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J Bertrams

Publications and source records attributed to J Bertrams.

At least 55 records · Page 3Linked to original sources

[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

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

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

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

[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

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

HLA-A, B, Bf three point association of 1,072 haplotypes in a German population.

Altogether 1,072 HLA-A, B, Bf haplotypes in 536 parents of 268 German families were analyzed by gene and haplotype counting in order to investigate the two and three point association of HLA-A and B antigens with Bf alleles. In agreement with previously published data (Albert et al. 1975, Bender et al. 1977) significant positive linkage disequilibria were found for HLA-A3 and BfF, B7 and BfS, B8 and BfS, Bw35 and BfF, whereas significant negative Delta values appeared to exist for HLA-A3 and BfS, B7 and BfF, B8 and BfF, B12 and BfS, as well as Bw35 and BfS. Significant positive three point Delta values were found for the following haplotypes: HLA-A11, Bw35, BfS, HLA-Aw23, Bw35, BfS, HLA-A28, B12, BfS, HLA-A2, B17, BF, HLA-A3, Bw35, BfF, HLA-Aw24, b12, BfF and HLA-A29, B12, BfF. According to the large number of comparisons performed calculating the level of significance of the three point associations, these data have to be corroborated by further investigation. The three point Delta values, obtained by calculation from the patients' phenotypes differed markedly from those results obtained by haplotype counting.

Alleles

Immunogenetical aspects of multiple sclerosis with special regard to the HLA-histocompatibility system.

In the HLA complex it is evident that some antigens occur rather frequently, while others are rare. A statistically significant increase or decrease of any of these antigens in a given number of patients suffering from the same disease therefore suggests an association between such a disease and the HLA-system. In this study the Author compared the HLA antigen frequencies of 1.000 M.S. patients and 1.000 healthy controls, tissue typed during the same time period by the identical antiserum-set.

HLA Antigens

Missing evidence for HLA antigen association with Eales' disease, chorioretinitis, central serous retinopathy, and malignant choroidal melanoma.

Patients with Eales' disease, chorioretinitis, central serous retinopathy, or malignant choroidal melanoma were tested for HLA antigen deviation. When corrected p values (pc) are used, the first three disorders did not show any significant deviation, whereas a significant increase of HLA-Aw32 (pc = 0.026) was found in the malignant melanoma group. For conclusive evidence the latter finding needs confirmation by analysis of a greater number of patients with this disorder.

Chorioretinitis