Immune reconstitution assessed during five years after allogeneic bone marrow transplantation

Immune reconstitution is an important component of successful allogeneic bone marrow transplantation. Immune reconstitution was evaluated for 5 years after transplantation. While the number of CD8+ T cells and CD56+ cells recovered early post transplantation, a low number of CD4+ and CD4+ CD45RA+ T cells and reversal of the CD4/CD8 ratio continued up to 5 years. Although early recovery of IgG and IgM was seen at day 100 post transplantation, serum concentration of IgA was below the normal range at 6 months and increased gradually up to 5 years. Development of acute GVHD did not affect the numbers of CD4+, CD8+, CD4+ CD45RA+ and CD4+ CD29+ T cells, but the number of CD56+ cells in patients who developed grades II-IV acute GVHD was low. The number of CD4+ CD29+ T cells had a tendency to be higher in the patients with extensive chronic GVHD than in those without chronic GVHD 2 years after transplantation whereas the number of CD4+ CD45RA+ T cells was low in spite of the absence of chronic GVHD. Serum concentration of IgA was lower in patients with extensive chronic GVHD than in those without chronic GVHD at 180 days. The number of CD4+ CD45RA+ cells in 10-19-year-old patients was higher than that in 40-49-year-old patients. Response to the Con A and PHA in 10-19-year-old patients was higher than that in older patients at 1 and 2 years. There was no significant difference in the ability of immune reconstitution between related transplant recipients and unrelated transplant recipients. These results suggest that chronic GVHD and age of patients affected immune reconstitution post transplant.     

Valpha24+ natural killer T-cell responses against T-acute lymphoblastic leukaemia cells: implications for immunotherapy

Human Valpha24+ natural killer T (NKT) cells correspond to mouse Valpha14+ NKT cells, both cell types use an invariant T-cell receptor-alpha chain and are activated by glycolipids in a CD1d-dependent manner. Mouse Valpha14+ NKT cells have been reported to have an antitumour effect in vivo. Human Valpha24+ NKT cells can kill a proportion of tumour cells in a CD1d-dependent manner in vitro. We report here that many human leukaemic T-cell lines express CD1d and can be directly killed by Valpha24+ NKT cells. This killing activity was enhanced in the presence of alpha-galactosylceramide (alpha-GalCer), a ligand of Valpha24+ NKT cells. Moreover, primary leukaemic T cells from five of eight T-cell acute lymphoblastic leukaemia (T-ALL) patients expressed CD1d and were good targets of Valpha24+ NKT cells. This cytotoxicity was increased in the presence of alpha-GalCer. Our results suggest that T-ALL is a good candidate for Valpha24+ NKT-cell-based immuno-cell therapy.     

Pseudoautologous blood stem cell transplantation for refractory chronic graft-versus-host disease

A female patient with AML received an allogeneic BMT from her brother. She experienced two relapses managed with chemotherapy and donor leukocyte infusions. The patient subsequently developed extensive therapy-refractory chronic GVHD. Pseudoautologous blood stem cell transplantation was performed as a salvage treatment for chronic GVHD. Her blood stem cells were easily mobilized with cyclophosphamide and G-CSF. The conditioning regimen was well tolerated and consisted of 200 mg/kg cyclophosphamide and horse-derived antithymocyte globulin. A total of 4.03 x 10(6)/kg CD34+ cells were infused and hematological recovery was rapid. Chronic GVHD improved with the ability to taper steroids. Nine months post transplantation the patient died from leukemia.     

Donor CD8+ T cells facilitate induction of chimerism and tolerance without GVHD in autoimmune NOD mice conditioned with anti-CD3 mAb

Prevention of autoimmune diabetes and induction of islet transplantation tolerance in nonobese diabetic (NOD) mice can be reached by induction of mixed chimerism via bone marrow transplantation (BMT), but this procedure requires total body irradiation (TBI) conditioning of the recipients. The toxicity of radiation and potential for graft-versus-host disease (GVHD) prevents its clinical application. Donor CD8+ T cells play a critical role in facilitation of engraftment but also contribute to induction of GVHD in TBI-conditioned recipients. Here, we showed that high doses of donor CD8+ T cells in combination with bone marrow (BM) cells induced mixed chimerism without GVHD in NOD recipients conditioned with anti-CD3 monoclonal antibody (mAb). The prevention of GVHD in those recipients was associated with low-level production of inflammatory cytokines (ie, tumor necrosis factor alpha [TNF-alpha]), high-level production of anti-inflammatory cytokines (ie, interleukin 4 [IL-4] and IL-10), and confining of the donor CD8+ T-cell expansion to lymphohematopoietic tissues. The chimeric NOD recipients showed donor-specific tolerance and reversal of insulitis. These results demonstrate that donor CD8+ T-cell-mediated facilitation of engraftment can be separated from GVHD in nonirradiated recipients. This regimen may have potential application in the treatment of autoimmune disorders as well as induction of transplantation tolerance.     

A possible association between the presence of interleukin-4-secreting cells and a reduction in the risk of acute graft-versus-host disease

OBJECTIVE: We monitored cytokine-secreting cells using an enzyme-linked immunospot (ELISPOT) assay in a prospective study to assess the cytokine network after transplantation. PATIENTS AND METHODS: Peripheral blood mononuclear cells were collected from 23 patients who received allogeneic stem cell transplantation, from before the preconditioning regimen to 56 days after transplantation. The number of interleukin-4 (IL-4), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha)-secreting cells were measured by ELISPOT assay. For IL-4 and IFN-gamma, in vitro stimulation with phorbol 12-myristate 13-acetate and phytohemagglutinin was performed. RESULTS: The frequency of IL-4-secreting cells was significantly higher in five patients receiving peripheral blood stem cell transplantation (PBSCT) than that in 18 patients who received bone marrow transplantation (BMT). Based on IFN-gamma and TNF-alpha release, there was a trend toward a decrease in the number of cytokine-secreting cells in PBSCT compared with BMT. Furthermore, patients who did not develop acute graft-vs-host disease (GVHD, n=5) showed a significantly higher number of IL-4-secreting cells compared with those who developed acute GVHD (n=18). Both IFN-gamma-secreting cells and TNF-alpha-secreting cells showed a trend to increase in number in patients with acute GVHD. In patients who received reduced-intensity stem cell transplantation (n=7) compared with conventional stem cell transplantation (n=16), there was a large number of cytokine-secreting cells detected by IL-4 and IFN-gamma release. CONCLUSIONS: These results are consistent with the hypothesis that IL-4-producing cells inhibit the development of acute GVHD. In addition, the increased percentage of IL-4-secreting cells may be responsible for the unexpected low incidence of acute GVHD in PBSCT, despite the presence of large numbers of mature T cells in the donor infusion.     

Comparison of outcomes after transplantation of peripheral blood stem cells versus bone marrow following an identical nonmyeloablative conditioning regimen

This is the first study to examine the outcomes in 54 patients with hematologic malignancies who received an HLA-matched related donor bone marrow (BM, n = 42) or GCSF-mobilized peripheral blood stem cells (PBSC, n = 12) following identical nonmyeloablative conditioning with the intention of induction of mixed chimerism (MC) followed by prophylactic donor leukocyte infusion (pDLI) to convert MC to full donor chimerism (FDC) and capture a graft-versus-tumor effect without clinical graft-versus-host disease (GVHD). Neutrophil and platelet recovery were faster and transfusion requirement was less in PBSC recipients (P < 0.05). A total of 48% of BMT recipients achieved FDC with a median conversion time of 84 days, including 13 following pDLI. In contrast, 83% (P = 0.04) in the PBSC group had spontaneous FDC at a median of 14 days, precluding the administration of pDLI. There was no significant difference in the incidences of acute or chronic GVHD, though the rates of chronic GVHD were considerably higher in PBSC group than in the BM group (6/7, 86% vs 10/24, 42%). CD4 and CD8 T-cell recovery was faster in PBSC recipients. In PBSC recipients, a higher number of CD34+ cells was associated with increased rates of severe, grade III-IV acute GVHD.     

Analysis of immune reconstitution in children undergoing cord blood transplantation

OBJECTIVE: The aim of this study was to investigate and compare immune reconstitution in allogeneic cord blood transplantation (CBT) and bone marrow transplantation (BMT) recipients. MATERIALS AND METHODS: Twenty-three children underwent CBT from either human leukocyte antigen-identical siblings (11 cases) or unrelated donors (12 cases) were enrolled in the study, together with 23 matched children receiving BMT. Patients were analyzed 2-3 and 12-15 months after transplant. Recovery of T-, B-, and NK-lymphocyte subsets, proliferative in vitro response to mitogens, as well as cytotoxic activities, were investigated. RESULTS: CBT recipients showed a marked increase in the number of B lymphocytes as compared with patients who underwent BMT (p < 0.001). The absolute number of CD3(+) and CD8(+) T cells, as well as the proliferative response to T-cell mitogens, recovered with time after transplantation, irrespective of the source of stem cells used. Recipients of unrelated CBT had a better recovery of CD4(+) T lymphocytes (p < 0.01). Among patients experiencing acute graft-versus-host disease (GVHD), children given CBT had a much greater production of CD4(+) CD45RA(+) T cells than BMT recipients (p < 0.005). Recovery of NK cell number and innate cytotoxic activities was fast, irrespective of the source of stem cells used. CONCLUSIONS: Despite the much lower number of lymphocytes transferred with the graft, recovery of lymphocyte number and function toward normal in CBT recipients was rapid and comparable to that observed after transplantation of bone marrow progenitors. This prompt immune recovery possibly was favored by the reduced incidence and severity of GVHD observed in children who underwent CBT.     

Reduced-intensity stem cell transplantation using allogeneic peripheral blood stem cells from the same donor for relapsed leukemia after bone marrow transplantation

We report the clinical courses of two cases with relapsed acute lymphoblastic leukemia (ALL) after allogeneic bone marrow transplantation (BMT). After reinduction chemotherapy, the patients received reduced-intensity stem cell transplantation using allogeneic peripheral blood stem cells harvested from their previous BMT donors. The conditioning regimen used consisted of fludarabine and melphalan. Graft-versus-host disease (GVHD) prophylaxis was performed with low dose cyclosporin A (CsA, 1 mg/kg/day d.i.v.) on its own. The regimen related toxicity was minimal, and stable engraftment was achieved. Since acute GVHD had not developed by day 30, CsA was stopped abruptly in both cases. After CsA withdrawal, acute GVHD developed, and subsequent chronic GVHD. One of two cases is alive without any relapse of the leukemia 40 months after the peripheral blood stem cell transplantation (PBSCT). In the other case, ALL relapsed 15 months after the PBSCT, however, complete remission was again induced concomitantly with reactivated GVHD. In both these cases, the results suggest that using PBSC as a stem cell source and abrupt cessation of GVHD prophylaxis provided a potent graft-versus-leukemia effect.     

A randomized multicenter comparison of CD34(+)-selected progenitor cells from blood vs from bone marrow in recipients of HLA-identical allogeneic transplants for hematological malignancies

OBJECTIVE: Peripheral blood progenitor cells (PBPC) have been established as an alternative source of hematopoietic stem cells for allogeneic transplantation, but an increased incidence of both acute and chronic graft-vs-host disease (GVHD) has become apparent. We performed a prospective randomized trial comparing bone marrow transplantation (BMT) vs PBPC transplantation (PBPCT) using CD34(+) selection for T-cell depletion (TCD) in both study arms. PATIENTS AND METHODS: Between January 1996 and October 2000, 120 patients with a diagnosis of acute leukemia, myelodysplasia, multiple myeloma, or lymphoma were randomized to receive either filgrastim-mobilized PBPC or BM from HLA-identical sibling donors after standard high-dose chemoradiotherapy. Patient characteristics did not differ between study arms. RESULTS: Recipients of PBPC received more CD3(+) T cells (median: 3.0 vs 2.0 x 10(5)/kg, p<0.0001) and more CD34(+) cells (median: 3.6 vs 0.9 x 10(6)/kg, p<0.0001). Neutrophil and platelet recoveries occurred significantly faster after PBPCT. The cumulative incidence of acute GVHD grades II-IV was 37% after BMT vs 52% after PBPCT and was most significantly (p=0.007) affected by the number of CD3(+) T cells in the graft. Acute GVHD appeared strongly associated with increased treatment-related mortality (TRM) in a time-dependent analysis. Higher numbers of CD34(+) cells were associated with less TRM. With a median follow-up of 37 months (range: 12-75), overall survival at 4 years from transplantation was 60% after BMT and 34% for recipients of PBPCT (p=0.04), which difference was largely due to increased GVHD and TRM in PBPC recipients receiving T-cell dosages greater than 2 x 10(5)/kg. CONCLUSION: Outcome following T cell-depleted PBPCT critically depends on the number of CD3(+) T cells, whereby high T-cell numbers may blunt a favorable effect of higher CD34(+) cell numbers.     

Generation of CD8 cytolytic T cells early after autologous or allogeneic bone marrow transplantation

Longitudinal in vitro assays related to cell-mediated immunity were performed in patients following allogeneic (32) or autologous (15) bone marrow transplantation (BMT). In both groups of reconstituted patients, low CD4+/CD8+ T cell ratio and weak allogeneic mixed lymphocyte reactions were found in the first 6 months after BMT, progressively reaching values similar to controls (bone marrow donors or unrelated individuals). In contrast, a strong generation of allogeneic cytotoxic cells, assessed by the number of lytic units per 10(6) cells, was frequently found (18/38 patients tested in both groups) in the first 4 months, despite the quantitative deficit of the CD4+ subset. This in vitro differentiation was found to be independent of in vivo acute graft-versus-host disease (GVHD) and chronic GVHD in allo-transplanted patients. As also documented in autologous recipients, this observation suggests that this phenomenon could be, at least partially, related to the transplantation per se. Preliminary characterization of the effector cells indicates that they belong to the CD8+ subset and that their differentiation is interleukin-2-dependent. Experimental depletion of the CD4+ subset in normal subjects did not increase the number of lytic units in allogeneic cultures. This implies qualitative differences between BMT recipients and normal subjects, namely in CD8+ subset: i.e. that following BMT early CD8+ T cells appear to produce their own growth factor (IL-2), while in normal adult individuals, such autocrine CD8+ T cells, if present, are very rare.     

A novel reduced-intensity stem cell transplant regimen for nonmalignant disorders

Bone marrow transplantation (BMT) benefits nonmalignant diseases but is limited by regimen-related toxicity, graft-versus-host disease (GVHD), donor availability, and graft rejection (GR). To overcome some of these barriers, we developed a new conditioning strategy for these patients. In total, 16 patients received Campath-1H (33/48 mg; days -21 to -19), fludarabine (150 mg/m(2); days -8 to -4), melphalan (140/70 mg/m(2); day -3), and transplant using related/unrelated stem cells. GVHD prophylaxis included cyclosporine/methylprednisolone for cord cells. Other recipients also received methotrexate. Risk factors for GR included multiple transfusions (6), low stem cell numbers (1), and immunologic/metabolic disorders (3). Donor engraftment was present in 14/16 recipients. Neutrophils (ANC>0.5 x 10(9)/l) and platelets (>50 x 10(9)/l) engrafted at a median of 13 and 24 days. Two patients died of Pseudomonas sepsis prior to engraftment, one of CMV disease, and another of intracranial hemorrhage. With median follow-up of 281 days (78-907), 12/16 are stable/improved, or cured. Acute GVHD was absent (n=10) or mild and transient (grade1-2 skin) (n=4). There was no chronic GVHD. Toxicities were predominantly early infections within 100 days, and correlated with lymphopenia (CD4+ T and B cells). Stable engraftment and low incidence of significant GVHD, irrespective of age or stem cell source, make this reduced-intensity regimen attractive for nonmalignant disorders.     

Host B cells produce IL-10 following TBI and attenuate acute GVHD after allogeneic bone marrow transplantation

Host antigen-presenting cells (APCs) are known to be critical for the induction of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT), but the relative contribution of specific APC subsets remains unclear. We have studied the role of host B cells in GVHD by using B-cell-deficient microMT mice as BMT recipients in a model of CD4-dependent GVHD to major histocompatibility complex antigens. We demonstrate that acute GVHD is initially augmented in microMT recipients relative to wild-type recipients (mortality: 85% vs 44%, P < .01), and this is the result of an increase in donor T-cell proliferation, expansion, and inflammatory cytokine production early after BMT. Recipient B cells were depleted 28-fold at the time of BMT by total body irradiation (TBI) administered 24 hours earlier, and we demonstrate that TBI rapidly induces sustained interleukin-10 (IL-10) generation from B cells but not dendritic cells (DCs) or other cellular populations within the spleen. Finally, recipient mice in which B cells are unable to produce IL-10 due to homologous gene deletion develop more severe acute GVHD than recipient mice in which B cells are wild type. Thus, the induction of IL-10 in host B cells during conditioning attenuates experimental acute GVHD.     

Dendritic cells are targets for human invariant Valpha24+ natural killer T-cell cytotoxic activity: an important immune regulatory function

OBJECTIVE: Human invariant Valpha24+ natural killer T (NKT) cells, a subpopulation of NK cell-receptor (NKR-P1A)-expressing T cells with an invariant Valpha24JalphaQ T-cell receptor (TCR), are stimulated by the glycolipid a-galactosylceramide (KRN7000), in a CD1d-dependent, TCR-mediated fashion. Little is known about invariant Valpha24+ NKT cell function or mechanisms of effector activity. Evidence suggests this cell population protects against autoimmunity and has antitumor effects against leukemia and solid tumors. MATERIALS AND METHODS: We compared the phenotype and function of invariant Valpha24+ NKT cells, from patients with chronic myeloid leukemia (CML) and normal donors, generated by stimulation of peripheral blood mononuclear cells with alpha-galactosylceramide pulsed monocyte-derived dendritic cells. The CD4(-)CD8(-) (double negative) population was studied further. RESULTS: Activated human invariant Valpha24+ NKT cells were cytotoxic against autologous and allogeneic peripheral blood dendritic cells and monocyte-derived dendritic cells but not against autologous or allogeneic T-cell PHA blasts, B-cell lymphoblastoid cell lines, monocytes, or leukemic cells from patients with CML. The findings are consistent with previous observations showing the importance of CD1d in target cell recognition. None of the Valpha24+ NKT cell lines expressed the NK markers CD16, CD56, CD94, or killer inhibitory receptors, but all expressed NKR-P1A. There was no difference in phenotype, function, or ease of generation of invariant Valpha24+ NKT cells between normal donors and patients with CML. CONCLUSION: Based on our results and the previous evidence linking reduced Valpha24+ NKT cells to autoimmunity, we propose that double-negative Valpha24+ NKT cells have important immune regulatory functions, including contribution to the prevention of excessive antigen stimulation by virtue of cytotoxic activity against antigen presenting cells, particularly in dendritic cells.     

Role of CXCR3-induced donor T-cell migration in acute GVHD

OBJECTIVE: The chemokine receptor CXCR3 has an important role in the migration of effector T cells. To investigate the role of CXCR3 on donor cells in acute graft vs host disease (GVHD) we used a well-defined experimental bone marrow transplantation (BMT) model where acute GVHD is mediated by donor CD8(+) T cells against minor histocompatibility antigens. METHODS; Lethally irradiated C3H.SW recipients were transplanted from either wild-type B6 or CXCR3(-/-) B6 donors. Donor T-cell expansion was analyzed in the spleen and small intestine of recipients by FACS. Donor T-cell function was analyzed by cytokine secretion. The severity of acute GVHD was assessed by histopathological analysis of intestine and liver, GVHD clinical scores, and survival after BMT. RESULTS: Significantly higher numbers of donor CD8(+) CXCR3(-/-) T cells were found in the spleen on days +7 and +14 compared to donor wild-type T cells. By contrast, the number of CD8(+) T cells in the small bowel of BMT recipients from CXCR3(-/-) donors was sevenfold lower than from wild-type donors. Systemic concentrations of INF-gamma and TNF-alpha were equivalent between groups. Animals that received CXCR3(-/-) donor T cells demonstrated diminished GI tract and liver damage and showed improved survival after BMT compared to recipients of wild-type donor cells (43% vs 0%, p<0.001). CONCLUSION: The migration of donor CD8(+) T cells to GVHD target organs such as the intestine depends on the expression of CXCR3 and contributes significantly to GVHD damage and overall mortality.     

A comparison of postengraftment infectious morbidity and mortality after allogeneic partially T cell-depleted peripheral blood progenitor cell transplantation versus T cell-depleted bone marrow transplantation

OBJECTIVE: Postengraftment infections are a major cause of transplant-related morbidity and mortality following allogeneic hematopoietic stem cell transplantation (allo-SCT). Allogeneic peripheral blood progenitor cell transplantation (PBPCT) is associated with faster hematopoietic recovery compared to bone marrow transplantation (BMT) and unmanipulated PBPCT may be associated with fewer postengraftment infections. We set out to evaluate and compare the incidence, cause, and outcome of postengraftment infections following HLA-identical sibling T cell-depleted PBPCT vs T cell-depleted BMT between days 30 and 365 posttransplant. PATIENTS: Forty recipients of peripheral blood progenitor cells (PBPC) and 47 recipients of bone marrow (BM) were included. The two groups of patients were comparable with respect to their baseline characteristics. RESULTS: PBPC grafts contained significantly more CD34+ cells and PBPCT was associated with significantly faster neutrophil and lymphocyte recovery as compared to BMT. PBPC recipients experienced more chronic graft-vs-host disease (GVHD; 55% vs 34%; p=0.02). The number of definite and clinical infections per 100 patient days was comparable between recipients of PBPC and BM with similar contribution of causative microorganisms. At one year post SCT, 68% of PBPC recipients had experienced at least one CTC grade 3-4 infection vs 65% of BM recipients. Treatment-related mortality at one year from transplantation was 34% after PBPCT vs 30% after BMT, and no difference in infection-related mortality was observed. CONCLUSION: Postengraftment infectious morbidity and mortality were comparable between recipients of PBPC and BM despite a higher CD34+ cell content of PBPC grafts and faster lymphocyte recovery after PBPCT, which may in part be explained by the higher incidence of chronic GVHD.     

Feasibility and safety of peripheral blood stem cell transplantation from unrelated donors: results of a single-center study

We compared the outcomes in patients receiving unrelated peripheral blood stem cell transplants (PBSCT) with those receiving bone marrow transplants (BMT) in a matched pair analysis. Seventy-four patients with hematological malignancies with HLA-matched (77%) and mismatched (23%) donors were analyzed in this study. Thirty-four patients (45%) were considered as high risk patients. Sixty-eight patients received standard conditioning regimens with Bu/Cy or TBI/Cy. Six patients received an intensified conditioning regimen with the addition of etoposide, thiotepa or melphalan. GVHD prophylaxis consisted of prednisolone, cyclosporine and methotrexate. Groups were matched for patient, donor, transplant characteristics and HLA compatibility. Peripheral blood stem cell collection led to the collection of a higher number of CD34+ and CD3+ cells in comparison to bone marrow collection. Leukocyte engraftment in the PBSCT group occurred in 14 days (median; range 6-26 days) and in the BMT group in 19 days (range 9-29 days; P < 0.02). The time of platelet engraftment did not differ significantly. The incidence of grades II-lV acute GVHD in the group of HLA-identical patients was 35% in the PBSCT group and 25% in the BMT group (P < 0.33, log-rank). However, there was a significant difference (P < 0.05, log-rank) in incidence and time to onset of acute GVHD II-IV comparing all patients, including the 17 mismatched transplants. Disease-free survival was 51% (19 patients) with a median of 352 days and 59% (21 patients) with a median of 760 days for PBSC and BMT transplants, respectively. In conclusion, our results indicate that allogeneic PBSCT led to significantly faster leukocyte engraftment but is associated with a higher incidence and more rapid onset of severe acute GVHD comparing all patients, including the 17 mismatched transplants. However, the incidence of severe acute GVHD in HLA-identical patients was not different between the PBSCT and BMT groups.     

Serum IgE levels after bone marrow transplantation

Total serum IgE levels were followed in 135 bone marrow transplant recipients in order to determine the clinical significance of post-transplant serum IgE monitoring. Patients with IgE levels less than 60 U/ml at the time of bone marrow transplantation (BMT) (59%) experienced at least one IgE peak. Patients with pretransplant IgE levels greater than or equal to 60 U/ml (16%) showed decreasing values following BMT. In 19% of patients, IgE levels were low and did not change up to 3 months after BMT. Increase in IgE levels coincided in time with engraftment (p less than 0.01) and acute graft-versus-host disease (GVHD) (p less than 0.01). Early IgE peaks were also seen in patients without GVHD. Maximal IgE values did not differ during grades II-IV GVHD compared with grades 0-1, but two or more peaks were more common in patients with grades II-IV (p less than 0.001). IgE peaks also appeared in patients receiving T cell-depleted marrow without GVHD. Syngeneic bone marrow recipients had high IgE levels after BMT. Two patients had increasing IgE values following reconditioning and retransplantation, but booster grafts had no effect on IgE levels. IgE levels were not changed during septicemia, herpes simplex virus or cytomegalovirus infections, and chronic GVHD. No linear correlation was found between serum IgE levels and CD4+/CD8+ ratios, percentages, or absolute numbers of either group of cells. It was concluded that serum IgE elevation is found in association with engraftment and acute GVHD, but is mainly caused by the conditioning treatment.     

Administration of interleukin-7 after allogeneic bone marrow transplantation improves immune reconstitution without aggravating graft-versus-host disease

Prolonged immunodeficiency after allogeneic bone marrow transplantation (BMT) causes significant morbidity and mortality from infection. This study examined in murine models the effects of interleukin-7 (IL-7) given to young and middle-aged (9-month-old) recipients of major histocompatibility complex (MHC)-matched or -mismatched allogeneic BMT. Although administration of IL-7 from day 0 to 14 after syngeneic BMT promoted lymphoid reconstitution, this regimen was ineffective after allogeneic BMT. However, IL-7 administration from day 14 (or 21) to 27 after allogeneic BMT accelerated restoration of the major lymphoid cell populations even in middle-aged recipients. This regimen significantly expanded donor-derived thymocytes and peripheral T cells, B-lineage cells in bone marrow and spleen, splenic natural killer (NK) cells, NK T cells, and monocytes and macrophages. Interestingly, although recipients treated with IL-7 had significant increases in CD4(+) and CD8(+) memory T-cell populations, increases in naive T cells were less profound. Most notable, however, were the observations that IL-7 treatment did not exacerbate graft-versus-host disease (GVHD) in recipients of an MHC-matched BMT, and would ameliorate GVHD in recipients of a MHC-mismatched BMT. Nonetheless, graft-versus-leukemia (GVL) activity (measured against 32Dp210 leukemia) remained intact. Although activated and memory CD4(+) and CD8(+) T cells normally express high levels of IL-7 receptor (IL-7R, CD127), activated and memory alloreactive donor-derived T cells from recipients of allogeneic BMT expressed little IL-7R. This might explain the failure of IL-7 administration to exacerbate GVHD. In conclusion, posttransplant IL-7 administration to recipients of an allogeneic BMT enhances lymphoid reconstitution without aggravating GVHD while preserving GVL.     

Outcome of transplantation for standard-risk leukaemia with grafts depleted of lymphocytes after conditioning with an intensified regimen

One hundred and eighty-one consecutive patients with standard-risk leukaemia were transplanted with HLA-identical sibling grafts depleted of lymphocytes using counterflow centrifugation. In 116 patients, standard conditioning was intensified by the addition of anthracyclines.
Multivariate analysis revealed significantly more acute GVHD  grade 2 and a trend towards more chronic GVHD in patients conditioned with the addition of anthracyclines. For all patients the risk for chronic GVHD, but not for acute GVHD, increased with a higher number of T cells in the graft. The projected 5-year probability of relapse was significantly lower in the group of patients conditioned with anthracyclines; 26% versus 52% ( P  = 0.015). In multivariate analysis the addition of anthracyclines to the conditioning regimen was the only significant factor contributing to a lower probability of relapse. The projected 5-year probability of leukaemia-free survival [LFS] in the patients conditioned with and without the addition of anthracyclines was 56% and 36%, respectively ( P  = 0.004). In multivariate analysis the addition of anthracyclines to the conditioning regimen correlated significantly with a lower number of mixed chimaeras in patients at 6 and 12 months after BMT. Mixed chimaerism at 6 months after transplantation did not significantly correlate with a higher incidence of relapse in further follow-up. In contrast, mixed chimaerism at 12 months after BMT was significantly associated with higher relapse rate.
We conclude that the addition of anthracyclines to the conditioning regimen improves outcome of BMT using T-cell-depleted grafts.     

异基因造血干细胞移植治疗高危恶性血液病

目的 分析HLA配型相合同胞供者异基因造血干细胞移植（allo-HSCT）治疗高危恶性血液病的疗效及影响疗效的相关因素。方法 回顾性分析90例有高危因素的恶性血液病患者,其中急性髓细胞白血病（AML）43例,急性淋巴细胞性白血病（ALL）28例,急性混合细胞性白血病（AHL）2例;移植前处于第1次完全缓解期（CR1）11例,均为Ph染色体阳性,第二次及以上CR期23例,未缓解／复发39例;骨髓增生异常综合征（MDS）-难治性贫血伴原始细胞增多或难治性贫血伴原始细胞增多一转化型17例。预处理方案采用全身照射加环磷酰胺（CY／TBI）方案11例,白消安加环磷酰胺方案79例。干细胞来源包括骨髓移植（BMT）27例,外周血造血干细胞移植（PBSCT）30例,BMT＋PBSCT33例;移植物抗宿主病（GVHD）预防采用经典环孢素A加短程甲氨蝶呤（MTX）。平均随访时间为15个月。结果 至随访终点,62．2％（56／90）存活,55．5％（50／90）无病存活,31．1％（28／90）复发。HSCT后预计4年累积总体生存率（OS）为45．5％,无病生存率（DFS）为34．9％。移植前处于CR、未缓解／复发和MDS患者HSCT后4年的累积0s分别为54．0％、28．2％和70．1％（P=0．027）。发生0～Ⅰ和Ⅱ～Ⅳ度GVHD的患者HSCT后的4年OS分别为57．6％和26．7％（P=0．015）,而患者性别、年龄、移植前有无脑膜白血病、预处理方案、干细胞来源均不是OS,DFS及复发的影响因素。多因素分析表明,移植前处于CR期者长期生存率明显提高,而ALL长期生存率明显低于AML／MDS。结论 对有高危因素的血液系统恶性肿瘤患者,选择allo—HSCT可使部分患者延长无病生存乃至根治。移植前处于CR期者长期生存率明显提高,ALL复发率明显高于AML／MDS。对于急性白血病挽救性治疗争取在取得CR后移植;对于MDS患者一经诊断,无需化疗,可尽早移植。