Search results for "Virology"

16thIHIW: Anti-HLA alloantibodies of the of IgA isotype in re-transplant candidates

2012

Summary In this multicentre study, sera from 803 retransplant candidates, including 775 kidney transplant recipients, were analysed with regard to the presence and specificity of anti-HLA alloantibodies of the IgA isotype using a modified microsphere-based platform. Of the kidney recipients, nearly one-third (n = 237, 31%) had IgA alloantibodies. Mostly, these antibodies were found in sera that also harboured IgG alloantibodies that could be found in a total of 572 (74%) of patients. Interestingly, IgA anti-HLA antibodies were preferentially targeting HLA class I antigens in contrast to those of the IgG isotype, which targeted mostly both HLA class I and II antigens. Donor specificity of th…

Development of cytochrome P450 2D6-specific LKM-autoantibodies following liver transplantation for Wilson's disease -- possible association with a st…

1999

Abstract Background/Aims: Antibodies to cytochrome P450 2D6, also knownas LKM1-autoantibodies, are characteristic for a subgroup of patients with autoimmune hepatitis, but can also occasionally be found in hepatitis C. We observed the occurrence of LKM1-autoantibodies 4 months after liver transplantation for Wilson's disease, in close association with a steroid-resistant rejection episode, in the absence of evidence for autoimmune hepatitis or hepatitis C. Methods: Sera from several time points prior to and following transplantation were tested for LKM-reactivity by immunofluorescence, ELISA and Western blotting. Antigen specificity was confirmed by Western blotting analysis on different cy…

Hepatitis B surface antigen presentation and HLA-DRB1*– lessons from twins and peptide binding studies

2005

Summary The aim of this study was to investigate the underlying mechanisms of the genetic association between certain HLA-DRB1* alleles and the immune response to HBsAg vaccination. Therefore, HBsAg peptide binding to HLA-DR molecules was measured in vitro by peptide binding ELISAs. Additionally, HBsAg-specific T cell reaction and cytokine profile of immune response were analysed ex vivo in ELISPOT assays and DR-restriction of T-cell proliferative responses was investigated with HBsAg specific T cell clones. In addition, we compared HBsAg specific T cell responses of 24 monozygotic and 3 dizygotic twin pairs after HBsAg vaccination. Our results showed that the peptide binding assays did not…

The influence of major histocompatibility complex class II genes and T-cell Vbeta repertoire on response to immunization with HBsAg.

1998

Nonresponsiveness to HBsAg vaccination is observed in 5-10% of vaccine recipients and is possibly caused by a defect in the T helper cell compartment. The immune response to HBsAg is influenced by genes of the major histocompatibility complex. We have investigated MHC class I and class II antigens in 53 adult responders and 73 nonresponders. Results obtained in this first study were tested in a second study with 56 responders and 62 nonresponders from an infant vaccination trial. In addition, the peripheral Vbeta-chain T-cell receptor repertoire was investigated using monoclonal antibodies and flow-cytometry in 26 adult responders and 38 nonresponders. As previously reported, nonresponsiven…

Selection of a precore mutant after vertical transmission of different hepatitis B virus variants is correlated with fulminant hepatitis in infants

1995

The incidence of perinatal transmission of hepatitis B virus (HBV) depends on the HBeAg/anti-HBe status of the mother. While children of HBeAg-positive mothers have a 90% probability of acquiring a chronic hepatitis B virus carrier state, babies of anti-HBe-positive mothers are more likely to develop fulminant hepatitis within the first 3 to 4 months of life. There is evidence that precore (pre-C) mutations of the HBV can be associated with fulminant hepatitis. The pre-C region was therefore examined in sera from nine infants with fulminant hepatitis after vertical transmission, one HBeAg-positive and seven anti-HBe-positive mothers by polymerase chain reaction (PCR) and direct sequence ana…

HLA-DRB1*1301 AND *1302 protect against chronic hepatitis B

1997

Abstract Background/Aims: The outcome of acute hepatitis B infection may be influenced by host factors like the major histocompatibility complex (MHC). We have investigated MHC class I and class II antigens in patients with chronic hepatitis B compared to a healthy control population. To confirm the findings of this first study we performed a second study in a group of subjects who had spontaneously recovered from acute hepatitis B infection. Methods: Frequencies of MHC class I and class II antigens were analyzed in patients with chronic hepatitis B virus infection and in control subjects. MHC class I typing was done by standard microlymphocytotoxicity assays. DRB1 and DQA1 genotypes were d…

Schistosomiasis and antiviral treatment of chronic hepatitis C

2003

HPV genotype prevalence in cytologically abnormal cervical samples from women living in south Italy

2007

Human papillomavirus (HPV) infection is the commonest sexually transmitted infection, and high-risk HPV types are associated with cervical carcinogenesis. This study investigated: the HPV type-specific prevalence in 970 women with an abnormal cytological diagnosis; and the association of HPV infection and cervical disease in a subset of 626 women with a histological diagnosis. HPV-DNA was researched by nested PCR/sequencing and the INNOLiPA HPV Genotyping assay. The data were analysed by the chi-square test (p ? 0.05 significant). Overall, the HPV prevalence was 37.7%; high-risk genotypes were found in 88.5% of women and multiple-type infections in 30.9% of the HPV-positive women. The commo…

Human herpesvirus type 8 DNA sequences in biological samples of HIV-positive and negative individuals in Sicily.

1997

Objective: To evaluate the circulation of a new human herpesvirus (HHV), HHV-8 or Kaposi's sarcoma (KS)-associated herpesvirus in a geographical area where a high incidence rate of classical KS was already present before the appearance of the AIDS epidemic. Design and methods: The study was carried out by analysing: (i) bioptic samples from classic, AIDS-associated KS, and controls; (ii) peripheral blood mononuclear cells (PBMC) from classic KS, HIV-positive subjects with and without KS and healthy HIV-negative individuals; (iii) semen samples from heterosexual HIV-positive and HIV-negative individuals affected or not by KS; and (iv) cervical swabs from HIV-negative healthy heterosexual fem…

No Association between Mannose-Binding Lectin Alleles and Susceptibility to Chronic Hepatitis B Virus Infection in German Patients

1998

Variants of the mannose-binding lectin (MBL) have been shown to be associated with low serum concentrations of the protein and to predispose to bacterial, fungal and viral infections. A recent small study on 33 Caucasian patients had suggested that a mutation at codon 52 of the MBL gene is associated with chronic hepatitis B virus (HBV) infection. Exon 1 of the MBL gene was amplified by PCR in 61 patients with chronic HBV infection, 28 patients with acute infection and in 60 controls. MBL variants were detected by subsequent restriction enzyme digestion and agarose gel electrophoresis. The occurrence of the codon 52 mutation in patients with chronic HBV infection did not differ significantl…