Search PubMed⌕ Search

Biomedical subjects

J Rakela

Publications and source records attributed to J Rakela.

At least 55 records · Page 3Linked to original sources
PubMed1998

Hepatitis C virus quasispecies in patients infected with HIV-1: correlation with extrahepatic viral replication.

Hepatitis C virus (HCV) sequences recovered from serum, peripheral blood mononuclear cells (PBMCs), and various tissues from human immunodeficiency virus type 1 (HIV-1) positive patients were compared by single strand conformational polymorphism (SSCP) and sequencing. In five patients, paired serum and PBMCs samples were analyzed while in two other patients multiple autopsy tissues were studied. Sequences amplified from the NS5 and E2 regions were consistently identical in the same patient; however, three PBMCs samples and three different tissue samples (pancreas and adrenal gland in one patient and lymph node in the other patient) contained 5' untranslated region (5'UTR) sequences that were different from circulating sequences. The presence of 5' UTR sequences differing from circulating sequences correlated with the presence of HCV RNA negative strand, as the latter was detected by a Tth-based strand-specific assay in all but one of these samples. These two independent lines of evidence: viral sequence differences and the presence of RNA negative strand in the same tissues strongly argue for the genuine presence of extrahepatic HCV replication, at least in the setting of HIV-1 infection.

Base Sequence↗
PubMed1998

Association between hepatitis B virus core promoter rearrangements and hepatocellular carcinoma.

Hepatitis B virus (HBV) is the major etiological agent of hepatocellular carcinoma (HCC). Whether any particular viral variants are associated with HCC is unknown. We studied 53 Gambian patients with HCC and 33 HBsAg positive controls. A functional part of HBV core promoter and whole precore region were sequenced directly and/or after cloning. HBV DNA was amplified from sera from 27 HCC patients and in all controls. Fourteen (52%) patients and 12 (36%) controls (NS) were found to harbor an HBV strain with G to A transition mutation at position 1896 leading to HBeAg negative phenotype. Nine (33%) HCC patients and 2 (6%) controls (p < 0.01) harbored a mixture of wild type and HBV strains with deletions/insertions; strong consensus sequences for topoisomerase I breakage were located in the vicinity of these changes. In Africa, HCC is associated with HBV strains that have deletions/insertions in the HBV core promoter region.

Base Sequence↗
PubMed1998

Effects of immunotherapy on experimental immunodeficiency-related lymphoproliferative disease.

BACKGROUND: Human lymphokine-activated cells (LAK cells) and interferon alpha (IFN-alpha) have been used clinically in the therapy of posttransplant lymphoproliferative disease (PTLD). However, the efficacy of such therapy has not been extensively tested under controlled experimental conditions. METHODS: A B-cell line, derived from PTLD tissue and clonally related to the parent lesion, was tested for its response to IFN-alpha in vitro. The effects of LAK cells and IFN-alpha therapy were examined in a severe combined immunodeficiency disease (SCID) mouse model in vivo. RESULTS: The PTLD cell line studied showed a 30% decrease in the rate of growth upon incubation with 500 U/ml of IFN-alpha. This in vitro response was also reproduced in vivo, in tumor therapy studies conducted in SCID mice. The magnitude of this inhibitory effect in vivo was a function of tumor burden and dose of IFN-alpha. In parallel experiments, LAK cells reduced the tumorigenicity of a lymphoblastoid cell line derived from the peripheral blood of a patient with PTLD, and prolonged the survival of SCID-beige mice with established lymphoproliferative disease. In contrast with two prior studies, in which the use of autologous cytotoxic T cells was found to be necessary, we found the administration of third-party non-HLA-matched LAK cells also to be effective in reducing tumor burden. CONCLUSIONS: These observations demonstrate the efficacy of immunotherapy for lymphoproliferative disease under controlled experimental conditions, and validate currently ongoing efforts exploring the utility of such therapy in the clinical setting.

Animals↗
PubMed1998

Search for hepatitis C virus extrahepatic replication sites in patients with acquired immunodeficiency syndrome: specific detection of negative-strand viral RNA in various tissues.

The existence of extrahepatic reservoirs of hepatitis C virus (HCV) replication remains highly controversial. We searched for the presence of HCV-RNA negative strand in various tissues from eight HCV-infected patients who died of acquired immunodeficiency syndrome (AIDS)-related complications. Negative-strand RNA was detected by a Tth-based reverse-transcriptase polymerase chain reaction (RT-PCR), which was optimized for sensitivity and strand specificity on synthetic RNA templates. This assay was capable of detecting about 10(2) genomic Eq molecules of the correct strand while unspecifically detecting >/=10(8) genomic Eq molecules of the incorrect strand. Negative-strand viral RNA was detected in all but one liver, in lymph nodes (5 cases), in pancreas (5 cases), in adrenal gland (2 cases), in thyroid (2 cases), in bone marrow (1 case), and in spleen (1 case). These data suggest a possible presence of HCV replication sites outside the liver, at least in AIDS patients. Whether these findings relate to various extrahepatic manifestations of HCV infection remains to be determined.

Acquired Immunodeficiency Syndrome↗
PubMed1998

The influence of hepatitis C virus genotypes on the outcome of liver transplantation.

BACKGROUND: The aim of this study was to report the influence of hepatitis C virus (HCV) genotypes and HLA matches on the outcome of liver transplantation, hepatitis recurrence, and progression to cirrhosis after transplantation. METHODS: HCV genotypes were determined from pretransplantation sera and/or liver explant tissues from 202 patients with HCV-related end-stage liver disease. One hundred fifty patients with known infecting genotype for whom posttransplantation biopsy specimens were available or who had normal results of liver injury tests constituted the group analyzed. Patients were followed up for up to 4.5 years. Hepatitis activity index scores at the time of disease recurrence were used to assess disease activity. Cirrhosis was diagnosed by using histological evidence. The number of HLA matches with respect to A, B, DR, and DQ loci was determined. RESULTS: The rates of hepatitis recurrence were 25% and 75% at 1 year and 4 years, respectively; Kaplan-Meier survival analysis did not reveal significant differences between the infecting genotypes with respect to overall rates of survival or recurrence of hepatitis. At hepatitis recurrence, hepatitis activity index scores did not differ between the genotype groups. The distribution of infecting genotypes among the 7 patients who developed cirrhosis is reflective of pretransplantation distribution. Neither HLA site-specific nor total matches affected the rates of survival or disease recurrence. CONCLUSIONS: The infecting HCV genotype had no influence on the incidence or severity of recurrent hepatitis, rate of survival, or development of cirrhosis. HLA matching does not influence transplantation outcome for HCV-related disease.

Adult↗
PubMed1998

Incidence and severity of acute allograft rejection in liver transplant recipients treated with alfa interferon.

Interferon alfa-2b (IFN-alpha) therapy has been shown to be effective in the treatment of viral hepatitis B (HBV) or viral hepatitis C (HCV) in patients who did not undergo transplantation. However, in allograft recipients, treatment with IFN-alpha often leads to allograft rejection. The aim of the present study was to determine if IFN-alpha therapy increases the incidence or severity of acute rejection in human liver allograft recipients. One hundred five orthotopic liver transplant (OLT) recipients with HBV (n = 32), HCV (n = 58), or Non A Non B Non C (n = 15) viral infections were treated with a 6-month course of IFN-alpha, 5 million U subcutaneously three times a week, which began 2 to 97 months after transplantation. The mean hepatitis activity index (HAI) at the beginning of the therapy was 10.1 +/- 3.0. The baseline immunosuppression was achieved by tacrolimus in 77 patients and by cyclosporine A (CyA) in 28 patients. Contemporaneous controls consisted of 132 OLT patients (100 who received tacrolimus and 32 who received CyA) who did not receive IFN-alpha. A retrospective analysis was performed on this group of patients. The incidence of rejection and the baseline immunosuppression were compared. All biopsies were reviewed without knowledge of clinical data and scored for HAI and for rejection activity index (RAI). The biochemical response to IFN-alpha was also examined. The mean baseline maintenance dose of prednisone was greater by 2 mg daily in patients who received IFN-alpha with tacrolimus compared with control patients who did not receive IFN-alpha with tacrolimus (IFN-alpha 5. 3 +/- 5.2 mg daily v controls 3.3 +/- 4.9 mg daily; P </= .05). Similarly, the mean maintenance dose of prednisone was greater by 2.5 mg daily in patients who received IFN-alpha compared with controls who received CyA-based immunosuppression (IFN-alpha 9.8 +/- 3.1 mg daily v controls 7.3 +/- 3.3 mg daily; P = .01). Acute rejection episodes were detected in 10.5% (n = 11) of IFN-alpha-treated patients compared with 8.8% of controls for the similar time period from OLT and period of exposure to risk of rejection. Mean RAI was 2.0 +/- 2.4 for the IFN-alpha-treated group and 2.1 +/- 1.7 for controls. Rejection episodes with IFN-alpha treatment were mild and responded to steroid therapy. In OLT recipients, the risk of acute rejection was not increased by the introduction of IFN-alpha. However, in this study, patients were exposed to greater levels of immunosuppression.

Biopsy↗
PubMed1998

Undetected hepatocellular carcinoma: clinical features and outcome after liver transplantation.

The aim of the study was to define the clinical characteristics and outcome of patients found to have an undetected hepatocellular carcinoma (HCC) at liver transplantation. Patients who underwent liver transplantation and were found to have a hepatoma with a prior workup showing normal alpha-fetoprotein levels and no corresponding lesion on radiological evaluation were defined as having an undetected HCC. Detailed information was collected, and the last abdominal computed tomographic (CT) scan before transplantation was performed was retrospectively reviewed. Thirty-nine patients had a tumor that met the criteria for an undetected hepatoma. The most common causes for pretransplantation liver disease were hepatitis C virus (HCV) (49%) and alcohol use (28%). Tumor size was 2 cm or less in 85% of the patients, vascular invasion was detected in 31% of the patients, and tumor, node, metastasis (TNM) classification was stage I or II in 77% of the patients. Review of the last CT scan before transplantation showed that the lesion was evident in retrospect in only 15% of the patients. Thirty-two patients (82%) remained alive at the time of the study with a mean follow-up of 30 months. Metastatic HCC was detected in 1 patient 7 months after transplantation. There were no other tumor recurrences. Survival analysis showed no significant differences when tumor size, stage, presence of vascular invasion, or causes of pretransplantation liver disease were compared. Undetected HCCs represent a significant percentage of total hepatomas in patients undergoing liver transplantation. Most patients have small, early-stage tumors, but tumors greater than 2 cm or of advanced stage are also frequently found in this population. Overall and tumor-free survival appear to be favorable.

Adult↗
PubMed1998

Clinical outcome of patients infected with hepatitis C virus infection on survival after primary liver transplantation under tacrolimus.

The outcome of hepatitis C virus (HCV) infection on patient and graft survival after orthotopic liver transplantation (OLT) has been controversial. An earlier experience with a higher dose of tacrolimus (>/=0.1 mg/kg/d intravenously and >/=0.2 mg/kg/d orally) was associated with a worse clinical outcome in patients infected with HCV. The clinical outcome of 183 liver transplant recipients with end-stage liver disease (ESLD) secondary to HCV infection (HCV group) was compared with a contemporary cohort of 556 patients with HCV infection who underwent transplantation for nonviral, nonmalignant ESLD (control group). All patients were prospectively screened for anti-HCV antibodies and HCV RNA by reverse-transcriptase polymerase chain reaction. All OLT patients were receiving low-dose tacrolimus immunosuppression. Cumulative patient survival rates for the HCV group were 80% after 1 year and 75% after 3 years compared with rates of 84% and 78%, respectively, in the control group (P = .452). Primary graft survival rates at the same time intervals for the HCV group and the control group were 72% and 77.5% at 1 year and 67% and 72% at 3 years, respectively (P = .144). The incidence of re-transplantation (re-OLT) in the HCV group and the control group was 12.6% and 10.4%, respectively (P = .42). Chronic HCV infection as an indication for OLT with a lower dose of tacrolimus immunosuppression (</=0.05 mg/kg/d intravenously and </=0.1 mg/kg/d orally) is associated with a similar patient and graft survival as those without HCV infection.

Adult↗
PubMed1998

Lack of evidence for GB virus C/hepatitis G virus replication in peripheral blood mononuclear cells.

BACKGROUND/AIMS: The recently identified hepatitis G virus (HGV) has been found to be common in patients with various forms of chronic liver disease, particularly chronic hepatitis C. However, replication sites of this new viral agent have not been studied. METHODS: We searched for the presence of HGV RNA in peripheral blood mononuclear cells and serum samples from nine chronic hepatitis C patients coinfected with hepatitis G virus. The presence of negative viral RNA strands was determined by strand-specific Tth-based assay which was optimized on synthetic template. RESULTS: All peripheral blood mononuclear cell samples were negative for the presence of the HGV RNA minus strand and only five were positive for the presence of the positive strand, albeit at a low level of 10-10(2) genomic equivalents/10(6) cells. CONCLUSIONS: These findings imply that hepatitis G virus does not replicate in peripheral blood mononuclear cells, at least in the population of HCV/HGV coinfected patients.

Flaviviridae↗
PubMed1998

Clinical intestinal transplantation: new perspectives and immunologic considerations.

BACKGROUND: Although tacrolimus-based immunosuppression has made intestinal transplantation feasible, the risk of the requisite chronic high-dose treatment has inhibited the widespread use of these procedures. We have examined our 1990-1997 experience to determine whether immunomodulatory strategies to improve outlook could be added to drug treatment. STUDY DESIGN: Ninety-eight consecutive patients (59 children, 39 adults) with a panoply of indications received 104 allografts under tacrolimus-based immunosuppression: intestine only (n = 37); liver and intestine (n = 50); or multivisceral (n = 17). Of the last 42 patients, 20 received unmodified adjunct donor bone marrow cells; the other 22 were contemporaneous control patients. RESULTS: With a mean followup of 32 +/- 26 months (range, 1-86 months), 12 recipients (3 intestine only, 9 composite grafts) are alive with good nutrition beyond the 5-year milestone. Forty-seven (48%) of the total group survive bearing grafts that provide full (91%) or partial (9%) nutrition. Actuarial patient survival at 1 and 5 years (72% and 48%, respectively) was similar with isolated intestinal and composite graft recipients, but the loss rate of grafts from rejection was highest with intestine alone. The best results were in patients between 2 and 18 years of age (68% at 5 years). Adjunct bone marrow did not significantly affect the incidence of graft rejection, B-cell lymphoma, or the rate or severity of graft-versus-host disease. CONCLUSIONS: These results demonstrate that longterm rehabilitation similar to that with the other kinds of organ allografts is achievable with all three kinds of intestinal transplant procedures, that the morbidity and mortality is still too high for their widespread application, and that the liver is significantly but marginally protective of concomitantly engrafted intestine. Although none of the endpoints were markedly altered by donor leukocyte augmentation (and chimerism) with bone marrow, establishment of the safety of this adjunct procedure opens the way to further immune modulation strategies that can be added to the augmentation protocol.

Actuarial Analysis↗
PubMed1998

The presence of active hepatitis C virus replication in lymphoid tissue in patients coinfected with human immunodeficiency virus type 1.

The existence of extrahepatic replication sites of hepatitis C virus (HCV) remains controversial. Highly strand-specific Tth-based reverse transcriptase-polymerase chain reaction was used to search for the presence of viral RNA negative strand in lymph nodes from 16 patients with AIDS and in peripheral blood mononuclear cells (PBMC) from 14 other human immunodeficiency virus (HIV)-positive patients. Negative-strand HCV RNA was detected in lymph node samples from 10 patients (63%) and in PBMC from 5 (36%). This suggests that, at least under circumstances of impaired immunity associated with HIV infection, HCV is lymphotropic in vivo. However, the clinical implications of these findings need to be further investigated.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Treatment of chronic hepatitis C with interferon with or without ursodeoxycholic acid: a randomized prospective trial.

The only effective and approved therapy for chronic hepatitis C is interferon-alpha. Because sustained response rates with interferon alone are disappointingly low, multidrug treatment regimens are currently being investigated. Ursodeoxycholic acid has been used in other chronic liver diseases and can limit hepatocyte injury. To evaluate the potential benefit of ursodeoxycholic acid in combination with interferon-alpha for the treatment of chronic hepatitis C, we conducted a prospective, double-blinded, randomized, placebo-controlled trial comparing the combination therapy of interferon-alpha 2b and ursodeoxycholic acid with interferon alone. Thirty-one patients with chronic hepatitis C were randomized to receive 3 million units of interferon-alpha 2b subcutaneously three times per week and either 13 to 15 mg/kg/day ursodeoxycholic acid or placebo orally for 6 months. The 6-month treatment period was followed by 6 months of observation. Biochemical normalization at the end of treatment occurred in 5 of 14 (36%) patients receiving monotherapy versus 8 of 15 (53%) patients (p = 0.34) receiving combination therapy. No patient treated with interferon alone had a sustained biochemical response 6 months after therapy; however, 3 of 12 patients (25%) treated with combination interferon and ursodeoxycholic acid maintained biochemical normalization at 6 months after therapy (p = 0.08). No difference in liver histology or clearance of hepatitis C viral RNA was noted 6 months after treatment. We conclude that combination therapy with ursodeoxycholic acid and interferon-alpha 2b was no more effective than interferon monotherapy in inducing a biochemical response in previously untreated patients with chronic hepatitis C. Ursodeoxycholic acid, however, may be useful in prolonging the biochemical response to interferon therapy.

Adult↗
PubMed1998

Detection of hepatitis G virus replication sites by using highly strand-specific Tth-based reverse transcriptase PCR.

The replication sites of the recently discovered hepatitis G virus (HGV) remain unknown. Using highly strand-specific Tth-based reverse transcriptase PCR, we searched for the presence of viral RNA negative strand in multiple autopsy tissues from four patients with AIDS and in peripheral blood mononuclear cells from six other human immunodeficiency virus-positive patients. Negative-strand HGV RNA was detected in three of four bone marrow samples, in two of two spleen samples, and in one of four liver tissue samples. However, the specific cellular site of replication within the positive tissues was not determined. This study does not support HGV as a primary hepatotropic virus.

AIDS-Related Opportunistic Infections↗