[The first part of the goal of a project on xenotransplantation is achieved: porcine kidney in human circulation].
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Animals↗
Biomedical subjects
L Rydberg
Publications and source records attributed to L Rydberg.
Increased anti-Gal activity in diabetic patients transplanted with fetal porcine islet cell clusters.
The natural anti-Gal antibody seems to create a major obstacle for discordant xenotransplantation in humans. Anti-Gal, which is produced in large amounts in humans (1% of circulating IgG), interacts specifically with the carbohydrate structure Gal alpha 1-3Gal beta 1-4Glc-NAc-R (termed the alpha-galactosyl epitope). This epitope is present in large amounts on porcine cells, as well as on cells of other nonprimate mammals (1 x 10(6) to 35 x 10(6) epitopes/cell). The interaction of anti-Gal with alpha-galactosyl epitopes on the xenograft was found to mediate the immune destruction of discordant xenografts. In the present study, the human immune response to alpha-galactosyl epitopes on xenografts was assessed by measuring changes in anti-Gal titers and affinity in sera of diabetic patients transplanted with fetal porcine islet cell clusters. The activity of this antibody was assessed by a hemagglutination assay with RBC, by ELISA with mouse laminin as a solid-phase antigen, and by equilibrium dialysis with the radiolabeled free haptenic form of the alpha-galactosyl epitope, i.e. [3H]Gal alpha 1-3Gal beta 1-4GlcNAc. All assays revealed a marked increase in anti-Gal activity after transplantation. The increase in anti-Gal titers ranged between 8- and 64-fold. A similar increase was observed in the binding of free alpha-galactosyl epitopes to anti-Gal, as assayed in equilibrium dialysis. Immunoglobulin concentration did not increase after transplantation, suggesting that the observed increase in anti-Gal activity is the result of a specific immune response against alpha-galactosyl epitopes on the xenograft. The elevation in anti-Gal activity was observed in all three immunoglobulin classes and the highest activity was found within the IgG class. Analysis of IgG binding to fixed porcine endothelial cells suggested that most of the observed increased activity against these cells in transplanted patients may be attributed to the elevation in anti-Gal activity.
Animals↗
The platelet-specific alloantigen PlA1 (HPA-1a): a comparison of flow cytometric immunophenotyping and genotyping using polymerase chain reaction and restriction fragment length polymorphism in a Swedish blood donor population.
BACKGROUND: There is an increasing interest in the development of rapid and reliable techniques for platelet alloantigen typing. STUDY DESIGN AND METHODS: By use of standardized flow cytometry and a specific human alloantiserum, 236 Swedish blood donors were immunophenotyped for the platelet-specific alloantigen, PlA1 (HPA-1a). RESULTS: Ten individuals (4.2%) had low fluorescence intensities and were considered PlA1-negative (HPA-1a-negative); all of them also demonstrated a PlA2/PlA2 (HPA-1b/1b) genotype in a polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assay of the underlying DNA polymorphism. The remaining population had clear positive fluorescence and was regarded as PlA1-positive (HPA-1a-positive). The fluorescence distribution histogram among PlA1-positive (HPA-1a-positive) individuals was dome-shaped, and those individuals who were homozygous for PlA1 (HPA-1a) could not be distinguished from those who were heterozygous. This finding was further substantiated by PCR-RFLP analysis of the PlA1/PlA2 (HPA-1a/1b) genotype; a heterozygous genotype was found among those having a medium fluorescence intensity as well as among those having a strong fluorescence intensity. CONCLUSION: Flow cytometry is a valuable tool for large-scale detection of PlA1 (HPA-1a). However, flow cytometry based on only one antiserum cannot distinguish between homozygous and heterozygous carriers of PlA1 (HPA-1a). For zygosity testing and when platelets are difficult to obtain, the PCR-RFLP technique is the assay of choice.
Antigens, Human Platelet↗
CD4+ and CD8+ T cell expansions using selected TCR V and J gene segments at the onset of giant cell arteritis.
OBJECTIVE: To investigate T cell receptor (TCR) V alpha/V beta (and in selected cases, J beta) usage in CD4+ and CD8+ peripheral blood lymphocytes of patients with giant cell arteritis (GCA), before and after treatment, as well as to analyze the HLA types of these patients. METHODS: Flow cytometry, with 10 anti-TCR V-specific monoclonal antibodies (MAb), was used. To analyze J beta usage by cell populations expressing certain V beta, we used the polymerase chain reaction (PCR) technique, with V beta- and C beta-specific primers, Southern blotting of PCR products, and subsequent hybridization with radiolabeled J beta-specific probes. HLA typing was performed using the microlymphocytotoxicity technique. RESULTS: Seven of the 9 GCA patients had increased anti-TCR V MAb reactivities (interpreted as T cell expansions), which in many cases, correlated with clinical signs of disease. A strict preference for particular J beta segments was found in 3 of 3 expanded CD4+ T cell populations. CONCLUSION: T lymphocytes expressing specific antigen receptors are implicated in the pathogenesis of GCA.
Aged↗
Characterization of the anti-A antibody binding in an ABO-incompatible living donor renal transplantation.
A 57-year-old female, blood group B, with polycystic kidney disease, received an ABO-identical, HLA-A,B,DR 5-mismatched renal allograft in 1986. Due to graft artery thrombosis and vascular rejection, she lost the kidney 6 months after transplantation and developed HLA antibodies with a panel reactivity of 99%. Despite 5 years on a European waiting list for highly immunized patients, she was not offered a second kidney. An attempt to remove her HLA antibodies by plasmapheresis combined with cyclophosphamide therapy did not succeed. Her 53-year-old HLA-identical, but ABO-incompatible sister (blood group A1), was then accepted as a donor. After immunoadsorption on Biosynsorb-A columns, transplantation was performed. The post-transplant course was uneventful without any signs of rejection. Studies on the anti-A antibody binding characteristics before and after immunoadsorption and after transplantation, showed that IgM and IgG antibodies recognizing the A trisaccharide epitope based on the type 1, 2, and 4 core saccharide chains, were effectively removed by Biosynsorb-A adsorption, but the column failed to remove anti-A antibodies recognizing the A type 3 antigen. These antibodies probably requires part of the core saccharide chain for binding. The presence of these antibodies did not seem to influence the outcome of the ABO-incompatible transplantation.
ABO Blood-Group System↗
Visual impairment related to cognition and loneliness in old age.
Reported problems in visual acuity were examined as determinants of loneliness experienced by community dwelling people with either impaired or unimpaired cognition. The Mini-Mental State Examination (MMSE) was used as a screening instrument to form a cognitively-impaired (MMSE 20-23/30) and a cognitively-intact group (MMSE 28-30/30). A total of 147 subjects took part in the study and were examined by an optometrist. Subjects with intact cognition tended to report visual problems more often than subjects with cognitive deficits. One out of two subjects had slight visual impairment, in both cognitive groups. After acuity had been optimally corrected, six to seven out of ten subjects' visual acuity did improve. In a multiple regression analysis, higher MMSE score and visual improvement were significantly related to lower levels of self-reported loneliness among the elderly with their cognition intact, but not among the subjects with impaired cognition.
Aged↗
Natural antibodies and human xenotransplantation.
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Animals↗
Specificity of human xenoantibodies formed in response to fetal porcine isletlike cell clusters.
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Animals↗
An ABO incompatible sibling as rescue kidney donor.
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ABO Blood-Group System↗
Genotypic heterogeneity among Lewis negative individuals.
We have identified a C to T mutation at nucleotide No 314 in the coding region of the human alpha (1,3/1,4) fucosyltransferase III (FT-III) gene held responsible for synthesis of Lewis a and b antigens. The mutation gives rise to an additional cleavage site for restriction enzyme NlaIII and was found in both alleles in 5 of 18 Lewis negative but in none of 22 Lewis positive individuals. Heterozygous individuals were found both among Le negative (10 of 18) and Le positive (4 of 22) individuals. The mutation corresponds to a threonine to methionine substitution and was found by partial sequencing of the coding sequence of one of five Lewis negative individuals homozygous for this transition.
Amino Acid Sequence↗
Expression of glycolipid blood group antigens in single human kidneys: change in antigen expression of rejected ABO incompatible kidney grafts.
Total neutral glycolipid fractions were separated into molecular species on thin-layer chromatography plates and detected by immunostaining with monoclonal anti-blood group antibodies. Blood group A antigens based on type 1, 2, 3 and 4 carbohydrate core saccharides were present in kidneys of A1 and A1B individuals. Blood group A2 individuals expressed only small amounts of A antigen compared to A1 individuals especially of the type 3 and 4 compounds. Kidneys from non-secretor individuals contained less A antigen compared to secretor individuals, and in both groups a variation in the antigen expression between single individuals was noted. Blood group A type 2 and 3 (which is an extension of A type 2) antigens were present both as basic 6 and 9 sugar structures as well as extended saccharide chains migrating in the 8 to 11 sugar interval. In contrast, the type 1 chain based A and Lewis antigens were only present as their basic 5 to 7 sugar chains, and no elongated structures were found. Four cases of A2 kidneys initially transplanted into O recipients and removed after 5, 12, 21 days and 4 years, respectively, were also analyzed. Two of these kidneys, originating from the same donor, showed a difference in A antigen expression. The kidney functioning for four years (lost due to chronic rejection) completely lacked X antigen with five sugar residues (present in all other individuals) and contained a large amount of A antigens.(ABSTRACT TRUNCATED AT 250 WORDS)
ABO Blood-Group System↗
Cell-mediated immune responses in renal transplant recipients treated with cyclosporin and prednisolone with or without azathioprine.
The cell-mediated immune response was studied, using mixed lymphocyte reactivity (MLR) and cell-mediated lympholysis (CML) tests, in patients with well-functioning kidney grafts from living donors at 6 and 12 months and at 2-5 years after transplantation. The patients were allocated to treatment with cyclosporin A (CyA) and prednisolone (group A) or with CyA, prednisolone and azathioprine (group B). The MLR towards a third party were in the range of that of untreated controls while the anti-donor activities were reduced after 6 months in both groups. The CML activities in group A towards a third party were in the range of that of untreated controls at all times, while the anti-donor activities were decreased. By contrast, the CML activities in group B towards a third party were decreased during the first year and were in the range of that of normal controls at 2-5 years. The anti-donor CML activities were low at all times in group B. In summary, the two CyA protocols allowed the induction of donor-specific unresponsiveness within the first post-transplant year. The anti-third party activities were low during the first post-transplant year in recipients with triple therapy but not in those without azathioprine.
Adult↗
Glycosphingolipid expression in spontaneously aborted fetuses and placenta from blood group p women. Evidence for placenta being the primary target for anti-Tja-antibodies.
A 12-week-old fetus and one 17-week-old fetus + placenta were obtained after spontaneous abortions from two women of blood group p. The 17-week-old fetus was dissected into intestine, liver, brain and residual tissue. Nonacid glycosphingolipid fractions were prepared from the tissues. Glycolipid characterization was carried out using thin layer chromatography immunostained with monoclonal antibodies and bacteria and by 1H NMR spectroscopy and mass spectrometry. In the placental fraction substantial amounts of globotetraosylceramide (P-antigen) and globotriaosylceramide (Pk-antigen) were identified. In contrast, the fetuses contained only trace amounts of these structures, as revealed by immunostaining. These results indicate that the primary target for the antibodies of the anti-Tja serum is the placenta tissue, resulting in termination of the pregnancy.
Abortion, Spontaneous↗
Characterisation of the anti-A antibody response following an ABO incompatible (A2 to O) kidney transplantation.
Anti-A,B antibodies produced in a blood group OLe(a-b-) recipient receiving a kidney graft from a blood group A2Le(a-b+) donor have been analysed for their ability to bind to different glycosphingolipid antigens. Solid-phase RIA using pure glycosphingolipid antigens and a chromatogram binding assay using total nonacid glycosphingolipid fractions from erythrocytes of different human blood group phenotypes together with pure glycolipid antigens were used as assay systems. Serum antibodies were shown to bind equally well to A (types 1, 2, 3 and 4) and B (types 1 and 2) antigenic structures but no binding to H antigens (types 1, 2 and 4) was detected. After adsorption of serum antibodies on A1 Le(a-b+) erythrocytes there was a residual anti-A antibody activity which could not be adsorbed by synthetic A-trisaccharides coupled to crystalline silica (Synsorb-A). These residual antibodies, which are not present in a pretransplant serum sample, had a specificity for the A antigen with type 1 core saccharide chain and the binding epitope obviously included both the N-acetylgalactosamine and the N-acetylglucosamine. The fucose residue was apparently not obligate for binding. The conformation of the sugar units involved in the binding epitope was determined.
ABO Blood-Group System↗
Serological and immunochemical characterization of anti-PP1Pk (anti-Tja) antibodies in blood group little p individuals. Blood group A type 4 recognition due to internal binding.
Serum samples from 13 blood group little p individuals were tested by radioimmunoassay for their IgG antibody subclass distribution against the P, P1 and Pk antigens. There was no uniform subclass distribution pattern, although all but one had IgG3 antibodies against all the P system antigens tested. Studies were performed adsorbing anti-Tja serum sequentially to columns with synthetic carbohydrate antigenic determinants within the P system coupled to silica beads (SynsorbsR). The effect on agglutinin and indirect antiglobulin titers was determined after adsorption to SynsorbsR with different P-system antigens (P1, Pk, P). Adsorption to all the three SynsorbsR was needed to eliminate or strongly reduce antibody titers. The effect on IgM, IgG, IgA as well as IgG subclass antibody binding to P, P1 and Pk antigens was also determined by radioimmunoassay and chromatogram binding assay. Anti-PP1Pk antibodies from a little p woman with repeated abortions were shown to bind to glycosphingolipid antigens prepared from one of the aborted placentae using a chromatogram binding assay. This binding was eliminated by serum adsorption to SynsorbsR with P1, Pk and P carbohydrates. Anti-PP1Pk antibodies were also shown to bind to extended structures in the globoseries, i.e. globopentaosylceramide, globohexaosylceramide (globo-H) and globoheptaosylceramide (globo-A). This binding is most probably due to antibodies recognizing internal sequences in the carbohydrate chain. Attempts were made to visualize the binding epitope of the antibodies by computer molecular modelling.
Adult↗
Presence of glycosyltransferase inhibitors in the sera of patients with long-term surviving ABO incompatible (A2 to O) kidney grafts.
In the sera of blood group O recipients with long-term surviving blood group A2 kidney grafts, inhibitors of A-glycosyltransferase (alpha-3-N-acetyl-D-galactosaminyl transferase) have been identified in four out of six patients. The inhibitors seem to be of IgG antibody nature and do not appear until at least 1 year after transplantation. The inhibitors are also active against B-transferase (alpha-3-D-galactosyl transferase) as well as against A-glycosyltransferase of pig origin. The importance of these A-glycosyltransferase inhibitors is not clear. They may have a modifying effect on the antigenic expression of the graft. The immunogenicity of soluble glycosyltransferases is well known and the development of antibodies against them might prevent their enzymatic activity.
ABO Blood-Group System↗
ABO-incompatible kidney transplantation (A2 to O). Qualitative and semiquantitative studies of the humoral immune response against different blood group A antigens.
The humoral immune response against blood group A antigens with different core saccharide structures has been investigated in four blood group O recipients transplanted with kidneys from two blood group A2 donors. Radioimmunoassay and thin-layer chromatogram binding assay studies showed that different individuals responded differently to the same antigenic stimulus. Antibodies were produced in the recipient that bound to the terminal trisaccharide of the blood group A antigens. In some cases antibodies that bound to a larger antigen epitope, including the fourth and fifth sugar in the polysaccharide core chain, also occurred. Immunoglobulin class-specific, as well as subclass specific, responses were seen. The antibody response in the blood group O recipients receiving an A2 graft seem to be dependent on the antigenic expression in the transplanted kidney. In view of the recent findings of individuality of A antigen expression in kidneys within the A1 and A2 subgroups, an extended typing of A2 donors may be important. The humoral immune response in the recipient may also be dependent on earlier contacts with ABO incompatible pregnancies, vaccinations, or infections. A possible correlation between pre- and posttransplant findings was noted in one case and deserves further notice.
ABO Blood-Group System↗
Evidence of donor-specific cellular suppressor activity in donor-specific cell-mediated lympholysis unresponsiveness in renal transplant patients.
Twenty patients with well-functioning kidney grafts from one-haplotype-mismatched related donors, were studied 1-10 years after transplantation (A). Another group of six patients were studied at various times after transplantation (B). The presence of donor-specific transplantation tolerance, using mixed lymphocyte culture (MLC) and cell-mediated lympholysis (CML) tests was investigated, as well as the possible existence of cells with suppressive activity. All recipients were transfused prior to transplantation and treated with conventional immunosuppression. The patients in group A showed MLC reactivity against donor and third-party cells, indicating a allogeneic response capacity. The CML activity against the donor was low, however, and remained low also following removal of adherent cells. The CML activity toward third-party cells was within the normal range of unmatched individuals. In group B, two of six recipients and high postoperative CML activity against the donor. Both recipients showed clinical signs of rejection. In the remaining four recipients, the antidonor CML reactivity one week after transplantation was lower than the preoperative level. The decrease was even more pronounced at 12 months, although the reactivity against third-party cells was unaltered. The CML reactivity from unrelated fourth-party individuals toward donors was suppressed when cells from recipients with long-term functioning kidneys were added to the cell cultures. The results suggest the presence of a donor-specific cellular suppressor mechanism underlying the donor-specific CML unresponsiveness in recipients with long-term-functioning kidney allografts.
Adolescent↗