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F Vartdal

Publications and source records attributed to F Vartdal.

At least 55 records · Page 3Linked to original sources
PubMed1991

HLA-DQA1 and HLA-DQB1 genes may jointly determine susceptibility to develop multiple sclerosis.

Serologic DR typing and genomic DRB1, DQA1, DQB1, DPA1, and DPB1 typing using sequence-specific oligonucleotides were performed in 69 multiple sclerosis (MS) patients and 181 healthy controls on in vitro amplified DNA. The frequencies of DR2 as well as the DR2-associated DQA1*0102 and DQB1*0602 alleles were increased whereas DR7 was decreased among MS patients. The distribution of DR4 subtypes as well as DP alleles were similar in patients and healthy controls. All but one of 23 DR4-positive MS patients carried the DQB1*0302 allele, whereas five of five DR7-positive MS patients carried the DQB1*0303 allele. Of the MS patients, 99% compared to 79% of the controls carried DQA1 alleles encoding glutamine at residue 34, while 97% of the MS patients compared to 72% of the controls carried DQB1 alleles encoding DQ beta chains sharing long polymorphic stretches. A combination of such DQA1 and DQB1 alleles was carried by 96% of the MS patients and 60% of the controls, suggesting an association between MS and a combination of particular DQA1 alleles and DQB1 alleles. The corresponding DQ alpha beta heterodimers may have in common an ability to bind a particular peptide.

Alleles↗
PubMed1991

Myasthenia gravis patients with thymus hyperplasia and myasthenia gravis patients with thymoma display different HLA associations.

Thirty myasthenia gravis (MG) patients (9 with thymoma, 12 with thymus hyperplasia and 9 with thymic atrophy) and 181 Norwegian healthy controls were serologically typed for HLA-A, -B and -DR antigens and genomically typed for HLA-DQA1 and HLA-DQB1 alleles by probing in vitro amplified DNA with sequence-specific oligonucleotides. In patients with thymus hyperplasia the frequency of the DQB1*0201 allele was increased compared to controls (RR = 3.5, p less than 0.05), whereas among the patients with thymoma this allele was not observed (RR = 0.06, p less than 0.01). The frequencies of HLA-B8, -DR3 and -DQA1*0501, which are in strong linkage disequilibrium with DQB1*0201, were increased in patients with hyperplasia and reduced in patients with thymoma. The data suggest that different HLA genes predispose to two different forms of MG.

Alleles↗
PubMed1991

Distribution of HLA-DRB1, -DQA1 and -DQB1 alleles and DQA1-DQB1 genotypes among Norwegian patients with insulin-dependent diabetes mellitus.

We have studied 87 unrelated Caucasian insulin-dependent diabetes mellitus (IDDM) patients and 181 healthy controls by oligotyping for 20 DRB1, eight DQA1 and 13 DQB1 alleles, and established their DR-DQ haplotypes and DQ genotypes. An increase of DRB1 alleles encoding DR4 was found among IDDM patients, but the distribution of DR4 subtypes did not differ among DR4-positive IDDM patients and controls. The frequency of certain DRB1-DQA1-DQB1 haplotypes and DQA1-DQB1 genotypes was significantly increased among IDDM patients. Taken together, the data suggest that IDDM is primarily associated with several (at least five) different DQ alpha beta heterodimers.

Adolescent↗
PubMed1991

Novel HLA-DR2 and -DR3 haplotypes among Norwegian Caucasians.

In the Northern European population, all DR2 haplotypes encoded by DRB1*1501 have previously been found to carry the DQA1*0102 and DQB1*0602 alleles, and DR3 haplotypes have been found to carry the DQA1*0501 and DQB1*0201 alleles. Here we report a novel recombinant DR2 haplotype carrying the DRB1*1501, DQA1*0102 and DQB1*0603 alleles as well as a novel recombinant DR3 haplotype carrying the DRB1*0301, DRB3*0101, DQA1*0102 and DQB1*0602 alleles.

Alleles↗
PubMed1991

HLA-DRB1, -DQA1, -DQB1, -DPA1 and -DPB1 genes in Japanese multiple sclerosis patients.

Japanese MS patients and controls were examined for the distribution of HLA-DRB1, -DQA1, -DQB1, -DPA1 and -DPB1 alleles using in vitro amplification of genomic DNA and probing with sequence-specific oligonucleotides. No significant difference in frequency of the examined alleles was observed among the two groups. This is in contrast to Norwegian MS patients, where an association to a combination of certain DQA1 and DQB1 alleles has previously been demonstrated.

Alleles↗
PubMed1991

Few infected CD4+ T cells but a high proportion of replication-competent provirus copies in asymptomatic human immunodeficiency virus type 1 infection.

The virus load in CD4+ T cells from six asymptomatic human immunodeficiency virus type 1 (HIV-1)-infected individuals was determined by limiting-dilution analysis with a sensitive virus isolation procedure and the polymerase chain reaction (PCR). Both methods allowed detection of one HIV-1-infected cell among 10(5) uninfected cells. The number of provirus-containing CD4+ T cells was found to be 1 per 4,000 to 150,000 (median, 1 per 29,000), as determined by virus isolation and 1 per 2,500 to 26,000 (median, 1 per 12,000), as determined by PCR. Infected cells contained an average of 1 to 2 provirus copies, and a high proportion of the provirus copies (1 in 1 to 1 in 6; median, 1 in 2) were replication competent. The results suggest that only a few CD4+ T cells are likely to be lost as a direct consequence of the presence of HIV-1 in infected cells in asymptomatic individuals and that additional mechanisms may contribute to the depletion of CD4+ T cells observed in vivo.

Acquired Immunodeficiency Syndrome↗
PubMed1991

In vitro replication of HIV-1 in naturally infected CD4+ T cells is inhibited by rIFN alpha 2 and by a soluble factor secreted by activated CD8+ T cells, but not by rIFN beta, rIFN gamma, or recombinant tumor necrosis factor-alpha.

The effect of lymphokines on the replication of HIV-1 has previously been investigated using HIV-1-infected cell lines or PBMCs infected in vitro with HIV-1. We have examined the effect of rIFN alpha 2, rFIN beta, and rIFN gamma and recombinant tumor necrosis factor-alpha (rTNF alpha) on the replication of HIV-1 in vitro in naturally HIV-1-infected CD4+ T cells from asymptomatic HIV-1-seropositive individuals. rIFN alpha 2 inhibited the replication of HIV-1 effectively at concentrations that can be achieved in vivo. The inhibitory activity was most efficacious when rIFN alpha 2 was added as the CD4+ T cells were being activated, and less but still considerable when rIFN alpha 2 was added 4-96 h after CD4+ T-cell activation. rIFN alpha 2 exerted a suppressive effect on the proliferation of the CD4+ T cells, but this effect was small at concentrations that caused 90% inhibition of the replication of HIV-1. rIFN beta, rIFN gamma, and rTNF alpha had no effect on the replication of HIV-1, but rIFN beta and rTNF alpha had a costimulatory effect on CD4+ T-cell proliferation. Activated CD8+ T cells secrete a HIV-1-inhibitory soluble factor. Blocking experiments using an IFN alpha 2-neutralizing MAb showed that this HIV-1-inhibitory factor is not IFN alpha 2.

Antibodies, Monoclonal↗
PubMed1990

CD8+ T cells inhibit HIV replication in naturally infected CD4+ T cells. Evidence for a soluble inhibitor.

This study describes the inhibitory effect exerted by activated CD8+ T cells on the replication of HIV in naturally infected CD4+ T cells. Highly purified CD4+ T cells from asymptomatic HIV seropositive individuals were stimulated with anti-TCR mAb-coated beads in the presence of IL-2. HIV was subsequently reproducibly isolated in cell supernatants from all study participants (53 cultures from 42 individuals). Both autologous and allogeneic CD8+ T cells from asymptomatic HIV seropositive and healthy HIV seronegative individuals inhibited the replication of HIV in these cultures in a dose-dependent manner. CD8+ T cells from patients with AIDS showed reduced or no such inhibitory activity. The inhibitory effect was not dependent on direct cell-cell contact: an inhibitory effect was exerted by CD8+ T cells across a semipermeable membrane, and an inhibitory activity was also exerted by the cell-free supernatants from activated CD8+ T cells. These results suggest that activated CD8+ T cells secrete a soluble inhibitor of HIV replication.

Antibodies, Monoclonal↗
PubMed1990

[Costs of care in uremia. How much does kidney transplantation cost?].

The cost of kidney transplantation and hemodialysis have been recorded (in 1986). Tissue typing, operation and initial stay in hospital cost NOK 103,000 per patient, and further treatment for the first year after operation NOK 114,000. Subsequent annual costs were NOK 70,000, mainly for drugs. Hemodialysis costs NOK 287,000 per year. Transplantation was cost-effective by almost NOK one million per patient over a five-year period. If the current high national rate of transplantation (42 patients per million), which keeps both the national waiting list (23 patients per million) and the dialysis population at a low level, is sustained over the next five years, then total national expenditures for dialysis and transplantation are predicted to be approx. NOK 400 millions. If no transplants were performed during this period the waiting list would increase to 175 patients per million, and expenditures (for dialysis) to approx. NOK 750 millions. Additional huge investments would be needed in order to expand the facilities for dialysis. Because of high transplant rate, only 18 per cent of all treated uremics in Norway are now on dialysis, versus 73 per cent in Western Europe. Since transplantation is much cheaper than dialysis, national expenditures per treated patient are lower in Norway than in any other country.

Costs and Cost Analysis↗
PubMed1990

Distribution of HLA class II alleles among Norwegian Caucasians.

We report genomic HLA class II typing of 181 randomly selected Norwegian controls. Seventeen DRB1, 7 DQA1, 10 DQB1, 2 DPA1, and 16 DPB1 alleles were found in the tested population. HLA class II antigen and allele frequencies are given, as well as the distribution of DRB1, DQA1, DQB1 haplotypes. Linkage disequilibrium between some DPB1 alleles and DRB1 and/or DQB1 alleles are also reported.

Alleles↗
PubMed1990

Susceptibility to develop celiac disease is primarily associated with HLA-DQ alleles.

We have recently reported that the susceptibility to develop celiac disease (CD) seems to be primarily associated to a particular combination of an HLA-DQA1 (DQA1*0501) and an HLA-DQB1 (DQB1*0201) allele: i.e., a particular DQ alpha/beta heterodimer. To investigate whether certain DP alleles might also contribute to the genetic susceptibility, DPA1 and DPB1 genes of 94 CD patients and 132 healthy controls were examined by probing in vitro amplified DNA with sequence-specific oligonucleotide probes corresponding to all hitherto known DPA1 and DPB1 alleles. The frequencies of the DPA1*0201 and of the DPB1*0101 alleles were increased in CD patients compared to healthy controls (0.31 versus 0.14 and 0.25 versus 0.08, respectively). However, these DP alleles were in linkage disequilibrium with CD-associated DQ alleles in the normal population, and the difference in frequency of these DP alleles was no longer significant when CD patients and healthy controls carrying the CD-associated DQA1*0501 and DQB1*0201 alleles were compared. DQB1*0201 homozygous individuals were overrepresented among DQB1*0201-positive patients compared to controls. When DQB1*0201 heterozygous patients and controls were compared, nearly identical frequencies of the DPA1*0201 and the DPB1*0101 alleles were found. Thus, the observed increase of the DPA1*0201 and DPB1*0101 alleles among CD patients seems mainly to be caused by linkage disequilibrium to the CD-associated DQ alleles.

Alleles↗
PubMed1990

Rheumatoid arthritis may be primarily associated with HLA-DR4 molecules sharing a particular sequence at residues 67-74.

Genomic typing of in vitro amplified DNA with sequence-specific oligonucleotide (SSO) probes was performed for DRB1, DQA1, DQB1, DPA1 and DPB1 alleles in 54 random Norwegian rheumatoid arthritis (RA) patients and 181 healthy controls. DRB1 alleles encoding the serological specificity DR4 were found in 80% of the patients, compared to 34% of the controls (relative risk = 7.9, p less than 0.0001). All DR4-positive RA patients carried either DRB1*0401 (Dw4), 0404 (Dw14), or 0405 (Dw15), while no patients were found to carry DRB1*0402 (Dw10) or 0403 (Dw13). The frequency of the DRB1*0101 allele encoding DR1 was not increased, even among DR4-negative RA patients, and we were unable to detect any sharing of other class II alleles among DR4-negative patients. No contribution of any DQA1, DQB1, DPA1 or DPB1 alleles to RA susceptibility could be detected. The results suggest that in the Norwegian population RA is primarily associated with a shared sequence at residues 67-74 of the DR beta 1 chain, but only when this sequence is expressed on DR4 molecules.

Alleles↗
PubMed1990

IgG and IgA subclass distribution of total immunoglobulin and rheumatoid factors in rheumatoid tissue plasma cells.

The subclass distribution of IgG and IgA plasma cells, and in IgG and IgA rheumatoid factor (RF) producing cells was studied in sections of synovial tissue from seropositive RA and various types of seronegative arthritis, including ankylosing spondylitis, psoriatic arthritis, and Reiter's syndrome. The study was performed with immunofluorescence technique and monoclonal IgG and IgA subclass specific antibodies. IgG RF producing cells were identified by their ability to bind and activate factors both in the early (C3) and late (C5b-9) part of the complement cascade. IgA RF cells were identified by double staining experiments with heat-aggregated IgG and monoclonal antibodies to IgA subclasses. In 23 tissues tested for total IgG, IgG1 cells were usually predominant, while the frequency of IgG3 cells was usually higher than that of IgG2. In 19 tissues also tested for IgA, both IgA subclasses were present in all tissues. IgA1 plasma cells were always predominant, with a mean ratio of IgA1 to IgA2 cells of approximately 10. In the 13 tissues tested for RF-producing cells, the highest frequency of IgG RF cells was found among the IgG3 cells, followed by IgG1 and IgG2. IgA RF cells were found in only one case, all cells being IgA1.

Antigen-Antibody Complex↗
PubMed1989

[Gene technology in immunologic research, diagnosis and treatment].

T- and B-lymphocytes recognize foreign material (antigens) by means of specific receptors. After the antigen-specific recognition, lymphocytes and other cells communicate both through membrane-bound and soluble signal molecules. Gene technology has enabled mapping and sequencing of several genes which encode receptor or signal molecules. Gene sequencing has provided essential new information on the structure of receptor and signal molecules, and has thus formed the basis for our rapidly growing knowledge of the physiology and pathophysiology of the immune system. Molecular genetics has also produced techniques which are already being used in the diagnosis of immunologic diseases, and which can possibly be used therapeutically in gene transplantation of various immune defects.

Animals↗
PubMed1989

Evidence for a primary association of celiac disease to a particular HLA-DQ alpha/beta heterodimer.

Typing of DNA from 94 unrelated children with celiac disease (CD) with HLA-DQA1 and -DQB1 allele-specific oligonucleotide probes revealed that all but one (i.e., 98.9%) may share a particular combination of a DQA1 and a DQB1 gene. These genes are arranged in cis position on the DR3DQw2 haplotype and in trans position in DR5DQw7/DR7DQw2 heterozygous individuals. Thus, most CD patients may share the same cis- or trans-encoded HLA-DQ alpha/beta heterodimer.

Celiac Disease↗
PubMed1989

Reliable isolation of human immunodeficiency virus from cultures of naturally infected CD4+ T cells.

A procedure for reliable and reproducible isolation of human immunodeficiency virus (HIV) from cultures of CD4+ T cells from healthy HIV seropositive individuals is described. Using immunomagnetic cell separation techniques, CD4+ T cells were positively selected from blood or peripheral blood mononuclear cells from 34 HIV infected individuals in CDC group II. The cells were stimulated with beads coated with a monoclonal antibody specific for the T cell receptor alpha/beta dimer and cultured in medium containing recombinant IL 2. HIV was isolated from 100% of the 41 cultures from 34 individuals. As this culture system allows reproducible isolation of HIV from cultures of naturally infected CD4+ T cells in the absence of other autologous or allogeneic cells, it may provide a good test system for the study of factors affecting the replication of HIV at low multiplicities of infection.

Antibodies, Monoclonal↗