Cell-mediated lymphocytotoxicity directed against HLA-D gene products.

Cytotoxic effector cells were generated in human mixed lymphocyte cultures (MLCs) between cell donors differing at the HLA-D/DR region but not at HLA-A,B(C). These cells killed Epstein-Barr virus-infected lymphoblasts (EBV blasts) from donors sharing the HLA-D/DR determinants with the normal MLC-stimulating cells, but not phytohaemagglutinin (PHA) lymphoblasts from the same donors. Because EBV blasts are derived from B cells and express HLA-D/DR antigens, the most likely interpretation of these findings is that the HLA-D/DR antigens may, by themselves, act as targets for cell-mediated cytotoxicity.

Renal transplants from HLA-haploidentical living-related donors. The influence of donor-specific transfusions and different immunosuppressive regimens.

A total of 151 potential recipients of kidney grafts from one-HLA-haplotype-mismatched MLC-positive (RR greater than 20%) donors treated during 1980-1984 was investigated. The recipients were divided retrospectively into four groups: (A) 42 patients who received pretransplant donor-specific transfusions (DST) and posttransplant azathioprine/prednisolone (DST-only); (B) 10 patients who received DST with azathioprine before and azathioprine/prednisolone after grafting (DST-aza); (C) 42 patients who received no pretreatment and azathiprione/prednisolone posttransplant (aza group) and (D) 57 patients who also received no pretreatment but cyclosporine/prednisolone posttransplant (CsA group). DST-only led to persistently positive crossmatch in nine (21%) and transient positive crossmatch in two patients, while no sensitization occurred in the DST-aza group. Posttransplant, early acute rejection episodes were frequent in the DST-only group, but no graft was lost to acute rejection during first year; one-year graft survival (GS) = 94%. Similar GS (93%) was obtained in the CsA group, while in the aza group poorer results were obtained; GS = 69%. In the DST-aza group clinical problems including serious infections were observed. As CsA treatment without DST gave as high graft survival as in the DST groups, but avoided the sensitization risk by DST alone and the bone marrow complications of DST-aza, such treatment has become our preferred therapy for haploidentical renal transplants.

Depletion of T lymphocytes from human bone marrow. Use of magnetic monosized polymer microspheres coated with T-lymphocyte-specific monoclonal antibodies.

A new technique for depletion of T cells from bone marrow is presented. Bone marrow cells (BMC) were rosetted with magnetic monosized polystyrene microspheres coated with monoclonal antibodies (MAbs) specific for T cell CD2 and CD3 antigens. Rosetted T cells were subsequently removed from non-T cells with the aid of a magnet. This immunomagnetic separation procedure was carried out in less than 40 min and reproducibly removed T cells, leaving a maximum of 0.025% sheep-red-blood-cell (SRBC) rosette-forming cells and less than 0.02% T cells as detected by a T cell limiting dilution assay. The efficacy of the depletion procedure was further shown by flow cytometry data, by effective removal of cells from a T cell line added to the BMC prior to immunomagnetic separation, and by abrogation of interleukin 2 (IL-2)-producing capacity in T-cell-depleted BMC (BMC-T). The T cell depletion procedure provided a 43-74% recovery of non-T cells present in the Isopaque-Ficoll-isolated bone marrow mononuclear cell fraction and did not disturb the growth potential of stem cells, as assayed by hematopoietic stem cell assays.

A randomized trial of cyclosporine and prednisolone versus cyclosporine, azathioprine, and prednisolone in primary cadaveric renal transplantation.

A randomized trial was performed with the aim to compare two immunosuppressive treatment schedules in adult recipients of first cadaveric renal transplants. A total of 229 patients were randomized to double therapy with cyclosporine and prednisolone and 234 patients were randomized to triple therapy with cyclosporine, azathioprine, and prednisolone. Minimum follow-up was 4 years. The actuarial 5-year patient survival was 79.8% in the double therapy group and 82.3% in the triple therapy group (n.s.). The corresponding graft survival figures were 54.4% and 59.6% in the two groups, respectively (n.s.). There were no differences between the groups regarding cause of death or cause of graft loss. Renal function as determined by serum creatinine did not differ between the groups and was stable throughout the observation period. Azathioprine was instituted in a total of 51 patients randomized to double therapy. This subgroup of patients had a patient and graft survival not different from the remaining patients randomized to double therapy or from the patients randomized to triple therapy. There were no differences between the double and triple therapy groups regarding incidence and timing of acute rejection or infections. The incidence of other medical diseases and adverse events such as nephrotoxicity or malignancy did not differ between the groups. Azathioprine-induced leukopenia was uncommon (19 episodes in the triple therapy group). In a multivariate analysis of the whole series the only covariates that significantly influenced graft survival were age of recipient and occurrence of acute rejection, while among other factors treatment schedule did not. Thus this prospective study, in accordance with previous such studies, failed to find support for the use of triple therapy as first choice immunosuppression in first cadaveric renal transplantation. However, the study could not rule out the possibility that some patients at risk for the development of irreversible rejection or nephrotoxicity of CsA might benefit from the addition of azathioprine to the treatment schedule.

Ischemic heart disease--major cause of death and graft loss after renal transplantation in Scandinavia.

Causes of graft loss and death were studied in 1347 recipients of primary renal transplants followed for 5 years after transplantation irrespective of graft function. Immunosuppression consisted of high or medium dose CsA and prednisolone or low dose CsA and prednisolone and azathioprine. In recipients of cadaver grafts, death with a functioning transplant was more common than graft rejection after the first posttransplant year, accounting for 49% and 41% of the graft losses, respectively. Of deaths with a functioning graft, 53% were due to ischemic heart disease (IHD) and 10% were due to other vascular disease. In the 55- to 64-year-old age group, the risk of death from IHD was 6.4 times higher in the transplanted nondiabetic patients, 8.6 times higher in the dialysis patients (European Dialysis and Transplant Association figures), and 20.8 times higher in the transplanted diabetic patients than in the general population (national figures). A multivariate Cox regression analysis showed that old age, diabetes mellitus, occurrence of acute rejection, pretransplant transfusions, delayed onset of graft function, and male gender were significant for death in IHD. We conclude that, in comparison to reports from other regions, Scandinavian renal transplant recipients are at high risk of dying of IHD. Future advances in long-term renal graft survival will depend largely on the success of preventing myocardial infarction and death in this patient population.

Significance of HLA matching in renal transplantation. A prospective one-center study of 485 transplants matched or mismatched for HLA-A, B, C, D, and DR antigens.

Matching for HLA haplotypes as well as for HLA-A and B antigens improved graft survival in 112 living related first transplants. In cadaveric first transplants, matching for HLA-A and B antigens had a beneficial effect on the fate of 373 grafts, while matching for HLA-C antigens had no predictive value. One hundred seventeen cadaveric transplants and their recipients were prospectively typed for the HLA-DR antigens. Compatibility for HLA-DR was found to be prognostically beneficial irrespective of matching for HLA-A and B antigens, and with no difference between transfused and nontransfused patients. Matching both for HLA-A , B and D/DR was thus found to influence the outcome of renal transplantation.

The impact of acute rejection episodes on long-term graft function and outcome in 1347 primary renal transplants treated by 3 cyclosporine regimens.

To characterize factors of importance for the occurrence of acute rejection as well as study the impact of these episodes on long-term renal survival and function, a total of 819 acute rejection episodes were studied in 951 primary cadaveric donor kidney recipients (CD) and in 396 primary living donor kidney recipients (LD). The patients were treated by three immunosuppressive schedules, namely, CsA given in a high dose, a medium dose, or a low dose. Additionally, all patients received PRED and patients in the low-dose group received AZA. The incidence of acute rejection was higher and occurred earlier after transplantation in the CsA medium dose and low dose groups than in the CsA high dose group (P < 0.05 and P < 0.01, respectively). Although the incidence of first acute rejection was similar in CD and LD patients, 59.1% vs. 60.6%, it was successfully reversed by antirejection treatment in a higher percentage in LD patients. The estimated graft half-life was shorter in patients who had acute rejection episodes than those who did not, 6.6 years vs. 12.5 years in CD patients (P < 0.0001). Renal function at 1-5 years after transplantation was stable, but significantly poorer in CD patients who had experienced acute rejection than in patients who had not, with the mean creatinine clearance rates in the ranges 45-47 vs. 54-60 ml/min in the other groups (P < 0.0001). In a stepwise Cox regression analysis in CD recipients, risk factors for acute rejection were CsA (low dose) treatment schedule, immunization as displayed by presence of panel-reactive antibodies and positive B cell cross-match, young recipient age, disease of diabetes mellitus, and HLA-DR mismatching. In LD recipients, the corresponding risk factors were treatment schedule, young recipient, HLA mismatching, and transplantation from parent to child. Thus, the study has demonstrated some factors of importance for acute rejection episodes in CsA-treated patients as well as showing the detrimental effect of these episodes on long-term graft survival and renal function. These results suggest that a primary aim of future treatment strategies should be to reduce the incidence of these episodes.

Pretransplant plasma exchange or immunoadsorption facilitates renal transplantation in immunized patients.

Patients with preformed antibodies against HLA molecules accumulate on renal transplant waiting lists and have inferior graft survival compared with nonsensitized patients. One hundred patients were included in a program of pretransplant removal of antibodies by plasma exchange (n = 90) or immunoadsorption (n = 10) in addition to prednisolone and cyclophosphamide medication. After plasma exchange, the panel reactivity and the antibody titer were reduced in about half of the patients, and after immunoadsorption the panel reactivity fell in 6 of 10 patients. Of the 83 patients who received grafts, 17 received a graft from a living donor (LD) and 66 received a graft from a cadaver donor (CD). Patients with a positive crossmatch against their LD were included in the program and were thus grafted with a recent positive, current negative crossmatched organ. Fifteen CD graft recipients had a pretreatment positive crossmatch toward their donor. No episodes of hyperacute rejection were seen. One- and 4-year graft survival rates in LD transplants with a recent positive and current negative crossmatch were 77% and 64%, respectively. At 1 and 4 years, graft survival rates were 70% and 57% in pretreated first CD graft recipients (n = 27) and 61% and 47% in pretreated regrafted patients (n = 39), respectively. In this program, a high rate of transplantation among the sensitized patients was achieved. Graft survival was inferior to that seen in nonsensitized patients, but was comparable to graft survival in sensitized patients at other centers.

Unrelated living donors in 141 kidney transplantations: a one-center study.

BACKGROUND: Kidney transplantation is the optimal treatment for the majority of patients with end-stage renal disease. However, the shortage of kidneys for transplantation is a global problem, and any attempt to improve the donor situation would be of benefit to the growing number of patients on transplant waiting lists. PATIENTS AND METHODS: Since 1984, we have transplanted 141 kidneys from genetically unrelated living donors. Donors were most often spouses and were accepted regardless of HLA match grade. Preemptive transplantation was performed in 39% of the patients. Standard triple-drug immunosuppression with prednisolone, cyclosporine, and azathioprine was used. The patients were followed from 6 months to 13 years. RESULTS: The incidence of acute rejection during the first 3 months after transplantation was higher in recipients of grafts from unrelated donors than in recipients of grafts from related living donors or cadaveric donors. However, unrelated living donor grafts survived significantly better than did cadaveric grafts (P < 0.02) and had a survival rate similar to that of living-related donor grafts mismatched for one or both HLA haplotypes. The perioperative complication rate for the donor was low. CONCLUSION: We consider unrelated living donors an excellent source for alleviating the shortage of donor kidneys.

Immunomagnetic depletion of CD6+ cells from bone marrow and peripheral blood.

Depletion of donor CD6+ cells in HLA-identical allogeneic bone marrow transplantation has been reported to reduce graft-versus-host disease without interfering with engraftment. We have established an immunomagnetic cell separation technique capable of producing a 2-3 log depletion of CD6+ cells. Median recovery of CD6- cells and hematopoietic progenitor cells was 65-70%, and cell viability was unaffected. Significant numbers of CD2+, CD3+ cells responsive to phytohemagglutinin (PHA), OKT3, recombinant interleukin-2 (rIL-2), and allogeneic cells remained after depletion, and the number of cells able to respond to stimulation with PHA and IL-2 in vitro was reduced by only 1-2 log. These observations are not easily reconciled with the ability of CD6 depletion to prevent GVHD, but raise the question whether the depletion causes a sufficient reduction of the T cell load or removes a critical T cell subset.

Donation of stem cells from blood or bone marrow: results of a randomised study of safety and complaints.

Biological consequences and physical complaints were compared for donors randomly assigned either to blood stem cell (BSC) or bone marrow (BM) donation. In the period 1994-1999, 61 consecutive donors were included. The BSC donors were given G-CSF 10 microg/kg s.c., daily during 5 days before the first leukapheresis. Nineteen donors had one leukapheresis, 10 required two and one donor needed three leukaphereses in order to reach the target cell number of 2 x 10(6) CD34(+) cells/kg bw of the recipient. A median platelet nadir of 102 x 10(9)/l was reached shortly after the last leukapheresis. Three weeks post harvest, 17 of 30 BSC donors had a mild leukopenia. Six had a leukopenia lasting more than a year before returning to normal values. Both groups were monitored prospectively through a standardised questionnaire completed by the donors. BSC donation was significantly less burdensome than BM donation and was preferred by the donors. The short-term risks of BSC mobilisation and harvest seem negligible. The potential long-term effects of G-CSF are unresolved and the donors must be followed closely.

Fewer relapses and increased chronic GVHD in patients transplanted with blood stem cells: a 5-year follow-up in a single centre study.

A total of 61 consecutive adult patients with haematological malignancies with an HLA-identical or one antigen-mismatched haploidentical family donor were randomised to allogeneic transplantation with blood stem cells (BSC) or bone marrow (BM). The median observation time was 5 years. Apart from engraftment parameters and acute graft-versus-host disease (GVHD), transplant-related mortality (TRM), incidence and severity of chronic GVHD, relapse, leukaemia-free survival (LFS) and overall survival (OS) were recorded. In the BSC and BM group, respectively, TRM was 8/30 and 4/30 (P=0.405), the incidence of chronic GVHD was 15/26 and 11/30 (P=0.138), extensive chronic GVHD was 10/26 and 4/30 (P=0.034), and relapse one and 10 patients (P=0.007). In log-rank test restricted to the cases allografted from HLA-identical donors, the difference remained significant with regard to relapse incidence (P=0.039), but not extensive chronic GVHD (P=0.072). No difference in LFS and OS was observed. In conclusion, our study strongly indicates an enhanced graft-versus-leukaemia effect in BSC recipients, which is not expressed in increased survival. The increased chronic GVHD in these patients may contribute, but the relation is complex and not yet understood.

No prevention of cytomegalovirus infection by anti-cytomegalovirus hyperimmune globulin in seronegative bone marrow transplant recipients. The Nordic BMT Group.

A randomized multicentre study was conducted to evaluate the effect of anti-CMV hyperimmune globulin in the prophylaxis of CMV infections in CMV seronegative allogeneic BMT patients who received a transplant from a seropositive donor or who had received blood products unscreened for CMV during the treatment before BMT. Twenty-eight patients were included in the study. Thirteen were randomized to receive and 15 not to receive intravenous CMV hyperimmune globulin. A dose of 0.4 g/kg of immunoglobulin was given on day -8 and 0.2 g/kg on days -1, +7, +14, +21, +28, +35, +42, +56 and +70 in relation to the day of transplantation. Among the 15 patients not given immunoglobulin CMV was isolated in three, and two of them developed clinical CMV disease. In addition, one more patient developed CMV antibodies without virus isolation. In five of the 13 patients given immunoglobulin the virus could be isolated, and four of them developed CMV disease. One additional patient showed seroconversion but no other findings of CMV infection. The incidence of acute and chronic GVHD was similar in the two arms. There was no significant difference in survival. In conclusion, the present results do not indicate a beneficial effect of CMV hyperimmune globulin infusions in the prophylaxis of CMV infection or disease in seronegative allogeneic bone marrow transplant recipients from a seropositive donor.

A randomised study of allogeneic transplantation with stem cells from blood or bone marrow.

Sixty-one consecutive adult patients with leukaemia, primary myelofibrosis or myelodysplastic syndrome with an HLA-identical or one antigen mismatched family donor were randomised to allogeneic transplantation with PBPC or BM. Progenitor cells were mobilised into the blood by giving the donors 10 microg/kg/day G-CSF subcutaneously for 5-7 days. G-CSF was not given to patients after transplantation. The time to neutrophil counts >0.5 x 109/l was 17 days (95% CI 15.2-18.8 days) in the PBPC group compared to 23 (95% CI 20.3-25.7 days) in the BM group (P = 0.0005). The time to platelet counts >20 x 109/l was 13 days (95% CI 11.7-14.3 days) in the PBPC group and 21 days (95% CI 18.7-23.3 days) in the BM group (P = 0.0005). Acute GVHD of grades II-IV developed in six patients transplanted with PBPC and three patients transplanted with BM. The numbers of patients with chronic GVHD were 15 and 8, respectively. Transplant-related mortality and leukaemia-free survival showed no significant differences. Transplantation with PBPC appears preferable for the recipient due to faster neutrophil and platelet recovery. However, the final conclusion can not be drawn before long-term results on chronic GVHD and relapse incidence in longer randomised trials are available.

Experience with cyclosporine in 1519 kidney transplantations from living donors in a national transplant programme, 1983-2002.

Following the introduction of cyclosporine as basic immunosuppression in our national transplant programme in 1983, the pool of grafts from living donors (LDs) was expanded 2 years later by also accepting LDs mismatched for 2 HLA haplotypes and living unrelated donors (LURDs), mostly spouses. A policy of approaching family members to promote donation was consistently pursued. During 1983 through 2002, nephrectomy was performed on 1519 LDs without mortality. From 1983 through 1988, our learning phase in managing cyclosporine-immunosuppression, 382 patients received first grafts from LDs. One-year graft survival (GS) rates were 94.4%, 90%, 89%, and 82% in 71 HLA identical, 260 haploidentical, 18 2-haplotypes disparate, and 33 LURD graft recipients, respectively. Corresponding half-lives were 15.8, 10.3, 11, and 9.1 years, respectively. Results improved in 1028 patients receiving first LD grafts from 1989 through 2002. Corresponding 1-year GS rates were 96.6% (n=117), 93.5% (n=650), 90.4% (n=73), and 88.8% (n=188), and half-lives were 30, 13.3, 13.5, and 12.3 years, respectively. Similar GS rates were observed in 109 recipients of repeat grafts from LDs. LDs contributed 44% and 21.6% of all first and repeat grafts transplanted, providing grafts to 11 patients (in 1983) increasing to 23 patients (in 2002) per million population per year (pmp/y). When added to grafts from cadaveric donors, 40 to 48 pmp/y were provided with a first or repeat graft since 1990, thus covering at least 65% of the national need for kidney transplantations.

Aluminium accumulation and immunosuppressive effect in recipients of kidney transplants.

Aluminium that has accumulated in the body is thought to have a generalised cytotoxic effect. A prospective study of aluminium accumulation in bone-that is, subclinical aluminium toxicity--was carried out in 94 recipients of kidney allografts, who were followed up for three years. Subclinical aluminium toxicity was found in 66 patients. A significantly smaller proportion of patients with aluminium accumulation experienced a rejection episode: 30 (58%) nu 12 (86%) who received grafts from cadavers and 4 (29%) nu 10 (71%) who received grafts from living donors. On multivariate analysis only the source of the kidney and aluminium accumulation were found to influence the rejection rate. These findings suggest that aluminium accumulation has an immunosuppressive effect.

HLA-DR typing and B cell cross-match tests in cadaveric renal transplantation.

Prospective HLA-DR typing and B cell cross-match tests were performed in 177 cadaveric transplants using a modified NIH technique, 24 selected HLA-DR typing sera and B cells separated from peripheral blood in recipients and from spleen in donors. Actuarial graft survival after one year was 60% in HLA-DR compatible transplants and 30% and 18% in transplants mis-matched for 1 and 2 HLA-DR antigens. The favorable prognostic influence of HLA-DR compatibility was observed both among HLA-A, -B compatible and incompatible transplants. Sharing of HLA-DR antigen(s) between donor and recipient was also prognostically beneficial. Standard cross-match tests were negative in all transplants. B cell cross-match tests were positive in 17 cases, and one of these transplants was very acutely rejected. Actuarial graft survival after three months was 35% in B cell cross-match positive grafts versus 53% in negative ones.