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T H Eiermann

Publications and source records attributed to T H Eiermann.

At least 37 records · Page 2Linked to original sources
PubMed1994

Analysis of TAP2 and HLA-DP gene polymorphism in psoriasis.

TAP2 is a gene, located between HLA-DP and HLA-DQ, whose products form a transporter molecule involved in endogenous antigen processing. Polymorphic residues have been described in this gene. TAP2 is of particular interest because its involvement in antigen presentation makes it a candidate for a disease susceptibility gene. In psoriasis, two clinical subtypes analogous to the situation in diabetes type I with early onset and family history and type II with later onset and without family history have been described. We have previously shown that type I but not type II psoriasis is associated with the HLA-DRB1*0701/2, -DQA1*0201, -DQB1*0303 haplotype. To investigate whether this haplotype extends to include particular TAP2 and/or DP alleles, we tested the TAP2 and HLA-DP alleles of a control group (n = 199), patients with psoriasis type I (n = 66), and patients with psoriasis type II (n = 35) by hybridization with SSOs. Our data show that there is no significant correlation between TAP2 and/or HLA-DP gene polymorphism and psoriasis type I and/or type II. We conclude that disease association in type I psoriasis is associated with the extended haplotype HLA-B57, -Cw6, -DRB1*0701/2, -DQA1*0201, -DQB1*0303.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Semiautomated HLA-DQB1 typing by fluorescent dye photometry of amplified DNA on microtiter plates.

We report a simple semiautomated HLA class II typing method that suits the demands of a 24-hour-duty transplantation service for preorgan retrieval donor typing. The procedure consists of sequence-specific amplification of HLA alleles by the polymerase chain reaction (nested PCR-SSP) followed by fluorescent dye photometry of the resulting PCR products on microtiter plates. The entire typing procedure is semiautomated and completed in less than 90 minutes after DNA isolation. The test was evaluated for the definition of the specificities DQ1-DQ9 (generic HLA-DQB1 typing). Sensitivity and specificity as judged by DNA reference typing in a different laboratory was 99.5% (n = 202 alleles).

Alleles↗
PubMed1994

[Bone marrow transplantation].

Bone marrow transplantation from HLA-identical siblings has become an accepted therapy for leukaemia and a variety of lympho-haematopoietic disorders. In recent years the marrow of unrelated donors is increasingly used for patients lacking a family donor. In this paper current principles and methods of donor selection are presented with special regard to the search for an unrelated donor.

Bone Marrow Transplantation↗
PubMed1993

Human monoclonal islet specific autoantibodies share features of islet cell and 64 kDa antibodies.

The first human monoclonal islet cell antibodies of the IgG class (MICA 1-6) obtained from an individual with Type 1 (insulin-dependent) diabetes mellitus were cytoplasmic islet cell antibodies selected by the indirect immunofluorescence test on pancreas sections. Surprisingly, they all recognized the 64 kDa autoantigen glutamate decarboxylase. In this study we investigated which typical features of cytoplasmic islet cell antibodies are represented by these monoclonals. We show by double immunofluorescence testing that MICA 1-6 stain pancreatic beta cells which is in agreement with the beta-cell specific expression of glutamate decarboxylase. In contrast an islet-reactive IgM monoclonal antibody obtained from a pre-diabetic individual stained all islet cells but lacked the tissue specificity of MICA 1-6 and must therefore be considered as a polyreactive IgM-antibody. We further demonstrate that MICA 1-6 revealed typical features of epitope sensitivity to biochemical treatment of the target tissue which has been demonstrated for islet cell antibodies, and which has been used to argue for a lipid rather than a protein nature of target antigens. Our results provide direct evidence that the epitopes recognized by the MICA are destroyed by methanol/chloroform treatment but reveal a high stability to Pronase digestion compared to proinsulin epitopes. Conformational protein epitopes in glutamate decarboxylase therefore show a sensitivity to biochemical treatment of sections such as ganglioside epitopes. MICA 1-6 share typical features of islet cell and 64 kDa antibodies and reveal that glutamate decarboxylase-reactive islet cell antibodies represent a subgroup of islet cell antibodies present in islet cell antibody-positive sera.

Animals↗
PubMed1993

TAP2 gene polymorphism segregates with DR-DQ in DR/DP recombinant siblings.

RING 11, a second transport-associated gene (TAP2), has been recently identified in the DR-DP interval of the human class II region. Two predominant alleles, TAP2A and TAP2B, differing by 17 amino acids at the C-terminus of the ATP-binding domain are present in the Caucasoid population at frequencies of 79% and 21%, respectively. In the rat, polymorphism of the TAP genes were found to influence peptide loading of MHC class I molecules and, in humans, it was speculated that variation in peptide loading of HLA-B27 molecules might be also linked to factors altering antigen presentation presumably encoded in the HLA region. To determine whether TAP2 gene polymorphism may be relevant to peptide loading in humans, we typed 41 HLA-ABC, DR-identical pairs for TAP2A and TAP2B by PCR-SSO hybridization or direct genomic sequencing. In eight cases, GLO-different and, in six cases, DP-different recombinant siblings were included. Allele frequencies for TAP2A and TAP2B were as previously reported (74% and 26%, respectively). In all pairs, TAP2 gene polymorphism segregated with the DR-DQ type, mapping the TAP2 gene telomeric to the recombination hot spot in the DR-DP interval of the human class II region. We conclude that, in HLA-identical siblings, TAP2 gene differences are very unlikely to occur. Thus, in HLA-identical siblings, minor histocompatibility antigenic differences cannot be attributed to variant peptide loading due to TAP2 gene polymorphism.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Oligonucleotide typing reveals association of type I psoriasis with the HLA-DRB1*0701/2, -DQA1*0201, -DQB1*0303 extended haplotype.

Although the pathogenesis of psoriasis is still a matter of debate, there are several lines of evidence supporting the concept of this disease being immunologically mediated with T cells playing a crucial role. Because a considerable portion of the cellular infiltrate in psoriasis consists of activated T-helper cells, expression of HLA class II antigens might be of particular importance for the understanding of its pathogenesis. Therefore, we investigated the HLA type of patients with type I (early onset, positive family history) and type II (late onset, no family history) psoriasis by means of serology (n = 89) and genotyping using sequence-specific oligonucleotide probes (n = 64). Serologic analysis of class I documented the association of type I psoriasis with HLA-Cw6, -B13, and -B57, whereas type II psoriasis showed a weaker correlation with HLA-Cw2 and -B27. Genotyping using SSO for class II detected the elevation of the HLA-DRB1*0701/2 allele frequency from 13% in normal population to 36% in type I, but only to 15% in type II psoriatics. Moreover, positive correlations with type I psoriasis were detected for HLA-DQA1*0201 and HLA-DQB1*0303. The HLA-DRB1*0701/2, -DQA1*0201, -DQB1*0303 extended haplotype was found exclusively in type I psoriasis. This is the first report documenting the association of distinct HLA class II alleles with type I psoriasis as detected on the DNA level, an approach both more specific and more sensitive when compared to serology.

Adult↗
PubMed1993

HLA DNA preorgan retrieval donor typing in renal transplantation.

For the first time, a DNA technique was used in clinical practice for pre-organ donor retrieval typing in renal transplantation. The method is based on the polymerase chain reaction with nested sequence-specific pairs (nested PCR-SSP) for all serological HLA-DR specificities of DR1-DR18. A panel of reference-typed individuals (n = 101) was investigated in a blind quality control study and the results revealed a sensitivity of 99.5% and a specificity of 100%. Semi-automation of PCR-SSP provided rapid, accurate and reliable typing results demonstrating that this DNA test is most suitable for replacing the error-prone HLA-DR serological technique. Twenty-seven consecutive cadaveric organ donors have been successfully typed so far. The results were available within less than 3 h after blood sampling and in all cases prior to the retrieval of organs. In conclusion, the introduction of this accurate DNA typing in HLA matching programs may significantly improve the graft survival rate in renal transplantation.

Blood Grouping and Crossmatching↗
PubMed1993

[Indications for irradiated blood components: dose and side effects].

Transfusion-associated graft versus host disease (ta-GvHD) is a rare but almost lethal complication of blood transfusion in immunocompromised patients. To prevent ta-GvHD, irradiated blood products should be given to patients at risk: patients after bone marrow transplantation, newborns and children in the 1st year, patients with severe combined immunodeficiency, and patients receiving blood from first-degree relatives. Blood products should be irradiated at least with 30 Gy just before transfusion. With this regime in practice for 4 years, no complications and side effects were seen.

Blood↗
PubMed1992

Human monoclonal islet cell antibodies from a patient with insulin-dependent diabetes mellitus reveal glutamate decarboxylase as the target antigen.

The autoimmune phenomena associated with destruction of the beta cell in pancreatic islets and development of type 1 (insulin-dependent) diabetes mellitus (IDDM) include circulating islet cell antibodies. We have immortalized peripheral blood lymphocytes from prediabetic individuals and patients with newly diagnosed IDDM by Epstein-Barr virus transformation. IgG-positive cells were selected by anti-human IgG-coupled magnetic beads and expanded in cell culture. Supernatants were screened for cytoplasmic islet cell antibodies using the conventional indirect immunofluorescence test on cryostat sections of human pancreas. Six islet cell-specific B-cell lines, originating from a patient with newly diagnosed IDDM, could be stabilized on a monoclonal level. All six monoclonal islet cell antibodies (MICA 1-6) were of the IgG class. None of the MICA reacted with human thyroid, adrenal gland, anterior pituitary, liver, lung, stomach, and intestine tissues but all six reacted with pancreatic islets of different mammalian species and, in addition, with neurons of rat cerebellar cortex. MICA 1-6 were shown to recognize four distinct antigenic epitopes in islets. Islet cell antibody-positive diabetic sera but not normal human sera blocked the binding of the monoclonal antibodies to their target epitopes. Immunoprecipitation of 35S-labeled human islet cell extracts revealed that a protein of identical size to the enzyme glutamate decarboxylase (EC 4.1.1.15) was a target of all MICA. Furthermore, antigen immunotrapped by the MICA from brain homogenates showed glutamate decarboxylase enzyme activity. MICA 1-6 therefore reveal glutamate decarboxylase as the predominant target antigen of cytoplasmic islet cell autoantibodies in a patient with newly diagnosed IDDM.

Adolescent↗
PubMed1992

Selection of unrelated bone marrow donors: does the current procedure warrant complete MHC class II identity?

Bone marrow transplantation from unrelated donors is being used increasingly for the treatment of patients with leukemia and several other hematologic disorders. Selection of unrelated bone marrow donors currently relies on serological HLA identity and negative mixed lymphocyte reactions between donor/recipient pairs. As serological HLA-DP typing is not feasible, we used the HLA-DPB1 oligonucleotide typing method to investigate whether the current selection procedure can guarantee complete MHC class II identity. In 40 consecutive patients, one third (62/193) serologically HLA-A, -B, -C, -DR and -DQ identical donors were found to be MLC negative with a relative response below 5%. HLA-DPB1 oligonucleotide typing of these MLC negative donors revealed that again only one third (20/62) was also identical for DP with their presumptive recipients. In the majority of pairs a disparity in graft-versus-host direction or in host-versus-graft direction of at least one allele was seen. These data indicate that in spite of the strict MLC criteria used, the current procedure did not warrant complete MHC class II identity. This implies that oligotyping for DPB1 can improve matching and should be introduced for typing of volunteers. We speculate that DP differences may contribute to the higher incidence of graft-versus-host disease or graft rejection in unrelated transplants.

Bone Marrow Transplantation↗
PubMed1992

Selection of unrelated bone marrow donors: does the current procedure warrant complete MHC class II identity?

Bone marrow transplantation from unrelated donors is being used increasingly for the treatment of patients with leukemia and several other hematologic disorders. Selection of unrelated bone marrow donors currently relies on serological HLA identity and negative mixed lymphocyte reactions between donor/recipient pairs. As serological HLA-DP typing is not feasible, we used the HLA-DPB1 oligonucleotide typing method to investigate whether the current selection procedure can guarantee complete MHC class II identity. In 40 consecutive patients, one third (62/193) serologically HLA-A, -B, -C, -DR and -DQ identical donors were found to be MLC-negative with a relative response below 5%. HLA-DPB1 oligonucleotide typing of these MLC-negative donors revealed that again only one third (20/62) was also identical for DP with their presumptive recipients. In the majority of pairs a disparity in graft-versus-host direction or in host-versus-graft direction of at least one allele was seen. These data indicate that, in spite of the strict MLC criteria used, the current procedure did not warrant complete MHC class II identity. This implies that oligotyping for DPB1 can improve matching and should be introduced for typing of volunteers.

Bone Marrow Transplantation↗
PubMed1992

The incidence of DPB1 differences between serological and mixed lymphocyte culture matched unrelated individuals: implications for selection of bone marrow donors.

Bone marrow transplantation from unrelated donors is being used increasingly for the treatment of patients with leukaemia and other disorders of lymphohaemopoiesis. Selection of histocompatible unrelated bone marrow donors currently relies on serological HLA identity and negative mixed lymphocyte cultures (MLC) between potential donor-recipient pairs. Since serological HLA-DP typing is not feasible, we used the HLA-DPB1 oligonucleotide typing method to test whether the current selection procedure can also guarantee identity for HLA-DP. In 40 consecutive patients, one-third (62/193) of the serologically HLA-A, -B, -C, -DR and -DQ identical donors were judged as MLC negative (relative response below 5%) with the presumptive recipient. HLA-DPB1 oligonucleotide typing of the MLC negative donors revealed that only one-third of these (20/62) were also identical for DP. In the majority of the pairs, we found a DPB1 disparity. A difference in the graft-versus-host direction was seen in 25/62 cases in the host-versus-graft direction in 28/62 cases and in both directions in 29/62 cases. These data indicate that, in spite of the strict MLC criteria used, the current procedure did not guarantee complete MHC class II identity. Therefore oligotyping for DPB1 can improve matching for DP and should be introduced for typing of volunteers. We suspect that DP differences may contribute to the higher incidence of graft-versus-host disease or graft rejection in unrelated donor transplants.

Bone Marrow Transplantation↗
PubMed1991

How many probes are needed for HLA-DPB1 typing with sequence-specific oligonucleotide probes? A theoretical approach using computer simulation.

HLA-DP genotyping with sequence-specific oligonucleotides is used to detect known sequence variations in the polymorphic segments of the DPB1 second exon. This approach is a valuable method replacing the tedious cellular definition of DP polymorphism. We have addressed, by computer simulation, the question: what is the minimum number of probes needed to provide an unambiguous assignment of HLA-DP alleles by genotyping of heterozygous individuals? We were able to reduce the number of probes in a set defining the presently known 22 different alleles and most of the heterozygous combinations to 18 probes. Only two pairs of allelic combinations cannot be distinguished by this method, neither with our optimized set of probes nor with any larger set comprising probes of reasonable length. This is because two pairs of alleles may be the result of a reciprocal genetic exchange. These two pairs, however, could be distinguished by family analysis, direct sequencing, or DNA amplification using specific primers chosen from the polymorphic ends of the DPB1 second exon.

Alleles↗
PubMed1991

HLA-DPB1 oligonucleotide typing of a southwest German Caucasian population.

HLA-DP genotyping with sequence-specific oligonucleotides can detected known sequence variations in the polymorphic segments of the DPB1 second exon. Since the allelic polymorphism of the 22 published alleles is based on recombination of sequence motifs from six variable regions, DPB1 typing depends on the reactivity pattern of many different probes rather than from typing with single allele-specific probes. By computer simulation, we have previously shown that the minimal set of probes to define the 22 different alleles and most of the heterozygous combinations is 18. Here we describe HLA-DPB1 typing results and allele frequencies in a panel of 200 unrelated Caucasians from Southwest Germany. The result confirmed the power of the new HLA-DPB1 typing method, but we failed to detect three of the previously described alleles in our panel. To accommodate with the observed 19 different alleles, the sequence and hybridization conditions of 17 oligonucleotide probes are given, which are able to differentiate all except two, resolved by group-specific amplification, of the 190 possible heterozygous phenotypes.

Alleles↗
PubMed1990

Alloreactive T-cell clones raised in an HLA-B/D crossing-over family dissect HLA-DR5 and HLA-DQw3 subtypes.

This study was undertaken to resolve a positive mixed lymphocyte reaction between HLA-ABC identical, HLA-D different siblings. Three CD3+ CD4+ CD8- alloreactive T-lymphocyte clones, called 2/6, 7/1, and 7/2, were generated and extensively studied. Proliferation of 2/6 cells and 7/2 cells was blocked by anti-DQ monoclonal antibodies (mAbs), whereas anti-DR and DP were not effective. Stimulation of 7/1 cells was inhibited by anti-DR, but not by anti-DQ and DP mAbs. Testing on a well-characterized panel of reference B-lymphoblastoid cell lines showed that the DQ-specific clones 2/6 and 7/2 were able to proliferate upon stimulation by cells carrying the DQw7 and DQw8 but not the DQw9 subtype of DQw3. Clone 7/1 was proliferative towards cells expressing DRw11.1 but not towards DRw11.2- or DRw12-positive cells. Moreover, this clone detected determinants present on some DRw8 cells. Correlation of the reactivity of clone 7/1 with available sequence data suggests that amino acids 67, 71, and 86 of DR beta 1 molecules played a crucial role in forming the epitope recognized by this clone. In contrast, sharing of T-cell epitopes between DQw7 and DQw8 subtypes was not inferable from specific amino acid residues. The implication of these findings for T-cell allorecognition is discussed.

Amino Acid Sequence↗
PubMed1990

Effect of cytokines on proliferation of Epstein Barr virus-transformed B lymphocytes.

Plating efficiencies of EBV transformed human B cells seeded in single cell cultures are far lower (less than 1%) than observed in T cell cloning experiments. This report describes the stimulatory effect of several crude as well as recombinant growth factors on proliferation of EBV transformed B cells measured by [3H]thymidine uptake. Supernatant of LPS activated monocytes (HSF) and recombinant interleukin 4 (rIL-4), but not recombinant IL-1 beta, IL-2, IL-6, TNF alpha, GM-CSF, and interferon gamma increased [3H]thymidine incorporation. The combination of HSF and rIL-4 was found to be synergistic on B cell proliferation. Plating efficiency of EBV transformed B cells at limiting dilution was improved by HSF, but not by the combination of HSF and rIL-4.

B-Lymphocytes↗