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 1,729 records · Page 96Linked to original sources

Dicentric Y chromosome in a patient with gonadal dysgenesis and seminoma.

A male patient with ambiguous external genitalia developed a seminoma in the left inguinal region; his internal genitalia included a streak gonad on the right and a small uterus. Cytogenetic studies demonstrated a dicentric Y chromosome with unstable behavior during cell division, which resulted in 45,X/46,X,dic(Y)/47,X,dic(Y),dic(Y) mosaicism. Immunogenetic studies allowed the identification of the male-determining H-Y antigen on both leukocytes and red cells of the patient. The significance of these results is discussed with respect to recent data on the genetic control of H-Y antigen.

Adult↗

Class I associations and frequencies of class II HLA-DRB alleles by RFLP analysis in children with rheumatoid-factor-negative juvenile chronic arthritis.

A total of 94 patients with juvenile chronic arthritis (JCA) was tested for HLA class I by serology and for class II by RFLP typing. Early onset JCA (EOPA) is associated with HLA-A2, DR5 and DR8 in both males and females. The combination (joint occurrence) of these JCA associated alleles (A2, DR5, DR8) is frequently seen in patients with chronic iridocyclitis. Late onset pauciarticular disease has an increased frequency of HLA-B27, especially in males. Our data confirm that polyarticular JCA with early childhood onset (< or = 4 years) is associated with DR5 and DR8 and has a different immunogenetic background from polyarticular JCA with later childhood (> 4 years) onset (associated with DR4).

Adolescent↗

The structural gene for F liver protein (Flp) maps to chromosome 5 of the mouse.

The BXD and AKXL panels of recombinant inbred mouse strains have been typed for the F liver protein alloantigen. The structural gene for F liver protein gene (Flp) is placed on the distal part of chromosome 5, between the known markers Bcd-1 and Gus-s. This excludes the possibility that F liver protein is a major histocompatibility complex molecule, and in turn raises a question about the uniqueness of F and certain other proteins as purgers of self-reactivity among T but not B cells. The typed RI strains have then been used for the immunogenetic studies presented in the succeeding article.

Animals↗

Immune suppression genes control the anti-F antigen response in F1 hybrids and recombinant inbred sets of mice.

The immune response to the liver protein F antigen which, in the mouse, occurs in two allelic forms, is under sharp immunogenetic control in that only mice that possess the Ak molecule can respond to allo-F antigen. This response has been studied in a number of F1 hybrids between inbred strains and with recombinant inbred lines all of which express Ak, and which thus enable immune suppression effects to be detected. In the AKXL and AKXD sets the hybrids with CBA are responders if H-2k/H-2k, and usually nonresponders if H-2k/H-2b or H-2k/H-2d. Although this may be due to gene dosage effects, this cannot be the explanation for the low responsiveness of the H-2k/H-2b relative to the H-2k/H-2d mice found in CBA x BXD hybrids. For this, and other reasons, it seems likely that low responsiveness in any mouse possessing a responder Ak allele is due to suppression, and that this is mediated by the immune suppression effects of the non-H-2k haplotype. These H-2-mediated effects can be modified, both positively and negatively, by background genes. Thus, of the ten H-2k/H-2d members of the CBA x AKXD cross, seven are low responders and three are high responders. No other typed marker has the same strain distribution pattern at present. Major unresolved questions, therefore, concern the location and mechanism of action of the background genes and the mechanism of action of the H-2 immune suppression genes.

Animals↗

The expression of Mlsc determinants on Mlsa, Mlsb, and Mlsx prototypic strains.

In the mouse system, specific determinants other than major histocompatibility complex (MHC) gene products are capable of inducing strong primary proliferative responses in naive T cells. These determinants are encoded by at least two gene loci designated as minor lymphocyte stimulatory (Mls) loci. In order to elucidate the biological role of the Mls system, an effort has been initiated to clarify the fundamental immunogenetic characteristics of the Mls system. In this report, we describe the unexpected finding that Mlsc determinants are expressed on splenocytes of strains including those which have been used as prototypic examples of three other Mls types: Mlsa (DBA/2, DBA/1), Mlsb (BALB/c), and Mlsx (PL/J). The expression of Mlsc by these strains was demonstrated both by the response patterns of unprimed T cells from MHC-identical inbred or F1 hybrid strains and by the responses of a panel of Mls-specific T-cell clones. The experimental results reported here also suggest that the expression of Mls determinants may be influenced by multiple other genes, including MHC-linked genes.

Animals↗

Partial C4 deficiency in subacute sclerosing panencephalitis.

In an immunogenetic study, 23 subacute sclerosing panencephalitis (SSPE) patients and their families were studied for the HLA region markers HLA-A, B, C, DR, BF, C2, C4A, C4B, GLO I, and PGM3. In addition, C3, C4, and factor B serum levels were determined. A highly significant association of C4A QO with SSPE was found. Furthermore, two rare haplotypes, C4A QOB QO, two C4ACh+ allotypes, and four Ch partial inhibitors were detected, which possibly impair the function of the C4 molecules. HLA-DR5 was increased. In addition, a number of rare HLA-A, C, B, DR haplotypes were observed. It is postulated that rare C4 molecular deficiency might be a predisposing factor in the pathogenesis of SSPE.

Complement C4↗

Lymphocyte subpopulations in solvent-exposed workers.

To estimate the cellular immune response of workers highly exposed to mixtures of organic solvents, subpopulations of peripheral blood lymphocytes (PBLs) were analyzed. For this, the PBLs of nine floorers (aged 25-58 years, exposure time 8-35 years) were subsequently labelled with monoclonal antibodies OKT4, OKT8, OKT11, anti-Leu 7 and anti-Leu 12. Analysis was made by a FACS IV cell sorter (Becton-Dickinson, USA). The control group consisted of matched pairs of healthy donors. In the exposed group we found a decrease in the OKT11 (all) T cell fraction, a decrease in the OKT4 helper cells, an increase in the anti-Leu 7 positive cells, mostly natural killer cells, an important increase in anti-Leu 12 labelled T cells, i.e., human B-lymphocytes, and no differences in the OKT8 suppressor cells. Total fluorescence intensity profiles between the exposed and the unexposed group did not differ, i.e., the marker density on the cell surfaces remained unchanged. Similar changes in lymphocyte subpopulations are found in states of immunodeficiency and immunogenetic forms of aplastic anemia, a disease whose etiological relationship may be due to long-term exposure to organic solvents.

Adult↗

Immunogenicity of intraperitoneal insulin infusion using programmable implantable devices.

Intraperitoneal insulin infusion using implantable devices in insulin-dependent diabetic (IDDM) patients is promising since it improves diabetic control and decreases frequency of hypoglycaemia. However, preliminary data show a striking increase in plasma levels of anti-insulin antibodies with this therapy. In order to more precisely evaluate the immunogenicity and its consequences, anti-insulin antibody levels in 62 IDDM patients were assessed every 3 months during a 2-year period following pump implantation. At the same time, diabetes control was evaluated with HbA1c, mean blood glucose levels, standard deviation of the daily blood glucose levels and the frequency of low blood glucose (< 3.58 mmol/l). Factors involved in antibody formation such as age, gender, HLA typing, and complement C4 alleles were also studied. After implantation, anti-insulin antibody levels increased significantly from 3.14% (range 0-26%) to 8.34% (0-49%) after 1 year and remained elevated. Patients were divided into two groups: responders able to show at least one antiinsulin antibody titre higher than 15% and non-responders whose titres were always lower than 6%. None of the factors studied was shown to statistically influence the anti-insulin antibody titres. Non-responders had significantly better metabolic results than the responders. Severe hypoglycaemic episodes decreased dramatically in both groups. Insulin requirements were comparable at time 0 and decreased initially in both groups. They remained low for the non-responders but returned to pre-implantation values for responders. Intraperitoneal insulin infusion led to a high immunogenetic response towards insulin in about half of the patients, leading to only moderately deleterious effects on metabolic control.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Association of malignant glioma with the human leukocyte antigen, HLA-A24(9).

Many immune responses are controlled by genes of the major histocompatibility complex (MHC). In humans these include the loci encoding the HLA-A, -B, -C, -DR, -DQ, and -DP antigens, and many diseases have been linked with these. However, little information is available about any connection between malignant tumors and HLA. In this study the possible association of HLA-A, -B, -C and -DR specificities with susceptibilities to malignant glioma was investigated in 42 patients with malignant glioma and 42 controls with non-glial intracranial tumors using the Terasaki-NIH standard method. The data were also compared with those of the 11th International HLA Workshop. The result showed that a high frequency of HLA-24(9) was observed in patients with intracranial malignant gliomas, which was not common in other, non-glial patient groups. In animals the MHC acts in defense against virally induced tumors, but until now there has been no evidence that they do so in human gliomas. Our discovery of its association with an HLA antigen is important for understanding the immunogenetic basis of susceptibility to glioma.

Adolescent↗

Biochemical genetics of rat esterases: another genetically determined variant, Es-7, is linked to five other esterase loci.

A new esterase variant has been isolated by electrophoresis of homogenized testis, heart, and lung tissues. This esterase variant is genetically determined. The carrier strain was crossed with another in which the enzyme was not originally present; the presence of the enzyme was investigated in successive generations and in backcrosses to the carrier strain. Linkage was found with other esterases linkage group V, while there was independent segregation from the immunogenetic markers Ly-1, Ly-2, LH-1 and Rt-la.

Alleles↗

Treatment of diabetes mellitus.

New treatment strategies for subjects with Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetes mellitus are being developed. Pilot studies utilising insulin itself have been reported to prevent Type 1 diabetes in subjects likely, by immunogenetic and physiologic criteria, to develop clinically overt disease, while the results of nicoti-namide trials in these subjects remain preliminary. Immunotherapy with cyclosporin A and azathioprine can slow disease progression and may produce long-term remissions when given within two months of onset of clinically overt disease. In subjects with established disease, familial clustering of diabetic nephropathy may be related to concomitant susceptibility to hypertension and elevated rates of Na/H countertransport. Treatment of hypertension associated with the nephropathy appears to slow renal deterioration. Whether reversal of the metabolic consequences of insulin deficiency or resistance also prevents chronic diabetic complications has not been firmly established. In the presence of a reduced Beta-cell mass, moderate hyperglycaemia may itself contribute to decreased muscle glucose uptake but not glycogen synthesis in Type 1 and Type 2 diabetes. Reversal of chronic hyperglycaemia by pancreas and islet cell transplantation, vanadate, and sulphonylureas are discussed as alternate strategies to insulin treatment in establishing normoglycaemia and furthering our understanding of insulin action and secretion at the cellular level. There remains a need to develop more sensitive biochemical and genetic markers to identify subjects at increased risk for developing chronic diabetic complications.

Animals↗

Proliferation of epineurial capillaries and smooth muscle cells in angiopathic peripheral neuropathy.

Proliferation of epineurial capillaries and smooth muscle cells in human sural nerves has been documented. These are basically independent changes, although both can occur in the same nerve. Proliferated epineurial capillaries were seen in association with arterial stenosis or occlusion with or without granulating or granulomatous inflammatory reactions. Although non-specific they appear to be of considerable diagnostic value indicating compensatory hypervascularization subsequent to peripheral focal ischemia. Separation and numerical increase of epineurial smooth muscle cells, on the other hand, was also recognised as a significant though non-specific alteration occurring in various inflammatory, immunogenetic, or other, non-inflammatory angiopathies. The youngest (1.3 years) and the oldest individual (104 years) studied, as well as many other documented and non-documented cases, did not show this type of change. Smooth muscle cells may survive isolated or focally separated from adjacent vessel walls in the epineurium.

Biopsy↗

MHC epitopes of KS and Dd restrict the same population of cytolytic T lymphocytes.

When A. SW (H-2S) mice are immunized with B10.S (H-2S) epidermal cells, cytolytic T lymphocytes are evoked that efficiently lyse B10.D2 (H-2d) as well as B10.S target cells. Immunogenetic analysis of this apparent H-2-unrestricted killing revealed that the most plausible explanation was a sharing of an H-2-restricting epitope by H-2KS and H-2Dd molecules.

Animals↗

Complexity at the mouse minor histocompatibility locus H-4.

The fine immunogenetics of the chromosome 7 mouse minor histocompatibility (H) locus H-4 was investigated. Both class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocytes (CTL) and class II MHC-restricted "helper" T cells (TH) specifically reactive with H-4 antigens were isolated as clones and were used as genetic probes for classical backcross segregation analysis. Results of a four point cross indicated that the H-4 locus was actually comprised of two genes, that have been designated H-46 and H-47. The former encodes antigens recognized by the TH and the latter encodes antigens recognized by the CTL. Moreover, these two genes could be separated from the gene pink-eyed dilution (p) which was found to be "sandwiched" between them. The functional significance of a minor H congenic strain differing by both TH-defined H-46 and CTL-defined H-47 was addressed using F1 complementation tests. Such studies indicated that immune responses against H-46 antigens was required for generation of H-47-specific CTL. Altogether, these results suggest selective presentation of different minor H gene products by class I or class II MHC proteins and that the minor H "locus" H-4 may have necessarily included both TH and CTL-defined genes because of requisite TH-CTL collaboration.

Animals↗

Pathogenesis of idiopathic IgA nephropathy.

Despite a prodigious amount of work on the physiology of IgA production in man, and many studies on the immunopathology of IgA nephropathy, ranging from the immunogenetics to the immune response to chemical characteristics of the IgA, we are hardly any nearer to defining the pathogenesis of this disease. One of the main changes in our understanding has been to recognise that the bone marrow, now known to produce normally one-third of the body's IgA, overproduces this immunoglobulin in IgA nephropathy. This alters the previous notion that IgA nephropathy was due simply to IgA production in the mucosa, although a mucosal component is not excluded. Certain characteristics of the IgA in the diseased kidney and the circulation have been defined: it is of subclass IgA1 and has a higher proportion of lambda light chains and negative charge than in normal subjects. The specificities of the IgA, either in the kidney or in complexes, have not helped to clarify the pathogenesis. They have been found for a wide range of endogenous and exogenous antigens, suggesting that the antibody activity represents polyclonal B cell activation. These findings have not helped to confirm the prevailing theory that IgA nephropathy is an immune complex disease. Other theories put forward are that IgA nephropathy is an autoimmune disease, glomerular components or IgA itself being among the candidate antigens, or that there is primary dysregulation of the IgA immune system. At this stage of development in our understanding of this common nephropathy, it is important to guard against the assumption that idiopathic IgA nephropathy is one disease and is the result of a single pathogenetic mechanism.

Glomerulonephritis, IGA↗

Human leucocyte antigens in idiopathic nephrotic syndrome in children.

An association of the idiopathic nephrotic syndrome (NS) with certain human leucocyte antigens (HLA) has been reported repeatedly. The aim of this study is to characterize further the clinical and histological features of patients with NS in relation to their HLA phenotypes. HLA antigens were determined in 132 paediatric patients with NS. In 91 steroid-sensitive patients (usually associated with minimal glomerular changes), the antigen frequencies of HLA-DR3, HLA-DR7, and HLA-B8, -DR3 combined were significantly increased compared with controls. The strongest association was observed with the combined occurrence of HLA-B8, -DR3, -DR7 (relative risk 21.5). This association and that with HLA-DR3 alone were strongest in the presence of frequent relapses and steroid dependence compared with children without or with infrequent relapses. The pattern of HLA antigens was similar in the 57 steroid-sensitive patients with biopsy-proven minimal glomerular changes. In 41 children with steroid-resistant NS (usually associated with focal segmental glomerulosclerosis) a similar trend for increased antigen frequencies was found but the data were significant only for the combined occurrence of HLA-B8, -DR3 and -DR7. In all patients combined the frequency of the HLA associations was significantly lower when the age of onset was greater than 8 years compared with that of younger patients. It is concluded that the immunogenetic background of the steroid-sensitive and steroid-resistant NS is different and age-dependent.

Adolescent↗

HLA complement gene polymorphisms in multiple sclerosis. A study on 80 Italian patients.

We studied C4A, C4B, and Bf complement gene polymorphisms in 80 Italian patients with multiple sclerosis (MS). We observed a significantly higher frequency of C4AQ0 allele in patients with the relapsing-remitting form of MS than in ethnically homogeneous controls. Restriction fragment length polymorphism analysis by Southern blotting of the C4/CYP21 gene complex showed that a structural gene deletion was present in 45% of patients with the C4AQ0 allele. Our data support the hypothesis that relapsing-remitting MS and primarily chronic progressive MS are immunogenetically distinct diseases; further, complement factor abnormalities typical of autoimmune diseases could influence the pathogenesis of MS.

Case-Control Studies↗

Immunoreactivity of antimitochondrial autoantibodies in Japanese patients with primary biliary cirrhosis.

The incidence and prevalence of primary biliary cirrhosis show wide geographic differences. The frequency of this disease in Japan is lower than in Northern Europe. To elucidate the immunoreactivity of serum with enzymes of the 2-oxo-acid dehydrogenase complex (2-OADC) and the M2 mitochondrial antigenic complex in Japanese patients, we examined sera from 107 patients with primary biliary cirrhosis from three geographically different regions of Japan. The sera were assayed by immunofluorescence on frozen tissue sections, immunoblotting on bovine heart mitochondria and recombinant E2 subunit of branched chain oxo-acid dehydrogenase complex (BCOADC-E2), ELISA using recombinant E2 subunit of human pyruvate dehydrogenase complex (PDC-E2) and purified porcine 2-oxoglutarate dehydrogenase complex (OGDC), and enzyme inhibition assay using procine PDC and OGDC. Of the 107 sera, 95 (88%) reacted by immunofluorescence, 102 (95%) by immunoblotting with at least one of the M2 autoantigens, although only 78 (73%) reacted with PDC-E2; 72 (67%) by ELISA with PDC-E2; and 81 (76%) with PDC by the enzyme inhibition assay. Thus, the frequency of reactivity with PDC-E2 by all assays was lower for Japanese than the reported frequency for Caucasian patients with primary biliary cirrhosis, whereas the frequency of reactivity by immunoblotting and ELISA against 2-OADC enzymes other than PDC was relatively higher. The relative frequency of reactivity of autoantibodies to the M2 autoantigens was similar for the three different regions of Japan. The different autoantibody profiles for Japanese and Caucasian patients with primary biliary cirrhosis point to immunogenetic and environmental determinants of this disease, which should provide new insights into its autoimmune origins.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗