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L Gebuhrer

Publications and source records attributed to L Gebuhrer.

At least 37 records · Page 2Linked to original sources
PubMed1992

The bare lymphocyte syndrome.

The bare lymphocyte syndrome is a combined immunodeficiency resulting from the lack of expression of either class I or class II HLA antigens at the cell surface. The main clinical manifestations are infections of the respiratory or the digestive tract. The immunodeficiency involves the absence of antibody formation and the absence of cell-mediated response, to specific antigen, contrasting with virtually normal transplant immunity to allogeneic determinants. The responsible gene(s) is not born by chromosome 6. The best treatment appears, at the present time, to be in utero stem cell transplantation into the sick fetus, and it may, in the future, be gene therapy.

Child, Preschool↗
PubMed1991

Selection of unrelated donors for bone marrow transplantation is improved by HLA class II genotyping with oligonucleotide hybridization.

As the demand for donors for bone marrow transplantation increases, the use of HLA-matched, genetically unrelated donors represents a promising strategy. It is well documented that the clinical outcome of bone marrow transplantation is directly dependent on optimal matching for HLA class I and class II specificities. Molecular studies have revealed the existence of a much larger number of HLA class II alleles than was anticipated, many of which cannot be recognized by routine serological typing. Currently this "hidden" polymorphism represents a major limitation to the generalized use of unrelated donors for bone marrow transplantation. It has recently become possible, however, to identify HLA allelic polymorphism directly at the DNA level by hybridization with sequence-specific oligonucleotide probes ("HLA oligotyping") after amplification of DNA by polymerase chain reaction. In this study, we have investigated whether donor-recipient pairs that are fully matched for HLA by serology are truly HLA-DR, -DQ, and -DP identical and to what extent class II differences influence the primary mixed lymphocyte culture. We show that HLA oligotyping, performed on 50 pairs of HLA class I and II serologically matched individuals, can indeed reveal phenotypically relevant allelic differences at either DRB or DQB loci in 56% of these pairs and can therefore improve HLA class II typing and the choice of bone marrow donors quite significantly. Oligotyping for DRB/DQB/DPB polymorphism also allows prediction of a positive mixed lymphocyte culture, as established in 31 donor/recipient combinations, and even detection of polymorphic differences that were not revealed by this test. This approach is well suited for accurate HLA typing of large pools of bone marrow donors and was successfully applied to select fully matched donors for bone marrow transplantation.

Bone Marrow Transplantation↗
PubMed1991

HLA-DRw11, DQw7 has four cellular subtypes revealed by homozygous typing cells and undetected by restriction fragment length polymorphism.

HLA-DRw11 is in strong linkage disequilibrium with DQw7. We have investigated the heterogeneity of DRw11, DQw7 by cellular typing and by HLA cDNA probes. The results obtained by local and other homozygous typing cells in four informative Caucasoid families and 20 genotyped individuals demonstrate the existence of at least four different cellular subtypes. The frequency of DRw11, DQw7 is 25.7% with the following distribution of subtypes: Dw5 (17.3%), JAC (4.2%), JVM (2.8%), TIS (0.7%), and blank (0.7%). JVM (10W 9039) has been previously described; TIS (10W 9042) and JAC are postulated new specificities from our laboratory. None of these subtypes typed for DRw11, DQw1 cells. The cellular heterogeneity contrasts with the absence of polymorphism observed by serology and by restriction fragment length polymorphism after hybridization with DRB, DQA, and DQB probes. Variation in amino acids of the DRB1 chain has been reported for at least three variants: Dw5, JVM, and TIS (more recently).

Amino Acid Sequence↗
PubMed1991

Diversity among DRw13 DQw7 haplotypes as revealed by serology Dw typing and restriction fragment length polymorphism.

HLA-DRw13 is in linkage disequilibrium with DQw6; an unusual association, DRw13 DQw7, is found in 2% of our Caucasoid population. Investigation of genotyped individuals and of families by two allosera and by Dw typing revealed two subtypes: one recognized by homozygous typing cell HAG and by two allosera, the other subtype remained unreactive with both reagents. Analysis of DNA fragments with DNA probes indicated that the HAG-negative subset had DNA fragments in common with DRw6 while the HAG-positive subset shared DNA fragments with DR5. However, all DRw13 DQw7 cells are Dw24 as seen by hybridization with DRB probe.

Genetic Variation↗
PubMed1991

Additional complexity within the HLA-D region: sequence analysis of two new DRw13-DQw7 haplotypes.

HLA-DRB1 is by far the most polymorphic locus within the HLA-D region with now well over 40 alleles. Nearly one fourth of these alleles are subtypes of DRw6, and these are in most cases undetectable by routine typing procedures. In this paper we present the molecular characterization of two new Caucasian DRw13-DQw7 haplotypes by DNA sequencing of the polymorphic first domain exons of DRB1 and DRB3 loci. The first haplotype, DRB1*1301-DRB3*0101-DQB1*0301, has arisen by a recombination between locus DRB1 from a DRw13-DQw6 haplotype and DQA1 from a DR4-DQw7 haplotype, as determined by DNA sequencing, DQ oligotyping, and restriction fragment length polymorphism typing. The second haplotype, DRB1*1305-DQB1*0301, is characterized by the novel DRB1*1305 allele differing from DRB1*1301 by three amino acids. It probably arose by a gene conversion event between a DRw13-DQw6 allele and DRB1*1101. This allele represents a DRw11/DRw13 hybrid DR molecule with a DRw13 serological epitope in the second hypervariable region and a Dw5 cellular epitope in the third hypervariable region. As determined by sequencing of locus DRB3, this allele is associated with DRw52b. Our molecular analysis of the complex HLA-DRw13 group now allows unambiguous DNA typing of all five DRw13 alleles with seven oligonucleotides, a significant improvement in the context of organ transplantation.

Amino Acid Sequence↗
PubMed1991

Bone marrow transplantation using voluntary donors. Role of European Secretariat.

Bone marrow transplantation using unrelated donors is one technique used for patients who have no HLA identical donor. The French Registry "France Greffe de Moelle" (F.G.M.), with 57.866 volunteer donors has allowed since its creation in 1987 the treatment of 143 French patients (December 1990). For the remaining 20 % patients who have no donor on F.G.M., the request are sent to other European registries. In order to improve the management of these request, an European Secretariat: European Donor Secretariat (E.D.S.) has been created and set up in Paris. It manages all European requests coming from European registries. This organization permits to reduce the waiting time of the patients and therefore, participates in the improvement of the clinical results.

Bone Marrow Transplantation↗
PubMed1991

New developments in stem cell transplantation with special reference to the first in utero transplants in humans.

Based on the experience acquired in post-natal liver transplantation since 1974, we recently initiated pre-natal, in utero stem cell transplantation from the human fetal liver. The first two fetuses that we treated had immunodeficiencies, the third one had thalassemia major. Donors and recipients were not matched. The fetal cells were infused in the umbilical vein of the first two patients and injected intraperitoneally into the third one, under ultrasonic visualization. The first patient, born in 1988, has both engraftment of donor cells and reconstitution of cell-mediated immunity. This child, who had bare lymphocyte syndrome, has no clinical manifestation of the disease and he lives normally at home. The second child, born in 1989, has not yet developed a significant reconstitution of immunity although donor cell engraftment has been proven (Y chromosome in this female patient). The third patient has also evidence of donor cell take (Y chromosome in a female patient) but the effect on thalassemia has not yet been fully analyzed (donor hemoglobin present in small quantity). In all 3 cases, no side-effect of any kind developed in the mother nor in the fetus. Several advantages appear to be associated with in utero FLT: increased probability of graft take, ideal isolation of patient (in the uterus), optimal environment for fetal cell development (in the fetal host).

Female↗
PubMed1989

DNA typing of DRw6 subtypes: correlation with DRB1 and DRB3 allelic sequences by hybridization with oligonucleotide probes.

Among MHC class II antigens, the DRw6/Dw6 complex represents a special situation where typing on a routine basis is often troublesome, mainly because monospecific alloantisera are rare and individual subtypes numerous. We demonstrate here that the use of oligonucleotide DNA typing permits an analysis of the polymorphism within DRw6 haplotypes and provides a molecular basis for correlations with functional data. Synthetic oligonucleotide probes, most of them locus- and allele-specific, were derived from the DNA sequences of three alleles of locus DRB1 and three alleles of locus DRB3. These probes allow the positive identification of distinct DRw6 subtypes. As analyzed on a panel of 26 well-defined DRw6 cell lines, oligotyping allows a direct and absolute correlation with the DRw13 serologic specificity and with the cellularly defined Dw9,Dw16,Dw18, and Dw19 specificities. Correlations of the polymorphism at the DRB1 locus with the polymorphism at the DRB3 locus (DRw52 alleles) allow us to identify preferential allelic associations such as DRw13-Dw18-DRw52a/52b, DRw13-Dw19-DRw52c, and DRw13/Dw19 haplotype, the Dw19 cellular reactivity might involve, at least DRw14-Dw9-DRw52b. In view of the absolute segregation of the DRw52c allele with the DRw13/Dw19 haplotype, the Dw19 cellular reactivity might involve, at least in part, epitopes on the DRw52c allele. The identification of DRw6 subtypes, as well as of other HLA class II subspecificities, by oligotyping can now complement and possibly replace serologic and cellular typing. It represents a particularly useful contribution to the optimization of class II matching in the case of bone marrow transplantation with unrelated donors.

Alleles↗
PubMed1989

A method of HLA class II typing using nonradioactive labelled oligonucleotides.

The typing of HLA class II genes using molecular biology techniques has brought undoubtedly new insights in the analysis of their polymorphism. Particularly interesting is the dot-blot analysis of enzymatically-amplified genomic DNA hybridized with sequence-specific oligonucleotides. In order to use this technique of typing on a routine basis, we established a non-radioactive detection method of enzymatically-amplified genomic DNA dot-blots. We could clearly demonstrate that, using biotin-labelled specific oligonucleotides, it was possible to specifically discriminate between DQB1 first domain DNA sequences displaying three, two or even only one base-pair difference at a given codon position. The very satisfactory sensitivity level reached by this non-radioactive detection method could safely allow its use for clinical applications of HLA typing at the DNA level.

DNA↗
PubMed1989

HLA antigens and infertility with sperm autoantibodies in man.

Vasectomized men with sperm auto-antibodies (S.A.A.) and high frequency of HLA-A20 antigen (Ag) were observed by Law et al. (1979); Hancock et al. (1983) observed the prevalence of HLA-A28 in infertile men with S.A.A. HLA-A, B and DR Ag were determined in a population of 80 Caucasian infertile men with (n = 22) or without (n = 58) agglutinating and/or cytotoxic S.A.A. in serum (S) and/or seminal plasma (SP), and the association between HLA-determinants and infertility with S.A.A. was investigated. The frequence of HLA-A28 Ag was found higher in the group with S.A.A. than without (18.2% vs 0.0%) but not statistically significant (chi 2 = 8.87; pc less than 0.15). The same result was obtained with HLA-B13 Ag (chi 2 = 8.87; pc less than 0.32). Lastly, there was no prevalence of HLA-DR Ag in men with S.A.A. In conclusion, no association was found between HLA-A, B and DR Ag and infertility with S.A.A. Nevertheless, two HLA-Ag were more frequently observed in the group with S.A.A.

Adult↗
PubMed1989

[Immunogenetics of Horton's disease and of rhizomelic pseudo-polyarthritis].

The etiopathogenesis of temporal arteritis and rhizomelic pseudo-polyarthritis still remains undefined. A genetic predisposition would seem probable in view of epidemiological data (higher frequency in white caucasian races and in certain countries), the existence of rare familial forms (25 families reported), and the significant increase in incidence in unconnected cases with HLA DR4 antigen (6 studies). Environment may intervene as a precipitating factor in the condition and the role of an infectious agent, to account for the seasonal incidence of this disorder and the rare existence of cases in non consanguineous couples, has been suggested but remains unproven. Disordered immune function probably plays an essential role in the creation of the vascular histological lesions characteristic of the condition. The disordered function involves cellular immunity (fall in OK T8. in blood) and especially humoral immunity with the very frequent presence of circulating immune complexes in the serum and deposition of immunoglobulins and complement at arterial wall level.

Antibody Formation↗
PubMed1988

Antigen recognition by MHC-incompatible cells of a human mismatched chimera.

Tetanus toxin (TT)-specific T cell clones of donor origin were obtained from a patient with severe combined immunodeficiency (SCID) successfully reconstituted by transplantation of allogeneic fetal liver and thymus cells from two different donors performed 10 yr ago. A series of these clones recognized TT in the context of "allo" class II HLA determinants expressed by recipient APC. The restriction element of two T cell clones with the HLA phenotype of the first donor (HLA-DR1,8) and one T cell clone with the HLA phenotype of the second transplant (HLA-DR3,9) was HLA-DR4 of the recipient, whereas other T cell clones derived from the second transplant recognized TT in the context of HLA-DR5 of the recipient's APC. These latter T cell clones were not able to proliferate in response to TT when autologous APC were used. These data demonstrate that recipient and donor cells having different HLA phenotypes could cooperate across the allogeneic barrier and that MHC restriction of antigen (Ag) recognition is independent from the MHC genotype of the T cells but is influenced by the environment in which the T cells mature. We also isolated T cell clones that were able to recognize processed TT presented by all allogeneic EBV cell lines tested, indicating that the Ag specificity of these clones was not restricted by a particular class II MHC molecule. The Ag-specific proliferative response of one of these clones could be blocked by anti-class II MHC mAbs. These results demonstrate that in addition to Ag recognition in the context of specific class II MHC Ags, other types of Ag-specific responses may occur in this human chimera. It is not clear whether this "allo" plus Ag recognition is the result of education of transplanted fetal cells in the host thymus. Taking into consideration our previous findings indicating that alloreactive T cell clones specific for the recipient cells could be isolated in vitro from the PBL of the same patient, our data suggest that the mechanism for deletion of self-reactive clones and the generation of MHC-restricted responses are different.

Antibodies, Monoclonal↗
PubMed1988

Islet cell and insulin autoantibodies in subjects at high risk for development of type 1 (insulin-dependent) diabetes mellitus: the Lyon family study.

Genetic determination as well as prospective analysis of islet cell autoantibodies and autoantibodies to insulin were conducted in a population of 479 first degree relatives of 174 Type 1 (insulin-dependent) diabetic patients. Analysis of HLA haplotypes within families illustrated the high frequency of DR3 and DR4 alleles with preferential transmission from parent to both affected and unaffected offspring. DR4 was preferentially associated with DQw3.2 (TA10-) in 60/73 (82.2%) patients and 101/127 (79.5%) relatives. Relatives have been followed for a period of 800 subject-years. Twenty-two out of 430 relatives (5.1%) were found islet cell antibodies (ICA-IgG) positive. Seven sera with low titres became negative 6 months later at two different determinations. Fifteen sera ICA-IgG and ICA-protein A positive with high titres remained positive thereafter. Half of the ICA positive relatives were also found insulin autoantibodies (IAA) positive. All but 3 ICA negative relatives did not have IAA in their sera. Analysis of IAA specificity with competition experiments indicated that most antibodies recognised epitopes shared between human and pork insulins while four were specific for human insulin determinants. Analysis of class I and class II HLA antigen distribution indicated no particular allelic restriction in antibody positive individuals. Metabolic status of antibody positive relatives was determined with oral and intravenous charge of glucose. Two haplo-identical DR3-DQw2 brothers became diabetic during the study. One child and one mother both with DR4-DQw3.2 became intolerant to glucose. Each of these relatives had high titre ICA prior to metabolic deterioration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[HLA and narcolepsy. Apropos of 28 cases including 2 negative HLA-DR2].

Association between narcolepsy and HLA-DR2 antigen is the strongest so far described between an HLA antigen and a disease. Among 28 narcoleptic patients, we found two HLA-DR2 negative cases: a caucasoid woman also suffering from dystrophia myotonica and a negroid. All of our patients were HLA-DQW1 positive. An hypothetical narcolepsy susceptibility gene could be located in the HLA region, closer to the DQ than to the DR gene. It could be a pathologic allele of a sleep controlling gene in linkage disequilibrium with DQW1. Presence of DQW1 is a quasi-requisite for the expression of narcolepsy. It is not sufficient as it is observed in 70 p. 100 of controls.

Adolescent↗
PubMed1987

[Distribution of HLA-DR antigens in unrelated giant cell arteritis].

HLA-DR antigen distribution was determined by lymphotoxicity on total lymphocytes for locus A.B.C. antigens numbering 14,28 and 7 respectively, and by a search on B lymphocytes for the 12 antigens of locus DR. The normal population included 124 subjects typed for HLA-A.B.C. and 200 subjects typed for HLA-DR. The frequency of alleles was compared to that of the different groups of patients. Significant variations were evaluated by the X2 test, using Woolf's method; the P value obtained was multiplied by the number of antigens looked for (P corrected, or pc). No deviation in frequency was found with the HLA-A.B.C. antigens. Only the DR 4 antigen, present in 23% of the normal population, was increased in proportions that depended on clinical classification: 39.4% (Pc = 0.05) in all patients with giant cell arteritis: 27% (NS) in the 37 polymyalgia rheumatica patients with negative biopsy of the temporal artery; 46.8% (P 0.05) in the 62 patients with Horton's disease presenting either as clinical and histological temporal arteritis (26 cases; DR 4 = 38.5%; NS), or as clinical and/or histological temporal arteritis associated with polymyalgia rheumatica (36 cases; DR 4 = 52.8%; Pc less than 0.005). The frequency of DR 4 antigen in Horton's disease with typical temporal artery biopsy (37 cases) was 46% (Pc = 0.05).

Aged↗