. Mathematical models have been developed that accurately predict the natural history of primary biliary cirrhosis in individuals. Despite advances in understanding of the disease, it remains one of the major indications for liver transplantation worldwide.

Management of primary biliary cirrhosis. The American Association for the Study of Liver Diseases practice guidelines

Primary biliary cirrhosis (PBC) is a presumed autoimmune disease of the liver, which predominantly affects women once over the age of 20 years. Most cases are diagnosed when asymptomatic (60%). The antimitochondrial antibody is present in serum in most, but not in all, patients with PBC. The disease generally progresses slowly but survival is less than an age- and gender-matched general population. The symptomatic patient may have fatigue, generalized pruritus, portal hypertension, osteoporosis, skin xanthomata, fat soluble vitamin deficiencies, and/or recurrent asymptomatic urinary tract infections. Many nonhepatic autoimmune diseases are found in association with PBC and may prompt initial presentation. To date, immunosuppressive therapy has not been shown to prolong survival in PBC. The hydrophilic bile acid, ursodeoxycholic acid (UDCA), has been shown when given in a dose of 13 to 15 mg/kg daily for up to 4 years to delay the time to liver transplantation or death. This therapy also causes a significant improvement of all the biochemical markers of cholestasis but has no beneficial effects on any of the symptoms or associated disorders. Treatment with UDCA does not obviate the need for liver transplantation. Therapies to prevent complications arising from malabsorption, portal hypertension, and/or osteoporosis are required as well. Good control of pruritus can be achieved in most patients. PBC is diagnosed with increasing frequency, but the agent(s) responsible for this slowly progressive destruction of the interlobular bile ducts remains elusive and hence a specific therapy remains unavailable.

Primary biliary cirrhosis and primary sclerosing cholangitis

Primary biliary cirrhosis and primary sclerosing cholangitis are the most common chronic cholestatic liver diseases in adults that lead to biliary cirrhosis and its inherent complications such as portal hypertension and liver failure. Although important advances in the understanding of the pathogenesis of these conditions have been accomplished in the last two decades, much work is needed to uncover the interaction of genetic and immunologic mechanisms involved in their pathogenesis. Ursodeoxycholic acid at dosage of 13 to 15 mg/kg/d is the only agent that can currently be recommended in the treatment of PBC. No medical therapy aimed at disrupting disease progression is available for patients with primary sclerosing cholangitis, although several agents with different properties are currently under evaluation. Liver transplantation is the treatment of choice for patients with primary biliary cirrhosis and primary sclerosing cholangitis with end-stage liver disease.

Steatorrhea and weight loss in a 72-year-old man: primary biliary cirrhosis? Celiac disease? Bacterial overgrowth? What else?

Unintentional weight loss is an ominous sign, particularly when it occurs in the elderly; concern for malignancy is especially worrisome. In this report, we describe a 72-yr-old man who presented with weight loss and was found to have massive steatorrhea. An extensive evaluation revealed evidence of primary biliary cirrhosis (PBC), celiac disease, and small intestinal bacterial overgrowth. No malignancy was identified. The weight loss was attributed to severe steatorrhea due, in part, to intraluminal bile salt deficiency, small bowel mucosal disease, and bacterial overgrowth. Several points are discussed regarding gastrointestinal function in elderly patients with chronic liver disease secondary to PBC. The rare association between PBC and celiac disease in adults is also discussed. Finally, we suggest that bacterial overgrowth plays a significant role in the development of steatorrhea in some persons with PBC and that an assessment for bacterial overgrowth should be performed on persons with steatorrhea and PBC.

Dark adaptation in early primary biliary cirrhosis

BACKGROUND

The role of vitamin A in early primary biliary cirrhosis (PBC) remains uncertain.

METHODS

We assessed dark adaptation and assayed vitamin-A-related compounds in 10 patients with early PBC and a group of age- and sex-matched controls.

RESULTS

In patients compared with controls: (i) mean final light threshold value was 11.8% greater (p < 0.004), (ii) time taken to see the first light stimulus was longer (2.8 +/- 0.6 vs 1.4 +/- 0.2 min, mean +/- SEM; p < 0.03) and (iii) sensitivity to light stimuli was impaired after 6 min in the dark (p < 0.03). Three patients had an abnormal final light threshold despite receiving regular vitamin A; two had a low serum vitamin A. Raised serum bilirubin and increased age were the most important determinants of impaired dark adaptation.

CONCLUSIONS

Patients with early PBC have modestly impaired dark adaptation, despite standard vitamin A supplementation, although these changes may not have a significant effect on visual function. Vitamin A supplementation should be recommended for older patients with jaundice, but its effect should be carefully monitored.

Primary biliary cirrhosis: clinical and associated autoimmune features and natural history

Primary biliary cirrhosis, a chronic liver disease, predominately affects middle-aged women. The diagnosis is established by the presence of disease-specific autoantibodies and compatible liver histology showing focal immune-mediated damage to the intrahepatic bile ducts. Patients now are detected prior to the onset of symptoms typical of cholestasis with abnormal liver function tests, or even prior to the onset of abnormal liver function tests, with positive antimitochondrial antibodies. Earlier diagnosis is changing not only our appreciation of the prevalence of this condition, but also of the natural history. The disease appears to be heterogeneous with some patients having a slow progression and a normal life-expectancy, although other patients have a more aggressive course developing symptoms and end-stage disease that leads to death or liver transplantation.

Determinants of decreased fecal consistency in patients with diarrhea

BACKGROUND/AIMS

Loose stools are a common and troublesome feature in diarrhea. The purpose of this study was to investigate factors that determine different degrees of stool looseness in diarrhea.

METHODS

Fecal consistency was measured visually. Stools were analyzed for content of water and solids. Water-holding capacity of insoluble solids was measured in vitro.

RESULTS

Formed stools from normal subjects had a near constant ratio of water to solids despite a sevenfold variation in daily stool weight. In diarrhea, loose consistency was correlated directly with percent fecal water. For any level of percent water, steatorrhea stools were looser than nonsteatorrhea stools. Ingestion of psyllium reduced stool looseness without changing the percent water. Both the effect of fat and psyllium could be explained by consideration of the ratio of fecal water to water-holding capacity of insoluble solids.

CONCLUSIONS

(1) The normal intestine delivers stools that differ widely in quantity but maintains percent fecal water within a narrow range. (2) Stool looseness in diarrhea is determined by the ratio of fecal water to water-holding capacity of insoluble solids. (3) In patients with diarrhea with normal stool weight, loose stools are due to low output of insoluble solids without the concomitant reduction in water output that occurs in normal subjects when insoluble solids are low.

Primary biliary cirrhosis: the molecule and the mimic

Our understanding of the immunobiology of PBC has dramatically changed with the application of molecular biology to clinical medicine. Because of the molecular characterization and identification of the mitochondrial autoantigens, it is now possible to define explicitly mitochondrial autoantigens and examine recognition sites at the primary sequence level. In addition, the expression of cloned antigens has facilitated the development of more reliable assays for mitochondrial autoantibodies. The use of cloned recombinant antigens should, one day, replace the traditional AMA immunofluorescence for diagnostic assays. Possible genetic and environmental factors associated with risk for PBC can also be investigated. It is now also possible to begin the task to defining the role of T cells in the immunopathology of PBC and exploring the issue of whether specific immunotherapy is feasible. There is increasing evidence that PDC-E2 or a similar molecule is located on the cell membrane of biliary epithelial cells. The mechanism for this expression remains to be studied. The explosion of data in PBC is an example of the application of new techniques to investigate old problems. This has occurred because of networking between laboratories in many countries and the generous exchange of sera and donation of livers removed at transplantation. Unfortunately, there is no animal model for PBC; if an animal model was found it would have major importance. Finally, we emphasize the need to study patients early in the course of disease in order to define the events that initiate pathology.

Current concepts in primary sclerosing cholangitis

OBJECTIVE

To describe primary sclerosing cholangitis (PSC) and its associated complications, as well as medical and surgical treatment.

DESIGN

A review of PSC and its associated etiopathologic factors is presented; numerous studies of agents that are used to treat patients with PSC are discussed.

RESULTS

PSC, a slowly progressive disease that often involves autoimmune damage to the biliary tree, is frequently associated with inflammatory bowel disease, usually chronic ulcerative colitis. Long-term follow-up of patients with PSC has revealed a high incidence of colon cancer and bile duct cancer, both of which are most likely related to the chronic inflammation involving these two organs. Although PSC is an unusual disease, it is now diagnosed with approximately the same frequency as is primary biliary cirrhosis. The histopathologic evolution of PSC results in irreversible damage to bile ducts, which ultimately leads to cholestasis, cirrhosis, liver failure, and premature death from liver failure unless liver transplantation is performed. Therefore, the best chance of achieving success is to treat patients with early-stage disease rather than those with irreversible end-stage cirrhotic disease. Although several medical therapies for PSC have been evaluated, only D-penicillamine, cyclosporine, methotrexate, and, most recently, ursodeoxycholic acid have been studied in controlled clinical trials. Furthermore, several surgical therapies for PSC and its associated complications have been assessed.

CONCLUSION

Currently, no therapy achieves a complete clinical, biochemical, or histologic remission in this disease. Until the etiopathogenesis of PSC is further defined, effective therapy is unlikely to be found. Thus, liver transplantation will continue to be an important therapeutic intervention for the management of patients with end-stage PSC.

Serum bile acids in companion animal medicine

Quantification of total serum bile acids is used as a method for appraising liver function and perfusion in contemporary small animal practice. This article provides a historical perspective and a comprehensive review of bile acid physiology, laboratory methodologies for bile acid quantification, and normal values published for total serum bile acids measured using the spectrophotometric enzymatic method and for serum bile acids measured using validated radioimmunoassay procedures. The variables influencing the enterohepatic circulation of bile acids and, consequently, the fasting and postprandial serum bile acid concentrations are discussed with the intent of clarifying the application of test results to clinical patients. A brief discussion of the therapeutic use of dehydrocholate and ursodeoxycholic acid in clinical patients is provided.

Primary biliary cirrhosis

Primary biliary cirrhosis is a chronic liver disease of unknown etiology characterized by slowly progressive intrahepatic cholestasis due to an inflammatory destruction of small intrahepatic bile ducts. The clinical course of PBC is variable ranging from a few years in rapidly progressive cases to a normal life-expectancy in a proportion of asymptomatic cases. The typical patient is a middle-aged woman who may present with pruritus, increasing pigmentation of the skin, and eventually jaundice. The level of serum alkaline phosphatase is almost invariably elevated, serum mitochondrial antibodies are present in more than 90 per cent, and an elevated serum IgM is usually present. PBC is associated with many immunologic abnormalities and appears to be a classic autoimmune disease. Some of the immune defects may be epiphenomena; others such as a marked defect in suppressor T cell function seem to be related to the pathogenesis of the disease. All drug therapy that is aimed at slowing the disease process is experimental. A place for immunosuppressive drugs in the management of PBC would be anticipated. However, no drug has to date been definitively shown to have a beneficial effect on the disease. Currently, the main treatments used are aimed at preventing or correcting the complications of intractable cholestasis. Patients with PBC and evidence of hepatic decompensation and/or poor quality of life make good candidates for liver transplantation. The current aim of therapy is to find an effective regime of immunosuppression that will make hepatic transplantation redundant for this disease.

Intestinal malabsorption of vitamin E in primary biliary cirrhosis

We studied intestinal absorption of vitamin E in 26 adults with primary biliary cirrhosis (PBC) and 6 control subjects. Seven (27%) PBC patients were vitamin E-deficient based on the ratio of serum vitamin E to serum total lipid concentrations. An oral vitamin E tolerance test was performed in all patients and control subjects using a loading dose of 2000 IU alpha-tocopheryl acetate with measurement of serial serum vitamin E concentrations over 24 h. Vitamin E absorption was expressed as the maximal rise in serum vitamin E above baseline, the area under the oral tolerance test curve, and these two values divided by the fasting total serum lipid concentration. Absorption of vitamin E was significantly impaired in all PBC patients vs. control subjects (p less than 0.01), in vitamin E-deficient vs. vitamin E-sufficient PBC patients (p less than 0.05 to p less than 0.01), and in PBC patients with serum vitamin E levels below 10 micrograms/ml vs. those with serum vitamin E levels above 10 micrograms/ml (p less than 0.01). Vitamin E absorption was inversely related to stage of PBC, serum cholylglycine, total bilirubin, cholesterol, alkaline phosphatase, aspartate aminotransferase, and prothrombin time. Patients with serum vitamin E below 10 micrograms/ml, serum total bilirubin above 3 mg/dl, serum cholylglycine above 600 micrograms/dl, or serum alkaline phosphatase above 1000 IU/L had severe malabsorption of vitamin E and would be at high risk for the development of vitamin E deficiency. Therefore, vitamin E supplementation should be considered not only in patients in whom overt vitamin E deficiency is present, but also in PBC patients meeting these criteria.

Fat-soluble vitamin nutriture in primary biliary cirrhosis

We measured serum levels of vitamins A, E, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D, as well as levels of abnormal (des-gamma-carboxy) prothrombin, in 52 patients with primary biliary cirrhosis. Decreased serum levels of retinol (vitamin A) and 25-hydroxyvitamin D and elevated levels of abnormal prothrombin were common in these patients and correlated with the histologic stage of the disease and with the clinical severity of disease as judged by elevated serum bilirubin levels and decreased serum albumin levels. The increased levels of abnormal prothrombin were due primarily to vitamin K deficiency but also, in part, to the severity of the liver disease itself. Vitamin E deficiency was rare. Only 1 patient had clinical manifestations of fat-soluble vitamin deficiency, night blindness, and gastrointestinal bleeding related to a marked prolongation of the prothrombin time. Deficiencies of fat-soluble vitamins are most likely to be present in jaundiced patients with long-standing, severe cholestasis. We suggest that fat-soluble vitamin status be determined in all patients with primary biliary cirrhosis by appropriate blood tests and that vitamin supplements be given only to those patients who require them.

Steatorrhea in patients with intrahepatic cholestasis of pregnancy

A prospective study was undertaken to evaluate fat malabsorption during intrahepatic cholestasis of pregnancy (ICP), a disease characterized by a mild cholestasis of short duration appearing in otherwise healthy young women. An abnormal fecal fat excretion (mean 15.8 g/24 h, range 6-31 g/24 h) was demonstrated in 10 of 12 patients with the icteric form of ICP and in 2 of 11 patients with pruritus gravidarum. The increased fecal fat excretion was generally asymptomatic, could be detected as early as 3 wk after the clinical onset of ICP, remained stable during the affected pregnancies, and returned to normal from 3 to 9 wk after delivery. Steatorrhea correlated with the severity of ICP, estimated by serum levels of bilirubin, total bile salts, and glutamic pyruvic transaminase. A significant fall in the maternal weight/height index was detected after the onset of ICP, being more intense in patients with steatorrhea than in those without it (to 92.6% +/- 3.0% of initial values versus 96.7% +/- 2.8%, respectively; p less than 0.05). A high risk of premature deliveries and fetal distress was demonstrated in these patients, also correlating with the severity of ICP. No direct relationship could be established between steatorrhea or maternal nutritional impairment and fetal prognosis.