Biomedical subjects

A Sönnerborg

Publications and source records attributed to A Sönnerborg.

At least 55 records · Page 3Linked to original sources

PubMed1999

Long-term pattern of HIV-1 RNA load in perinatally infected children.

The objective of this study was to describe the natural history of HIV-1 RNA load in vertically HIV-1-infected children. HIV-1 RNA in 156 plasma or serum samples (1-14, median 4 from each child) from 32 vertically HIV-1-infected children was detected with the NASBA technique (Organon Teknika, The Netherlands). Twenty-one children were prospectively followed from birth, and 11 were identified and included at the age of 7-89 (median 61) months. The highest numbers of HIV-1 RNA copies were seen at 1.5-3 months of age. A quadratic curve model showed a reduction of HIV-1 RNA with increasing age up to approximately 8 years, and thereafter increasing numbers, p(age) = 0.002, p(age2) = 0.008. This pattern was not typical for individual children in whom a great variation in HIV-1 RNA numbers was seen over time. The interval from birth to the first HIV-1 RNA peak ranged from 1.5 months to more than 2 years. The HIV-1 RNA levels remained relatively high and fluctuating over the years in symptomatic as well as in long-term asymptomatic children. This makes HIV-1 RNA determination in children more difficult to use than in adults, as the only tool for prediction of disease progression and for initiation of therapy.

CD4 Lymphocyte Count↗

PubMed1999

Longitudinal quantification of human immunodeficiency virus type 1 DNA and RNA in long-term nonprogressors.

Twenty patients with human immunodeficiency virus type 1 (HIV-1) infection for >7 years, no HIV-1-related symptoms, no treatment, and CD4+ cell counts >500/microL were included in a prospective study in 1993. Four years later, 12 patients had progressed (SPs), while 8 had not (long-term nonprogressors [LTNPs]). At inclusion, HIV-1 RNA, but not DNA, levels were higher in SPs. During follow-up, a consistent increase in HIV-1 RNA was seen in only 1 LTNP. In 2 LTNPs, plasma viremia was persistently undetectable or <110 copies/mL. Infectious virus was isolated from only 1 LTNP and from 11 SPs. In 4 LTNPs, HIV-1 DNA levels decreased spontaneously with time. The restricted viral replication and the declining HIV-1 DNA levels suggest that the HIV-1 infection can be controlled efficiently in a few LTNPs, leading to a decrease in the total virus burden with time.

DNA, Viral↗

PubMed1999

Reappearance of founder virus sequence in human immunodeficiency virus type 1-infected patients.

Different patterns of temporal evolution in human immunodeficiency virus type 1 V3 and p17 regions are described for eight patients studied during the first years following primary infection. In samples from three patients, a rapid replacement of the major sequence occurred but the original sequence reappeared later simultaneously with clinical deterioration and increased plasma viral load.

Base Sequence↗

PubMed1999

Relation between GB virus C/hepatitis G virus and fulminant hepatic failure may be secondary to treatment with contaminated blood and/or blood products.

BACKGROUND: The role of the recently discovered GB virus C (GBV-C)/hepatitis G virus in fulminant hepatic failure (FHF) has been debated. Although GBV-C RNA has been detected in many cases of FHF, recent data suggest that the relation between GBV-C and FHF may be accidental. AIMS: To retrospectively investigate the possible relation between the presence of GBV-C markers (RNA or antibodies to the GBV-C envelope 2 (E2) glycoprotein) and FHF. METHODS: The presence of GBV-C RNA was determined in serum samples from 58 patients diagnosed with FHF using a reverse transcriptase polymerase chain reaction. Amplified genetic fragments were directly sequenced by the dideoxy chain termination method. Antibodies to GBV-C in serum samples were detected by enzyme immunoassay based on a recombinant GBV-C E2 protein. RESULTS: Nine (16%) patients with FHF had GBV-C RNA and 13 (22%) [corrected] had GBV-C E2 antibodies, which are higher frequencies than in healthy subjects (p<0.01 and p<0.05 respectively). Six of nine [corrected] patients with GBV-C markers during FHF tested negative for these markers before therapy with blood and/or blood products. Sequence analysis of the GBV-C NS3 region fragments of six FHF patients showed no common sequence pattern or motif. CONCLUSIONS: The frequencies of both GBV-C RNA and antibodies are higher in patients with FHF than in healthy subjects. However, these increased frequencies may in many cases be explained by the use of contaminated blood and/or blood products given as therapy.

Adolescent↗

PubMed1999

Kinetics of beta-chemokine levels during anti-HIV therapy.

Chemokines are pro-inflammatory cytokines that inhibit human immunodeficiency virus type 1 (HIV-1) replication in vitro. We studied the kinetics of the beta-chemokines, macrophage inhibitory protein (MIP)-1 alpha, MIP-1 beta, RANTES, and monocyte chemotactic protein (MCP)-1 in plasma during 12 months of antiretroviral therapy in 26 HIV-1-infected patients and in 11 untreated subjects. Eleven patients with moderate immunodeficiency had HIV-1 RNA levels < 50 copies/ml after 1 year, whereas 12 out of 15 patients with severe immunodeficiency had detectable virus. At baseline, MCP-1 levels correlated positively with HIV-1 RNA and DNA levels and inversely with CD4 cell counts. A reverse pattern was seen for the MIP-1 beta levels. No correlation was seen between MIP-1 alpha or RANTES and any of the parameters. Also, there was a dichotomy between the different beta-chemokines in response to therapy. Decreases of MCP-1 and RANTES levels were found, but no durable changes of MIP-1 alpha and MIP-1 beta. The MCP-1 levels rebounded back to baseline after 1 year in the patients who responded virologically, which could possibly reflect an increased immune activation. The biological consequences of the changes in beta-chemokines levels during antiretroviral treatment are still unknown and deserve further studies.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Variations in HIV-1 pol gene associated with reduced sensitivity to antiretroviral drugs in treatment-naive patients.

OBJECTIVE: Various drugs against the HIV-1 enzymes reverse transcriptase (RT) and protease have been introduced in the last few years: protease inhibitors, nucleoside RT inhibitors (NRTI) and non-NRTI (NNRTI). Several sequence variations associated with reduced drug sensitivity have been described in the HIV-1 pol gene. DESIGN: To analyse the occurrence of mutations associated with drug resistance in treatment-naive individuals. METHODS: RNA was extracted from sera of treatment-naive individuals, who were first diagnosed to be HIV-1 infected between August 1996 and February 1998. The pol region was amplified by RT-PCR and directly sequenced. Data on mutations associated with resistance to antiretroviral drugs were obtained from literature. RESULTS: Fifty protease genes and 53 RT genes from 57 individuals were sequenced. In the RT we analysed 20 amino-acid positions associated with resistance to NRTI and NNRTI. In total, 1054 amino acids at critical positions were analysed and three (0.3%) mutations known to contribute to RTI resistance were detected. In the protease, 16 amino-acid positions associated with resistance to protease inhibitors were analysed. By analysing a total of 768 amino acids at key positions in the protease, 50 (7%) mutations were detected that were associated with reduced drug sensitivity. Thirty-one (61%) patients showed between one and six mutations at the analysed protease amino-acid positions. In eight out of 16 analysed amino-acid positions, up to 44% of all patients carried mutations associated with resistance to protease inhibitors. CONCLUSIONS: Very few pre-existing mutations to RTI were found, suggesting that the transmission of RT-resistant strains is still uncommon. However, about two-thirds of the patients had one or more mutations associated with resistance to protease inhibitors. In addition, at some amino-acid positions up to almost half of the patients carried variations claimed to contribute to protease inhibitor resistance. Most of these mutations are likely to reflect the natural polymorphism of the protease. Their impact on the long-term effect of antiretroviral treatment should be evaluated in future studies.

Adolescent↗

PubMed1998

Coexisting members of HIV-1 p17 gene quasispecies represent proteins with distinct antigenicity and immunogenicity.

BACKGROUND: Despite the comparatively conserved nature of the HIV-1 gag gene, countless quasispecies of the p17 gene coexist in HIV-1-infected patients. It is not known if the minor genetic differences in quasispecies will affect immune recognition. OBJECTIVE: To characterize the antigenicity and immunogenicity of three different members of HIV-1 p17 quasispecies. METHODS: Three members of HIV-1 p17 gene quasispecies, one from patient A (clone 9; qsA9) and two from patient E (clones 5 and 8; qsE5 and qsE8), were expressed and purified from Escherichia coli. The antigenicity of the p17 proteins was analysed using sera from HIV-1-infected individuals, and the immunogenicity was evaluated using sera and lymphocytes from primed mice of three different haplotypes. RESULTS: The antigenicity of the qsE5 and qsE8 p17 recombinant proteins were distinct when tested for reactivity with human p17 antibodies. The qsE5 and qsE8 p17 were equally immunogenic in H-2d mice, but not in H-2b and H-2k mice. In H-2b mice the qsE8 protein induced higher levels of anti-p17 IgG2a, IgG2b and IgG3 than the qsE5 protein. Corroborating the IgG subclass pattern, H-2b-restricted qsE5-specific T cells produced higher in vitro levels of interferon-gamma, but not of interleukin (IL)-4, IL-5 and IL-6, than qsE8-specific T cells, suggesting a more pronounced T-helper (TH)1-like response. CONCLUSIONS: The p17 gene quasispecies coexisting in the same patient at the same time may represent antigenically and immunogenically distinct proteins despite sequence homologies of above 90%. Subsequently, subtle differences between two p17 protein quasispecies are enough to prime different TH1/TH2 subsets. These findings will have implications for therapeutic HIV-1 immunizations.

Amino Acid Sequence↗

PubMed1998

Multiple dideoxynucleoside analogue-resistant (MddNR) HIV-1 strains isolated from patients from different European countries.

OBJECTIVE: To study the prevalence of multiple dideoxynucleoside (ddN)-resistant (MddNR) HIV-1 in European patients under treatment with multiple ddN analogues, and to characterize MddNR strains genotypically and phenotypically. DESIGN AND METHODS: Blood samples from patients after > or = 6 months of treatment with multiple ddN were screened for the MddNR mutation Q151M. After confirmation of MddNR in 15 patients from five European countries, genotypic resistance was evaluated by DNA sequencing of the reverse transcriptase (RT) gene. Phenotypic resistance was measured by the recombinant virus assay. Results were compared with the clinical evolution of the patients. RESULTS: The prevalence of MddNR strains in European patients treated with multiple ddN analogues was 3.5%. Viruses typically contained amino acid substitutions V75F, F77L, F116Y and Q151M in the RT gene. A new mutation, S68G, was frequently associated with MddNR. Phenotypically, viruses displayed high-level resistance to zidovudine (ZDV), didanosine (ddl), zalcitabine (ddC), stavudine (d4T) and partial resistance to lamivudine (3TC) once multiple mutations were present. Under in-vivo treatment pressure, some MddNR strains additionally developed resistance to protease inhibitors or non-nucleoside RT inhibitors (NNRTI). Clinically, most patients had advanced HIV disease with low CD4 cell counts, high viral loads and a rapid progression, but two patients harbouring MddNR virus responded well to dual protease inhibitor associations. CONCLUSIONS: MddNR resistant HIV-1 can be found in European patients. MddNR is characterized by a specific set of drug resistance mutations, cross-resistance to most ddN analogues and a fast clinical progression. MddNR can be associated with protease inhibitor or NNRTI resistance.

Amino Acid Sequence↗

PubMed1998

[Treatment of HIV infections--an update. The easy work is done--the difficult is still to be done].

Explore the source record for details and available documents.

Antiviral Agents↗

PubMed1998

Erratum to "Immunocytochemical detection of cytokines and chemokines in Langerhans cells and in vitro derived dendritic cells".

We have developed a direct immunocytochemical technique to identify cytokine and chemokine production in epidermal Langerhans cells (LC) and in vitro derived CD14-, CD1a+, CD83+, CD40+ dendritic cells (DC) at the single cell level. Formaldehyde fixation combined with saponin permeabilization preserved cellular morphology and generated a characteristic juxtanuclear staining signal due to the accumulation of cytokine to the Golgi organelle. This approach was used for the assessment of TNF-alpha, IL-6, IL-8, IL-10, IL-12, GM-CSF, MIP-1alpha, MIP-1beta and RANTES producing cells. In contrast, a diffuse cytoplasmic staining was evident for IL-1ra, IL-1alpha and IL-1beta production. IL-1ra and IL-1alpha were expressed in 10-25% of unstimulated cultured cells, while all the other cytokines were undetectable. IL-1ra, IL-1alpha and IL-1beta were also the dominating cytokines, expressed in up to 85% of the DC, after 3 h of LPS stimulation. A significantly lower number of cells (0-5%) synthesized TNF-alpha, IL-6, IL-10, IL-12 and GM-CSF. The incidence of chemokine producing cells (IL-8, RANTES, MIP-1alpha, MIP-1beta) peaked 10 h after LPS stimulation in up to 60% of the DC. Both immature CD83- and mature CD83+ DC as well as LC had a similar cytokine production pattern. Thus, in comparison to monocytes, LPS stimulation of DC generated a lower incidence of TNF-alpha, IL-6, IL-10 and IL-12 producing cells while IL-1 was expressed in a comparable number of cells.

Antigens, CD↗

PubMed1998

Characterization of the viral population during primary HIV-1 infection.

OBJECTIVE: To study viral heterogeneity at a very early phase of primary HIV-1 infection. DESIGN: Samples were drawn very early during primary HIV-1 infection. A virus population-based approach was used to study the viral heterogeneity in the C2-V3 and p17 regions. METHODS: Plasma samples (n = 33) were obtained before or shortly after onset of acute symptoms in 15 patients. In all subjects, the first sample was drawn within 10 days after onset of symptoms. Peripheral blood mononuclear cells (PBMC) were available in two patients. The number of polymorphic sites in the C2-V3 (15 patients) and p17 regions (eight patients) were determined by direct sequencing. RESULTS: The sequence heterogeneity was restricted in most patients, although only two out of 15 patients had a completely homogeneous C2-V3 sequence. However, pronounced individual differences were seen. Rapid sequence changes occurred during the first month in two patients. In one patient, the major DNA species at day 12 later became the major species in plasma. CONCLUSIONS: The viral population is seldom completely homogeneous during primary HIV-1 infection, although the heterogeneity is restricted in most, but not all, patients. These individual differences do not seem to be due to sex or viral subtype. Rapid changes of the virus population may occur during primary HIV-1 infection. The DNA species detected in PBMC do not only represent earlier viral quasispecies but are also a potential source of future viral RNA species.

Base Sequence↗

PubMed1998

Immunocytochemical detection of cytokines and chemokines in Langerhans cells and in vitro derived dendritic cells.

Chemokines↗

PubMed1998

Pronounced anti-HIV-1 activity of foscarnet in patients without cytomegalovirus infection.

Combined therapy using reverse transcriptase (RT) and protease inhibitors is the current established treatment for HIV-1 infection. Foscarnet is an RT inhibitor that is a product analogue, in contrast to the widely used nucleoside analogues. In this study, the anti-HIV-1 effect of foscarnet, 50 mg three times per day administered intravenously for 4 weeks, was evaluated in 10 patients with minor or no symptoms. Serious adverse events developed in 2 patients, although most patients experienced some side effects. The levels of HIV-1 RNA decreased from a median value of 4.7 to 2.6 10log copies/ml. The effect was sustained through 4 weeks. One week after cessation of treatment, HIV-1 RNA levels increased to baseline. In contrast, no increase in the number of CD4+ cells was observed. The anti-HIV-1 effect was considered to be a direct effect on HIV-1 replication because no patient had concomitant cytomegalovirus (CMV) infection.

AIDS-Related Complex↗

PubMed1998

Cerebrospinal fluid mononuclear cell counts influence CSF HIV-1 RNA levels.

This study evaluated the relation between cerebrospinal fluid (CSF) mononuclear cells (MNC) and CSF HIV-1 RNA levels. HIV-1 RNA levels in plasma and CSF were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) in 58 consecutive patients with neurologic symptoms and late HIV-1 infection. The majority of the patients had no central nervous system (CNS) complication (n = 36), 11 had AIDS dementia complex (ADC) and 11 had CNS opportunistic infection (CNS OI). CSF cell counts were analyzed using a method that also evaluated hypocellular CSF (i.e., from 0.1 x 10(6) cells/L). A strong correlation was found between CSF MNC and CD4+ lymphocyte counts in blood (r = 0.58; p < .0001). HIV-1 RNA was detected in all plasma samples and in 38 of 58 (66%) of the cell-free CSF samples. CSF HIV-1 RNA was less frequently detected in patients with hypocellular CSF than in patients with normocellular or pleocytic CSF (13 of 28 patients [46%] versus 10 of 14 patients [71%] versus 15 of 16 patients [94%], respectively). The levels of CSF HIV-1 RNA correlated with the CSF MNC count (r = 0.61; p < .0001). The correlation also remained strong within the clinical subgroups of CNS asymptomatic patients (r = 0.55; p < .001) and ADC patients (r = 0.79; p < .001), but not among CNS OI patients (r = 0.19). Patients with CNS OI were found to have higher CSF HIV-1 RNA levels than the patients without evidence of CNS complication. Thus, a close relation was found between CSF HIV-1 RNA levels and CSF MNC counts. These data support the hypothesis that a substantial part of the virus in the CSF of HIV-1-infected patients is locally produced by CSF MNC.

AIDS Dementia Complex↗

PubMed1998

Nonsynonymous mutations within the human immunodeficiency virus type 1 p17 gene are clustered to sequences binding to the host human leukocyte antigen class I molecules.

We have analyzed the relation between intrapatient variabilities of the p17 gene and the location of known host p17 cytotoxic T lymphocyte (CTL) epitopes in five patients infected with human immunodeficiency virus type 1 (HIV-1). All patients were typed with respect to the human leukocyte antigen (HLA) class I type. One to seven previously fine-mapped p17 CTL epitopes corresponded to the HLA class I restriction elements of each patient. An average of 28+/-16% of the p17 gene of each patient encoded CTL epitopes corresponding to the HLA restriction elements of the host. Twenty full-length p17 gene clones were sequenced from each patient. The intrapatient homology between the p17 sequences ranged from 96.4 to 98.9%. The interpatient homology between the consensus sequences of each patient ranged from 83.1 to 91.6%. A total of 246 nucleotide differences within the 100 p17 clones was noted. Fifteen (16%) of 96 synonymous substitutions were found within host CTL epitopes, whereas 72 (48%) of 150 nonsynonymous nucleotide changes were found within CTL epitopes corresponding to the HLA restriction elements of the host (p < 0.0001; Fisher's exact test). Subsequently, variable residues indicating the evolution of at least two major p17 species (i.e., >20% of the clones) were determined to be more common at positions contained within these CTL epitopes (p < 0.01). The present data suggest that the evolution of the p17 gene is influenced by contact areas with the host HLA class I molecules.

Adult↗

PubMed1998

Full-length sequence of human immunodeficiency virus type 1 subtype A, recombined with subtype C in the env V3 domain.

Explore the source record for details and available documents.

Base Sequence↗

PubMed1998

Randomised, double-blind, placebo-controlled trial of interferon alpha-2b with and without ribavirin for chronic hepatitis C. The Swedish Study Group.

BACKGROUND: Pilot studies suggested that more patients with chronic hepatitis C virus (HCV) infection had a sustained virological response when treated with the combination of interferon alpha-2b and ribavirin than with interferon alpha-2b alone. We investigated the biochemical and virological responses and safety of treatment with interferon alpha-2b and ribavirin compared with interferon alpha-2b alone. METHODS: In this double-blind trial 100 patients were randomly assigned to treatment with interferon alpha-2b (3 MU three times a week) in combination with ribavirin (1000 or 1200 mg per day) or placebo for 24 weeks and then followed up for a further 24 weeks. A further follow-up was done 1 year after active treatment stopped. The primary endpoint was the sustained virological response, defined as no detectable HCV RNA by PCR at both week 24 and week 48. Retrospectively, the baseline HCV-RNA load was analysed as a predictor of a sustained virological response. Data were analysed by intention to treat. FINDINGS: 18 (36%) of the 50 patients in the interferon alpha-2b and ribavirin group had a sustained virological response compared with nine (18%) of the 50 patients in the interferon alpha-2b and placebo group (p = 0.047). At the 1 year follow-up the proportion of patients with a virological response was greater in the interferon alpha-2b and ribavirin group than the interferon alpha-2b and placebo group (42 vs 20%, p = 0.03), respectively. More patients with baseline HCV-RNA concentrations greater than 3 x 10(6) genome equivalents (Eq) per mL had a sustained response with interferon alpha-2b and ribavirin than with interferon alpha-2b and placebo (12/29 vs 1/26, p = 0.009), whereas the sustained response did not differ between the two treatment groups for HCV-RNA amounts less than 3 x 10(6) Eq per mL (6/21 vs 8/24, p = 0.67), respectively. INTERPRETATION: More patients with chronic hepatitis C have a sustained virological response with interferon alpha-2b and ribavirin than with only interferon alpha-2b treatment. We suggest that patients with high HCV-RNA loads should be treated with interferon alpha-2b and ribavirin.

Adult↗

PubMed1998

Variation in the hepatitis C virus NS5a region in relation to hypervariable region 1 heterogeneity during interferon treatment.

The putative interferon sensitivity determining region (ISDR) in the NS5a region of the hepatitis C virus (HCV) was analyzed in 13 interferon alpha (IFN-alpha) treated patients representing genotypes 1a, 1b, and 2b. These patients had previously been followed longitudinally during treatment with respect to viral load and to virus heterogeneity using the hypervariable region 1 (HVR1) sequence as a marker. In the present study, the NS5a region was analyzed for nonresponders and sustained responders using direct DNA sequencing. While the previous results of analyzing viral composition and load showed evidence of selection, no corresponding selection of specific NS5a ISDR sequences was observed in the nonresponders, and identical ISDR sequences were observed among both sustained responders and nonresponders. Thus, we cannot verify a correlation between ISDR sequence and the observed selection of IFN-alpha-resistant quasispecies demonstrated as a restriction of HVR1 heterogeneity. This indicates that the potential for using ISDR as a diagnostic or prognostic marker during IFN-alpha treatment is limited.

Amino Acid Sequence↗