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Biomedical subjects

R A de Man

Publications and source records attributed to R A de Man.

At least 91 records · Page 5Linked to original sources
PubMed1998

Relation between laboratory test results and histological hepatitis activity in individuals positive for hepatitis B surface antigen and antibodies to hepatitis B e antigen.

BACKGROUND: Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B e antigen (anti-HBe) commonly coexist, and laboratory tests are often requested to assess histological hepatitis activity. An optimum panel of tests has not been found and the usefulness of hepatitis B virus (HBV) DNA assays in this context has not been established. We assessed various blood tests to find which best predicted hepatitis activity. METHODS: Routine plasma biochemical liver tests and serum HBV DNA (hybridisation and PCR assays) were assessed prospectively in 123 patients positive for HBsAg and anti-HBe. We scored histological hepatitis activity (hepatitis activity index) and determined whether chronic active hepatitis (chronic hepatitis with portal and periportal lesions) was present. We analysed the relation between laboratory data and the hepatitis activity index or risk of chronic active hepatitis by multiple regression and multiple logistic regression, respectively. FINDINGS: The analyses provided models for predicting either the hepatitis activity index or the risk of chronic active hepatitis. Aspartate aminotransferase was the most important test in the two models. The contribution of HBV DNA and other assays, especially alanine-aminotransferase activity, were of no practical importance. INTERPRETATION: Because screening by aspartate-aminotransferase activity could not be improved by the addition of other assays or HBV DNA, patients positive for HBsAg and anti-HBe could be screened for chronic active hepatitis with a single assay and counselling of patients can be improved if proper reference values are used.

Adult↗
PubMed1998

The sequential occurrence of viral mutations in a liver transplant recipient re-infected with hepatitis B: hepatitis B immune globulin escape, famciclovir non-response, followed by lamivudine resistance resulting in graft loss.

BACKGROUND/AIMS: The purpose of this study was to characterize the clinical, histological and virological events in an orthotopic liver transplant (OLT) recipient with recurrent hepatitis B infection who was initially managed with hepatitis B immune globulin (HBIg) and when viral recurrence occurred, with nucleoside analogue salvage therapy. The aims were to document the mutations occurring in the hepatitis B virus (HBV) polymerase gene as a consequence of HBIg escape, famciclovir non-response and subsequent lamivudine resistance. METHODS: Throughout the follow-up of 796 days, the patient was seen at least at 4-week intervals. Clinical, biochemical and virological data were registered according to protocol. HBV DNA was quantified throughout the treatment period. The viral polymerase gene was sequenced from serum samples collected at representative time intervals. Consecutive liver biopsies were scored according to the modified Knodell classification. RESULTS: Clinically, the patient was in excellent condition until the development of acute hepatitis during the lamivudine therapy period, 765 days post-OLT. Until this terminal event, serum transaminase activity was only 1-2 times the upper limit of normal with serum bilirubin and prothrombin time within the normal range. Subsequent liver biopsies showed chronic active hepatitis with no signs of fibrosis. The post-mortem biopsy showed severe acute hepatitis B with massive necrosis. The HBV polymerase gene was sequenced during HBIg, famciclovir and lamivudine treatment. One mutation I533L was detected during HBIg treatment. No amino acid changes were selected during famciclovir treatment. Three amino acid changes were selected while the patient was on lamivudine treatment, which include L533I, S559T and M550I. CONCLUSIONS: We have documented HBV recurrence in a liver transplant recipient with the emergence of a multidrug resistant HBV which caused graft loss. The primary resistance to famciclovir in spite of therapeutic penciclovir levels may be as a result of a combination of the mutations found in the polymerase region. After 300 days of lamivudine treatment, a drug-resistant population emerged which was associated with a greater than three log increase in HBV DNA and contributed to loss of graft function. This is the first report of such an adverse clinical outcome due to the emergence of a mutant virus as a consequence of immunoprophylactic and antiviral therapy in a liver transplant recipient.

2-Aminopurine↗
PubMed1998

Jaundice associated with acenocoumarol exposure.

A 69-year-old man developed cholestatic liver enzyme disturbances three and a half weeks after starting treatment with acenocoumarol because of a deep venous thrombosis in his leg. Serological testing showed no signs of recent viral infections. A presumptive diagnosis of hepatotoxicity caused by the use of acenocoumarol was made and the anticoagulant was replaced by low molecular weight heparin. Three weeks after withdrawal of the acenocoumarol, the enzymes had improved. The patient made a full recovery within two months. This case suggests a causal relationship between acenocoumarol exposure and liver damage.

Acenocoumarol↗
PubMed1998

Recovery from life-threatening, corticosteroid-unresponsive, chemotherapy-related reactivation of hepatitis B associated with lamivudine therapy.

Although exacerbations of previously quiescent HBV infection, associated with chemotherapy, have been attributed to enhanced immunological responses to hepatocytes harboring reactivated HBV, the recommended treatment, prednisolone, is often unsuccessful. A young HBsAg-positive, anti-HBe-positive carrier, who received chemotherapy for choriocarcinoma, developed icteric hepatitis. The serum HBV DNA level was 34,000 x 10(6) genomic equivalents per milliliter serum. Treatment with prednisolone alone did not prevent progression to overt hepatic failure. By three days after initiating lamivudine therapy, however, there was reversal of stage III hepatic encephalopathy. With further lamivudine treatment, substantial further improvement in hepatocellular function occurred and HBV-DNA levels became undetectable. When an immunocompromised patient develops an exacerbation of hepatitis B associated with high HBV DNA levels, treatment with prednisolone seems inappropriate, as hepatocytotoxic HBV replication may be stimulated further. In this situation inhibition of HBV replication, eg, by administering lamivudine, may be life-saving.

Adult↗
PubMed1998

Review article: glycyrrhizin as a potential treatment for chronic hepatitis C.

Chronic hepatitis C is a slowly progressive liver disease that may evolve into cirrhosis with its potential complications of liver failure or hepatocellular carcinoma. Current therapy with alpha-interferon is directed at viral clearance, but sustained response is only achieved in 20-40% of patients without cirrhosis, and less than 20% in patients with cirrhosis who have the greatest need for therapy. Treatment for those who do not respond to anti-viral therapy is highly desirable. In Japan glycyrrhizin has been used for more than 20 years as treatment for chronic hepatitis. In randomized controlled trials, glycyrrhizin induced a significant reduction of serum aminotransferases and an improvement in liver histology compared to placebo. Recently, these short-term effects have been amplified by a well-conducted retrospective study suggesting that long-term usage of glycyrrhizin prevents development of hepatocellular carcinoma in chronic hepatitis C. The mechanism by which glycyrrhizin improves liver biochemistry and histology are undefined. Metabolism, pharmacokinetics, side-effects, and anti-viral and hepatoprotective effects of glycyrrhizin are discussed.

Antiviral Agents↗
PubMed1998

Quantitative hepatitis B virus DNA assessment by the limiting-dilution polymerase chain reaction in chronic hepatitis B patients: evidence of continuing viral suppression with longer duration and higher dose of lamivudine therapy.

Lamivudine, a novel cytosine analogue, exhibits potent antiviral activity against hepatitis B virus (HBV) in vitro and in vivo. The standard HBV DNA hybridization assay used in phase II clinical studies has a low sensitivity, the detection limit of HBV DNA levels being approximately 10(7) genome equivalents per ml (geq ml-1). In this work we used a semiquantitative polymerase chain reaction (PCR) assay (detection limit approximately 10(3) geq ml-1) to determine HBV DNA levels during a 24-week study of lamivudine in 51 stable chronic hepatitis B patients who were positive for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). Patients were randomly allocated to receive oral doses of 25, 100 or 300 mg lamivudine once daily. At week 24 the median serum concentration of HBV DNA had fallen from 10(8) to 10(4) geq ml-1, a 4-log median reduction. A trend towards more profound suppression of viral replication with an increased dose of lamivudine was observed. After 12 weeks of therapy, 12% of patients had an HBV DNA level that was undetectable in the PCR assay; this increased to 26% after 24 weeks, while in an additional 20% of patients, HBV DNA decreased to the level of detection of the PCR assay. We conclude that a 24-week course of lamivudine decreases serum HBV DNA to the level of PCR detection in 46% of patients. Such additional viral suppressive activity with higher doses and more protracted lamivudine may be of clinical utility prior to liver transplantation. Further studies are needed to define the degree of virus suppression required in clinical practice, and methods are required to increase the efficacy of virus suppression.

Administration, Oral↗
PubMed1998

Laparoscopy as a day-case procedure in patients with liver disease.

BACKGROUND AND STUDY AIMS: The present study was aimed at exploring the feasibility of diagnostic laparoscopy on a day-case basis in patients with liver disease. PATIENTS AND METHODS: Retrospective analysis was carried out of 85 consecutive day-case laparoscopies performed between January 1990 and January 1994. During this period, patients were observed in day-care facilities for a period of three hours. Patients' perception and acceptance of the procedure were assessed using a postal questionnaire. RESULTS: Laparoscopy was successful in 84 of the 85 patients; adequate liver biopsies were obtained in 83 patients. In three cases, the procedure was converted to a one-night hospital admission because of pain (1), persistent sedation (1) and collapse (1). Abdominal skin hematomas were reported by eight patients, and fever by two. Serious complications were not observed. The majority of patients experienced no complaints, or minor ones, after the procedure, and they expressed a preference for an outpatient procedure in case a renewed investigation might be indicated. Compared with in-hospital procedures, day-case laparoscopy was associated with a 33% reduction in cost. CONCLUSIONS: Diagnostic laparoscopy, with the hospital stay reduced to three hours, can be performed safely as a day-case procedure in selected patients.

Adult↗
PubMed1998

Identification of more than one mutation in the hepatitis B virus polymerase gene arising during prolonged lamivudine treatment.

Lamivudine has been shown to be a potent and nontoxic inhibitor of hepatitis B virus (HBV) replication in chronically infected patients. During prolonged treatment, drug resistance may develop, related to a mutation of Met to Val or Ile in the YM552DD motif of the HBV DNA polymerase gene. Analysis of the HBV DNA polymerase gene from 8 chronic hepatitis B patients with suspected resistance to lamivudine showed that in addition to a mutation in the YM552DD motif, a second mutation located in the B domain of this gene, a Leu528-to-Met528 change, was consistently and exclusively found in 4 patients showing the YV552DD motif. This suggests a functional or structural relationship between these domains. Since the presence of both the YI552DD and YV552DD motif sometimes preceded the exclusive presence of the YV552DD motif, we conclude that the YI552DD motif could occur as a temporal intermediate. After cessation of therapy, the wild type sequences reemerged.

Amino Acid Substitution↗
PubMed1998

Transmission of hepatitis B virus among heart transplant recipients during endomyocardial biopsy procedures.

BACKGROUND: The unexpected conversion to HBsAg seropositivity of three cardiac allograft recipients prompted us to conduct a multidisciplinary study to identify the source, transmission mode, and extent of the hepatitis B virus (HBV) infection among the 256 cardiac allograft recipients of our hospital. METHODS: All recipients were retrospectively screened for serum markers of HBV infection. A selected genomic region defining subtypes of the viruses involved was amplified and sequenced. An epidemiologic case-control study for possible risk factors was conducted to identify the mode of transmission. RESULTS: Eighteen additional HBV-infected patients were identified, none of whom had shown symptoms of HBV infection. The involvement of one virus (subtype ayw 3) was shown in 20 of the 21 HBV-infected patients. This virus is found in less than 10% of HBV-infected individuals in The Netherlands. The demonstration of a common source of infection, combined with results of the epidemiologic study, identified posttransplantation endomyocardial biopsy procedures as the most likely mode of transmission. However, we also found evidence of secondary virus transmission by cardiac catheterization procedures to nonallograft recipients. CONCLUSIONS: The immunosuppressive therapy practiced in these patients to prevent allograft rejection may have not only facilitated virus transmission by causing high levels of viremia but also left the spreading of HBV undetected by causing a subclinical course of the infection. These findings stress the necessity of strict hygienic precautions during intravascular diagnostic procedures and indicate that vaccination against and routine monitoring for certain bloodborne infections in cardiac allograft recipients should be considered.

Adult↗
PubMed1997

[Severe hepatitis attributed to paroxetine (Seroxat)].

A 52-year-old man suffering from chronic hepatitis B related liver cirrhosis was treated for depression with paroxetine (Serotax) 5 mg and subsequently 15 mg once daily. A severe hepatitis with liver failure (jaundice, hypoalbuminaemia, edemas, and ascites) developed. After the drug was withdrawn the patient recovered completely. The adverse reaction may be explained by a change in the pharmacokinetics of the drug caused by the liver cirrhosis. Caution is required in prescribing long-term paroxetine therapy for patients with documented liver cirrhosis. The liver function should be monitored and administration of the drug should be discontinued when functional disturbances are noticed.

Antidepressive Agents, Second-Generation↗
PubMed1997

Effect of lamivudine on morphology and function of mitochondria in patients with chronic hepatitis B.

Nucleoside analogues can induce mitochondrial dysfunction leading to severe clinical syndromes. Lamivudine, a new nucleoside analogue, is an active inhibitor of hepatitis B viral replication without apparent clinical toxicity. To assess subclinical mitochondrial toxicity, we studied the morphology and function of the mitochondrial system in 15 patients treated with lamivudine. Morphology was investigated by routine histological evaluation and electron-microscopic studies of mitochondria in liver biopsy specimens. Mitochondrial function was assessed by 2-keto[1-14C] isocaproic acid decarboxylation (KICA breath test) and by measuring the activity in liver biopsy specimens of the mitochondrial enzymes encoded by nuclear and mitochondrial DNA (mt-DNA) (complex I and IV) as well as a mitochondrial and a cytosolic enzyme both encoded by nuclear DNA only (complex II and lactic dehydrogenase [LDH]). All 15 patients underwent a liver biopsy before treatment and a KICA breath test before and during treatment; 13 agreed to undergo a repeat liver biopsy during lamivudine treatment. Liver tissue with no or minimal fibrotic changes from 7 patients treated for 6 months with lamivudine was suitable for assessment of the mitochondrial enzyme activity. We observed no signs of toxicity by routine histological or electron-microscopic evaluation. KICA breath tests revealed no differences in either peak exhalation or the area under the curve from 0 to 60 minutes between healthy controls (3.0% and 19.3%), untreated patients with chronic hepatitis B (3.4% and 19.3%), and patients treated with lamivudine (3.1% and 20.6%). The activities of the mt-DNA-encoded enzymes remained normal after lamivudine therapy. Unexpectedly a significant decrease in the activity of nuclear-DNA-encoded enzymes in patients with chronic hepatitis B in comparison with normal controls was found. The mean activity of complex II dropped from 45.3 to 20.0 micromol x min(-1), that of lactic dehydrogenase from 106 to 44 micromol x min(-1) (Wilcoxon rank sum; P < .05). In conclusion, no subclinical signs of mitochondrial toxicity resulting from lamivudine therapy for 6 months were observed.

Adult↗
PubMed1997

Dynamics of hepatitis B virus infection in vivo.

BACKGROUND/AIMS: Information on the kinetics of the pretreatment steady-state of HBV can be obtained from serial measurements of serum hepatitis B virus (HBV) DNA concentrations following lamivudine ((-)enantiomer of 3'-thiacytidine)-induced perturbation of the balance between virus production and clearance. METHODS: In a placebo-controlled, dose-ranging trial, lamivudine (5 to 600 mg per day) was administered for 4 weeks to 17 patients with chronic replicative hepatitis B. Serum HBV DNA levels were quantified by standard liquid hybridization techniques. The time-dependent concentrations of serum HBV DNA following lamivudine administration were subjected to iterative least-squares regression in order to obtain kinetic data on HBV life-time and viremia. RESULTS: In patients with stable HBe-antigen positive chronic hepatitis B responding to lamivudine, HBV DNA declined exponentially with a half-life of approximately 2-3 days. The minimum virus production and clearance per day in patients with chronic hepatitis B was calculated to be 6.09 x 10(11) virions/day (range 0.26 to 21.06 x 10(11) virions/day). Compared to the HBeAg levels before treatment, relative amounts of HBeAg were 1.00 +/- 0.16 and 0.96 +/- 0.20 at days 22 and 28 of treatment, respectively. Four weeks after termination of lamivudine treatment, the relative amount of HBeAg was 1.04 +/- 0.19. CONCLUSIONS: The half-life of HBV in chronically infected patients is longer and in vivo turnover rates are higher compared to recently published data on the human immunodeficiency virus type 1 and the hepatitis C virus. The constant expression of HBeAg observed in the present study during a 28-day lamivudine treatment period does not allow calculation of a definite decay rate for virus-producing cells. Our data, however, imply that the minimum half-life of infected cells may exceed 100 days.

Adolescent↗
PubMed1997

Lamivudine resistance in immunocompetent chronic hepatitis B. Incidence and patterns.

BACKGROUND: Lamivudine is a non-toxic, potent inhibitor of hepatitis B virus replication. Recently, hepatitis B virus resistance to lamivudine has been described in patients using immunosuppressive drugs after liver transplantation. METHODS: From our cohort of 81 consecutive patients treated with lamivudine, we selected all immunocompetent patients who received lamivudine monotherapy for a period over 26 weeks (n=14). RESULTS: Lamivudine resistance with the characteristic mutation in the YMDD motif was observed in four patients (actuarial cumulative incidence: 39%). Two patterns of viral resistance were observed: incomplete response (n=2) and viral breakthrough (n=2). CONCLUSIONS: The observed high frequency of lamivudine resistance may have implications for the concept of long-term virus-suppressive therapy of chronic hepatitis B by lamivudine monotherapy.

Adolescent↗
PubMed1997

Histological improvement in patients with chronic hepatitis B virus infection treated with lamivudine.

Lamivudine is an oral nucleoside analogue with strong antiviral activity against hepatitis B virus (HBV). In previous clinical studies, a course of lamivudine for 4-12 weeks induced a profound decrease in HBV viraemia with excellent tolerance, but data on histology have not yet been reported. We studied the liver histology of 13 patients with stable chronic HBV infection treated with 25 mg, 100 mg or 300 mg lamivudine daily for 6 months. All patients became HBV-DNA negative during treatment. The paired biopsies taken at entry and during treatment were scored by two independent observers, using the components of the histology activity index (HAI) and fibrosis (modified Knodell). The items scored were piecemeal necrosis, focal necrosis, confluent necrosis, portal inflammation and fibrosis. Before treatment, the biopsies yielded a mean HAI of 4.4 (+/- 0.8), which decreased to HAI 2.8 (+/- 0.5) during treatment. An analysis of the individual components of the classification system showed a significant decrease in piecemeal necrosis from a pre-treatment 1.4 (+/- 0.3) to 0.8 (+/- 0.1) during treatment (p = 0.02). Although a trend was found for the other components, it was not statistically significant, probably due to the number of pairs examined. In conclusion these results suggest that prolonged suppression of viral replication by lamivudine can improve liver histology. In contrast to previously published reports on alpha-interferon therapy, this study indicates that the improvement in liver histology with lamivudine is independent of HBe-seroconversion.

Adolescent↗