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J Bertrams

Publications and source records attributed to J Bertrams.

At least 55 records · Page 3Linked to original sources
PubMed1986

Human C81 (alpha-gamma) polymorphism: detection in the alpha-gamma subunit on SDS-PAGE, formal genetics and linkage relationship.

The molecular basis of human C81 (alpha-gamma) polymorphism could be elucidated by immunoprecipitation of human C81 allotypes and separation of the alpha-gamma and beta subunits on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions. If the C8 molecules were completely reduced, C81 polymorphism was no longer detectable on SDS-PAGE. It is concluded that C81 variation depends on charge rather than molecular weight differences. Four C81 allotypes, the common A and B and two rare allotypes provisionally named A2 and B1, could be distinguished. The rare allotype A1 as detected by isoelectric focusing with subsequent C8 (alpha-gamma)-dependent functional overlay could no longer be visualized on SDS-PAGE. This allotype may therefore be elicited only in the intact C8 molecule. The beta-chain polymorphism named C82, probably also reflecting charge variation of the C8 molecule, could not be detected yet on SDS-PAGE. The distributions of C81 phenotypes and their respective allele frequencies were in good agreement with previously reported data. In the study of 30 families with 100 offspring, no deviation from the rule of at least four codominant alleles at one genetic locus was found. Linkage between C81 gene(s) and PGM1a encoded on chromosome 1 could be confirmed. The following estimates were obtained: (formula; see text) with S theta being the standard error of the maximum likelihood estimate theta. The new technique for allotyping human C81 at the subunit may provide a new tool for the differentiation of qualitative and quantitative variation of the eighth component of human complement.

Alleles↗
PubMed1986

Clinical features of inflammatory joint and spine manifestations in Crohn's disease.

167 patients with Crohn's disease were investigated for joint and spine inflammation. Arthritis was observed in 23 patients (14%), sacroiliitis in 24 (14%), and sacroiliitis in combination with arthritis in 11 patients (7%). 15 patients (9%) had ankylosing spondylitis; 9 of them were HLA-B27 positive (60%). A parallel pattern in the course of bowel disease and joint inflammation was observed in 22 out of 34 patients with arthritis (59%). An association between the localization of Crohn's disease and the type of spondylarthritis could not be demonstrated. Patients with arthritis alone developed erythema nodosum (35%) or aphthous stomatitis more often (21%) than patients without spondylarthritis+ (6% and 12%, respectively). Other extra-intestinal manifestations of Crohn's disease did not reveal any association with the development of spondyloarthritis.

Adolescent↗
PubMed1985

[Genetics of Crohn disease: study of the HLA association in 169 patients].

Histocompatibility (HLA) antigen phenotypes have been studied in 169 patients with Crohn's disease. The following results could bei shown: HLA-Aw33, -B45 and -Cw3 showed a positive association and HLA-A26, -DR3 and -DRw8 a negative association with Crohn's disease compared to healthy controls. However, when the p-values were corrected by multiplying them by the number of determined antigens per gen-locus, the differences were not significant. Patients with a late onset of the disease (greater than 25 years) showed a statistical significant negative association with HLA-DR3. Numerous studies revealed no significant association between Crohn's disease and HLA-antigens except Smolen et al. (HLA-B12). The significant association of Crohn's disease and HLA-B12 reported by Smolen et al. could be caused by an increased frequency of HLA-B45 as we found in our patients.

Adolescent↗
PubMed1985

Another family with a silent allele of properdin factor B polymorphism (BF QO).

In five of eight members of a three generation family the existence of a silent allele of the properdin factor B polymorphism (BF QO) was indicated by immunofixation of BF electrophoretic variants and by the hemolytic overlay after isoelectric focusing of BF allotypes. This was further supported by the results of HLA-A, B, C, DR, C2, C4A, C4B, GLO-typing. BF protein was decreased in all heterozygous BF deficient family members. The absolute hemolytic activity, however, was obviously compensated for by an increased relative functional activity of the normal S or F alleles on the other chromosome.

Alleles↗
PubMed1985

No interaction between HLA and immunoglobulin IgG heavy chain allotypes in early onset type 1 diabetes.

Immunoglobulin heavy and light chain genes are often discussed as susceptibility genes for insulin dependent (type 1) diabetes mellitus (IDDM) in addition to HLA-DR3 and DR4. Accordingly we analysed 175 unrelated patients for an interaction between immunoglobulin allotype antigens (Gm) and HLA. While DR3 and DR4 antigens and DR3/DR4 heterozygotes occur significantly more often among diabetics than among normal controls, their Gm allotype frequencies are very similar. An interaction between special Gm allotypes and phenotypes, on the one side, and DR3, DR4 or DR3, 4 on the other side could not be demonstrated.

Diabetes Mellitus, Type 1↗
PubMed1985

Genetic restriction of autoreactive acetylcholine receptor-specific T lymphocytes in myasthenia gravis.

Human autoreactive helper T lymphocytes with specificity for acetylcholine receptor (AChR) were isolated from three HLA-DR3-positive patients who had myasthenia gravis (MG), an autoimmune disease known to be associated with HLA-DR3 in the North European population. The antigen-specific T cells were evaluated for genetic restriction. Antigen presentation studies were performed with mitomycin C-treated accessory cells from a panel of HLA-typed unrelated donors. AChR-induced proliferation of the autoreactive T cells was maximal in the presence of autologous or HLA-DR-compatible antigen-presenting cells. In two DR-heterozygous patients both parental DR specificities served as restriction elements of the polyclonal AChR-reactive T cell populations. Preferential restriction to HLA-DR3 was observed in one patient, but this was also seen with PPD-specific T cells from the same donor. A series of monoclonal antibodies against HLA class II molecules was used for inhibition experiments. The inhibitory effects of the antibodies were not due to unspecific toxicity and could be observed after separate treatment of the antigen-presenting cells but not of the responding T cells. Several monoclonal antibodies against monomorphic HLA-DR determinants (DA 231, MAS 53, MAS 54, L243, OKIa1) had pronounced inhibitory effects. Anti-HLA-DQ(DC) monoclonal antibodies (Leu-10; TU 22) had only mild or no inhibitory effects in two patients but significantly inhibited AChR-specific T cells in one patient. A monoclonal antibody against HLA-DR3 (antibody 16.23) was not or was only weakly inhibitory in the DR3-positive patients, although it bound to autologous T line cells and B cells by indirect immunofluorescence. In one patient it was possible to compare the inhibition patterns of AChR-specific and PPD-specific T cells. Most of the monoclonal antibodies affected AChR- and PPD-specific T cells to a similar extent, but three antibodies (TU 22, 36, 39) inhibited PPD-specific T cells more than AChR-specific T cells, indicating the possibility of differential restriction of antigen- and autoantigen-specific T cells. It is suggested that the in vitro system described here may be helpful for the evaluation of anti-HLA class II antibodies as potential immunotherapeutic reagents.

Animals↗
PubMed1985

[HLA haplotype study in familial Crohn disease].

Among others, genetical factors have been discussed in the aetio-pathogenesis of inflammatory bowel diseases. This is supported by many studies reporting familial accumulation of Crohn's disease and ulcerative colitis. The use of HLA typing to demonstrate a genetical disposition has so far proved disappointing. Accordingly, if there is any association with definite HLA antigens, it is likely to be weak. We therefore investigated the HLA haplotypes in 13 families with multiple occurrences of Crohn's disease. Comparing observed and expected occurrences of HLA-haplotypes, we found a pronounced tendency towards common haplotypes in the affected siblings, uncles and nieces, and cousins. Although the data suggest a possible genetical disposition, additional factors such as microorganisms or possibly nutritional habits must be considered as causes for Crohn's disease.

Crohn Disease↗
PubMed1984

The influence of common variables on T cell subset analysis by monoclonal antibodies.

Normal values for T cell subsets as defined by the most commonly used monoclonal antibodies of the OKT series were determined in a group of 142 unrelated normal individuals. In most age classes females had significantly greater portions of OKT3 and OKT4 antigen bearing lymphocytes and accordingly a higher T4/T8 index. The range of individual normal values within the control population was remarkably wide. Intra-individual differences between the T subset composition remained rather constant over a period of 2 months. Time of day, food absorption and physical exercise had no influence on the results of subset analyses. Storage of the blood sample and freezing of isolated lymphocytes can result in significantly reduced OKT3 and OKT4 positive cell numbers. If lymphocytes were isolated soon after the blood was taken and resuspended in a stabilization medium they exhibited only minimal change.

Activity Cycles↗
PubMed1984

Gene and haplotype frequencies of the fourth component of complement (C4) in type 1 diabetics and normal controls.

C4 gene and haplotype frequencies were calculated from phenotype data of 380 unrelated Caucasian patients with insulin dependent (type 1) diabetes mellitus and were compared with analogous frequencies of 382 unrelated healthy Caucasian individuals. In diabetics, a significantly increased frequency of the rare allele C4B 3 (p less than 10(-7] and of the silent alleles C4A Q0 (p less than 10(-7] and B Q0 (p less than 0.002) was observed. Accordingly, insulin dependent diabetes is associated with partial C4 deficiency, which may contribute to the pathogenesis of the disease.

Alleles↗
PubMed1984

The HLA association of insulin-dependent (type I) diabetes mellitus.

Insulin dependent diabetes mellitus (IDDM) is closely associated with special MHC gene products. The class II gene products, HLA-DR3 and DR4, may be the primary susceptibility genes for IDDM. They mediate the pathogenetical immune mechanisms which, under the additional influence of special MHC-genes of class I and III, lead to diabetes. The extremely high frequency of HLA-DR3, DR4 heterozygotes among diabetic patients and the genetic heterogeneity in B8, DR3 positive patients on the one hand and B15, DR4 positive diabetics on the other with regard to various clinical, epidemiological and immunological parameters, point to the existence of at least two different diabetes susceptibility genes. They act synergistically when they occur together. Thus simple genetic models (autosomal dominant, autosomal recessive, gene dosage) do not appear to be relevant here. The increased diabetic risk for the identical siblings of DR3, DR4-positive patients offers a good opportunity of studying genetically influenced immune deviations in the prediabetic phase which result in the suppression and destruction of Beta cells and finally in the manifestation of diabetes.

Adolescent↗
PubMed1983

[Pathogenesis and immunotherapy of insulin-dependent (type I) diabetes mellitus].

The association of insulin-dependent (type I) diabetes mellitus with HLA-DR3 and DR4 and with several epidemiological, virological, immunological, and clinical data suggests a heterogenous pathogenesis. the initial lesion in most cases is a virologically induced autoimmune process. It is only rarely that insulin-dependent diabetes results from a pure viral infection or as part of polyendocrine autoimmune deficiencies. The knowledge of the genetical risk factors and of disease-specific humoral and cellular immune deviations exhibits possibilities of successful intervention by means of immunotherapy.

Autoimmune Diseases↗
PubMed1983

IgG and IgA heavy chain allotypes in Type 1 diabetes.

IgG and IgA heavy chain allotypes were determined in the sera of 483 Caucasian Type 1 diabetes patients and 503 Caucasian healthy controls. There was no significant difference between patients and controls neither on the level of Gm phenotype frequencies nor on the level of Gm three-locus and two-locus haplotype frequencies. A selective IgA deficiency was found in 14 patients (2.9%) but in none of the control individuals (P less than 10(-4].

Diabetes Mellitus↗
PubMed1982

Virologic, immunologic, and genetic factors in insulin-dependent diabetes mellitus.

A 16-month-old girl presented with an episode of fever and acute thrombocytopenic purpura caused by a Coxsackie B5 virus. On days 13 to 23, laboratory evidence of diabetes mellitus was present, followed by a 2 1/2-month remission, then by definitive insulin-dependent diabetes. The involvement of virologic, immunologic, and genetic factors in the pathophysiology was substantiated by the following data: (1) Virus-induced glucose intolerance was produced in selected mouse strains. (2) Islet-cell antibodies were found one week before onset of diabetes; however, circulating lymphocytes of the child at that time suppressed insulin release from islets in vitro. (3) Immunogenetic analysis of the child revealed the presence of high-risk genetic markers. It is suggested that the convergence of an insulotropic variant virus, genetic predisposition, and perhaps some uncontrolled adjuvant factors, e.g. steroid therapy and DPT vaccination, may have determined insular damage and anti-islet autoimmune reactions, leading to insulin-dependent diabetes mellitus.

Antibodies↗
PubMed1981

[HLA association of insulin-dependent diabetes mellitus type I (author's transl)].

HLA antigens A, B, C, DR and BF were determined in 14 sibling pairs with type I diabetes and in 61 patients without familial risks. Significantly positive associations of the disease with HLA DR3 and DR4 and a negative association with DR2 were found. Positive and negative associations with the various HLA A, B and C antigens (A1, A2, B8, B15, B18, Cw3) are of a secondary nature due to strong genetic coupling with primarily associated DR alleles. Localisation of diabetes-associated genes in the HLA DR region could be demonstrated in two families with HLA recombinations. In both cases the hypothetic disease gene segregated with the HLA DR segment. Joint evaluation of these data in an international series involving 1200 type I diabetics showed furthermore that around 90% of all patients are DR3 and/or DR4 positive, that the highest morbidity risk exists in DR3/4 heterozygosity and that DR4 positive persons usually fall ill before their 20th year of life and frequently in the last 3 months of the year. Allotment of clinical, epidemiological, virological and immunological criteria of type I diabetes to only one of the both risk factors indicates heterogeneous immunopathogenesis of the disease. HLA DR3 predisposes particularly to endocrine autoimmune disease and DR4 to increased virus susceptibility.

Adult↗