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E Westphal

Publications and source records attributed to E Westphal.

At least 37 records · Page 2Linked to original sources
PubMed1993

[HLA typing in high risk keratoplasty].

UNLABELLED: Improved microsurgical techniques and better immunosuppressive treatment have led to an increase in the number of corneal transplantations. However, graft rejection due to a disparity between donor and recipient major histocompatibility antigens remains the major complication. The risk of graft rejection is further increased in patients with vascularized graft beds and in presensitized persons. Well-designed experimental studies and clinical experience have clearly shown the importance of class-I-antigens. However, class-II antigens have not yet been studied to the same extent. METHODS: Multiorgan donors and corneal graft recipients were HLA typed using the lymphocytotoxicity test previously described by Terasaki. The recipients were typed retrospectively. Cadaver corneal graft donors were typed using a novel HLA typing technique on retinal pigment epithelial cells, as previously described by us. Postoperatively, all recipients were routinely examined for rejection over a period of 2 years. RESULTS: Graft rejection was observed in 25% of the 133 high-risk patients. Of the 13 class-I-typed patients who showed a rejection 9 persons had two or more major histocompatibility mismatches. Of the 12 patients without rejection problems only 5 had two or more HLA class-I-mismatches. Of the patients with one or two matches at the HLA-DR locus there were only 4 out of 9 patients with at least one graft rejection; 5 out of 6 patients showed no signs of rejection. CONCLUSIONS: Mismatches at either class-I- or class-II- gene loci lead to a higher frequency in corneal graft rejection. Apart from the major histocompatibility mismatches, other factors also influence graft rejection, such as the distance between the corneal transplant and corneal vessels, presensitization, and the indication for corneal grafting. If we are to define the factors influencing graft rejection better and further increase our knowledge on the role the major histocompatibility antigens play in corneal graft rejection in a larger patient group, then cooperation with other transplantation centers will be required.

Graft Rejection↗
PubMed1992

Maternal immunization by husband's leukocytes for repeated fetal death associated with mild pre-eclampsia--case report with successful outcome.

We report a case of repeated fetal death at 31 gestational weeks associated with mild non-proteinuric pre-eclampsia and intrauterine growth retardation. After double intradermal immunisation with paternal leukocytes, a third pregnancy proceeded uneventfully until it ended at 38 weeks. Maternal anti-paternal blocking antibody activity was assessed by the erythrocyte antibody inhibition (EAI) test. Serologic testing revealed that the couple did not share HLA class I antigens. The mechanisms underlying the likely benefit from immunotherapy are discussed.

Antibody Formation↗
PubMed1992

Alloimmune neonatal neutropenia is a potential side effect of immunization with leukocytes in women with recurrent spontaneous abortions.

Alloimmunization of a mother against granulocytes causing alloimmune neonatal neutropenia (ANN) in her newborn was found likely to be attributed to previous intradermal injections of paternal lymphocytes. Immunotherapy with leukocytes which was performed for recurrent spontaneous abortions hence provides the possibility of granulocyte alloimmunization and increases the risk of the occurrence of ANN.

Abortion, Habitual↗
PubMed1992

Post-mortem HLA tissue typing of retinal pigment epithelial cells.

Retinal pigment epithelial cells (RPE) were derived from bulbi of cornea donors and maintained in culture. The time-span between donor's death and cell cultivation ranged from 2 to 122 h. The mean numbers of hours was 25.6 (n = 130). After IFN-gamma stimulation, cells were serologically typed for class I and class II antigens. Unclear class I allospecificities were verified by one-dimensional isoelectric focusing. Data from the serological typing of lymphocytes and those of the serological and biochemical typing of RPE from the same donors were compared in 22 cases. There was a discrepancy of less than 5%, whereby either the typing on lymphocytes could not identify some specificities declared as blanks or the RPE typing had failed to clearly define a specificity. Our data show that the strategy adopted here is very successful for tissue typing post mortem, thus increasing the number of available HLA-matched corneas and consequently reducing the number of corneal graft rejections.

Adolescent↗
PubMed1991

Malignant lymphoma of donor origin after renal transplantation: a case report.

A case of non-Hodgkin's lymphoma of polymorphous centroblastic type presenting in a renal allograft is reported. The kidney graft was explanted 10 months after transplantation because of chronic rejection. No other manifestations of lymphoma were found in the recipient. Since the human leukocyte antigen patterns of the renal allograft and the recipient differed at two loci, the donor origin of the malignancy could be clearly demonstrated by immunohistochemistry.

Adult↗
PubMed1991

Expression of MHC class I and II molecules by cadaver retinal pigment epithelium cells: optimization of post-mortem HLA typing.

The objective of this study was to investigate the expression of MHC antigens by retinal pigment epithelium cells (RPE) after stimulation with interferon-gamma (IFN-gamma) and to improve the currently practised technique of cadaver HLA typing. A concentration of 100 U/ml IFN-gamma induced expression of class I molecules up to greater than 90% 3 days after stimulation, whereas 50 U/ml were required for the expression of HLA-DR to greater than 90%. A concentration of 750 U/ml induced 35-45% expression of HLA-DP and less than 25% HLA-DQ after 3 days. Cells were serologically typed using the standard lymphocytotoxicity assay 3 days after stimulation with 250 U/ml IFN-gamma. Typing of class I specificities was complemented by one-dimensional isoelectric focusing (1D-IEF). We observed high concordance between the results of the RPE typing and the lymphocytotoxicity test on the same donors. Our results show complete typing of class I and II antigens post-mortem, which, in particular, enables graft matching and improvement of graft survival in recipients of organs removed many hours after death such as the cornea.

Adolescent↗
PubMed1991

[Postmortem serologic and biochemical HLA typing with cultivated retinal pigment epithelium cells].

A quick and reliable method for HLA typing of human cadavers has been established. Retinal pigment epithelial cells (RPE) were obtained from cadaver bulbi 8-36 h post mortem (n = 24). After 24 hours, cell growth correlated inversely with the time lapse between the donor's death and bulbus explantation. Cultivated human RPE were stimulated by different Y-interferon (IFN) concentrations and examined by FACS analysis for the expression of MHC class I and II molecules. A concentration of 100 units/ml human Y-IFN was sufficient to induce maximal class I antigen expression by about 90% of cells after 3 days. At 50 units/ml Y-IFN, the cells showed maximal class II antigen expression for HLA-DR, whereas 100 units/ml I-IFN was required for maximal HLA-DQ expression. Higher concentrations of Y-IFN induced a further HLA-DP expression. However, serological HLA typing was performed after cell stimulation with 250 units/ml Y-IFN for 3 days. A concentration of 500 units/ml Y-IFN yielded equivalent results, but 750 units/ml Y-IFN led to poor identification of class I MHC specificities. Unclear serological results on class I specificities were clarified by 1D-isoelectric focusing (1D-IEF), thus allowing full HLA typing of all donor bulbi examined. In summary, successful HLA typing of cultivated RPE is dependent on both the Y-IFN concentration and the time lapse between stimulation and typing of the RPE. The method provides a much improved basis for cadaver cornea grafting.

Adolescent↗
PubMed1990

Improved test to identify heterozygotes for congenital adrenal hyperplasia without index case examination.

In an attempt to improve detection of heterozygote carriers of the gene for congenital adrenal hyperplasia (21-hydroxylase deficiency; CAH) 64 families with at least 1 affected member (72 homozygotes and 191 clinically healthy subjects) were studied by HLA genotyping and by the single-dose corticotropin stimulation test. Plasma samples were drawn immediately before corticotropin and 60 min after its injection, and they were analysed simultaneously for eight adrenal steroids by radioimmunoassay after extraction and automated gel chromatography. Heterozygosity was defined as the presence of one HLA haplotype in common with the affected relative. Of the various basal and corticotropin-stimulated steroid levels and their ratios, the ratio of 17-hydroxyprogesterone to 11-deoxycorticosterone after corticotropin had the greatest power to discriminate between heterozygotes and normal relatives; that ratio was significantly higher in the heterozygotes (n = 116) than in the normal relatives (n = 75) and there was no overlap between the groups (range 12.2-214 vs 1.2-11.9). Thus, it is possible to detect all CAH heterozygotes without examining the index case by means of specific steroid analysis.

17-alpha-Hydroxyprogesterone↗
PubMed1990

Characterization of soluble HLA molecules in sweat and quantitative HLA differences in serum of healthy individuals.

Soluble class I molecules were immunoprecipitated from human sweat and serum using the BB7.7 monoclonal antibody (mAb) coupled to immunomagnetic beads. Molecules were analysed biochemically on SDS-PAGE gels and finally by ID-isoelectric-focusing (IEF). Serum- and sweat-HLA IEF-band patterns of the same individual were fully identical, showing that HLA excreted in sweat possess polymorphic structures like those in serum. Quantitatively, we used a highly sensitive competitive enzyme-linked immunosorbent (ELISA) assay to determine soluble class I concentrations. The first group was that of non-HLA-A9 and -Bw62 sera, which were found to contain HLA levels with a mean concentration of 0.82 +/- 0.63 microgram/ml (n = 44). However, sera that were HLA-A23 or -24 (splits of HLA-A9) contained higher levels, with a mean of 3.2 +/- 0.94 microgram/ml (n = 20). Similarly, HLA-Bw62 individuals had a higher mean of 2.05 +/- 0.65 micrograms/ml (n = 10). The difference of the HLA-A9 group to the first group was statistically highly significant, P less than 0.0001, and that of the HLA-Bw62 to the first was also significant, P less than 0.004. Individuals who were both HLA-A9 and -Bw62 (n = 5) did not express significantly higher levels than those who only had one of these specificities. Sweat HLA levels had a mean of 0.42 +/- 0.4 microgram/ml (n = 10). These results show for the first time that soluble class I peptides are excreted in relatively high concentrations in sweat and possess polymorphic structures identical to those of serum HLA and that serum HLA levels are allotype dependent.

Female↗
PubMed1989

Pregnancy-maintaining antibodies: workshop report (Giessen, 1988).

To analyse the nature of antibodies which are purported to be essential for the maintenance of normal human pregnancy, six centers participated in a workshop of "blind" tests on 19 allosera. Fc-receptor dependent assays detected antibodies with specificity only for HLA. In addition to cytotoxic antibodies, the Fc-receptor dependent immune phagocytosis inhibition test revealed two non-cytotoxic alloantibodies with HLA specificity. These antibodies had high titers and may, therefore, be essentially non-cytotoxic. Murine monoclonal antibodies to HLA-A, B, C or DR (W6/32 and 2MC3) were used to evaluate the methods. These antibodies inhibited immune rosette formation as well as immune phagocytosis. Diluted to concentrations below the threshold of complement-dependent cytotoxicity, the monoclonal antibodies still inhibited the mixed lymphocyte reaction and the immune phagocytosis. A human monoclonal immunoglobulin M with specificity for monomorphic non-HLA lymphocyte antigens inhibited the mixed lymphocyte reaction. The immune rosette inhibition test exhibited several false positive reactions, e.g. three out of four with a serum that did not contain alloantibodies to blood cells. Non-cytotoxic antibodies were therefore rare in the selected sera of the workshop and they exhibited HLA specificity only. No participant was able to identify pregnancy-maintaining non-HLA-antibodies.

Abortion, Habitual↗
PubMed1989

Serological mapping of HLA-epitopes with monoclonal antibodies and its interpretation by sequenced HLA-molecules.

For the study of the epitope distribution on HLA class I molecules, blocking studies were carried out with a competitive radioimmuno assay using 3H labelled monoclonal antibodies (MAbs) against various HLA epitopes. The results were discussed with the help of known HLA amino acid sequences, and the positions of the following epitopes were suggested: A2/Aw69; A2/28; A2/11/25/26/28/29/30/31/Aw33/34; A25/32; Bw4; B7/Bw22,42; Bw6.

Amino Acid Sequence↗
PubMed1989

Immunoelectron microscopic demonstration of antigenic sites on lymphoid cells using a human monoclonal antibody (Ha6D3).

The reactivity of a human monoclonal antibody directed against human B and T lymphocytes was tested for the first time at the ultrastructural level. The antigenic sites detected by this antibody were localized on the surface membrane of lymphocytes and, to a lesser extent, in the cytoplasm on membranes of the endoplasmic reticulum and perinuclear envelop of some centroblasts and immunoblasts. Ultrastructural demonstration of target antigen detected by human monoclonal antibodies may be important prior to therapeutic application of these antibodies.

Antibodies, Monoclonal↗
PubMed1988

Human monoclonal antibody against human lymphocytic cells. A human monoclonal antibody that reacts preferentially with human lymphocytic cells.

Human monoclonal antibodies may replace human or xenogeneic antisera and mouse monoclonal antibodies for therapeutic applications. The human IgM monoclonal antibody Ha6D3 was produced after in vitro immunization and fusion with a mouse myeloma. Its reactivity against human normal and leukemic cells was investigated in cytotoxicity assays, and the antigen distribution in normal tissues was investigated with biotinylated Ha6D3 and avidin-peroxidase complexes. It was shown that Ha6D3 reacts preferentially with human lymphocytic cells. Only moderate reactions with epithelial cells in some organs were observed in cryostat sections, but because of poor accessibility in vivo these reactions were considered to be negligible.

Antibodies, Monoclonal↗
PubMed1988

Production and applications of new monoclonal antibodies against human lymphocyte antigen-A and -B antigens.

Monoclonal antibodies (MAbs) against HLA antigens can give better information about the serology and biochemistry of the human major histocompatibility complex (MHC) than HLA antisera obtained from pregnant women. To increase the very limited panel of MAbs against HLA we immunized mice with human cultured cell lines and fused their spleen cells with the Ag8-653 myeloma. We produced MAbs against HLA-A1, A2/w69, A2/28, A2/11/25/26/28/29/30/31/33/34, A25/32, B7/22, and B13. The best dilution medium to store the MAbs in Terasaki plates was RPMI 1640 supplemented with 7% bovine serum albumin. The MAbs are also excellent reagents to investigate public HLA antigens and to stain HLA antigens in cryosections of transplanted organs.

Animals↗