Stem cell mobilization in normal donors

We studied peripheral blood and apheresis samples from 39 consecutive normal donors who were parents or siblings of patients who received matched or mismatched bone marrow transplants using a combination of rhG-CSF-mobilized peripheral blood stem cells (PBSCs) and bone marrow (BM). BM was harvested from donors 1-7 days before starting rhG-CSF treatment: 12 micrograms/kg/day rhG-CSF was administered by continuous s.c. infusion for 4-7 days. Peripheral blood progenitor cells were harvested by leukapheresis using an automated continuous-flow blood cell separator, beginning on day 4 of rhG/CSF, for 1-4 consecutive days. Peak peripheral blood CD34+ cell and CFU-GM levels were reached simultaneously on day 5 or 6 of rhG-CSF administration. Median peak levels were 1.65% for CD34+ cells (range 0.34%-4.7%) and 142 CFU-GM/10(5) plated cells (range 16-700). The greatest numbers of CD34+ cells and CFU-GM, expressed per liter of blood volume processed, were harvested during the second and third leukapheresis: CD34+ cells 37.77 +/- 25.48 x 10(6) and CFU-GM 3.32 +/- 2.51 x 10(6) during the second leukapheresis, and CD34+ cells 37.01 +/- 16.33 x 10(6) and CFU-GM 3.82 +/- 4.36 x 10(6) during the third. The number of CD34+ cells and CFU-GM did not correlate with the sex, age, or body weight of the donors. This study indicates that this protocol for administration of rhG-CSF mobilizes large numbers of hematopoietic progenitor cells into the peripheral blood and that bone marrow harvesting before G-CSF administration does not impair stem cell mobilization.

Peripheral blood stem cells for allogeneic transplantation. Recommendations from the GITMO 1996. Gruppo Italiano Trapianti di Midollo Osseo

Allogeneic transplants with PBSC are rapidly expanding, but a number of problems concerning both donors and recipients are still unsolved. GITMO (Italian Bone Marrow Transplant Group) has established a committee for allogeneic PBSC transplants. We present here an analysis of the main aspects of this evolving area and suggest revised guidelines for the use of allogeneic PBSC transplantation.

Allogeneic matched T-cell-depleted bone marrow transplantation for acute leukemia patients

PURPOSE

We evaluated the efficacy and toxicity of a conditioning regimen designed to overcome the increased risk of rejection and relapse associated with T-cell-depleted bone marrow transplants.

PATIENTS AND METHODS

Fifty-four patients with acute leukemia received an allogeneic T-depleted bone marrow transplant from an HLA-matched (n=52) or one locus mismatched (n=2) sibling donor between June 1989 and November 1993. Nineteen acute myeloid leukemia patients and 17 acute lymphoid leukemia patients were in complete remission, and 11 acute myeloid leukemia patients and 7 acute lymphoid leukemia patients were in relapse. Patients were preconditioned with hyperfractionated total body irradiation of 1.2 Gy three times a day on days -9 to -6 (total 14.4 Gy), 10 mg/kg thiotepa on day -5, 4 mg/kg rabbit antithymocyte globulin on days -4 to -1, and 50 mg/kg cyclophosphamide on days -3 and -2.

RESULTS

All patients were fully engrafted at a median of 15 days after transplant. No patient rejected the transplant or developed acute or chronic graft-versus-host disease. Of 19 patients with acute myeloid leukemia in complete remission, 14 survive. Four of the 11 patients with acute myeloid leukemia in relapse survive. Twelve acute myeloid leukemia patients died (three of relapse, eight of toxicity, one of other causes). Eleven of 24 patients with acute lymphoid leukemia (one treated in relapse) are alive in complete remission; the other 13 died (nine of relapse, four of toxicity). Interstitial pneumonia, the main cause of toxic death, occurred in 9.26% of total patients. The median follow-up time at this writing is 30 months.

CONCLUSIONS

The absence of rejection and graft-versus-host disease and the relatively low relapse and toxicity rates are evidence for the efficacy of our conditioning regimen.

Unusual split chimaerism after mismatched T-depleted BMT

We report a case of haploidentical T-depleted BMT that engrafted durably after a highly immunosuppressive conditioning regimen. DNA polymorphism analysis showed that granulocytes and monocytes were donor type but T and B lymphocytes were host derived. Host tolerance to donor antigens was documented. The patient suffered from serious recurrent CMV infections until split chimaerism shifted to full donor type 2 years post-BMT. Seven years after BMT the patient remains in complete remission.

Effect of ursodeoxycholic acid on hypertransaminasaemia and bile acid composition in patients undergoing bone marrow transplantation--a double-blind randomized control study

A double-blind randomized placebo controlled trial of ursodeoxycholic acid was performed in 31 patients undergoing T-cell depleted allogeneic or autologous bone marrow transplantation to determine the effectiveness of this hydrophilic bile acid in improving the increase in serum liver enzymes that generally accompanies this procedure. Neither group showed any significant difference in magnitude of the increases in serum transaminases and gamma-glutamyltranspeptidase following the conditioning regimen that included chemotherapy and total body irradiation. In the 6 months after transplantation, serum enzymes decreased in both groups, but were consistently higher in the placebo treated patients, indicating that ursodeoxycholic enhances normalization of liver. Faecal bile acid showed that following chemotherapy and irradiation in which intestinal bacteria are ablated, secondary bile acid formation was practically abolished and faeces contained mainly cholic and chenodeoxycholic acids. During bile acid treatment, ursodeoxycholic acid accounted for 31.3 +/- 10.9% of faecal bile acids compared with 4.0 +/- 2.1% in the basal period. Serum and urinary ursodeoxycholic acid concentrations (mean +/- SD, 13.3 +/- 6.9 mumol/L and 2.65 +/- 0.84 mumol/L, respectively) were significantly higher in patients receiving bile acid than in thos on placebo (mean +/- SD, 0.15 +/- 0.12 mumol/L and 0.29 +/- 0.35 mumol/L, respectively) thus confirming compliance.

Natural killer (NK)-cell function and antileukemic activity of a large population of CD3+/CD8+ T cells expressing NK receptors for major histocompatibility complex class I after "three-loci" HLA-incompatible bone marrow transplantation

We have shown that addition of granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cells to the marrow inoculum allows engraftment of T-cell depleted, "three loci" HLA-incompatible marrow transplants for acute leukemia. The event-free survival of patients at high risk for potential of this transplant. Tumor-cell lysis by natural killer (NK) cells is regulated by inhibitory receptors for specific HLA class I alleles. Here, we report the postgrafting emergence of a large, donor-type CD3+/CD8+ T-cell receptor (TcR)-alpha beta+ cell population, barely detectable in normal subjects, that expresses 58 kD, "p58," NK receptors for HLA-C locus alleles. Analysis of > 900 clones revealed that 40% to 80% of these T cells exhibit NK-like function, i.e., they lysed class I- targets and were functionally blocked by class I alleles on target cells. Monoclonal antibody-mediated blocking of class I recognition by these cells induced lysis of HLA-protected, autologous targets. The class I-mediated inhibitory signaling through the NK receptors also blocked TcR/CD3-triggered cytotoxicity of these cells, indicating that their antigen-specific responses may be impaired. However, the NK-like function of these cells allows them to discriminate normal cells, protected from lysis, from leukemic cells that were lysed and may be targets for a graft-versus-leukemia effect.

Unrelated donor marrow transplantation: initial experience of the Italian bone marrow transplant group (GITMO)

From 1 September 1988 to 30 September 1993, a search for an unrelated donor (URD) was started for 633 Italian patients. Eighty-five of them (13%) were transplanted. Despite the introduction of more strict criteria for the selection of compatible donors, the percentage of patients who reached transplant increased significantly after December 1992. For patients who started a search before and after January 1993, respectively the probability of transplant by 8 and 16 months from search activation was 4 and 10%, compared to 22 and 37% (P = 0.0001). The average intervals between search activation and graft were 15 and 8 months respectively, for the first and second group (P = 0.0001). Data of 75 consecutive transplants performed up to March 1994 were analyzed. Actuarial 2-year survival was 15% for patients grafted before 1992 and 40% for those grafted after January 1992. In this latter period, survival of patients with malignant and non-malignant disorders was 32 and 67%, respectively. In univariate analysis, patients younger than 16 years (P = 0.01), patients grafted after 1992 (P = 0.01) and patients receiving the marrow from a 6-antigen matched donor (P = 0.01) showed a higher survival probability. Multivariate analysis did not show any difference, probably due to the low number of patients and to short follow-up. The adoption of stricter and more accurate HLA-matching criteria and the consequent reduction of deaths related to acute GVHD were the main reasons for the improvement of survival observed in patients grafted after 1992.

Allogeneic transplants of rhG-CSF-mobilized peripheral blood stem cells (PBSC) from normal donors. GITMO. Gruppo Italiano Trapianto di Midollo Osseo

There is a growing interest in the use of peripheral blood stem cells (PBSC) for allogeneic transplantation. This is due in part to the idea that, as with autologous transplantation, increasing the number of allogeneic hemopoietic progenitors infused may lead to reduced complications. However, introducing the PBSC technique into allogeneic transplants implies theoretical as well as ethical problems involving both patient and donor. We are still uncertain whether the PBSC technique will result in an increase of GVHD or (better) of GVL. G-CSF, necessary for effective PBSC mobilization, is safe but its use in normal subjects should be regarded with caution. For this reason, a Study Committee promoted by the GITMO (Gruppo Italiano Trapianto di Midollo Osseo) evaluated the key aspects of allogeneic PBSC collection and transplantation. The present paper summarizes the scientific data and suggests some guidelines for the introduction of allogeneic PBSC transplantation into clinical practice. The procedure should be considered experimental and the Committee strongly recommends the use of allogeneic PBSC in experienced centers, initially in patients with advanced disease. The donor should be given a complete explanation of the advantages and risks of G-CSF therapy, leukapheresis and general anesthesia. A careful monitoring of both patient and donor should also be included to watch for short-term and long-term side effects.

Successful engraftment of T-cell-depleted haploidentical "three-loci" incompatible transplants in leukemia patients by addition of recombinant human granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cells to bone marrow inoculum

Patients who undergo transplantation with haploidentical "three-loci" mismatched T-cell-depleted bone marrow (BM) are at high risk for graft failure. To overcome the host-versus-graft barrier, we increased the size of the graft inoculum, which has been shown to be a major factor in controlling both immune rejection and stem cell competition in murine models. Seventeen patients (mean age, 23.2 years; range, 6 to 51 years) with end-stage chemoresistant leukemia were received transplants of a combination of BM with recombinant human granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cells from HLA-haploidentical "three-loci" incompatible family members. The average concentration of colony-forming unit-granulocyte-macrophage in the final inoculum was sevenfold to 10-fold greater than that found in BM alone. The sole graft-versus-host disease (GVHD) prophylaxis consisted of T-cell depletion of the graft by the soybean agglutination and E-rosetting technique. The conditioning regimen included total body irradiation in a single fraction at a fast dose rate, antithymocyte globulin, cyclophosphamide and thiotepa to provide both immunosuppression and myeloablation. One patient rejected the graft and the other 16 had early and sustained full donor-type engraftment. One patient who received a much greater quantity of T lymphocytes than any other patient died from grade IV acute GVHD. There were no other cases of GVHD > or = grade II. Nine patients died from transplant-related toxicity, 2 relapsed, and 6 patients are alive and event-free at a median follow-up of 230 days (range, 100 to 485 days). Our results show that a highly immunosuppressive and myeloablative conditioning followed by transplantation of a large number of stem cells depleted of T lymphocytes by soybean agglutination and E-rosetting technique has made transplantation of three HLA-antigen disparate grafts possible, with only rare cases of GVHD.

Outcome for patients who relapse after allogeneic bone marrow transplantation for chronic myeloid leukemia. Chronic Leukemia Working Party. European Bone Marrow Transplantation Group

We studied the clinical course of 130 chronic myeloid leukemia (CML) patients (89 males and 41 females) in the European Bone Marrow Transplantation Group (EBMT) registry who received transplants before January 1, 1988 and who subsequently had evidence of recurrent leukemia. All patients had received a pretransplant conditioning regimen including total body irradiation (TBI). The first evidence of relapse was cytogenetic only in 74 (57%) patients and hematologic in 56 (43%). The overall actuarial survival from relapse was 36% at 6 years, with a significantly higher proportion of survivors among female patients (53% v 30%; P < .002). In univariate analysis, the 6-year probability of survival was 52% for patients with cytogenetic relapse and 30% for patients relapsing in chronic phase (CP), while no patient who relapsed in advanced phase (AP or BC) survived more than 3.5 years from relapse (P < .0001). The actuarial survival of patients relapsing before 6 months, between 6 and 12 months, and later than 12 months after transplant was 27%, 26%, and 45%, respectively (P < .002). Among patients with cytogenetic relapse, partial or complete disappearance of Ph-positive cells occurred in 40% of untreated patients and in 42% of those treated with interferon (IFN). However, IFN therapy significantly delayed progression toward hematologic disease. Cytogenetic responses were observed in 25% of patients who received IFN for relapse into CP, while only one minor cytogenetic response was reported in patients on conventional chemotherapy. For patients presenting with cytogenetic relapse as well as for those in hematologic relapse, IFN therapy significantly improved the 2-year probability of survival. However, long-term survival for IFN-treated patients in either group was not different from long-term survival in comparable patients not receiving IFN therapy. Twenty-nine patients of this series underwent a second bone marrow transplant (BMT) and the projected survival at 4 years after the second transplant is 28%. In multivariate Cox regression analysis, four factors remained significantly associated with survival: disease phase at relapse (P < .0001), duration of time interval from BMT to relapse (P = .0001), interferon therapy at relapse (P = .0024), and patient sex (P = .0032). This retrospective study provides evidence that some patients who relapse after BMT may benefit from treatment with IFN; a second BMT may offer the chance of cure. Data from this analysis may be useful in designing future prospective trials on posttransplant CML relapse.

Residual clonable host cell detection for predicting engraftment of T cell depleted BMTs

Rejection of T-depleted BMTs is predominantly mediated by alloreactive host T cells. A low but significant number of radiochemoresistant clonable T cells can be detected following a conventional cytoreductive protocol given prior to T-depleted BMT. Elimination of these cells increases the engraftment rate. We found no clonable T cells at the end of the conditioning regimen in 100 ml of peripheral blood from 47 patients who received an HLA-identical T-depleted BMT. None rejected the graft and none displayed mixed chimerism. In addition, although no clonable T cells were detected in nine patients who received a mismatched BMT, two rejected their graft. However, in three mismatched patients, who for clinical reasons received a modified pre-BMT schedule, the presence of host clonable T cells was associated with immunological rejection. These findings suggest that the detection of clonable T cells should prove a valuable indicator for optimising immunosuppression prior to T-depleted BMT.

Is there any future for T-cell depleted bone marrow transplantation in chronic myeloid leukaemia?

There is no doubt that the poor reputation of T-cell depleted bone marrow transplant arises from its use in CML patients, where an increase in graft rejection and, above all, in leukaemia relapse has been reported by almost all centres. Evidence suggests that the standard conditioning regimen (once thought to be sufficiently immunosuppressive and myeloablative in unmanipulated transplants) should no longer be considered adequate when the immunological balance has shifted in favour of unopposed host-versus-graft reactivity and the GvL effect is lacking. Since GvHD remains the major problem in BMT, we suggest T-cell depletion should be considered the most effective method for GvHD prophylaxis but the cytoreductive effect of the conditioning regimens and the anti-leukaemia immune reactivity should be enhanced.

Response of refractory Hodgkin's disease to monoclonal anti-CD30 immunotoxin

In Hodgkin's disease, Hodgkin and Reed-Sternberg cells consistently express the antigen CD30. We investigated the possible therapeutic role of an immunotoxin prepared by covalent linking of an anti-CD30 monoclonal antibody (Ber-H2) to saporin (SO6), a type-1 ribosome-inactivating protein. The immunotoxin (0.8 mg/kg in one or two doses) was given to four patients with advanced refractory Hodgkin's disease. In three, there was rapid and substantial reduction in tumour mass (50% to greater than 75%). Clinical responses were transient (6-10 weeks). In-vivo binding of the immunotoxin to tumour cells was shown by immunohistology in two patients. Antibodies to both parts of the immunotoxin developed in all patients.

Interstitial pneumonitis after hyperfractionated total body irradiation in HLA-matched T-depleted bone marrow transplantation

Interstitial pneumonia is one of the major causes of morbidity and mortality after bone-marrow transplantation. We here report a series of 58 patients suffering from hematological malignancies who received HLA-matched T-lymphocyte depleted bone-marrow transplants between July 1985 and January 1990. Interstitial pneumonia occurred in 7/58 patients (12%) and was fatal in six. Three different pre-bone-marrow transplantation conditioning regimens were employed. Total body irradiation was delivered according to a hyperfractionated scheme of 12 fractions given three per day 5 hr apart for 4 days. Twenty-three patients received 36 mg/Kg procarbazine, 1275 UL/Kg antithymocite globulin, 14.4 Gy hyperfractionated total body irradiation and 120 mg/Kg cyclophosphamide. Only one patient developed interstitial pneumonia, but two rejected the graft and 10 relapsed. As a consequence, the total hyperfractionated scheme was increased to 15,6 Gy, cyclophosphamide to 200 mg/Kg, antithymocite globulin to 3400 UL/Kg and procarbazine eliminated. There were three cases of interstitial pneumonia, no rejection and four relapses in the 17 patients who received this regimen. In the last 18 patients hyperfractionated total body irradiation was reduced to 15 Gy, cyclophosphamide to 100 mg/Kg, and 10 mg/Kg of the myeloablative agent thiothepa added to enhance the cytoreductive effect without significantly increasing extramedullary toxicity. Three cases of interstitial pneumonia, one relapse but no rejection were recorded. Our results demonstrate that the absence of graft-versus-host disease due to T-cell depletion, and radio-chemotherapy doses and schedules used for the conditioning regimen each contributed to reducing the risk of interstitial pneumonitis. Hyperfractionated total body irradiation therefore, seems to play an important role in lowering the incidence of this complication.

Lung damage following bone marrow transplantation after hyperfractionated total body irradiation

From July 1985 to December 1989, 72 evaluable patients aged between 6 and 51 (median age 27 years) suffering from haematological malignancies received an allogeneic bone marrow transplant (BMT) depleted of T-lymphocytes to reduce the risk of graft-versus-host-disease (GvHD); 57 were matched and 15 mismatched. Three different conditioning regimens were used in an effort to enhance cytoreduction without increase extramedullary toxicity. Mismatched patients were treated with more immunosuppressive regimens. Total body irradiation (TBI) was given in three doses per day, 5 h apart, over 4 days for a total of 12 fractions. The dose to the lungs was 14.4, 15.6 and 9 Gy according to the conditioning regimen. The incidence of interstitial pneumonia (IP) was 12.3% in matched and 46.7% in mismatched patients. Our results seem to indicate that lung toxicity is correlated with the intensity of the conditioning regimen, the stage of disease and, in mismatched patients, with the degree of human leucocyte antigen (HLA) disparity and the poor post-BMT reconstitution, rather than the radiotherapy dose delivered to the lungs. On the contrary, the hyperfractionated scheme adopted, the absence of GvHD and, perhaps, the post-TBI administration of cyclophosphamide all seem to have contributed to the low incidence of IP in our matched patients.