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Biomedical subjects

E R Dickson

Publications and source records attributed to E R Dickson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Incidence of cancer in primary biliary cirrhosis: the Mayo experience.

Patients with primary biliary cirrhosis (PBC) may be at increased risk for malignancies. Several studies have addressed the risk of specific malignancies; however, there is little information about overall incidences of malignancies in these patients. We hypothesize that these patients may be at an increased risk for cancer. We performed a retrospective chart review evaluating patients with the diagnosis of PBC and malignancies. We reviewed records of patients with PBC presenting to the Mayo Clinic between 1976 and 1985. The diagnosis of PBC was made using evidence of cholestasis, positive antimitochondrial antibody titers and liver biopsy findings consistent with PBC. The incidence of malignancies were then compared with published data by the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute. Of the 1,692 patients with PBC in the Mayo Clinic data base, 114 patients were identified with primary cancer. The number of malignancies was higher than would be anticipated by chance alone; with 93 observed versus 62.4 expected events (P <.001). Hepatobiliary malignancies had a relative risk of 46 (P <.0001) for women and 55 (P <.0001) in men. There was a dramatic increased risk for development of hepatobiliary malignancies. PBC patients might benefit from more aggressive surveillance for hepatobiliary malignancies during their lifetime.

Adolescent↗
PubMed1999

The relative role of the Child-Pugh classification and the Mayo natural history model in the assessment of survival in patients with primary sclerosing cholangitis.

The Child-Pugh classification is a simple, convenient prognostic measure in patients with liver cirrhosis. We investigated the relative role of the Child-Pugh classification and the Mayo model in the assessment of survival in patients with primary sclerosing cholangitis (PSC). Of the 173 patients described in the original Mayo PSC natural history model, 147 patients had sufficient information in the medical record to allow computation of the Child-Pugh score. We used our most recent modification of the Mayo model to compute the risk score, based on patient's age, serum levels of bilirubin, albumin, and aspartate aminotransferase and history of variceal bleeding. Using the risk score (R), patients were divided into the low- (R < 0), intermediate- (0 </= R < 2), and high-risk (R >/= 2) groups. Kaplan-Meier estimates and proportional hazards analysis were used to evaluate the two prognostic models. Although there was a statistically significant correlation between the Child-Pugh and Mayo risk scores, two-thirds of the patients had a Child-Pugh score of 5 or 6 and a relatively wide range of risk scores (-1.1-4.3). The probability of survival for 7 years in patients in the low-, intermediate-, and high-risk groups was 92%, 74%, and 40% for Child-Pugh class A (n = 96) and 100%, 62%, and 28% for Child-Pugh class B patients (n = 44), respectively. There were only a small number (n = 7) of Child-Pugh class C patients. In our age-adjusted multivariate analysis, each unit increase in the Mayo risk score was associated with a 2.5-fold increase in the risk of death (95% confidence interval: 1.8-3.4, P <.01), whereas Child-Pugh classification had no significant impact on survival (Child-Pugh B vs. A: risk ratio = 1.1 [95% confidence interval: 0.6-2.0]; Child-Pugh C versus A: risk ratio = 0.6 [95% confidence interval: 0. 2-1.8]). In contrast to the Child-Pugh classification, which was developed for advanced liver cirrhosis, the Mayo model provides valid survival information, particularly in patients early in the course of PSC.

Adult↗
PubMed1999

Hepatic retransplantation in cholestatic liver disease: impact of the interval to retransplantation on survival and resource utilization.

The aim of our study was to quantitatively assess the impact of hepatic retransplantation on patient and graft survival and resource utilization. We studied patients undergoing hepatic retransplantation among 447 transplant recipients with primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) at 3 transplantation centers. Cox proportional hazards regression analysis was used for survival analysis. Measures of resource utilization included the duration of hospitalization, length of stay in the intensive care unit, and the duration of transplantation surgery. Forty-six (10.3%) patients received 2 or more grafts during the follow-up period (median, 2.8 years). Patients who underwent retransplantation had a 3.8-fold increase in the risk of death compared with those without retransplantation (P <.01). Retransplantation after an interval of greater than 30 days from the primary graft was associated with a 6.7-fold increase in the risk of death (P <.01). The survival following retransplantations performed 30 days or earlier was similar to primary transplantations. Resource utilization was higher in patients who underwent multiple consecutive transplantations, even after adjustment for the number of grafts during the hospitalization. Among cholestatic liver disease patients, poor survival following hepatic retransplantation is attributed to late retransplantations, namely those performed more than 30 days after the initial transplantation. While efforts must be made to improve the outcome following retransplantation, a more critical evaluation may be warranted for late retransplantation candidates.

Adult↗
PubMed1999

Effect of pretransplantation ursodeoxycholic acid therapy on the outcome of liver transplantation in patients with primary biliary cirrhosis.

As ursodeoxycholic acid (UDCA) delays the need for transplantation, this could result in patients with more comorbid disease, therefore more likely to have a worse outcome posttransplantation. The aim of this study is to compare posttransplantation outcome in patients who received UDCA versus placebo who subsequently required a liver transplant. Data on all trial patients referred for transplantation were retrospectively collected from three randomized controlled trials of UDCA in patients with primary biliary cirrhosis (PBC). An intent-to-treat analysis was conducted with patients assigned to their original treatment allocation. UDCA and placebo groups were compared at trial entry, transplant referral, just before transplantation, and 1 month and 1 year posttransplantation. From 1987 to 1996, 37 UDCA-treated and 53 placebo patients were referred for transplantation; their age, sex, and serum bilirubin levels were similar at study entry. Immediately before transplantation, these two groups were again similar with respect to age, bilirubin level, Mayo risk score, and serum creatinine level. Posttransplantation survival rates at 1 month were 93.9% in the UDCA group and 88.4% in the placebo group, and 1 year survival rates were 90.3% and 78.4%, respectively (not significant). Posttransplantation, the two groups had similar rates of infection (53.9% v 58%); however, rejection occurred significantly less often in the UDCA group; 42.9% versus 68. 8% in the placebo group (P =.04). The posttransplantation outcome of UDCA-treated patients with PBC is no different from those who were administered placebo. There is no evidence to suggest the beneficial effect of UDCA in delaying the need for transplantation is associated with a worse outcome once liver transplantation becomes necessary.

Age Factors↗
PubMed1999

Comparison of three doses of ursodeoxycholic acid in the treatment of primary biliary cirrhosis: a randomized trial.

BACKGROUND/AIM: Ursodeoxycholic acid in doses of 13-15 mg x kg(-1) x day(-1), is a safe and cost-effective treatment for patients with primary biliary cirrhosis. However, very limited information exists regarding the most appropriate dose of ursodeoxycholic acid. The aim of the study was to compare three dosages of ursodeoxycholic acid with respect to changes in liver biochemistries, Mayo risk score, biliary enrichment with ursodeoxycholic acid and side effects over at least a 1-year period. METHODS: A total of 155 patients were randomized to receive low- (5-7 mg x kg(-1) x day(-1)), standard-(13-15 mg x kg(-1) x day(-1)), and high- (23-25 mg x kg(-1) x day(-1)) doses of ursodeoxycholic acid. RESULTS: The improvements in alkaline phosphatase (p = 0.0001), aspartate aminotransferase (p = 0.0001), Mayo risk score (p = 0.002), and ursodeoxycholic acid enrichment (p = 0.0001) were significantly greater in the standard- and high-dose groups compared to the low-dose group, but not between the standard- and high-dose groups. Changes in serum bilirubin were similar between the three groups (p = 0.07). No significant effects on symptoms were noted with any dose. No patients discontinued ursodeoxycholic acid because of side effects or toxicity. CONCLUSIONS: Ursodeoxycholic acid in doses of 5-25 mg x kg(-1) x day(-1) is safe and well tolerated. The dose of 13-15 mg x kg(-1) x day(-1) appears to be the preferred dose for patients with primary biliary cirrhosis.

Alkaline Phosphatase↗
PubMed1999

Is routine cholangiography useful in men with suspected primary biliary cirrhosis?

The aim of this study was to assess the diagnostic value of cholangiography in men with chronic cholestasis and positive antimitochondrial antibody (AMA) titers who were suspected of having primary biliary cirrhosis (PBC). The authors reviewed retrospectively the records of men who had positive AMA titers over a 16-month period to determine the results of cholangiography. They also reviewed the records of 102 patients with primary sclerosing cholangitis (PSC) from 1989 to 1995 who had undergone cholangiography and testing for AMA. Of 35 men with positive tests for serum AMA, 12 of these patients were referred for cholangiography (11 endoscopic and 1 transhepatic). All completed cholangiograms were normal. A diagnosis of PBC was made in nine patients and atypical autoimmune hepatitis in one. Conversely, only two PSC patients had positive AMA titers (1:20 and 1:80). Both of these patients had coexisting inflammatory bowel disease and cholangiograms diagnostic of PSC. Cholangiography was negative in the male patients with positive AMA titers who were suspected of having PBC. In men with cholestatic liver biochemistries and strongly positive AMA titers, especially in the absence of associated inflammatory bowel disease, routine cholangiography does not add to the diagnostic evaluation.

Adult↗
PubMed1999

Utilization of the Mayo risk score in patients with primary biliary cirrhosis receiving ursodeoxycholic acid.

BACKGROUND/AIMS: Ursodeoxycholic acid (UDCA) is an effective therapy for most patients with primary biliary cirrhosis (PBC). During the management of these treated patients, a number of clinically important issues arose including which patients might be candidates for combined therapy, which patients require endoscopy for variceal bleeding, and how survival can be predicted during treatment. Our aims were: 1) to identify factors associated with a suboptimal response to UDCA in patients with PBC; 2) to define a simple, non-invasive method to predict those PBC patients most apt to have esophageal varices; and 3) to determine the reliability of the Mayo survival model in predicting the course of UDCA treated patients. METHODS: We analyzed the prospectively collected data of 180 patients, who we continue to follow, with PBC who participated in a randomized, placebo-controlled trial of UDCA. RESULTS: After six months of UDCA therapy, patients with serum alkaline phosphatase levels less than twice normal (p < 0.04), and/or a Mayo risk score < 4.5 (p < 0.04) were more likely to respond favorably to treatment over a two year period. The Mayo risk score was the single risk factor independently predictive of development of varices (p < 0.01); 93% of patients who developed varices had a Mayo risk score > or = 4. The Mayo survival model, recalculated after 6 months on UDCA therapy accurately predicted patient survival. CONCLUSIONS: Suboptimal responders to UDCA can be identified by assessment of serum alkaline phosphatase levels, and/or Mayo risk score. A Mayo risk score above 4 helps in selecting patients for endoscopic surveillance for varices and the Mayo survival model accurately predicts the clinical course in patients with PBC receiving UDCA.

Adult↗
PubMed1998

Cost-effectiveness of ultrasound-guided liver biopsy.

The risk of a major complication from "blind" percutaneous liver biopsy is reported to be in the range of 0.24% to 3.8%. In a recent randomized trial, patients whose liver biopsies were performed with ultrasonography had a significant reduction in complications requiring hospitalization compared with patients without ultrasound-guided biopsies (0.5% vs. 2.2%, P < .05). Despite this, routine use of ultrasonography for liver biopsies has not been implemented because of controversies with respect to cost-effectiveness. The aim of our study was to analyze the relative cost-effectiveness of performing ultrasound-guided liver biopsies using decision analysis. A decision tree was constructed to compare a strategy of liver biopsy using ultrasonography with a strategy without ultrasonography. The major outcomes included were minor complications such as pain requiring analgesics and major complications, which require hospitalization. Costs included were direct medical costs from the payer's perspective. In our baseline model, the cost from complications per patient with and without ultrasonography was $62 and $129, respectively. The marginal effectiveness expressed as the number of major complications avoided was 1.2/100 liver biopsies. The incremental cost to avoid one major complication was $2,731. The model was most sensitive to the frequency of major complications and the additional cost of ultrasonography. Our decision analysis model suggests that ultrasound-guided liver biopsy is cost-effective. Future studies assessing the efficacy of image-guided liver biopsies should be conducted.

Biopsy, Needle↗
PubMed1998

Optimal timing of liver transplantation for primary biliary cirrhosis.

In 1989, we reported on the efficacy of liver transplantation in primary biliary cirrhosis (PBC) by demonstrating that the actual patient survival following transplantation was significantly better than without transplantation as predicted by a mathematical survival model ("Mayo natural history model"). Our aim in this investigation was to determine an optimal time to perform liver transplantation in PBC. One hundred forty-three patients with PBC undergoing liver transplantation were followed prospectively. Disease severity was measured immediately before transplantation by a summary score ("risk score") used in the Mayo natural history model, namely age, bilirubin, albumin, prothrombin time, and the presence or absence of edema. Proportional hazards analyses were performed assessing patient survival following transplantation. The influence of disease severity immediately pretransplantation on resource utilization for liver transplantation was assessed. Compared with our report in 1989, liver transplantation was performed at an earlier stage of disease (e.g., median risk score: 7.5 vs. 8.3; P < .01). Following transplantation, patient survival probabilities at 1, 2, and 5 years were 93%, 90%, and 88%, respectively. In the proportional hazards analysis, the risk of death following transplantation remained low until reaching a risk score of 7.8. In contrast, risk scores greater than 7.8 were associated with a progressively increased mortality. Resource utilization measured by the days in the intensive care unit (ICU) and hospital and the requirement for intraoperative blood transfusions was significantly greater in recipients who had higher risk scores before transplantation. Our data suggest that an optimal timing for liver transplantation, as determined by patient survival and resource utilization, appears to be at a risk score around 7.8 in patients with PBC.

Adult↗
PubMed1998

Bone disease in patients with primary sclerosing cholangitis: prevalence, severity and prediction of progression.

BACKGROUND/AIMS: Osteopenia is a common complication in some chronic cholestatic liver diseases. Our aims were to determine the prevalence and severity of bone disease in patients with primary sclerosing cholangitis; and identify risk factors to predict the presence and progression of osteopenia. METHODS: Eighty-one patients involved in a randomized trial of ursodeoxycholic acid were analyzed. Bone mineral density of the lumbar spine was determined at entry and at annual intervals. RESULTS: Bone mineral density of the lumber spine in primary sclerosing cholangitis patients was significantly lower than expected when compared to normal values adjusted for age, sex and ethnic group at entry (p<0.005), and after 1 year (p<0.05), 2 years (p<0.05), 4 years (p<0.005) and 5 years of follow-up (p<0.005). Seven patients (8.6%) had bone mineral density of the lumber spine below the fracture threshold at entry. These patients were significantly older, had a longer duration of inflammatory bowel disease and more advanced primary sclerosing cholangitis. The rate of bone loss in primary sclerosing cholangitis patients and expected in normal controls was 0.01+/-0.02 g x cm(-2) x year(-1) and 0.003+/-0.003 g x cm(-2) x year(-1), respectively (p = NS), and was similar in patients receiving placebo and ursodeoxycholic acid. Age was the only variable inversely related with baseline bone mineral density of the lumber spine (p<0.0001). None of the variables predicted progression of the bone disease. CONCLUSIONS: Severe osteoporosis occurs in few patients with primary sclerosing cholangitis, but it should be suspected in patients with longer duration of inflammatory bowel disease and more advanced liver disease. Its presence, severity and progression cannot be accurately evaluated by routine clinical, biochemical, or histological variables. Ursodeoxycholic acid does not affect the rate of bone loss in primary sclerosing cholangitis.

Adult↗
PubMed1998

Predictive models of natural history in primary biliary cirrhosis.

Primary biliary cirrhosis is a slow, progressive disease. Although many years may elapse before asymptomatic primary biliary cirrhosis patients begin experiencing symptoms of liver disease, their overall survival is significantly lower than the normal population. The Mayo natural history model has been developed to depict patient survival in the absence of effective therapeutic intervention. Although there are a number of caveats in applying this model, it has been validated using external data sets and established as an accepted tool for clinical or research purposes. Furthermore, recent data suggest that the Mayo natural history model continues to provide useful, predictive information in the presence of ursodeoxycholic acid therapy, which has been shown to lower the serum bilirubin to the natural history model for patient survival. In addition to the natural history model for patient survival, mathematical models have been developed to describe histologic progression and development of esophageal varices.

Disease Progression↗
PubMed1998

Autoimmune conditions associated with primary biliary cirrhosis: response to ursodeoxycholic acid therapy.

OBJECTIVES: A variety of autoimmune conditions occur in association with primary biliary cirrhosis. Among these conditions are sicca syndrome, Raynaud's phenomenon, arthritis, and Hashimoto's thyroiditis. Information is sparse regarding the prevalence and natural history of these conditions when associated with primary biliary cirrhosis and their response to ursodeoxycholic acid treatment. We evaluated the prevalence, natural history, and response to ursodeoxycholic acid therapy of these conditions coassociated with primary biliary cirrhosis. METHODS: One hundred-eighty patients with primary biliary cirrhosis, enrolled in a prospective randomized controlled trial of ursodeoxycholic acid (13-15 mg/ kg/day), were included. Patients were assessed at study entry and annually. RESULTS: At entry, 77/180 patients (43%) had one of the four conditions, and 18/180 patients (10%) had two or more conditions. Sicca syndrome was the most common, occurring in 58/180 patients (32%). After 2 yr, there was no difference between the treatment groups with regard to resolution or spontaneous onset of these autoimmune features. Sicca syndrome was the most common spontaneously developing condition (9% per yr). Sicca syndrome was the most common associated autoimmune condition, present in one-third of our patients. The associated conditions tended to improve over time, with a low rate of spontaneously developing these conditions. Although ursodeoxycholic acid therapy leads to improvement in the underlying liver disease, it did not appear to influence either the development or resolution of these autoimmune features. CONCLUSIONS: Although ursodeoxycholic acid is beneficial in the treatment of primary biliary cirrhosis, it had no measurable effect on the autoimmune conditions coassociated with the disease.

Arthritis↗
PubMed1998

Relationship between biliary and serum bile acids and response to ursodeoxycholic acid in patients with primary biliary cirrhosis.

OBJECTIVE: Ursodeoxycholic acid (UDCA) improves liver biochemistries and enriches the bile with UDCA in patients with primary biliary cirrhosis. The aim of this study was to determine whether the degree of enrichment of bile correlated with that of serum and whether either of these measures correlated with improvement in measures of liver disease. METHODS: In a randomized study, biliary and serum bile acid analyses were performed at entry and after 2 yr of UDCA or placebo. RESULTS: The percentage of ursodeoxycholic acid in bile increased by 42% in the UDCA group (n = 61) compared with 8% in the placebo group (n = 57) (p < 0.0001). Measurement of serum bile acids in 32 patients (18 ursodeoxycholic acid, 14 placebo) indicated that at 2 yr, ursodeoxycholic acid comprised 65% of serum bile acids in the treated group and 7% in the placebo group. Agreement between bile and serum was fair (r = 0.75, p < or = 0.00002) because in some patients, plasma but not biliary bile acids were enriched with UDCA. Changes in biliary ursodeoxycholic acid correlated significantly but weakly with the changes in serum alkaline phosphatase, AST, bilirubin, and in Mayo risk score. Correlations between changes in serum bile acid composition and biochemical measures of disease activity were even weaker. CONCLUSION: The measurement of biliary bile acids is superior to that of serum bile acids for assessing the compliance and changes in the circulating bile acids in patients receiving ursodeoxycholic acid for the treatment of primary biliary cirrhosis. Furthermore, measures to further increase the proportion of ursodeoxycholic acid in circulating bile acids should be explored.

Bile↗
PubMed1997

Cost-effectiveness of 6 and 12 months of interferon-alpha therapy for chronic hepatitis C.

BACKGROUND: Interferon-alpha is effective in only a small number of patients with chronic hepatitis C, although prolonged treatment may increase the response rate. There is concern that the expense of interferon-alpha therapy may not be justified by the low response rates and uncertain long-term benefit. OBJECTIVE: To compare clinical and economic outcomes after 6 months and 12 months of interferon-alpha therapy for chronic hepatitis C. DESIGN: A Markov model depicting the natural progression of chronic hepatitis C. On the basis of this model, a simulated trial compared no therapy with 6 and 12 months of interferon-alpha therapy at standard doses (3 million U three times weekly). PATIENTS: Four age-specific cohorts (30, 40, 50, and 60 years of age) with chronic hepatitis C. MEASUREMENTS: Number of deaths from liver disease, total costs, and cumulative quality-adjusted life-years (QALYs). RESULTS: Six and 12 months of interferon-alpha treatment gained 0.25 QALYs at an incremental cost of $1000 and 0.37 QALYs at an incremental cost of $1900, respectively. Thus, although 6 months of interferon-alpha therapy was less efficacious than 12 months of therapy, it was more cost-effective ($4000 per QALY gained compared with $5000 per QALY gained). Nonetheless, in patients younger than 60 years of age, both 6 and 12 months of therapy compared favorably with other established medical interventions, such as screening mammography and cholesterol reduction programs. Important variables affecting the cost-effectiveness of interferon-alpha treatment included the cost and efficacy of interferon-alpha, the cost of treatment for decompensated cirrhosis, and quality of life in patients with chronic hepatitis C. CONCLUSION: From the standpoint of cost-effectiveness, interferon-alpha therapy for 6 or 12 months may be justified in patients with chronic hepatitis C. The possible exception is patients older than 60 years of age.

Adult↗
PubMed1997

Quantitative measurement of autoantibodies to recombinant mitochondrial antigens in patients with primary biliary cirrhosis: relationship of levels of autoantibodies to disease progression.

We examined the clinical usefulness of measurements of antimitochondrial autoantibodies (AMA) in predicting disease progression in patients with primary biliary cirrhosis (PBC). We determined the relationships between AMA levels measured by indirect immunofluorescence (IF) and those measured by quantitative enzyme immunoassays (EIAs) using recombinant 2-oxo-acid dehydrogenase complex (2-OADC) proteins and the Mayo Risk Score, an established indicator of disease progression in primary biliary cirrhosis (PBC). Results of tests for AMA by either method correlated weakly (r = .24 to .30) with disease progression as indicated by Mayo Risk Scores. The levels of AMA to 2-OADC proteins varied by more than 200-fold between patients but remained relatively constant over time in individual patients. Despite being positively correlated with Mayo Risk Score results, the levels of AMA to 2-OADC proteins were not useful for predicting disease progression in individual patients with PBC. In addition, we found no significant differences in the levels of autoantibodies to 2-OADC proteins among patients with different histological stages of disease. Our results show that measurements of AMA by IF or by quantitative EIA methods with recombinant 2-OADC proteins are not useful parameters for predicting disease progression in patients with PBC.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1997

A prognostic model for the outcome of liver transplantation in patients with cholestatic liver disease.

We studied the outcome of 436 patients with primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC) who underwent orthotopic liver transplant (OLT) at three major liver transplant centers. Univariate predictors of outcome included age, Karnofsky score, Child's class, Mayo risk score, United Network for Organ Sharing (UNOS) status, nutritional status, serum albumin, serum bilirubin, international normalized ratio, and the presence of ascites, encephalopathy, renal failure (serum creatinine > 2 mg/dL), and edema refractory to diuretics. Using these predictors, we developed a four variable mathematical prognostic model to help the liver transplant physician predict the following: 1) the amount of intraoperative blood loss; 2) the number of days in the intensive care unit (ICU); and 3) severe complications after surgery. The model uses age, renal failure, Child's class, and United Network for Organ Sharing status. This study is the first to model the outcome of liver transplant in patients with a specific etiology of chronic liver disease (PBC or PSC). The model may be used to help select patients for OLT and to plan the timing of their transplantation.

Analysis of Variance↗