Pruritus associated with cholestasis. A review of pathogenesis and management

Plasmapheresis for Refractory Pruritus due to Drug-Induced Cholestasis

Pruritus can be a distressing symptom seen in various cholestatic disorders. It is treated with medications like bile acid sequestrants. Drug-induced cholestasis usually resolves with withdrawal of the causative medication. We describe a case of refractory pruritus due to drug-induced cholestasis, not improved with withdrawal of the drug, managed effectively with multiple sessions of plasmapheresis.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

This is an update of the original Cochrane review published in 2013 (Issue 6). Pruritus occurs in patients with disparate underlying diseases and is caused by different pathologic mechanisms. In palliative care patients, pruritus is not the most prevalent but is one of the most puzzling symptoms. It can cause considerable discomfort and affects patients' quality of life.

OBJECTIVES

To assess the effects of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

For this update, we searched CENTRAL (the Cochrane Library), and MEDLINE (OVID) up to 9 June 2016 and Embase (OVID) up to 7 June 2016. In addition, we searched trial registries and checked the reference lists of all relevant studies, key textbooks, reviews and websites, and we contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of different pharmacological treatments, compared with a placebo, no treatment, or an alternative treatment, for preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the identified titles and abstracts, performed data extraction and assessed the risk of bias and methodological quality. We summarised the results descriptively and quantitatively (meta-analyses) according to the different pharmacological interventions and the diseases associated with pruritus. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 10 'Summary of findings' tables.

MAIN RESULTS

In total, we included 50 studies and 1916 participants in the review. We added 10 studies with 627 participants for this update. Altogether, we included 39 different treatments for pruritus in four different patient groups.The overall risk of bias profile was heterogeneous and ranged from high to low risk. However, 48 studies (96%) had a high risk of bias due to low sample size (i.e. fewer than 50 participants per treatment arm). Using GRADE criteria, we downgraded our judgement on the quality of evidence to moderate in seven and to low in three comparisons for our primary outcome (pruritus), mainly due to imprecision and risk of bias.In palliative care participants with pruritus of different nature, the treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, reduced pruritus by 0.78 points (numerical analogue scale from 0 to 10; 95% confidence interval (CI) -1.19 to -0.37; one RCT, N = 48, quality of evidence: moderate) compared to placebo.For participants suffering from uraemic pruritus (UP), gabapentin was more effective than placebo (visual analogue scale (VAS): 0 to 10), mean difference (MD) -5.91, 95% CI -6.87 to -4.96; two RCTs, N = 118, quality of evidence: moderate). The κ-opioid receptor agonist nalfurafine showed amelioration of UP (VAS 0 to 10, MD -0.95, 95% CI -1.32 to -0.58; three RCTs, N = 422, quality of evidence: moderate) and only few adverse events. Moreover, cromolyn sodium relieved UP participants from pruritus by 2.94 points on the VAS (0 to 10) (95% CI -4.04 to -1.83; two RCTs, N = 100, quality of evidence: moderate) compared to placebo.In participants with cholestatic pruritus (CP), data favoured rifampin (VAS: 0 to 100, MD -24.64, 95% CI -31.08 to -18.21; two RCTs, N = 42, quality of evidence: low) and flumecinol (RR > 1 favours treatment group; RR 1.89, 95% CI 1.05 to 3.39; two RCTs, N = 69, quality of evidence: low) and showed a low incidence of adverse events in comparison with placebo. The opioid antagonist naltrexone reduced pruritus for participants with CP (VAS: 0 to 10, MD -2.26, 95% CI -3.19 to -1.33; two RCTs, N = 52, quality of evidence: moderate) compared to placebo. However, effects in participants with UP were inconclusive (percentage difference -12.30%, 95% CI -25.82% to 1.22%, one RCT, N = 32). Furthermore, large doses of opioid antagonists (e.g. naltrexone) could be inappropriate in palliative care patients because of the risk of reducing analgesia.For participants with HIV-associated pruritus, it is uncertain whether drug treatment with hydroxyzine hydrochloride, pentoxifylline, triamcinolone or indomethacin reduces pruritus because the evidence was of very low quality (e.g. small sample size, lack of blinding).

AUTHORS' CONCLUSIONS

Different interventions tended to be effective for CP and UP. However, therapies for patients with malignancies are still lacking. Due to the small sample sizes in most meta-analyses and the heterogeneous methodological quality of the included trials, the results should be interpreted cautiously in terms of generalisability.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

Pruritus is not the most prevalent but one of the most puzzling symptoms in palliative care patients. It can cause considerable discomfort and has a major impact on patients' quality of life. In the field of palliative care, pruritus is a symptom occurring in patients with disparate underlying diseases and based on different pathologic mechanisms but ending in the same phenomenon. The pathogenesis of pruritus is complex and not fully elucidated. Thus, it is still very difficult to treat pruritus effectively. Evidence-based treatment approaches are needed.

OBJECTIVES

The objective was to evaluate the efficacy of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

A systematic literature search up to January 2012 was performed and it was updated in August 2012. The following databases were searched: The Cochrane Library (CENTRAL, DARE, CDSR) (2012, issue 8 of 12); MEDLINE (1950 to August 2012); EMBASE (1980 to August 2012) and three other databases. In addition, we searched trials registries and checked the reference lists of all relevant studies, key textbooks, reviews, and websites, and contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of different pharmacological treatments on preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified titles and abstracts. Three independent review authors performed assessment of all potentially relevant studies, data extraction, assessment of risk of bias and methodological quality. Results were summarised descriptively according to the different pharmacological interventions and the type of underlying pruritus. Where possible, results were presented in meta-analyses.

MAIN RESULTS

In total, 38 reports comprising 40 studies and 1286 participants were included in the review. Altogether, 30 different treatments for pruritus in four different patient groups were included.The findings of this review indicated that the treatment of pruritus for palliative care patients is challenging and requires an individualistic approach. Results showed that effective therapeutic choices have to be guided by the pathophysiology of the pruritus. Various forms of pruritus occur, especially in the field of palliative care, and sometimes the origin of the pruritus is difficult to determine. Therefore, identifying the underlying cause of pruritus is of prime importance in order to develop tailored treatment plans, even if in palliative care the treatment is focused towards the symptom and not necessarily the underlying disease.Results show that in palliative care patients with pruritus of different natures, treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, may be beneficial. For patients suffering from pruritus associated with HIV infection, indomethacin was described as the most effective drug, although the evidence was weak. For patients suffering from chronic kidney disease-associated pruritus, gabapentin may be an option. An alternative treatment for this patient group seems to be the κ-opioid receptor agonist nalfurafine, which has shown significant amelioration of pruritus and acceptable adverse effects. As they have exhibited a low incidence of adverse effects, rifampicin and flumecinol may be recommended for patients with cholestatic pruritus. The opioid antagonist naltrexone has been shown to offer a therapeutic alternative for patients suffering from uraemic or cholestatic pruritus. However, these drugs are often inappropriate in the palliative population because of the risk of reducing analgesia when giving high doses of naltrexone.

AUTHORS' CONCLUSIONS

The findings of this review indicate that the number of systemic and topical drugs used for the different subforms of pruritus is increasing. Different interventions have been shown to be effective in the treatment of pruritus of different origins. Nevertheless, an optimal therapy for pruritus is constrained due to the limited understanding of crucial itch mediators and receptors in the various subforms of itch. Ideal antipruritic therapies are still lacking, especially for palliative care patients.This systematic review also indicates that there is insufficient evidence to give any concrete recommendations regarding treatment of pruritus in palliative care patients. Due to the very small sample sizes and poor methodological quality of the majority of studies that were included, the results of this review need to be interpreted with caution. Furthermore, the generalizability is questionable. Additional studies, and particularly carefully designed treatment trials, are needed to provide valid evidence for adequate treatment of pruritus in palliative care patients.

Intrahepatic cholestasis of pregnancy in women with a multiple pregnancy: an analysis of risks and pregnancy outcomes

OBJECTIVE

This study was conducted to assess the incidence and perinatal outcomes of multiple pregnancies complicated by intrahepatic cholestasis of pregnancy in an urban population.

METHODS

We performed a retrospective chart review of all multiple gestation deliveries at our institution between January 2004 and December 2005. Antepartum and delivery data were collected for all patients. Symptoms and treatment were also abstracted for patients in whom intrahepatic cholestasis was diagnosed. We used the Student two-tail t test and Fisher exact test to examine the differences between multiple gestation pregnancies with and without cholestasis of pregnancy.

RESULTS

Data were available for 263 multiple pregnancies. The incidence of cholestasis was 4.2% (11/263), with a mean onset at 29.4 weeks. There were no differences in mean gestational age at delivery, preterm delivery rate, meconium histiocytosis, incidence of preeclampsia, or incidence of postpartum hemorrhage between women with and those without cholestasis. There were no intrauterine fetal deaths in the cholestasis group.

CONCLUSION

Women with multiple gestations complicated by cholestasis of pregnancy do not have increased adverse perinatal outcomes. The absence of unexplained fetal demise may be a result of routine delivery before 40 weeks' gestation in multiple pregnancies.

Intrahepatic cholestasis of pregnancy: review of the literature and evaluation of current evidence

OBJECTIVE

To provide an overview of the epidemiology, etiology, pathogenesis, diagnosis, and management of intrahepatic cholestasis of pregnancy.

METHODS

We searched the Medline and PubMed database using the key words intrahepatic cholestasis of pregnancy, obstetric cholestasis, diagnosis, management, and complications.

RESULTS

Intrahepatic cholestasis of pregnancy, or obstetric cholestasis, is a liver condition that develops during pregnancy. It is associated with increased perinatal morbidity and mortality. Pruritus and risk of postpartum hemorrhage are the main causes of maternal morbidity. Intrahepatic cholestasis of pregnancy is a diagnosis of exclusion. The current management policies depend on regular fetal and maternal monitoring and delivery at fetal maturity. The analysis of the quality of previous studies provided in this review highlights the areas of deficiency in evidence-based knowledge of this subject.

CONCLUSIONS

More research is required into the etiology, pathogenesis, and monitoring modalities that can specifically predict fetal outcome in intrahepatic cholestasis of pregnancy. Clinical trials are required to identify the most suitable drugs for treatment.

The efficacy and safety of bile Acid binding agents, opioid antagonists, or rifampin in the treatment of cholestasis-associated pruritus

OBJECTIVES

The objective of this review was to evaluate the efficacy and safety of rifampin, opioid antagonists, or bile acid binding agents in the treatment of cholestasis-related pruritus (CAP) from available randomized controlled trial evidence.

METHODS

In addition to a comprehensive gray literature search, the Cochrane Library, MEDLINE, EMBASE, PubMed, and Web of Science were searched. Only full-text RCTs in participants (>75% adult) with CAP on at least one of the three medications were included. The primary outcome was change in pruritus score, recorded as a continuous or dichotomous outcome. Two independent reviewers performed trial selection and quality assessment.

RESULTS

From 487 citations, 12 RCTs were included. Rifampin (standardized mean difference [SMD]-1.62, 95% CI -3.05 to -0.18) and opioid antagonists (SMD -0.68, 95% CI -1.19 to -0.17) significantly reduced CAP. The two cholestyramine studies were too heterogeneous to pool. Although cholestyramine (P= 0.35) and rifampin (P= 0.96) were not associated with greater side effects compared with placebo, opioid antagonists were (number needed to harm = 2.6, 95% CI 1.4-25).

CONCLUSIONS

The available RCTs are small, few in number, and use varying scales for measuring pruritus. Although both opioid antagonists and rifampin demonstrated a reduction in pruritus, there were insufficient data to judge the efficacy of cholestyramine. Opioid antagonists were associated with transient side effects in a significant proportion of patients. A longer well-designed randomized controlled trial is needed to confirm the efficacy of bile acid binding agents and accurately assess adverse events.

Effect of oral naltrexone on pruritus in cholestatic patients

AIM: To determine the efficacy and potential complications of oral naltrexone used in the treatment of pruritus in cholestatic patients and to compare them with other studies.

METHODS: Thirty-four enrolled cholestatic patients complaining of pruritus were studied. In the initial phase, pruritus scores during day and night were e v a l u a t e d . Subsequently, patients were given a placebo for one week followed by naltrexone for one week. In each therapeutic course (placebo or naltrexone) day and night pruritus scores were distinguished by a visual analogue scale (VAS) system and recorded in patients’ questionnaires.

RESULTS: Both naltrexone and placebo decreased VAS scores significantly. Naltrexone was more effective than placebo in decreasing VAS scores. Both day and night scores of pruritus decreased by half of the value prior to therapy in thirteen patients (38%). Daytime pruritus improved completely in two patients (5.9%), but no improvement in the nighttime values was observed in any patient.

Sixteen patients (47%) suffered from naltrexone complications, eleven (32%) of them were related to its withdrawal. Complications were often mild. In the case of withdrawal, the complication was transient (within the first 24-28 h of therapy) and self-limited. We had to cease the drug in two cases (5.9%) because of severe withdrawal symptoms.

CONCLUSION: Naltrexone can be used in the treatment of pruritus in cholestatic patients and is a safe drug showing few, mild and self-limited complications.

Efficacy and safety of oral naltrexone treatment for pruritus of cholestasis, a crossover, double blind, placebo-controlled study

BACKGROUND/AIMS

To assess the efficacy and safety of naltrexone for the short and long term treatment of pruritus of cholestasis.

METHODS

Twenty patients with pruritus and cholestasis were included. A baseline pruritus score was obtained over 1 week. Patients were then randomized to receive 50 mg/day of naltrexone or placebo for 2 weeks. Subsequently, a 1-week washout period ensued and patients were crossed over to the other therapy for 2 additional weeks. Pruritus was assessed daily with a visual analogue scale (VAS) from 0 to 10. Patients whose pruritus decreased >50% of basal with naltrexone received naltrexone 50 mg/day for 2 additional months.

RESULTS

Mean basal VAS was similar in both groups. VAS showed greater and more significant changes with naltrexone than with placebo (P<0.0003). In nine out of 20 patients (45%) receiving naltrexone, pruritus decreased >50% compared to basal value, including five whose pruritus disappeared completely. No significant changes were observed in serum biochemistry. Most of the adverse events that occurred during the first 48 h of naltrexone therapy were consistent with opioid withdrawal-like phenomena and spontaneously disappeared 2 days after starting treatment.

CONCLUSIONS

Naltrexone can be considered as an alternative option to treat pruritus of cholestasis. In the current study, side effects were transient and did not require specific medication.

Treatment of itching associated with intrahepatic cholestasis of pregnancy

OBJECTIVE

To review the drug therapy for the treatment of itching associated with intrahepatic cholestasis of pregnancy (ICP).

DATA SOURCES

A comprehensive literature search was conducted in MEDLINE (1966-July 2002) using the following MeSH terms: pregnancy, itching, intrahepatic cholestasis, cholestyramine, ursodeoxycholic acid, and phenobarbital. Current Contents (1966-July 2002), International Pharmaceutical Abstracts (1970-June 2002), and Cochrane Database were also searched using those terms. Web of Science search was used to search references found in articles.

DATA SYNTHESIS

Eight clinical trials and several observational studies were identified evaluating the safety and efficacy of ursodeoxycholic acid (UDCA) in the treatment of ICP. Although these studies were small and inconsistent, improvement in maternal and fetal morbidity was demonstrated. Observational studies suggest that cholestyramine may be associated with improved maternal morbidity without a documented improvement in fetal outcome. Two observational studies evaluated the efficacy of phenobarbital for ICP treatment. Phenobarbital use was not associated with improved maternal or fetal morbidity/mortality.

CONCLUSIONS

Data from large, well-designed, randomized, controlled trials of treatment of ICP are lacking. Data that are available support the use of UDCA as a first-line agent and cholestyramine as a second-line agent for treatment of ICP. There is little evidence to recommend phenobarbital in the treatment of itching associated with that condition.

Fibrates suppress chenodeoxycholic acid-induced RANTES expression through inhibition of NF-kappaB activation

Fibrates, hypolipidemic agents, are reported to be effective in treatment of primary biliary cirrhosis. However, the mechanism involved in therapeutic benefits of fibrates in primary biliary cirrhosis remains unknown. In contrast, hepatic regulated upon activation, normal T-cell expressed and secreted (RANTES) is increased in patients with primary biliary cirrhosis and bile acids up-regulate RANTES expression in hepatocytes. The role of fibrates in bile acid-induced RANTES expression was investigated in human hepatoma cells; 100 microM of bezafibrate and fenofibrate decreased expression of chenodeoxycholic acid-induced RANTES mRNA and protein. In addition, luciferase enzyme assay using RANTES promoter-luciferase reporter plasmid revealed that 100 microM of bezafibrate and fenofibrate transcriptionally reduced chenodeoxycholic acid-induced RANTES gene expression. Moreover, bezafibrate clearly repressed DNA-binding activity of nuclear factor-kappaB (NF-kappaB) induced by chenodeoxycholic acid. Therefore, fibrates might be inhibitory agents of inflammatory cell migration by RANTES to the liver in patients with primary biliary cirrhosis, possibly indicating that fibrates are therapeutic agents in primary biliary cirrhosis.

Regulation of cyp3a gene transcription by the pregnane x receptor

The pregnane X receptor (PXR) is a promiscuous nuclear receptor that has evolved to protect the body from toxic chemicals. PXR is activated by a structurally diverse collection of xenobiotics, including several widely used prescription drugs. Various lipophilic compounds produced by the body, such as bile acids and steroids, also activate PXR. PXR stimulates the transcription of cytochrome P450 3A monooxygenases and other genes involved in the detoxification and elimination of these potentially harmful chemicals. Assays that detect PXR activation have important implications for the design of future drugs in two respects. On the one hand, PXR activation assays can be used to determine whether candidate drugs are likely to induce CYP3A gene expression and interact with other medicines. On the other hand, PXR agonists may prove useful in the treatment of diseases in which toxic metabolites accumulate, such as cholestatic liver disease.

Parenteral nutrition-associated liver complications in children

Parenteral nutrition is a life-saving therapy for patients with intestinal failure. It may be associated with transient elevations of liver enzyme concentrations, which return to normal after parenteral nutrition is discontinued. Prolonged parenteral nutrition is associated with complications affecting the hepatobiliary system, such as cholelithiasis, cholestasis, and steatosis. The most common of these is parenteral nutrition-associated cholestasis (PNAC), which may occur in children and may progress to liver failure. The pathophysiology of PNAC is poorly understood, and the etiology is multifactorial. Risk factors include prematurity, long duration of parenteral nutrition, sepsis, lack of bowel motility, and short bowel syndrome. Possible etiologies include excessive caloric administration, parenteral nutrition components, and nutritional deficiencies. Several measures can be undertaken to prevent PNAC, such as avoiding overfeeding, providing a balanced source of energy, weaning parenteral nutrition, starting enteral feeding, and avoiding sepsis.

Bile acids regulate RANTES gene expression through its cognate NF-kappaB binding sites

Regulated upon activation, normal T-cells expressed and secreted (RANTES) mainly migrates memory type CD4+ T-lymphocytes to inflamed tissues. In this study, we examined effects of bile acids on RANTES gene expression in human hepatoma cells. Upon stimulation with hydrophobic bile acids, RANTES proteins were clearly increased. Semiquantitative RT-PCR analysis revealed that chenodeoxycholic acid (CDCA) induced RANTES mRNA expression. Moreover, RANTES was transcriptionally induced in two hepatoma cell lines by CDCA, presumably via its cognate NF-kappaB binding sites in the RANTES promoter. Electrophoretic mobility shift assay revealed that hydrophobic bile acids induced DNA-binding activity of NF-kappaB. Additionally, the magnitude of inducibility was closely associated with the hydrophobicity of bile acids. In conclusion, we might indicate that bile acids induced RANTES gene expression in human hepatoma cells, possibly suggesting that bile acids play an important role in migration of inflammatory cells by RANTES to the liver in patients with primary biliary cirrhosis.

Effect of cholestyramine on bile acid pattern and synthesis during administration of ursodeoxycholic acid in man

BACKGROUND

Cholestyramine is the first-line treatment for cholestasis-induced pruritus and is prescribed along with ursodeoxycholic acid (UDCA) in patients with cholestatic liver diseases. Impairment of the intestinal absorption of endogenous hydrophobic bile acids by cholestyramine is well known. It is unclear, however, whether cholestyramine also impairs the absorption of the hydrophilic bile acid, UDCA, in man.

AIMS

To study serum levels of UDCA and endogenous bile acids as well as endogenous bile acid synthesis during simultaneous or separate administration of UDCA and cholestyramine in vivo; and absorption of UDCA both in the presence and absence of its hydrophobic epimer, chenodeoxycholic acid (CDCA), by cholestyramine in vitro.

PATIENTS AND METHODS

Five healthy subjects received UDCA (12.5 +/- 0.5 mg kg-1 daily) as a single dose for periods of 14 days with or without cholestyramine (4 g daily). Fasting serum levels of bile acids and of 7alpha-hydroxy-4-cholesten-3-one (alpha-HC), a measure of endogenous bile acid synthesis, were determined by gas chromatography and high pressure liquid chromatography, respectively. In vitro, bile acid solutions were incubated for 24 h in the presence or absence of cholestyramine, and bile acid concentrations were determined in the supernatant.

RESULTS

Simultaneous administration of UDCA and cholestyramine in man led to a decrease of fasting serum levels of UDCA by 60% when compared to UDCA serum levels during administration of UDCA alone. In contrast, serum levels of endogenous bile acids were not affected and alpha-HC serum levels were found increased 2. 7-fold indicating stimulation of endogenous bile acid synthesis by cholestyramine. Administration of cholestyramine and UDCA at an interval of 5 h tended to diminish the effect of cholestyramine on UDCA serum levels. In vitro, conjugated and unconjugated UDCA were effectively bound by cholestyramine both in the presence and absence of hydrophobic bile acids.

CONCLUSIONS

The results strongly support the recommendation to administer UDCA and cholestyramine at different times of day.

Ursodeoxycholic acid treatment in children with Byler disease

BACKGROUND

There have been a few reports of patients with Byler disease and the best medical treatment is not known. The aim of the present study is to show the effect of ursodeoxycholic acid (UDCA) on clinical, laboratory and histologic findings in children with Byler disease.

METHODS

Nine children aged between 1.5 and 9 years with Byler disease were administered UDCA orally at doses of 15-20 mg/kg per day. They were followed for at least 12 months. Clinical, laboratory and histologic outcomes were evaluated after 12 months of treatment.

RESULTS

Seven children presented in the first 6 months of life with itching and/or jaundice. Gamma-glutamyl transpeptidase and cholesterol levels were normal in all patients, despite severe cholestasis. With UDCA therapy, pruritus disappeared/diminished in four (44.4%) patients. The mean serum concentrations of alanine aminotransferase, aspartate aminotransferase (AST), total and conjugated bilirubin decreased, although it was significant only for AST (P = 0.01). Before treatment, all biopsy materials showed cellular/canalicular cholestasis and fibrosis. After UDCA therapy cholestasis was ameliorated. Two patients died during follow up.

CONCLUSIONS

The results suggest that administration of UDCA leads to clinical and biochemical improvement in children with Byler disease. The UDCA ameliorates symptoms partially, improves the life quality of patients and may be given for as long as the disease continues.

Clinicopathological features of equine primary hepatic disease: a review of 50 cases

The clinicopathological features of 50 cases of equine hepatic disease were reviewed. There was a wide range of clinical signs and at least 50 per cent of the animals exhibited either dull demeanour, anorexia, abdominal pain, cerebral dysfunction and/or weight loss. Life-threatening complications of hepatic failure recorded were: gastric impaction in 10 cases, bilateral laryngeal paralysis in seven cases and coagulopathy in five cases. All the cases had high activities of gamma-glutamyl transferase (GGT) and most had high activities of glutamate dehydrogenase (GLDH) and high concentrations of bile acids. Fewer of the horses had abnormal concentrations of bilirubin, albumin and globulin. The horses that were euthanased or died had significantly higher concentrations of GGT, GLDH and bile acids than the survivors. There were biochemical data for 18 cases with signs of hepatic encephalopathy, all of them had plasma ammonia levels greater than 90 micromol/litre but this was not significantly correlated with the clinical severity of the condition. Half of the cases with hepatic encephalopathy were hyperglycaemic, none was hypoglycaemic, and none had abnormally low levels of plasma urea.

Pruritus in pregnancy and obstetric cholestasis

Pruritus is often considered a common but minor symptom of pregnancy. However, pruritus caused by obstetric cholestasis is increasingly being recognized as a cause of so-called 'unexplained' stillbirths. This article reviews recent literature and outlines possible management strategies with the aim of reducing maternal morbidity and improving perinatal outcome.

Medical complications in long-term survivors with X-linked myotubular myopathy

OBJECTIVES

X-linked myotubular myopathy (MTM1) is a rare developmental disorder of skeletal muscle characterized by the presence of central nuclei in biopsy specimens from affected male subjects. Until recently, the disorder was usually fatal within the first year of life. This study was undertaken to determine the outcome in long-term survivors (>1 year of age) with MTM1.

METHODS

Clinical data were obtained on 55 male subjects from 49 independent North American families for which a mutation was identified in the X-linked myotubularin gene by direct genomic sequencing. Medical records were reviewed and families were interviewed to ascertain features at birth, length of survival, developmental milestones, and medical complications.

RESULTS

Seventy-four percent (26 of 35) of the affected male subjects over the age of 1 year are living (range, 1 to 27 years); 80% remain completely or partially ventilator-dependent. In the absence of significant hypoxia, cognitive development is normal, and the muscle disorder appears nonprogressive. Several patients have had other medical problems not previously reported to be associated with MTM1. These include pyloric stenosis (4 male subjects from 3 families), spherocytosis (2 patients), gallstones (4 patients), kidney stones or nephrocalcinosis (2 patients), a vitamin K responsive bleeding diathesis (2 patients), and height >/=90% for age (40% of the patients). Six patients have had biochemical evidence of liver dysfunction, and 2 patients died after significant liver hemorrhage.

CONCLUSIONS

These data suggest that the prognosis for X-linked MTM may not be as poor as previously reported. However, at least some long-term survivors appear at risk for medical complications involving other organ systems, and patients should be carefully monitored for these potentially life-threatening complications. The pleiotropic symptoms demonstrated in these patients strongly suggest that the function of the MTM1 protein is not limited to developing muscle cells.

Reduction of sodium deoxycholic acid-induced scratching behaviour by bradykinin B2 receptor antagonists

1. Subcutaneous injection of sodium deoxycholic acid into the anterior of the back of male ddY mice elicited dose-dependent scratching of the injected site with the forepaws and hindpaws. 2. Up to 100 microg of sodium deoxycholic acid induced no significant increase in vascular permeability at the injection site as assessed by a dye leakage method. 3. Bradykinin (BK) B2 receptor antagonists, FR173657 and Hoe140, significantly decreased the frequency of scratching induced by sodium deoxycholic acid. 4. Treatment with aprotinin to inhibit tissue kallikrein reduced the scratching behaviour induced by sodium deoxycholic acid, whereas treatment with soybean trypsin inhibitor to inhibit plasma kallikrein did not. 5. Although injection of kininase II inhibitor, lisinopril together with sodium deoxycholic acid did not alter the scratching behaviour, phosphoramidon, a neutral endopeptidase inhibitor, significantly increased the frequency of scratching. 6. Homogenates of the skin excised from the backs of mice were subjected to gel-filtration column chromatography followed by an assay of kinin release by trypsin from each fraction separated. Less kinin release from the fractions containing kininogen of low molecular weight was observed in the skin injected with sodium deoxycholic acid than in normal skin. 7. The frequency of scratching after the injection of sodium deoxycholic acid in plasma kininogen-deficient Brown Norway Katholiek rats was significantly lower than that in normal rats of the same strain, Brown Norway Kitasato rats. 8. These results indicate that BK released from low-molecular-weight kininogen by tissue kallikrein, but not from high-molecular-weight kininogen by plasma kallikrein, may be involved in the scratching behaviour induced by the injection of sodium deoxycholic acid in the rodent.

Unexpected clinical remission of cholestasis after rifampicin therapy in patients with normal or slightly increased levels of gamma-glutamyl transpeptidase

OBJECTIVE

Rifampicin is an effective drug against pruritus in intrahepatic cholestasis. However, there is no specific hepatic disease in which its use could cause undoubtedly biochemical improvement. The aim of this study was to describe patients with complete remission of cholestatic symptoms after rifampicin therapy.

METHODS

We reported three female patients with intrahepatic cholestasis with no evidence of viral, metabolic, or autoimmune liver diseases. Total bilirubin levels ranged from 13.2 to 27.2 mg/dl (before the first treatment with rifampicin), and in all of them gamma-glutamyl transpeptidase values were within the normal range or slightly increased. Rifampicin therapy was administered orally, without any concomitant drug, with an effective dosage of 5-17 mg/kg/day.

RESULTS

In all patients, pruritus ceased completely and bilirubin returned to normal values. The symptoms recurred after rifampicin withdrawal on, at least, three occasions in each patient, and these symptoms were always eliminated after its reintroduction. The patients had a total of 16 cholestatic episodes during a follow-up of 8 yr, with a complete clinical recovery in all of them. Undergoing therapy with a suitable dosage of rifampicin, none of the patients had a cholestatic crisis even during a period for as long as 12 months. The diagnosis of two patients was consistent with benign recurrent intrahepatic cholestasis, and it was not well defined in the remaining.

CONCLUSION

Rifampicin may induce clinical remission, and perhaps prevent clinical relapses of intrahepatic cholestasis with normal or slightly increased levels of gamma-glutamyl transpeptidase.

Pruritus--itching for a cause and relief?

The mechanisms of pruritus, an unpleasant irritation on the skin that provokes an urge to scratch, are reviewed. Whilst symptomatic treatment is only partially effective, antihistamines remain the first choice of treatment. However, recent novel treatment using opiate antagonists, propofol (subhypnotic doses) and serotonin antagonists offer attractive alternatives.

Diagnosis and therapy of cholestatic liver disease

The majority of cholestatic liver diseases can be diagnosed with a carefully performed history taking, physical examination, and appropriate imaging studies. In a minority of cases, however, liver biopsy may be necessary to establish the diagnosis. In addition to the treatment of the specific liver disease, therapy should address the management of complications unique to cholestasis and progressive liver failure.

Neurologic aspects of inflammatory bowel disease

To determine the frequency, spectrum, and clinical features of neurologic disorders associated with ulcerative colitis (UC) and Crohn's disease (CD).

BACKGROUND

Extraintestinal manifestations of inflammatory bowel disease (IBD) are well documented, but the association of IBD with neurologic involvement is rare and often controversial.

METHODS

Tertiary care center ambulatory and hospital services data bank retrospective computerized search with subsequent file review.

PATIENTS

From among 638 IBD patients diagnosed from 1981 to 1991, we identified 10 CD patients and nine UC patients with neurologic involvement unrelated to a defined systemic or iatrogenic cause. Neurologic disorders diagnosed 15 or more years before the intestinal symptomatology were excluded.

RESULTS

Three percent of IBD patients had neurologic involvement. In 14 of 19 (74%), it started within a mean of 5.7 years (range, 0.7 to 12 years) after the diagnosis of bowel disease, and in two of 19 (10%) it occurred at the time of IBD exacerbation. During the course of IBD, 10 of 19 patients (53%) exhibited other extraintestinal manifestations. Peripheral nerve disorders were observed in six UC patients. Myelopathy (5 patients), myopathy (3), and myasthenia gravis (1) were diagnosed in eight CD patients and one UC patient. Cerebrovascular disorders occurred in two UC and two CD patients.

CONCLUSIONS

Neurologic disorders associated with IBD are more common than appreciated and follow a different pattern of involvement in UC and CD. A prospective study is required to define the nature of this association.