PubMed Health⌕ Search

Biomedical subjects

Marshall M Kaplan

Publications and source records attributed to Marshall M Kaplan.

At least 19 recordsLinked to original sources
PubMed2005

Risk factors and comorbidities in primary biliary cirrhosis: a controlled interview-based study of 1032 patients.

Primary biliary cirrhosis (PBC) is an autoimmune disease of unknown etiology, often associated with other autoimmune conditions. Controlled studies have so far provided conflicting data on risk factors and comorbidity rates in PBC. We enrolled patients with PBC (n = 1032) from 23 tertiary referral centers for liver diseases in the United States and random-digit-dialed controls (n = 1041) matched for sex, age, race, and geographical location. Patients and controls were administered a modified version of the US National Health and Nutrition Examination Study (NHANES III) questionnaire by trained personnel to evaluate associations between PBC and social, demographic, personal and family medical histories, lifestyle, and reproductive factors and the rates of comorbidity in affected individuals. Data indicate that having a first-degree relative with PBC (adjusted odds ratio [AOR] 10.736; 95% confidence interval 4.227-27.268), history of urinary tract infections (AOR 1.511, 95% CI 1.192-1.915), past smoking (AOR 1.569, 95% CI 1.292-1.905), or use of hormone replacement therapies (AOR 1.548, 95% CI 1.273-1.882) were significantly associated with increased risk of PBC. The frequent use of nail polish slightly increased the risk of having PBC. Other autoimmune diseases were found in 32% of cases and 13% of controls (P<0.0001). In conclusion, environmental factors, possibly including infectious agents through urinary tract infections or chemicals contained in cigarette smoke, may induce PBC in genetically susceptible individuals. Exogenous estrogens may also contribute to explain the female predominance of the disease.

Aged↗
PubMed2005

The natural history of PBC: has it changed?

The prognosis and natural history of primary biliary cirrhosis (PBC) have improved significantly during the last few decades. Patients are diagnosed at earlier stages, are more likely to be asymptomatic at diagnosis, and are more likely to receive medical treatment. The survival of asymptomatic patients is longer than the median survival of symptomatic patients. The natural history of PBC has been assessed in the presence of effective therapy, ursodeoxycholic acid (UDCA). Evidence suggests that UDCA delays histological progression in PBC and decreases the risk of development of esophageal varices. Survival of UDCA-treated patients is better than that of untreated patients and also is better than that predicted by the Mayo model. For patients in early stages of PBC, UDCA treatment may normalize survival. However, patients with stage III and IV PBC do not respond as well to UDCA. Therefore, there is a continued need for additional treatment in patients with advanced disease.

Cholagogues and Choleretics↗
PubMed2004

A randomized controlled trial of colchicine plus ursodiol versus methotrexate plus ursodiol in primary biliary cirrhosis: ten-year results.

Primary biliary cirrhosis frequently progresses despite treatment with ursodeoxycholic acid (UDCA), the only approved therapy. Previous studies suggested that colchicine and methotrexate may improve biochemical tests of liver function, symptoms, and liver histology. The aim of the present study was to determine if the addition of colchicine or methotrexate to UDCA would improve survival free of liver transplantation. Eighty-five patients with histologically confirmed primary biliary cirrhosis whose serum alkaline phosphatase levels were at least twice the normal level and who were not yet candidates for liver transplantation were randomly assigned to receive colchicine or methotrexate in a double-blind study. UDCA was administered to all patients after 2 years. The primary end point was survival free of liver transplantation. Patients were followed up for a total of up to 10 years or until treatment failure. Data were analyzed on an intention-to-treat basis. Transplant-free survival was similar in both groups: 0.57 for colchicine plus UDCA and 0.44 for methotrexate plus UDCA, results that are similar to those predicted by the Mayo prognostic model. Significant improvement in liver biochemical tests and liver histology was observed in a subset of patients in both treatment groups who remained in the study for all 10 years. In conclusion, neither colchcine plus UDCA nor methotrexate plus UDCA improved survival beyond that predicted by the Mayo prognostic model. However, clinical, histologic, and biochemical improvement observed among those who remained in the study for 10 years suggests a possible benefit of these drugs in a subset of patients.

Anti-Inflammatory Agents↗
PubMed2004

Aerobic capacity is associated with 100-day outcome after hepatic transplantation.

The shortage of donor organs highlights the need to better identify patients most likely to benefit from hepatic transplantation. Reduced aerobic capacity (decreased peak oxygen consumption [VO(2)] during symptom-limited cardiopulmonary exercise testing) is frequently present in cirrhosis. Peak VO(2) during cardiopulmonary exercise testing may predict short-term outcome after hepatic transplantation. Symptom-limited testing was performed on a cycle ergometer (continuous ramp protocol) and VO(2) determined using a metabolic cart. One hundred fifty-six patients were tested; 59 subsequently underwent hepatic transplantation. Results showed that survivors and nonsurvivors were similar in age, duration of liver disease, Child-Pugh score, MELD score, resting cardiovascular function, pulmonary function, and gas exchange. The 6 (10.2%) patients dying within 100 days of transplantation were more likely to have reduced aerobic capacity (peak VO(2) <60% predicted and VO(2) at anaerobic threshold [VO(2)-AT] <50% predicted peak VO(2)) compared to survivors (4/6 vs. 7/53, P <.01). Using a multiple logistic regression model controlling for duration and severity of liver disease and time to transplantation, reduced aerobic capacity was independently associated with 100-day mortality. In conclusion, reduced aerobic capacity during cardiopulmonary exercise testing is associated with decreased short-term survival after hepatic transplantation. Further study is needed to determine if cardiopulmonary exercise testing can be used to improve allocation of donor organs. To ensure optimum allocation of donor organs, it is important to identify patients most likely to benefit from transplantation. Investigators have identified a number of preoperative, intraoperative, and postoperative factors that predict increased risk for postoperative mortality. Unfortunately, predictive accuracy has not been high, and the timing of factor identification does not optimize organ utilization. Identification of predictors of survival at the time of listing for transplantation might lead to better resource allocation.

Adult↗
PubMed2004

A pilot study of etanercept in the treatment of primary sclerosing cholangitis.

There is no effective medical treatment for primary sclerosing cholangitis (PSC), a chronic cholestatic liver disease that usually progresses to cirrhosis and liver failure. The aim of this study was to determine the safety and efficacy of etanercept, an inhibitor of tumor necrosis factor, in the treatment of PSC. Ten patients with clinically active PSC were studied. All had elevated serum alkaline phosphatase levels, cholangiograms that were diagnostic of PSC, and liver histology consistent with PSC. Five patients had elevated serum bilirubin levels, five had pruritus, eight had failed to respond to ursodiol and/or methotrexate, and six had rapidly recurring dominant bile duct strictures. Patients were to receive etanercept, 25 mg subcutaneously twice weekly, for 6 months if there were no side effects and for 1 year if there was evidence of efficacy after 6 months. Biochemical tests of liver function did not improve in any patient. Mean serum bilirubin levels increased significantly, from 2.0 to 3.6 mg/dl (P = 0.026). Two of the five patients with pruritus had resolution of pruritus during treatment with etanercept, recurrence when etanercept was stopped, and resolution when it was restarted, although there was little change in liver enzymes or bilirubin levels. There was no decrease in the rate of stricture formation and there were no side effects. Etanercept, at the dosage used, was well tolerated but not effective in the treatment of PSC. It may be helpful in treating pruritus due to cholestasis.

Adult↗
PubMed2004

Novosphingobium aromaticivorans: a potential initiator of primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is characterized by a T-cell-mediated destruction of bile duct epithelial cells that line the small intrahepatic bile ducts. The targets of activated T-lymphocytes are the dihydrolipoamide acetyltransferase components of the 2 oxo acid dehydrogenases, enzyme complexes that are important in oxidative energy metabolism. Pyruvate dehydrogenase is the best known of these. Its dihydrolipoamide acetyltransferase component is referred to as PDC-E2. A major question in understanding the pathogenesis of PBC is why PBC patients lose their tolerance to antigens that are found in virtually every cell in the body. A possible cause is molecular mimicry between microbial agents and self-antigens. Infection with or exposure to a microorganism whose PDC-E2 bears close homology with human PDC-E2 could act as an immunological trigger that initiates the development of PBC. Emerging data suggest that there is a microorganism that may initiate the onset of PBC. Novosphingobium aromaticivorans is a gram negative strictly aerobic bacteria that is found worldwide in soil, water, and coastal plain sediments. Its PDC-E2-like proteins have a higher degree of homology with the immunodominant region of human PDC-E2 than any microorganism thus far studied (100-1,000 times greater than that of Escherichia coli). In addition, N. aromaticivorans can metabolize xenobiotics that are similar to the chemical compounds that react with sera from PBC patients. Some of these xenobiotics are immunologically related to lipoic acid, the cofactor that is at the active center of PDC-E2. Thus, N. aromaticivorans can theoretically break down self-tolerance in two ways: by molecular mimicry due to subclinical infection and by the metabolism of xenobiotics that are present in the environment. In an initial study, investigators found that antibodies against N. aromaticivorans were found in 77 of 77 PBC patients from Milan, Italy, who had antibodies to PDC-E2 and that the titers to N. aromaticivorans proteins were similar to those to human PDC-E2. The report in this issue of The American Journal of Gastroenterology confirms these earlier findings and demonstrates that exposure to N. aromaticivorans occurs in genetically different PBC patients from other regions. Thirteen of 14 Icelandic PBC patients who were AMA positive reacted against at least one of the 2 oxo acid dehydrogenase-E2 complexes. These observations provide additional evidence that exposure to N. aromaticivorans may trigger the development of PBC.

Autoantibodies↗
PubMed2003

Efficacy of colchicine in patients with primary biliary cirrhosis poorly responsive to ursodiol and methotrexate.

OBJECTIVE: Approximately 20-30% of patients with primary biliary cirrhosis (PBC) respond fully to treatment with ursodeoxycholic acid (UDCA). The rest have progressive disease and eventually develop cirrhosis and liver failure. More effective treatment is needed. Methotrexate improved biochemical tests of liver function and liver histology in patients with PBC who had failed to respond to UDCA in one report and induced sustained biochemical and histological remission in another. The role of colchicine in PBC is unclear. We describe three patients with symptomatic PBC who responded very well to the addition of colchicine after they had failed to respond to UDCA alone and in combination with methotrexate. We suggest that colchicine should be tried in PBC patients who clearly fail to respond to UDCA. METHODS: Three patients with symptomatic biopsy-proven, antimitochondrial antibody-positive PBC failed to respond to UDCA and then to the addition of methotrexate. Colchicine was eventually added to the regimen. Symptoms, biochemical tests of liver function, and percutaneous liver biopsies were done at baseline, after treatment with UDCA, UDCA plus methotrexate, and UDCA plus methotrexate plus colchicine. RESULTS: All three patients responded after colchicine was added to UDCA and methotrexate. Symptoms, biochemical tests of liver function, and liver histology improved in all, and blood tests normalized in two. CONCLUSIONS: Colchicine may be effective treatment in some symptomatic patients with PBC who respond incompletely to UDCA alone or in combination with methotrexate. Colchicine may be tried in such patients.

Adult↗
PubMed2002

Analysis of TCR antagonism and molecular mimicry of an HLA-A0201-restricted CTL epitope in primary biliary cirrhosis.

Although the etiology and mechanism of primary biliary cirrhosis (PBC) is unknown, growing evidence suggests a major role for T cells. We have recently identified the first CD8 T-cell epitope, amino acid 159-167 of the E2 component of pyruvate dehydrogenase complexes (PDC-E2). To seek for analogue peptide-antagonizing effector function of CTLs specific for this autoantigen, we examined the effector functions of the PDC-E2-specific CTLs against alanine substituted peptides. Furthermore, because molecular mimicry has been postulated as a possible cause of initiating PBC, we carried out studies aimed at identifying naturally occurring peptides for the 159-167 peptide of PDC-E2 that may serve as agonists. An alanine substitution at position 5 of this epitope significantly reduced peptide-specific effector functions of CTLs. Moreover, this analogue peptide inhibited effector functions of the CTLs to the prototype peptide, including cytotoxicity and IFN-gamma production. We also identified a peptide derived from Pseudomonas aeruginosa, which showed a higher binding affinity to the HLA-A*0201 than the prototype peptide. This homologous peptide was recognized by CTLs specific for the prototype epitope on PDC-E2. In conclusion, a modification of the immunodominant autoepitope can be utilized to manipulate the CD8 T-cell responses against the autoantigen PDC-E2. Our finding also supports the thesis that molecular mimicry may be implicated in the initiation of the autoreactive CD8 T-cell responses and has implications for the use of such peptides for immunotherapy.

Bacterial Proteins↗
PubMed2002

Management of primary sclerosing cholangitis.

Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double blind, placebo-controlled studies are preferable, but reports and expert review articles are also utilized in a thorough review of the literature conducted through the National Library of Medicine's MEDLINE. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject, without regard to specialty training or interests, and are intended to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care that are inflexible and rarely violated. Given the wide range of specifics in any health care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Each has been intensely reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision of analysis. The recommendations of each guideline are therefore considered valid at the time of their production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at an established time and indicated at publication to assure continued validity.

Cholangitis, Sclerosing↗