| 1. |
- Bengtsson, Anders, 1954, et al.
(författare)
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Extracorporeal ("ex vivo") connection of pig kidneys to humans. III. Studies of plasma complement activation and complement deposition in the kidney tissue.
- 1998
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Ingår i: Xenotransplantation. - 0908-665X. ; 5:3, s. 176-83
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Tidskriftsartikel (refereegranskat)abstract
- The complement system is one of the important factors involved in the hyperacute rejection of xenografts. This report deals with the activation of the complement system in a clinical trial where pig kidneys were extracorporeally connected to two volunteer dialysis patients who were pretreated with plasmapheresis in order to substantially reduce anti-pig xenoantibodies. The clinical data of the perfusion experiments and the patients humoral immune response to pig xenoantigens have been reported in detail (Xenotransplantation 1996; 3:328-339, 340-353). Three consecutive daily plasmapheresis treatments of the patients reduced the plasma complement protein (C3, C4, and C5) concentrations to 8-27% of the baseline values. The perfusion of the pig kidney connected to patient 1 was terminated at 65 min due to graft rejection and this patient was not hemodynamically affected by the experiment. The second experiment was terminated at 15 min due to an anaphylactic like reaction of the patient. In patient 1 a slight reduction of plasma C3, C4, and C5 and an increase of C5a and SC5b-9 occurred, while C3a decreased during the perfusion. Patient 2 had an increase of all complement parameters, most prominent for C4d and SC5b-9, which occurred concomitant with the appearance of the anaphylactic like side effects. In general, plasma levels of PMN elastase, IL6 and IL8 increased in both patients during the perfusion. Immunohistochemical investigation of the kidney tissues revealed deposition of human complement factors C1q, C4c, and C3c in a congruent pattern with the vasculature of the kidney in patient 1. In kidney 2 only trace amounts of C1q and C3c were found. Both kidneys were negative for properdin. Therefore, in this experimental set up with extracorporeal connection of pig kidneys to the human circulation the human complement cascade is activated mainly through the classical pathway.
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| 2. |
- Breimer, Michael, 1951, et al.
(författare)
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Blood group A and B antigen expression in human kidneys correlated to A1/A2/B, Lewis, and secretor status.
- 2006
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Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337. ; 82:4, s. 479-85
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In the revived interest in crossing ABO barriers in organ transplantation renal A/B antigen expression has been correlated with donor ABO, Lewis, and secretor subtype to predict antigen expression. METHODS: A/B antigen expression was explored by immunohistochemistry in LD renal biopsies. Donor A1/A2/B, Lewis, and secretor status were determined by serology and polymerase chain reaction. RESULTS: In the renal vascular bed, three distinct A antigen expression patterns with a major, minor, and minimal staining distribution, and intensity (designated as types 3+, 1+ and (+) respectively) were identified. Type 3+ had a strong A antigen expression in the endothelium of arteries, glomerular/peritubular capillaries and veins. The type 1+ showed an overall weaker antigen expression, whereas type (+) had faint staining of peritubular capillaries only. In all cases, distal tubular epithelium was focally stained, whereas proximal tubules were negative. Type 3+ were all from blood group A1 subtype individuals while A2 cases expressed either a 1+ or (+) pattern. The secretor gene did not appear to influence renal A antigen expression. All B kidneys examined showed a B antigen pattern slightly weaker but otherwise similar to A type 3+. CONCLUSION: Renal vascular A antigen expression correlates to donor A1/A2 subtypes, whereas B individuals show one singular antigen pattern. From antigen perspective, A1 and B donors are a "major" and A2 individuals a "minor" antigen challenge in ABO-incompatible renal transplantation.
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| 3. |
- Breimer, Michael, 1951, et al.
(författare)
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Extracorporeal ("ex vivo") connection of pig kidneys to humans. I. Clinical data and studies of platelet destruction.
- 1996
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X .- 1399-3089. ; 3:4, s. 328-39
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Tidskriftsartikel (refereegranskat)abstract
- The pioneering experiment by Welsh et al. (Immunological Lett 1991:29:167-170) connecting a pig kidney to the human circulation has been repeated in a modified manner. Two volunteer dialysis patients were pretreated by daily plasmapheresis on days -2,-1, and 0 to remove the naturally occurring anti-pig xenoantibodies. The anti-pig lymphocytotoxic liters were reduced from 1:8 to 1:2 in patient 1 and from 1:8 to 1:1 in patient 2. No steroids or immunosuppressive drugs were administrated before or during the experiments. A sterile pig kidney was extracorporeally ("ex vivo") connected to the patients a/v fistula using an arterial and a venous pump similar to a dialysis. The two experiments gave different results. In the first experiment the perfusion pressure was kept at 100 mmHg for the initial 25 min by reducing the pump speed until the minimum blood flow of 30 ml/min was reached. Thereafter, the pressure rose continuously and the experiment was terminated at 65 min at a perfusion pressure of 200 mmHg. The patient did not feel any discomfort during the perfusion. In the second experiment, a stable blood flow of 200 ml/min was reached at a pressure of 100 mmHg after a few minutes. The perfusion was terminated at 15 min when the patient developed chest and abdominal pain, hypotension, and electrocardiographic signs of myocardial ischemia. The patient recovered quickly. In the first experiment, small volumes of clear urine was produced until the pressure rose above 100 mmHg, which resulted in hematuria. In the second experiment clear urine (4 ml/min) was produced. (51)Chromium clearance values were after 15 min <1 ml/min for kidney 1 and 12 ml/min (8 ml/min/100 g) for kidney 2. A drastic reduction in platelet count (128 to 48 and 64 to 8 × 10(9)/1, respectively) during the passage through the kidney was found in blood samples collected simultaneously before and after the organ. No change in hemoglobin values and leucocyte counts were found. Light- and electron-microscopical analysis of the kidney tissues revealed for kidney 1 focal areas with obliteration of the glomerular and peritubular capillaries by platelets and PMN cells and severe damage of the endothelial cells comparable to a picture of a hyperacute rejection. In kidney 2, all vessels were patent but in the capillaries large amount of membrane fragments were detected by electron microscopy and a discrete damage of the endothelial cells were seen in some segments. No intact platelets were present in the vascular tree. These human experiments support the hypothesis that hyperacute rejection of pig to human xenografts is delayed in time by removal of the preformed anti-pig xenoantibodies. A new finding was a very rapid destruction of platelets occurring in the kidney of patient 2 who had very low liters of xenoantibodies. The humoral immune response is described in detail in an accompanying paper (Rydberg et al., this issue).
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| 4. |
- Breimer, Michael, 1951, et al.
(författare)
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Multicenter evaluation of a novel endothelial cell crossmatch test in kidney transplantation.
- 2009
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Ingår i: Transplantation. - 1534-6080. ; 87:4, s. 549-56
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite their clinical importance, clinical routine tests to detect anti-endothelial cell antibodies (AECA) in organ transplantation have not been readily available. This multicenter prospective kidney transplantation trial evaluates the efficacy of a novel endothelial cell crossmatch (ECXM) test to detect donor-reactive AECA associated with kidney allograft rejection. METHODS: Pretransplant serum samples from 147 patients were tested for AECA by a novel flow cytometric crossmatch technique (XM-ONE) using peripheral blood endothelial progenitor cells as targets. Patient enrolment was based on acceptance for transplantation determined by donor lymphocyte crossmatch results. RESULTS: Donor-reactive AECA were found in 35 of 147 (24%) patients. A significantly higher proportion of patients with a positive ECXM had rejections (16 of 35, 46%) during the follow-up of at least 3 months compared with those without AECA (13 of 112, 12%; P<0.00005). Both IgG and IgM AECAs were associated with graft rejections. Mean serum creatinine levels were significantly higher in patients with a positive ECXM test at 3 and 6 months posttransplant. CONCLUSIONS: XM-ONE is quick, easy to perform on whole blood samples and identifies patients at risk for rejection and reduced graft function not identified by conventional lymphocyte crossmatches.
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| 5. |
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| 7. |
- Dahlgren, Ulrika Skogsberg, et al.
(författare)
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Excellent outcome following emergency deceased donor ABO-incompatible liver transplantation using rituximab and antigen specific immunoadsorption
- 2022
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 57:1, s. 50-59
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Tidskriftsartikel (refereegranskat)abstract
- Background The acceptance of ABO-incompatible (ABOi) liver grafts will expand the donor pool for a patient in urgent need for a liver transplantation (LT). Here we report our results with emergency ABOi DD (deceased donor) LT using rituximab and antigen specific immunoadsorption. Patients and Methods 2009 to 2019 we performed 20 ABOi DD LTs (adults n = 17, children n = 3) for patients in urgent need for a LT. Immunosuppression consisted of rituximab (n = 20) and basiliximab (n = 15) or anti-thymocyte globuline (n = 4), intravenous immunoglobulin (IVIG; n = 6), tacrolimus, prednisolone and mycophenolate mofetil. Fifteen patients were treated with IA (n = 14) or both IA and plasmapheresis (PP; n = 1) pre-transplant and 18 patients were treated with IA (n = 15) or both IA and PP (n = 3) post-transplant. The median pre-transplant MELD- score was 40 (range 18-40). Patient and graft survival and complications were compared to a 1:4 case matched control group of ABO-identical or compatible (ABOid/c) DDLT. Results The 1-, 3- and 5-year patient and graft survival rates were 85, 85 and 78% for the ABOi recipients and not significantly different compared to ABOid/c controls. Only one ABOi patient developed antibody-mediated rejection. Conclusion Patient and graft survival after emergency ABOi DDLT using rituximab and immunoadorption was equal to ABOid/DDLT. ABOi DD LT was a successful approach to expand the donor pool for patients in urgent need for a liver graft.
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| 8. |
- Diswall, Mette, 1979, et al.
(författare)
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Glycolipid studies in small intestine and pancreas of alpha1,3-galactosyltransferase knockout miniature swine: alpha1,3GALT-KO animals lack alphaGAL antigens and contain novel blood group H compounds.
- 2008
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Ingår i: Transplantation proceedings. - : Elsevier BV. - 0041-1345. ; 40:2, s. 543-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: To avoid hyperacute rejection of xeno-organs, alpha1,3-galactosyltransferase knock-out (GalT-KO) pigs have been produced. However, Galalpha1,3Gal (Gal) determinant elimination may expose cryptic carbohydrate antigens and/or generate new antigens that might interfere with the human immune response. METHODS: Glycolipids isolated from small intestine and pancreas of two GalT-KO and one wild-type (WT) pig were tested for immune reactivity with antibodies on thin-layer chromatograms after separation by high-performance liquid chromatography, and selected fractions were analysed by proton NMR spectroscopy. RESULTS: Immunostaining using purified human anti-Gal Abs revealed that tissues from WT animals express large amounts of Gal-antigens whereas GalT-KO tissues lacked these antigens. Proton NMR spectroscopy on small intestine fractions revealed both linear and branched nona- and decaglycosylceramides, respectively, with terminal Gal-epitopes. In corresponding GalT-KO fractions, Gal-epitopes seemed to be replaced by terminal alpha1,2fucoses. Two novel branched blood group H compounds was found in the GalT-KO intestine. CONCLUSIONS: The structural complexity of alphaGal-terminating antigens in the WT organs is very high. Knockout of alpha1,3GalT by gene-targeting results in elimination of Gal-determinants. In addition structurally novel alpha1,2fucose-terminated blood group H compounds were identified in the GalT-KO tissue. These compounds are not expected to be recognized by the human immune system.
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| 9. |
- Diswall, Mette, 1979, et al.
(författare)
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Studies on glycolipid antigens in small intestine and pancreas from alpha1,3-galactosyltransferase knockout miniature swine.
- 2007
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Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337. ; 84:10, s. 1348-56
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: To avoid hyperacute rejection of xeno-organs, alpha1,3-galactosyltransferase knockout (GalT-KO) pigs have been produced. Galalpha1,3Gal determinant elimination may expose cryptic carbohydrate antigens and/or generate new antigens. This is the first biochemical study of carbohydrate antigens in GalT-KO pig organs. METHODS: Neutral and acidic glycolipids were isolated from small intestine and pancreas of two GalT-KO and one wild-type (WT) pig. Glycolipid immune reactivity was tested on thin-layer chromatograms. Small intestine neutral glycolipids were separated by high-performance liquid chromatography and selected fractions were analyzed by proton nuclear magnetic resonance spectroscopy. Total gangliosides were quantified on thin-layer chromatograms and in microtiter wells. RESULTS: Using Galalpha1,3nLc4 glycolipid reference, total Galalpha1,3Gal glycolipid antigens in the WT animal was estimated at about 30 microg (small intestine) and 3 microg (pancreas) per gram of dry tissue. Galalpha1,3Gal determinants were not detected in GalT-KO tissues at a detection limit of less than 0.25% (small intestine) and 0.5% (pancreas) of the WT tissues. Isoglobotriaosylceramide (iGb3) was absent but trace amounts of Fuc-iGb3 was found in both GalT-KO and WT pig small intestine. Blood group H type 2 core saccharide compounds were increased in GalT-KO pancreas. Total amount of gangliosides was decreased in GalT-KO tissues. The alpha1,3-galactosyltransferase acceptor, N-acetyllactosamine determinant, was not increased in GalT-KO tissues. Human serum antibodies reacted with WT organ Galalpha1,3Gal antigens and gangliosides, of which the ganglioside reactivity remained in GalT-KO tissues. CONCLUSIONS: Knockout of porcine alpha1,3-galactosyltransferase gene results in elimination of Galalpha1,3Gal-terminated glycolipid compounds. GalT-KO genetic modification did not produce new compensatory glycolipid compounds reactive with human serum antibodies.
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| 10. |
- Elmgren, A, et al.
(författare)
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DNA sequencing and screening for point mutations in the human Lewis (FUT3) gene enables molecular genotyping of the human Lewis blood group system.
- 1996
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Ingår i: Vox sanguinis. - 0042-9007. ; 70:2, s. 97-103
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Tidskriftsartikel (refereegranskat)abstract
- The human Lewis gene encodes an alpha(1,3/1,4)-fucosyltransferase responsible for synthesis of the Le(a) and a Le(b) antigens. To define the molecular background for non-functional Lewis genes we have sequenced PCR-amplified DNA fragments from two Le(a-b-) individuals. One was homozygously mutated at nucleotides 202(T --> C) and 314 (C --> T), altering Trp68 to Arg and Thr105 to Met, and the other was homozygously mutated at nucleotides 59 (T --> G) and 1067 (T --> A), altering Leu20 to Arg and Ile356 to Lys. Using PCR we screened for these and additionally one other mutation at nucleotide 508 (G --> A) among 40 Caucasians. Of 15 Le(a-b-) individuals, 7 typed as le59/1067le202/314, 4 as le202/314le202/314 and 1 as le59/1067le59/1067. Of 21 Le(a-b+) and 4 Le(a+b-), 17 typed as LeLe and 7 as Lele202/314. A pedigree study of 8 Lewis-positive individuals showed that the mutations at nucleotides 202 and 314 were located on the same allele.
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