PubMed Health⌕ Search

Biomedical subjects

G G Persijn

Publications and source records attributed to G G Persijn.

At least 91 records · Page 5Linked to original sources

Prognostic indices to predict survival of first and second renal allografts.

In order to predict kidney graft survival, the influence of independent prognostic factors can be examined multivariately and the factors combined into a prognostic index. Data on 7121 patients receiving an unrelated first and 1033 patients receiving an unrelated second transplant from nonliving donors, between 1 January 1984 and 31 December 1987, were analyzed to ascertain the most important prognostic variables up to 4.5 years posttransplantation. Factors found to be significant for graft survival were donor and recipient age and sex, recipient blood group, whether the recipient was diabetic, cold ischemic period, number of HLA-B and - DR mismatches, highest percent panel-reactive antibody, transplant center, and--for second transplants--duration of first graft. A risk score for graft failure, based on the prognostic factors, was developed using these factors and five risk groups (from excellent to very poor prognosis) were identified. This index was tested on an independent data set and showed a good fit when compared with the observed Kaplan-Meier graft survival: patients allocated by the risk score into the "excellent prognosis" group had an observed one-year graft survival of 90.4%, compared with a predicted value of 90.3% for first transplants. Corresponding results for second transplants were 86.2% (observed) and 86.0% (predicted). For the "very poor" prognosis group, the results were 73.4% (observed) and 74.4% (predicted), for first transplants, and 60.9% (observed) and 60.1% (predicted), for second transplants. A prognostic index can therefore identify patients likely to have a high or low graft survival, leading to improved decision-making and aiding the choice of patient management once a recipient has been transplanted.

ABO Blood-Group System↗

Analysis of the donor-specific cytotoxic T lymphocyte repertoire in a patient with a long term surviving allograft. Frequency, specificity, and phenotype of donor-reactive T cell receptor (TCR)-alpha beta+ and TCR-gamma delta+ clones.

In the present study the transplant specific CTL repertoire of a patient (HLA:A1,3, B8,18, Cw5,7 DR3, DQw2, DPw3) with a long term surviving HLA mismatched kidney graft (HLA: A1,24 B8,27 Cw2,7, DR3, w13 DQw2,6 DPw1,3) has been investigated. This patient was unable to generate specific cytolytic activity against donor-derived PHA-blasts in the MLC in which donor spleen cells or B lymphoblastoid cell line were used as stimulator cells. In addition, the CTL precursor frequencies against donor alloantigens were very low (1/67,000). The patient had otherwise normal immune responses in vivo and in vitro and no signs of transplant rejection. Transplant specific CTL clones were generated in high frequencies (1/195) from T cell bulk cultures activated by PHA in the absence of any sensitization by donor Ag in vitro. The repertoire of 14 donor-reactive CTL clones (12 TCR-alpha beta+ and 2 TCR-gamma delta+) was analyzed. Two TCR-alpha beta+ CD8+ clones were specific for B27. Ten TCR-alpha beta+ CTL clones directed against class II HLA Ag were isolated. Seven of these were CD4+ and recognized DRw13 (3), DQw6 (3), and DPw1 (1), whereas three of these clones were CD4-CD8+ recognizing DRw13 (1) and DQw6 (2). In addition, two donor-specific TCR-gamma delta+ CTL clones were obtained recognizing HLA-A9(23,24) and DQw6. Our data indicate that the precursors of CTL clones specifically directed against donor class I or II HLA Ag are not deleted from the repertoire and that part of this reactivity resides in the TCR-gamma delta+ fraction.

Adult↗

The effect of HLA matching on kidney graft survival in separate posttransplantation intervals.

The effect of matching for the HLA antigens has been well established as important in the prognosis of kidney grafts. By analyzing the effect of matching on first transplants from unrelated donors in specific intervals up to 3 years posttransplantation, we show that the effect of HLA-DR matching is strongest in the first 5 months following transplantation (relative risks of graft failure 1.31 and 1.77 for 1 and 2 HLA-DR mismatches, respectively, compared with no mismatches). For patients whose grafts remained functioning after 5 months, there was no significant further improvement in graft survival to 3 years (relative risks 1.16 and 0.98 for 1 and 2 HLA-DR mismatches, respectively, compared with no mismatches)--i.e., the gain in graft survival by matching for HLA-DR appears to be due to its influence in the first 5 months following transplantation. For HLA-B, the matching effect was evident both before and after 5 months (relative risks 1.11 and 1.27 for 1 and 2 HLA-B mismatches, respectively, compared with no mismatches and modelled as constant over the 3-year period), whereas no effect of HLA-A matching was evident in the period up to 3 years.

Graft Survival↗

An unexpected effect of matching for HLA-A9 in renal transplantation.

The observation of elevated levels of HLA class I molecules in sera of HLA-A9-positive individuals, and their potential role in the regulation of the immune response, motivated us to study the effect of the presence of HLA-A9 in either kidney donor or recipient on graft survival. Analysis of data from unrelated first transplants performed within the Eurotransplant area revealed that in the group of patients who were not treated with cyclosporine (n = 2051), transplants with no HLA-DR mismatches in which donors (D) and recipients (R) shared the HLA-A9 antigen (D+R+), had significantly poorer graft survival (P = 0.0001) than all other combinations, reaching a 20% difference at 5 years posttransplantation. This effect, which was not found in the CsA-treated patient group (n = 7297), was specific for HLA-A9. The implications of this findings are discussed in relation to the mechanisms of the alloimmune response.

Cyclosporins↗

Effect of one-HLA-DR-antigen-matched and completely HLA-DR-mismatched blood transfusions on survival of heart and kidney allografts.

Blood transfusions can influence the survival of organ allografts favorably, in spite of the danger of sensitization. We investigated the influence of HLA compatibility between blood donors and transfusion recipients on the production of HLA antibodies and on graft survival. Among recipients of transfusions who shared one HLA-DR antigen with their respective donors, antibodies developed in 6 of 28 who had received one transfusion, in 2 of 16 who had received three transfusions, and in 4 of 24 who had undergone renal transplantation. Among recipients who were mismatched with their donors for both HLA-DR antigens, the rate of sensitization was significantly higher in all three of these groups (18 of 30, P = 0.02; 12 of 16, P = 0.0007; and 12 of 22, P = 0.001). The survival of kidney allografts among graft recipients who were given transfusions and shared one HLA-DR antigen with their blood donors (81 percent at five years) was significantly higher than among recipients who were given transfusions and were mismatched for both HLA-DR antigens (57 percent; P = 0.02) or among recipients who were not given transfusions (45 percent; P = 0.001). There was no difference in graft survival between patients who received transfusions mismatched for two HLA-DR antigens and those who were not given transfusions. We conclude that allograft survival can be improved by pretransplantation blood transfusion when the transfusion recipients share at least one HLA-DR antigen with their donors. In view of the increased rate of sensitization and the lack of improvement in graft survival, the transfusion of blood mismatched for two HLA-DR antigens appears to be contraindicated in candidates for transplantation.

Antibody Formation↗

The impact of center variation on the HLA-DR matching effect in kidney graft survival.

Data from 7436 cases of first-cadaver transplants between 1981 and 1986 from 50 transplant follow-up centers within Eurotransplant, were analyzed with respect to the effect of HLA-DR matching on graft prognosis within the first year posttransplant. The use of cyclosporine was allowed for as well as the variation in graft survival rate between transplant follow-up centers. After adjustment for these variables, HLA-DR matching was still very significant. The effect of CsA on graft survival varied between centers--i.e., interaction was observed--but the effect of HLA-DR mismatching did not vary significantly between centers. Over all the centers there was a 1.4-fold increase in relative risk for each increase in HLA-DR mismatch, corresponding to predicted one-year graft survivals of 86.5%, 81.9%, and 75.4% for 0, 1, and 2 HLA-DR mismatches respectively, in patients receiving CsA, and 72.5%, 64.2%, and 53.6% in patients not receiving CsA.

Cyclosporins↗

Renal transplant patients monitored by the cell-mediated lympholysis assay. Evaluation of its clinical value.

Donor-specific cytotoxic T cell activity was measured over a period of 5 years after transplantation using the cell-mediated lympholysis (CML) test in 124 recipients of unrelated kidney allografts who received conventional immunosuppressive therapy consisting of azathioprine and prednisone. Since patients with a functioning transplant frequently display donor-specific CML non-responsiveness in vitro, we addressed the question of whether the CML status has a predictive value regarding the graft prognosis at any time interval until 5 years posttransplantation. From log-rank type analyses we conclude that the estimated relative risk calculated over the whole follow-up period of a CML-responder in the category of transplant rejectors is 1.25 with 95% confidence bounds between 0.94 and 1.65. Measurements of CML responder status during follow-up seem to have only limited prognostic value, although the relative risk is borderline significant when the analysis is restricted to the period between 2 weeks and 6 months posttransplantation.

Cytotoxicity Tests, Immunologic↗

Transplantation of highly sensitized patients on the basis of acceptable HLA-A and B mismatches.

We think that the determination of acceptable mismatches is an efficient approach to increase the chance of finding a crossmatch-negative donor for highly sensitized patients. This approach has several advantages (4,5) namely: 1. There is no need for distribution of patient sera to other tissue typing centers. 2. Rather than performing crossmatches with all donors, most of which will be positive, selection is based on a predictable negative crossmatch. 3. Selection of potential donors is based on data obtained by the recipient centers, which has all the information concerning the patient's immunological background (transfusion, specific alloantibodies, autoantibodies) rather than on a negative crossmatch at another tissue typing center. 4. Selection is based on HLA-DR compatibility between donor and recipient, which is, both in our and other analyses (6), important for an optimal prognosis of graft survival in highly immunized patients. Of course, there are still patients for whom this protocol is not very helpful (rare HLA-types, hardly any or no acceptable mismatches). For these patients it might be that other approaches, including removal of circulating antibodies (7), may be the only solution.

Clinical Protocols↗