A novel HLA-C allele, Cw*0617

Sequencing analysis of exons 1-3 of the human leukocyte antigen (HLA)-C gene showed a novel allele, HLA-Cw*0617. While the amino acid sequence is identical with the HLA-Cw*060201 allele, the leader peptide differs in three amino acids.

Impact of HLA class I high-resolution mismatches on chronic graft-versus-host disease and survival of patients given hematopoietic stem cell grafts from unrelated donors

There is consensus that matching of unrelated donors (URD) and patients for HLA class II alleles improves the outcome of hematopoietic stem cell transplantation (HSCT). However, the significance of HLA class I allelic mismatches for transplant outcome is under discussion and reports on long-term effects like chronic graft-versus-host disease (GVHD) are rare. Thus, we investigated the association of human leukocyte antigen (HLA) class I allele mismatches and outcome in 144 patients given HSCT from URD who were matched for HLA-DRB1, DRB3/4/5, and DQB1 alleles. The risk of chronic GVHD was significantly increased in patients with class I mismatched donors, the mismatch either detected by low- or high-resolution typing. A single HLA class I allele mismatch significantly increased the risk of chronic GVHD in multivariate analysis. Overall survival was significantly reduced in patient/donor pairs with more than one-allele class I mismatch. Thus, selection of unrelated donors for transplantation should be based on high-resolution HLA class I typing.

Successful immunotherapy in early relapse of acute myeloid leukemia after nonmyeloablative allogeneic stem cell transplantation

We report on a 35-year-old woman who underwent allogeneic stem cell transplantation (SCT) in second complete remission (CR) of acute myeloid leukemia (AML) after reduced-intensity conditioning with fludarabine and 2 Gy of total body irradiation. For graft-versus-host disease (GVHD) prophylaxis, cyclosporin A (CsA) and mycophenolate mofetil (MMF) were given. On day 27 after SCT complete hematological remission and donor chimerism was documented. However, in CD34(+) bone marrow cells 28% of recipient hematopoiesis persisted. On day +59 leukemic relapse occurred. After discontinuation of CsA and onset of GVHD, complete donor chimerism and hematological CR were achieved which has been maintained for 14 months.

Informed consent--suggested procedures for informed consent for unrelated haematopoietic stem cell donors at various stages of recruitment, donor evaluation, and donor workup

The Ethics Working Group of the World Marrow Donor Association (WMDA) was established to address the increasing and complex number of ethical issues surrounding unrelated haematopoietic stem cell donation where the selected donor and recipient reside in different countries. This paper considers the topic of informed donor consent, but recognises that the recommendations contained within the paper may be subject to cultural variances in interpretation, and to adjustment to meet the legal requirements of individual countries. Nevertheless, the extent of international cooperation establishes sufficient common denominators for the recommendations to be widely adhered to in the interests of best practice.

Long-term outcome and quality of life of patients who are alive and in complete remission more than two years after allogeneic and syngeneic stem cell transplantation

We assessed long-term outcome in 155 patients who had undergone an allogeneic/syngeneic stem cell transplant (SCT) and were in complete remission for more than 2 years after transplant. Probability of late transplant-related mortality was 6%, and affected only patients with chronic graft-versus-host disease (cGVHD). Thirteen percent of patients experienced relapse. Overall survival projected at 10 and 15 years was 83% and 76%, respectively. Secondary malignancies occurred in two patients, 7.5 and 11 years after SCT. Three female and four male patients parented children 19 to 84 months after SCT. Quality of life (QoL) was assessed in a cross-sectional study by the means of a 30-item questionnaire (QLQ-C30) of the EORTC. The questionnaire was sent to 127 patients remaining alive and answered by 106 patients. Seventy-three percent reported a good to very good QoL within 5 years after SCT and 78% after this time point. However, patients with cGVHD had significant impairment of physical, role and social functioning and only 60% of them were fit for work. These results from long-term survivors show that high cure rates with good to very good QoL can be achieved by allogeneic or syngeneic SCT.

Extracorporeal photochemotherapy in the treatment of severe steroid-refractory acute graft-versus-host disease: a pilot study

Extracorporeal exposure of peripheral blood mononuclear cells to the photosensitizing agent 8-methoxypsoralen and UV-A radiation has been shown to be effective in the treatment of selected diseases mediated by T cells, rejection after solid organ transplantation, and chronic graft-versus-host disease (GVHD). We present 21 patients with a median age of 38 years who developed steroid-refractory acute GVHD grades II to IV after stem cell grafting from sibling or unrelated donors and were referred to extracorporeal photochemotherapy (ECP). Three months after initiation of ECP 60% of patients achieved a complete resolution of GVHD manifestations. Complete responses were obtained in 100% of patients with grade II, 67% of patients with grade III, and 12% of patients with grade IV acute GVHD. Three months after start of ECP complete responses were achieved in 60% of patients with cutaneous, 67% with liver, and none with gut involvement. Adverse events observed during ECP included a decrease in peripheral blood cell counts in the early phase after stem cell transplantation (SCT). Currently, 57% of patients are alive at a median observation time of 25 months after SCT. Probability of survival at 4 years after SCT is 91% in patients with complete response to ECP compared to 11% in patients not responding completely. Our findings suggest that ECP is an effective adjunct therapy for acute steroid-refractory GVHD with cutaneous and liver involvement. However, in patients with acute GVHD grade IV or gut involvement other therapeutic options are warranted.

Excellent disease eradication by myeloablative therapy and stem-cell transplantation in patients with acute myelogenous leukemia

Between February 1982 and 1999, 118 consecutive patients (65 male, 53 female) with acute myelogenous leukemia (AML), with a median age of 35 years (range 17-56 years), received stem-cell grafts from a human leukocyte antigen-identical sibling (n = 71), one-antigen-mismatched family member (n=2), matched unrelated donor (n=15), one-antigen-mismatched unrelated donor (n = 4) or an autologous (n = 26) graft. At the time of transplant, 56 patients were in the first complete remission (CR), 27 in the second CR, 6 in untreated relapse, 17 in primary refractory, and 12 in refractory relapse. The French-American-British classification (FAB) subtypes were as follows: M1 (n=25), M2 (n=28), M3 (n=11), M4 (n =32), M5 (n=16), M6 (n = 6). For conditioning, most patients underwent total body irradiation-containing regimens. As of 28 February, 1999, probability of leukemia-free survival (LFS) is 58% for patients after related and 45% after unrelated stem-cell transplantation (SCT). The probability of LFS is 70% for patients given allogeneic transplants in the first CR compared with 33% for those beyond the first CR at SCT. In autologous stem-cell graft recipients, the probability of LFS is 37%. Transplant-related mortality was 28% after related, 20% after unrelated, and 4% after autologous SCT. Probability of relapse for patients given related-donor stem-cell grafts in the first CR and beyond the first CR is 30% and 67%, 55% after unrelated and 63% after autologous stem-cell grafting. Thus, myeloablative therapy followed by allogeneic stem-cell infusion has a high curative potential for patients with AML in remission and offers substantial benefits to patients in advanced disease.

Low transplant-related mortality in patients receiving unrelated donor marrow grafts for leukemia

Transplantation with unrelated donor (UD) marrow has been shown to potentially cure patients with leukemia. Between January 1991 and April 1998, 54 patients with leukemia have received an UD BMT at our institution. Five patients received their UD BMT as a second transplant after a preceding autologous or syngeneic BMT and were excluded from further analysis. Forty-nine patients with leukemia (acute leukemia n = 26; CML n = 23) and a median age of 36 years (range 19-51) were analyzed. For conditioning, all patients received a combination of fractionated TBI and CY. GVHD prophylaxis consisted of MTX and CsA in all patients. As of 30 April 1998, 27 of 49 (55%) patients survive after a median observation time of 18 months. The probability of overall survival for standard risk and high risk patients is 54% and 31% (P = 0.05). Probability of transplant-related mortality (TRM) is 27%, 24% in standard risk and 31% in high risk patients (P = 0.44). Patients younger than 40 years (n = 33) had a similar TRM as patients 40 years and older (n = 16). The probability of relapse is 41% for the whole group, 29% for standard risk and 55% for high risk pts (P<0.05). Our data confirm that UD BMT is an effective treatment for patients with leukemia. TRM is almost similar to related sibling BMT, most probably due to improvements in HLA typing technology, conditioning regimen and supportive patient care.

Matched unrelated donor marrow transplantation in patients with advanced acute leukemia

Patients with advanced acute leukemia (AL) have a poor prognosis with death due to disease or complications of therapy. High-dose chemoradiotherapy followed by allogeneic marrow transplantation (BMT) has been used to overcome resistance of the leukemic clone resulting in long-term survival of up to 20%. Due to lack of suitable related donors BMT from an HLA-compatible unrelated donor (MUD) has been increasingly applied in these patients during the last years. Between January 1991 and August 1997 twenty five patients with advanced acute myeloid (n=19) or lymphoid (n=6) leukemia, 11 males and 14 females, age 22 to 41 (median 32) years received MUD (n=22) or 1-antigen mismatched unrelated donor (n=3) grafts. In four patients an autologous BMT had been performed previously. For conditioning all patients were given total body irradiation containing regimens. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine (CSA) and methotrexate (n=24) or CSA and methylprednisone (n=1). In 23 patients (92%) class II region compatibility was assessed by DRB1, DRB3, DRB5, and DQB1 allele typing by hybridization of amplified DNA with ligation based typing. In 2 patients HLA-DR typing was performed by two colour fluorescence cytotoxicity test and mixed lymphocyte cultures. As of November 1997 10/25 patients (40%) are surviving leukemia-free after a median observation time of 17 (range, 3 to 38) months. Transplant-related mortality was an overall of 36% and 28% in patients receiving their first BMT. In 6/25 patients (24%) relapse occurred 2 to 26 months after BMT. Incidence of acute GVHD grade I to IV was 85%. The probability of relapse projected at 3 years was 35%. High-dose chemoradiotherapy followed by MUD marrow infusion has a curative potential for patients with advanced acute leukemia and offers the chance of long-term leukemia-free survival. Currently, up to 80% of patients with acute myelogenous leukemia (AML) and acute lymphoid leukemia (ALL) under the age of 50 years achieve complete hematological remission (CR) with conventional dose chemotherapy. However, in patients who are refractory to induction chemotherapy or relapse prognosis is still poor. There, high-dose chemoradiotherapy followed by allogeneic marrow infusion has been used to overcome resistance of the refractory leukemic clone and has resulted in long-term survival. For selected patients lacking a human leukocyte antigen (HLA) compatible family donor marrow transplantation (BMT) with a suitable unrelated marrow donor (MUD) has become a feasible and effective treatment. Here, we report our experience in patients with advanced acute leukemia given marrow grafts from unrelated donors.

A single centre experience with allogeneic stem cell transplantation for severe aplastic anaemia in childhood

BACKGROUND

Severe aplastic anaemia (SAA) is a rare disorder which has a fatal course when allogeneic stem cell transplantation (SCT) or an immunosuppressive regimen is not applied. Stem cell replacement is the only curative approach for these patients but it is limited by the availability of a compatible donor.

PATIENTS

Between 1982 and 1993, 18 children (15 boys, 3 girls) with SAA and HLA identical, MLC negative donors underwent SCT in our institution. SAA was preceded by viral infection in 8 patients (3x hepatitis, 1x measles, 1x herpes simplex infection and 3x viral upper respiratory tract infections). It was drug-associated in one and idiopathic in the 9 others. The median age at diagnosis was 9.7 years (range, 2 months to 16 years). Pretreatments included corticosteroids in 11/18 patients, androgens in 4 patients in addition, two had received cyclosporin A (CSA). One patient progressing from Diamond- Blackfan anaemia to SAA had multiple immunosuppressive treatment courses over 7 years before his grand-uncle was identified as donor while 4 patients had no treatment prior to SCT.

METHODS

Early SCT (within 90 days after diagnosis) was performed in 9/18 patients and the median interval between diagnosis and SCT was 2.6 months (range, 0.5 to 7 years). The stem cell source was the bone marrow (BM) of a syngeneic twin in 2 patients, the BM (13 patients) or the cord blood (1 patient) of a sibling whilst it was BM from a HLA-phenotypical family donor (1 father, 1 grand-uncle) in two patients. Cyclophosphamide 50 mg/kg on 4 consecutive days was given as preparative regimen to 16 patients but not to the two syngeneic twins. Rejection prophylaxis included total lymphoid irradiation in 5/16 patients while in the other 11 patients donor buffy coat cells were given on days +1 to +4. The syngeneic twins had no need for either approach. Patients received a median number of 3.7 x 10(8)/kg nucleated cells (range, 2.6 to 6.7). Prophylaxis of graft versus host disease (GVHD) was carried out with MTX alone (n = 12), with CSA alone (n = 2) or with both (n = 4). All patients received standard supportive care.

RESULTS

The overall survival is 89% at the median observation time of 100 months. The median time to reach 500 granulocytes was 24 days (range, 15 to 40). Median time to become transfusion independent after BMT was 30 days for platelets (range, 2 to 111) and was 28 days for packed red blood cells (range, 6 to 128). Acute GVHD was observed in 10/18 patients and involved only skin in 6 patients, skin and liver or gut in two patients and all 3 organs in another two patients. Seven of 10 patients had grade 1 to 2 a GVHD toxicity, whereas 3 patients experienced grade 3 to 4 acute GVHD. Chronic GVHD developed in 5 patients. Acute transplant related mortality was 5.5%. Cause of death was persisting non engraftment till day +180 after 2 transplant procedures in a boy with previous platelet transfusions from his mother. Late mortality occurred in 2 patients: one chronic GVHD associated haemorrhage 20 months after SCT and one chronic GVHD associated septicaemia 10 years after SCT.

CONCLUSION

Although this report reflects patients data accumulated over 15 years, results compare favourably with more recent survival data. Acute and late transplant related toxicity was low in patients undergoing early transplantation with adequate prior supportive care. This data confirms that SCT still should be the first treatment choice if an HLA identical sibling is available.

Excellent long-term survival after allogeneic marrow transplantation in patients with severe aplastic anemia

Between 1982 and 1996, 20 patients (10 male, 10 female) with severe aplastic anemia (SAA) with a median age of 25 years (17-37 years), received grafts from an HLA-identical sibling (n = 17), HLA-identical unrelated donor (n = 2) or identical twin (n = 1). The median time from diagnosis to marrow transplantation (BMT) was 15 months (range 1-96 months). More than half of the patients had received more than 10 units of red blood cells or platelet transfusions prior to BMT. Pretransplant immunosuppression consisted of cyclophosphamide (CY) alone (n = 10), CY in combination with total body irradiation (n = 8), and CY and antithymocyte globulin (n = 2). For graft-versus-host disease (GVHD) prophylaxis methotrexate (MTX) alone (n = 9) or MTX with cyclosporin A (n = 10) were given. One patient died on day 18 after marrow grafting due to infection; all other patients had complete and sustained engraftment (95%). Eight patients developed acute GVHD (42%), nine patients chronic GVHD (53%) including four with extensive disease manifestation. One patient experienced a secondary malignancy 11 years after BMT. Eighteen patients followed for a median of 9.45 years (0.42-14.7 years) have sustained hematological reconstitution and are alive and well with a Karnofsky performance score of at least 90%. Thus, excellent long-term survival and low morbidity make allogeneic or syngeneic BMT the treatment of choice for younger patients with severe aplastic anemia.

Correlation of minor histocompatibility antigen-specific cytotoxic T lymphocytes with graft-versus-host disease status and analyses of tissue distribution of their target antigens

Peripheral blood mononuclear cells (PBMC) from 17 patients receiving HLA-identical sibling bone marrow grafts were stimulated with host pretransplant PBMC. Cytotoxic T-cell lines (TCL) with specificity for host pretransplant PBMC were obtained from 9 of these patients, all presenting with severe graft-versus-host disease (GVHD), but from none of the remaining cases lacking evidence of disease. Cytotoxic TCL were specific for host targets and failed to lyse donor cells. Monoclonal antibodies (MoAbs) blocking experiments and donor population screening analyses demonstrated that minor histocompatibility antigen (MiHA)-specific lysis of host targets was restricted by class I major histocompatibility complex (MHC) determinants. Whereas hematopoietic cells such as phytohemagglutinin (PHA) blasts or lymphoblastoid cell lines were susceptible to lysis by MiHA-specific TCL, keratinocytes (K) representing the natural targets of GVHD were quite resistant. Quantitative radioimmunometric measurements indicated very low constitutive expression of class I MHC antigens on K targets, which was readily increased by treatment with interferon-gamma (IFN-gamma). IFN-gamma treatment at the same time rendered these cells susceptible to lysis by MiHA-specific TCL. Host leukemic cells of 3 patients were recognized by MiHA-specific TCL in a chromium release assay and in one experiment host leukemic cells were effectively killed and their growth specifically inhibited in a leukemia colony assay by a clone. These data demonstrate that (1) host-specific cytotoxic TCL are detected exclusively in the PB of patients with acute GVHD grades II through IV after allogeneic matched bone marrow transplantation, and (2) their target antigens are simultaneously expressed on several host cell lines, including lymphoblastoid cell lines, PHA blasts, leukemic cells, and K. We also extend previous findings by showing that, besides the expression of the nominal MiHA, the density of the restricting class I MHC elements also crucially determines the extent of TCL lysis. Because of its capacity to enhance class I MHC antigen expression, IFN-gamma represents a key cytokine for determining the susceptibility of MiHA targets for lysis by TCL and clones, and in one patient an MiHA-specific clone recognized host leukemic cells and also inhibited host leukemic cell growth in a colony inhibition assay.

Evidence that sensitivity to cyclosporine is influenced by the HLA-DR phenotype of kidney graft recipients

Clinical as well as experimental studies have shown a great interindividual variability in the immunosuppressive efficacy of CsA. Evaluating previous in vitro findings of a correlation between sensitivity of alloresponsiveness to CsA and the HLA-DR phenotype CsA levels were compared in kidney transplant recipients with and without rejections during the early posttransplant period and tested for a possible relationship to the HLA-DR phenotype of the recipient. In patients treated with CsA and prednisolone only, rejection frequency was significantly higher in HLA-DRw6 positive than in DRw6 negative graft recipients (77% vs. 53%, P = 0.045). In the DRw6 positive group incidence of rejection was independent of CsA blood levels, whereas in DRw6 negative patients frequency of rejection episodes decreased as a function of increasing CsA levels. Therefore the relative risk in developing graft rejection continuously increased in HLA-DRw6 positive patients. In HLA-DR2 positive graft recipients, however, a decrease in the relative risk could be observed with increasing CsA levels. Within patients with bioptically verified rejection episodes HLA-DR2 positive recipients had significantly lower CsA levels than DR2 negative patients (P = 0.01). In other HLA-DR phenotypes no association with CsA blood levels could be assessed. Also no statistically significant difference could be found in nonrejecting patients. These clinical findings demonstrate an association of sensitivity to immunosuppressive treatment and the HLA-DR phenotype of the graft recipient. Our results would indicate a very low CsA sensitivity of HLA-DRw6 positive graft recipients and thus might offer an explanation for previous findings about an increase in the incidence of rejection reported on those patients.

Insensitivity to cyclosporine may explain the HLA-DRw6 recipient effect

Clinical as well as experimental studies have found an interindividual variability in the immunosuppressive effect of cyclosporine (CsA). In renal transplant patients treated with CsA and prednisolone alone, biopsy-verified rejections were significantly more frequent in DRw6-positive than in DRw6-negative graft recipients. The relative risk for developing a graft rejection independently of the CsA blood levels increased in HLA-DRw6-positive transplant patients. Although no statistical significance of the CsA levels within different DR phenotypes could be assessed, HLA-DR2-positive graft recipients with biopsy-verified rejection episodes had significantly lower CsA levels than DR2-negative patients (P = 0.01). Our results would indicate a very low CsA sensitivity of HLA-DRw6-positive graft recipients and might explain previous results describing an increased incidence of rejection and decreased graft survival rates in these patients.

A reliable and safe way of shortening cadaver kidney ischemia time: prenephrectomy tissue typing using donor lymph node cells

The purpose of this study was to investigate the impact of prenephrectomy donor tissue typing on tissue typing quality and transplantation outcome in human kidney transplantation. We report on 680 consecutive kidney transplantations performed at the Vienna Transplantation Center from 1986 to June 1991. In 343 of them, HLA typing was performed using donor lymph node cells obtained in a small surgical procedure several hours before organ retrieval. The mean cold ischemia time (CIT) could be reduced to 17.7 h in these patients compared with 21.9 h in the control group (n = 337, conventional tissue typing using spleen lymphocytes obtained during the organ removal, P = 0.0001). There was a trend towards better initial and long-term function in the lymph node group; however, this did not reach statistical significance. The clarity of tissue typing results was significantly better when lymph nodes were used as the lymphocyte source. We conclude that prenephrectomy tissue typing is a feasable and inexpensive method of shortening CIT in renal transplantation and favors HLA typing, both likely to benefit transplantation outcome particularly within organ exchange programs.