Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “immunogenetics”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources

Two new immunogenetic polymorphisms of the apoB gene and their effect on serum lipid levels and responses to changes in dietary fat intake.

In previous studies, apoB polymorphisms have been shown to modify serum lipid responses to changes in dietary fat intake. The functionally important apoB DNA change or changes underlying these effects have, however, remained unknown. Using a single-strand conformation polymorphism analysis-based screening method, we identified two previously unreported apoB polymorphisms located close to each other in the 5' region of apoB gene exon 26. This DNA segment corresponds to the binding site of monoclonal anti-apoB antibody D7.2. The two A-->G changes at apoB cDNA nucleotides 5869 and 5896 produced an Asn-->Ser change at amino acid 1887 and a His-->Arg change at amino acid 1896. In the Finnish population, allele frequencies of the rare alleles of the apoB 1887 (Asn-->Ser) and apoB 1896 (His-->Arg) polymorphisms were .02 and .11, respectively. Both polymorphisms were shown to have an independent effect on the binding affinity of LDL with monoclonal antibody D7.2. The effect of these polymorphisms on serum lipid levels and responses to changes in dietary fat intake in 102 healthy free-living subjects was assessed. The apoB 1896 Arg allele was associated with a higher serum LDL cholesterol level during a low-fat, low-cholesterol diet in men.

Alleles↗

Apolipoprotein B: the Ag(a1/d) immunogenetic polymorphism coincides with a T-to-C substitution at nucleotide 1981, creating an Alu I restriction site.

Short cDNA fragments covering the entire coding region for apolipoprotein (apo) B have been cloned in the pING expression vector. A monoclonal antibody specific for the Ag(d) epitope on apo B has been used, together with the expressed apo B peptides, to locate this epitope to a stretch of 26 amino acids. Sequencing of this region from several genomic DNAs of known Ag(a1/d) genotype showed a single T-to-C substitution at nucleotide 1981, creating an Alu I restriction site and resulting in a val to ala residue change in the corresponding peptide (at position 591 in the mature protein). Southern blots, using the Alu I restriction endonuclease and a short probe for this region of the cDNA, showed perfect correspondence between the restriction fragment length polymorphism and the Ag(a1/d) immunochemical polymorphism in all 17 persons examined.

Apolipoproteins B↗

Immunogenetic susceptibility of atherosclerotic stroke: implications on current and future treatment of vascular inflammation.

The understanding of the pathophysiology governing atherosclerosis supports a prominent role for inflammation pathways in plaque initiation and progression that result in stroke and myocardial infarction. Elevated levels of inflammatory markers in the blood, such as C-reactive protein and CD40 ligand/CD40, in concert with increased expression of adhesion molecules, chemokines, cytokines, matrix metalloproteinases (MMP), and inflammatory cells in the plaque, characterize the symptomatic atherothrombotic state. Advances in predictive capabilities of vascular events using a number of these biomarkers are beginning to remodel our clinical practice in the use of medications such as statins and angiotensin receptor blockers for stroke prevention. Although the general inflammatory features of atherosclerosis are becoming widely recognized, factors resulting in individual variability in plaque formation and instability remain poorly defined. Emerging literature points toward several acquired and innate susceptibility factors in the immune pathways that may provide insight into why many plaques rapidly evolve from a "stable" to an "unstable" or symptomatic state. First, exposure of plaque memory T-lymphocytes to infectious or endogenous antigens may result in rapid clonal expansion of T-cell variable beta chain subtypes and stimulate macrophages to release MMPs, causing plaque destabilization. The effects of infectious agents can further be influenced by an individual's major histocompatibility complex class II molecule profiles, which can affect susceptibility to specific organisms. Second, functional polymorphisms of genes that regulate the immune pathway can predispose patients to a more robust inflammatory expression after risk factor exposure. Identification of a susceptibility gene profile and immunologic mediators that promote T-cell activation provides a unique opportunity for early identification of stroke risk and targets for future therapy.

Angiotensin II Type 1 Receptor Blockers↗

Familial pulmonary hypertension: immunogenetic findings in four Caucasian kindreds.

A postulated association between primary pulmonary hypertension (PPH) and autoimmune diseases prompted this study. To see if autoantibodies and an association with the major histocompatibility locus (MHC) accompany the familial form of pulmonary hypertension (PHT), we determined human leukocyte antigen (HLA)-class I (A,B,C) and HLA-class II (DR,DQ) typing serologically, serum immunoglobulin (Ig) isotypes, and antinuclear (ANA)-autoantibodies in three families in which more than one member had PPH (FPPH) and in a fourth family with PPH and PHT associated with congenital heart disease. The three FPPH families had 15 PPH + members, eight (in whom the alleles were determined or could be inferred) typed for HLA-DRw52 and seven for HLA-DR3,DRw52,DQw2. These three families each had one PPH+,DR3+ member, with an immunoglobulin isotype deficiency, one with IgA and two with mild IgG. The fourth family differed in that both the patient and asymptomatic relatives had varying autoantibodies and different HLA associations. This family had an anti-centromere+ child with PHT and a congenital heart lesion, a mother who died of PPH, and asymptomatic ANA+ relatives (father anti-Sm+/anti-RNP+; autoantibodies unknown in fraternal twin sister and in maternal grandmother). HLA typing showed that the proband and her fraternal twin sister received DR5,DRw52,DQw3 from their father whereas the proband received DR4,DRw53,DQw3 from the mother and her sister received DR2,DQw1. In summary, three FPPH families had multiple PPH+ members who lacked autoantibodies and typed for HLA-DR3,DRw52,DQw2, whereas a fourth family with familial PHT had PHT+ and PHT- members with autoantibodies and different HLA associations.

Adolescent↗

Immunogenetic analysis of silicosis in Japan.

We previously reported that a gene in linkage disequilibrium with HLA-Bw54, DR4, and DRw53 might control the susceptibility to silicosis (K. Honda et al. 1988. N. Engl. J. Med. 319:1610). To further define the HLA-linked gene and other genetic factors for predisposition of silicosis, we determined for HLA-DQ and DP alleles using the polymerase chain reaction and sequence-specific oligonucleotide probes and made a restriction fragment length polymorphism (RFLP) analysis of the fourth component of complement (C4) genes, immunoglobulin lambda variable chain (IGLV) gene, and T-cell receptor alpha and beta genes in 46 Japanese patients with silicosis. The frequency of DQB1*0401 (relative risk [RR] = 2.2, P < 0.02) was increased and that of DQB1*0601 (RR = 0.36, P < 0.01) was decreased in the patients. RFLP analysis of C4 and IGLV genes showed significant association between silicosis and a specific RFLP pattern of C4A3-C4B5 allotype (RR = 2.3, P < 0.05) and that of IGLV 5.3 kb (RR = 0.33, P < 0.003). No other genetic markers showed significant association. Statistical analyses of the associated genetic markers revealed that the HLA-Bw54 was the allele that showed primary association with silicosis and the frequencies of the C4 and HLA-DQ alleles were suggested to be increased due to their linkage disequilibrium with the HLA-Bw54. We conclude that the major gene for silicosis may be mapped near the HLA-B locus.

Adolescent↗

Immunogenetics of human haptoglobins. I. The antigenic structure of normal Hp phenotypes.

The various antigenic determinants of serum haptoglobins (Hp) may be studied semiquantitatively in a radioimmunoassay system. Using three antisera of overlapping specificities, we constructed an antigenic model of the various Hp phenotypes comprising four distinct determinants. This adds a new determinant, situated near the hemoglobin binding site, to the three determinants reported in the literature. The assay system is sensitive to 0.2 mug or less of serum Hp. Furthermore, it can detect determinants that are not recognized by double diffusion studies.

Animals↗

Immunogenetics of human haptoglobins. II. Hp Bellevue, a cross-reacting mutant.

Using a radioimmunoassay method in conjunction with double diffusion studies, we characterized the antigenic determinants of the three Hp Bellevue phenotypes. An antigenic model based on these data indicates that each phenotype comprises a heterogeneous group of proteins with properties depending on their content of normal (hpbeta) and of mutant (hpbeta-Bellevue) chains of haptoglobin. The loss of the hemoglobin binding capacity and of a specific Hb-sensitive antigenic determinant is a consequence of the structural alteration in hpbeta-Bellevue and is expressed to various extents by the populations of proteins containing this chain. It is suggested that those molecules with a preponderance of mutant beta-chains are without significant hemoglobin binding capacity and are degraded more slowly in vivo than the ones capable of hemoglobin binding.

Animals↗

Celiac disease: pathogenesis of a model immunogenetic disease.

Celiac disease is characterized by small-intestinal mucosal injury and nutrient malabsorption in genetically susceptible individuals in response to the dietary ingestion of wheat gluten and similar proteins in barley and rye. Disease pathogenesis involves interactions among environmental, genetic, and immunological factors. Although celiac disease is predicted by screening studies to affect approximately 1% of the population of the United States and is seen both in children and in adults, 10%-15% or fewer of these individuals have been diagnosed and treated. This article focuses on the role of adaptive and innate immune mechanisms in the pathogenesis of celiac disease and how current concepts of immunopathogenesis might provide alternative approaches for treating celiac disease.

Celiac Disease↗

Immunogenetically controlled autoimmune reactions induced by mercury, gold and D-penicillamine in laboratory animals: a review from the vantage point of premarketing safety studies.

Mercury and gold salts as well as d-penicillamine can cause glomerulonephritis by an autoimmune mechanism in man. The susceptibility to this effect of these chemicals is controlled by the genes of the major histocompatibility complex (MHC). The presence of certain alleles confers sensitivity. The role of MHC-linked genes has been demonstrated also in the rat and mouse in the development of autoimmunity induced by these chemicals. While Brown Norway rats and ASW mice were sensitive, several other strains were resistant. Also an interaction of MHC with background genes has been shown in determination of the response to HgCl2. In conventional toxicity studies, use of a single inbred strain of laboratory animals obviously handicaps the detection of a reaction of this nature.

Animals↗

Immunogenetic basis of environmental lung disease: lessons from the berylliosis model.

The role of genetic factors has been hypothesized in the pathogenesis of a number of chronic inflammatory lung diseases. The genes of the major histocompatibility complex (MHC) locus on human chromosome 6 have been identified as important determinants in diseases caused both by inorganic and organic compounds such as beryllium, gold, acid anhydrides, isocyanates and grass pollens. Since many environmental factors are the determinants of the immunopathogenesis of asthma, pulmonary granulomatous disorders, hypersensitivity pneumonitis and fibrotic lung disorders, an understanding of the interaction between environmental factors is crucial to epidemiology, prevention and treatment of these disorders. Berylliosis is an environmental chronic inflammatory disorder of the lung caused by inhalation of beryllium dusts. A human leukocyte antigen class II marker (HLA-DP Glu69) has been found to be strongly associated with the disease. In in vitro studies, the gene has been shown to play a direct role in the immunopathogenesis of the disease. In human studies, the gene has been shown to confer increased susceptibility to beryllium in exposed workers, thus suggesting that HLA gene markers may be used as epidemiological probes to identify population groups at higher risk of environmental lung diseases, to identify environmental levels of lung immunotoxicants that would be safe for the entire population and to prevent disease risk associated with occupation, manufactured products and the environment. Studies on the associations between human leukocyte antigens and chronic inflammatory lung disorders are reviewed in the context of the berylliosis model.

Animals↗

Immunogenetics of Hashimoto's thyroiditis.

Hashimoto's thyroiditis (HT) is an organ-specific T-cell mediated disease. It is a complex disease, with a strong genetic component. To date, significant progress has been made towards the identification and functional characterization of HT susceptibility genes. In this review, we will summarize the recent advances in our understanding of the genetic input to the pathogenesis of HT.

Journal Article↗

Clinical and immunogenetic characterization of Mexican patients with 'rhupus'.

The coexistence of systemic lupus erythematosus and rheumatoid arthritis (rhupus), is a rare clinical condition. To date, 50 cases of rhupus have been described worldwide; however, the lack of clinical criteria for this rheumatic condition has created confusion in the characterization of this disorder. Nevertheless, in this paper we describe a comprehensive clinical and serological characterization of a cohort of 22 Mexican patients with rhupus, supported by generic HLA-DR phenotyping. We found that rhupus patients have a special clinical behavior. In this setting, the signs and symptoms of rheumatoid arthritis prevail, little organic damage associated with systemic lupus erythematosus (SLE) exists and none of the cases present thrombosis or morbidity during pregnancy in spite of presenting a high frequency of anticardiolipin antibodies. We also found an increased frequency of HLA-DR1 and HLA-DR2 alleles compared to healthy ethnically matched controls, systemic lupus erythematosus and rheumatoid arthritis patients.

Adult↗

Polyglandular autoimmune syndromes: immunogenetics and long-term follow-up.

Polyglandular autoimmune syndromes (PAS) are rare polyendocrinopathies characterized by the failure of several endocrine glands as well as nonendocrine organs, caused by an immune-mediated destruction of endocrine tissues. This article summarizes extensive clinical, epidemiological, serological, and genetic data of a large collective of patients with PAS (n = 360). Since 1988, more than 15,000 adult patients with endocrine diseases have been screened at the endocrine center of the Mainz University, and 151 of 360 patients with PAS have regularly been followed. Type 1 diabetes, Graves' disease, Hashimoto thyroiditis, Addison's disease, vitiligo, alopecia, hypogonadism, and pernicious anemia were observed in 61%, 33%, 33%, 19%, 20%, 6%, 5%, and 5%, respectively. The most common disease combination was type 1 diabetes and autoimmune thyroid disease. In most patients, type 1 diabetes was the first manifestation of PAS (48%). The longest time intervals between manifestations of the first and second immune endocrinopathies occurred between type 1 diabetes and thyroid disease (13.3 +/- 11.8 yr) and between vitiligo and thyroid disease (16.3 +/- 13.3 yr), but a shorter time interval was observed between Addison's and thyroid diseases. Of the 471 patients with type 1 diabetes screened, 83 (17.6%) were positive for PAS. Subsequently, sera of 126 patients with PAS, 287 with type 1 diabetes, and 303 matched controls were compared for human leukocyte antigens. Patients with PAS had significantly higher frequencies of the human leukocyte antigens A24, A31, B8, B51, B62, DR3, and DR4 (relative risk, 2.35, 2.74, 2.47, 7.17, 2.22, 1.94, and 2.46) vs. controls, and for A31, B15, B52, B55, DR2, DR11, and DR13 (relative risk, 2.51, 7.96, 3.99, 5.36, 4.46, 2.89, and 3.26) vs. type 1 diabetes patients without PAS. In conclusion, patients with autoimmune endocrine disease should be followed on a regular basis. In subjects at risk for PAS, functional screening every 3 yr is warranted. If clinical disease is present, serological measurement of organ-specific antibodies should follow.

Adult↗