Donor lymphocyte infusion post-non-myeloablative allogeneic peripheral blood stem cell transplantation for chronic granulomatous disease

Bone marrow aplasia following donor lymphocyte infusion in 4-year-old patient with chronic granulomatous disease after allogeneic stem cell transplantation: case report

Donor lymphocyte infusion (DLI) is typically used in 3 clinical situations: therapeutically for proven relapse of malignancy, prophylactically in patients with high-risk of relapse, and in case of mixed chimerism. Mixed chimerism, which occur after transplantation can be a sign of possible rejection. In case of increased mixed chimerism, immunotherapy with donor lymphocyte infusions could reverse this process. After DLI, both acute and chronic graft-versus-host disease and marrow aplasia are well-known toxicities. In this paper, we present a case report of young patient with chronic granulomatous disease (CGD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), with successful immunotherapy following mixed chimerism, which was complicated by bone marrow aplasia that required a second stem cell infusion. DLI seems to be an effective and highly promising treatment method of transplant rejection in patients with CGD but can induce bone marrow aplasia and may require a second stem cell infusion.

Low-dose total-body irradiation and alemtuzumab-based reduced-intensity conditioning regimen results in durable engraftment and correction of clinical disease among children with chronic granulomatous disease

HSCT with MAC is associated with durable donor engraftment for patients with CGD; however, MAC is limited by high rates of RRT. We used a novel RIC regimen with LD-TBI (200 cGy × two doses), fludarabine (30 mg/m(2) × three doses), and proximal alemtuzumab (0.5 mg/kg/dose × one dose) and unrelated donor grafts for consecutive patients with high-risk CGD who were not candidates for MAC at our institution. Among four children with CGD transplanted at our institution, three PBSC recipients are alive with sustained donor engraftment (median follow-up: two yr) and resolution of pre-HSCT active infections while one patient with bone marrow graft is alive after graft failure and autologous recovery. RIC may be a curative option for children with high-risk CGD.

Allogeneic haematopoietic stem cell transplantation as therapy for chronic granulomatous disease--single centre experience

Chronic granulomatous disease (CGD) is phagocytic cell metabolic disorder resulting in recurrent infections and granuloma formation. This paper reports the favourable outcome of allogeneic transplantation in six high-risk CGD patients. The following donors were used: HLA-matched, related (two) and unrelated (three), and HLA-mismatched, unrelated (one). One patient was transplanted twice using the same sibling donor because of graft rejection at 6 months after reduced-intensity conditioning transplant (fludarabine and melphalan). Myeloablative conditioning regimen consisted of busulphan and cyclophosphamide. Stem cell source was unmanipulated bone marrow containing: 5.2 (2.6-6.5) × 10(8) nucleated cells, 3.8 (2.0-8.0) × 10(6) CD34+ cells and 45 (27-64) × 10(6) CD3+ cells per kilogramme. Graft-versus-host disease prophylaxis consisted of cyclosporine A and, for unrelated donors, short course of methotrexate and anti-T-lymphocyte globulin. Mean neutrophile and platelet engraftments were observed at day 22 (20-23) and day 20 (16-29), respectively. Pre-existing infections and inflammatory granulomas resolved. With the follow-up of 4-35 months (mean, 20 months), all patients are alive and well with full donor chimerism and normalized superoxide production.

Successful unrelated cord blood transplantation for chronic granulomatous disease: a case report and review of the literature

CGD is a rare inherited immunodeficiency disorder that is caused by disability of oxidative killing. We presented a two-yr-old boy with CGD who was suffering from multiple systemic abscesses. He received the first BMT from his HLA-haploidentical mother after conditioning with Flu, melphalan, and ATG. Although the maximum of 42% donor chimerism was achieved, it disappeared 73 days after the BMT. Then, we performed 5/6-matched unrelated cord blood re-transplantation after conditioning with Flu, Bu, and TBI (2 Gy). Engraftment and complete donor chimerism were achieved on days 18 and 19, respectively. The patient is now free from infection and maintains complete donor chimerism without GVHD 36 months after the cord blood re-transplantation. We postulate that the unrelated CBT has a potential to be an alternative strategy and might be beneficial for patients with CGD who do not have an HLA-identical donor.

Nonmyeloablative stem cell transplantation and cell therapy for malignant and non-malignant diseases

The conditioning prior to allogeneic stem cell transplantation was originally designed as a myeloablative conditioning, designed to eliminate malignant or genetically abnormal cells and then use the transplant procedure for rescue of the patients or to replace missing bone marrow products. However, allografts can induce effective graft vs. malignancy effects and can also eliminate undesirable hematopoietic stem cells in patients with genetic disorders and autoimmune diseases, thus documenting that alloreactive effects mediated by donor lymphocytes post-grafting can play a major role in eliminating hematopoietic cell of host origin, as well as provide effective immunotherapy for the treatment of disease recurrence. The efficacy of donor lymphocyte infusion (DLI) could be improved by activation with rIL-2 or by donor immunization. The cumulative experience over the years suggesting that alloreactive donor lymphocytes were most effective in eliminating tumor cells of host origin resulted in an attempt to reduce the intensity of the conditioning in preparation for the transplant procedure used for the treatment of hematological and other malignancies as well as life-threatening non-malignant disorders for which allogeneic stem cell transplantation may be indicated. Our working hypothesis proposed that the myeloablative conditioning which is hazardous and may be associated with early and late side effects, may not be required for treatment of patients with any indication for allogeneic stem cell transplantation. Instead, nonmyeloablative conditioning based on the use of reduced intensive preparatory regimen, also known as nonmyeloablative stem cell transplantation, may be sufficient for engraftment of donor stem cells while avoiding procedure-related toxicity and mortality, followed by elimination of undesirable cells of host origin by post-transplant effects mediated by alloreactive donor lymphocytes infused along with donor stem cells or administered subsequently as DLI. Improvement of the immediate outcome of stem cell transplantation using NST due to a significant decrease in transplant related mortality has broadened the spectrum of patients eligible for allogeneic stem cell transplantation, including elderly patients and other patients with less than optimal performance status. Likewise, the safer use of stem cell transplantation prompted expanding the scope of potential indications for allogeneic stem cell transplantation, such as metastatic solid tumors and autoimmune disorders, which now are slowly becoming much more acceptable. Current strategies focus on the need to improve the capacity of donor lymphocytes to eliminate undesirable malignant and non-malignant hematopoietic cells of host origin, replacing abnormal or malignant stem cells or their products with normal hematopoietic stem cells of donor origin, while minimizing procedure-related toxicity and mortality and improving the quality of life by reducing the incidence and severity of hazardous acute and chronic GVHD.

Control of advanced and refractory acute myelogenous leukaemia with sirolimus-based non-myeloablative allogeneic stem cell transplantation

Non-myeloablative conditioning has extended the use of allogeneic haematopoietic transplant to many previously ineligible patients. We added the immunosuppressive and antitumour agent sirolimus (rapamycin) to an established transplant regimen of fludarabine 25 mg/m(2) days -7 through -3 and cyclophosphamide 1000 mg/m(2) days -7 and -6, with tacrolimus and methotrexate immunoprophyllaxis. A total of 23 patients with acute myelogenous leukaemia (AML) were treated, with a median age of 59 years (range: 28-72) at transplant. Only seven patients in total were in complete remission prior to transplantation. Nine patients were in chemotherapy-refractory progression and seven were primarily refractory to induction therapy. Six patients received matched sibling, 11 unrelated donor, 1-5/6 matched and five haploidentical (haplo - three of six or four of six matched) transplants. The haplo-recipients also received antithymocyte globulin, all patients engrafted. Only two, both recipients of haploidentical cells, have died from transplant-related causes. Twelve of 23 patients survived at 198-1162-d post-transplant (median 578). Four of 12 survivors relapsed at 83, 88, 243 and 508 d and three were in remission after chemotherapy and donor lymphocyte infusion. Although follow up is short, this data suggests that non-myeloablative haematopoietic cell transplantation with sirolimus (rapamycin)-based immunosuppression may provide disease control over several years in some patients with advanced and poor prognosis AML.

Successful Low Toxicity Hematopoietic Stem Cell Transplantation for High-Risk Adult Chronic Granulomatous Disease Patients

BACKGROUND

Allogeneic hematopoietic stem cell transplantation for chronic granulomatous disease (CGD) is associated with a significant risk of transplant-related mortality. Adult age, overt infection, and residual inflammatory disease at transplant are major risk factors.

METHODS

Here we report the favorable outcome after bone marrow transplantation in three high-risk adult CGD patients (ages 18, 35, and 39) with severe disease-related complications (overt pneumonia, liver abscess, steroid-dependent granulomatous colitis, diabetes, restrictive lung disease, renal insufficiency, epilepsia). Bone marrow donors were human leukocyte antigen-matched related or unrelated. The conditioning regimen consisted of 2 x 4 mg/kg oral busulphan (d -3, -2), fludarabine 6 x 30 mg/qm (d -7 to -2), rabbit anti-T-cell-globulin (Fresenius) 4 x 10 mg/kg (d -4 to -1). Graft versus host disease prophylaxis consisted of cyclosporine A and mycophenolate-mofetil.

RESULTS

Mean neutrophil and platelet engraftment was observed at day +18.5 and +22.5, respectively. All infectious and inflammatory lesions resolved and restrictive lung disease improved. No signs of grade II-IV acute or chronic graft versus host disease were observed. With a follow-up of 12 to 27 months, all patients are alive and well with full donor chimerism, normalized superoxide production, and documented T- and B-cell function.

CONCLUSION

This modified reduced intensity conditioning protocol is a promising treatment modality for high-risk adult CGD patients.

Conventional versus reduced-intensity conditioning regimen for allogeneic stem cell transplantation in patients with hematological malignancies

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) from human leukocyte antigen (HLA)-compatible sibling donors is a potential curative treatment for hematological and non-hematological malignancies. Nevertheless, high mortality rates may be associated with this therapy, especially in older patients, those with other comorbidities or who receive a second HSCT.

PATIENTS AND METHODS

We analyzed the factors associated with transplant-related mortality (TRM) and overall survival in 157 consecutive adult patients (104 males and 53 females) who received a HSCT [29 bone marrow (BM) transplantation and 128 peripheral blood (PB) transplantation] from a HLA-identical sibling between January 1995 and March 2002 in our institution. One hundred patients received a standard conditioning prior to HSCT (STAND) and 57 patients received a reduced-intensity conditioning (RIC) HSCT. Fifty-eight patients were in an early phase at transplant and 99 in a non-early phase. Median age was 46 yr (16-66), and 90 patients (57%) were >45 yr of age.

RESULTS

Patients in the RIC group were older than those in the STAND group, and had a higher proportion of non-early disease phases including a prior autologous HSCT in 39%. Median follow-up for survivors was 28 and 15 months in the STAND and RIC groups (P < 0,001), respectively. Cumulative incidence of TRM at 2 yr was 30% [95% confidence interval (CI) 22-41%] for the STAND group and 22% (95% CI 13-37%) for the RIC group [non-significant (NS)]. Factors associated with a higher TRM in multivariate analysis were: STAND vs. RIC conditioning regimen [relative risk (RR) 5.4; 95% CI 2.3-12.8; P < 0.001]; age > or =45 yr vs. <45 yr (RR 5; 95% CI 2.4-10.8, P < 0.001); second vs. first HSCT (RR 2.8, 95% CI 1.3-6.3, P = 0.01) and non-T-cell-depleted vs. T-cell-depleted graft (RR 2.7, 95% CI 1.3-5.8, P = 0.009). Overall survival (OS) at 2 yr was 52.5 +/- 10.4% for STAND group and 59 +/- 16.8% in RIC group. Factors associated with poorer OS in multivariate analysis were: STAND vs. RIC conditioning regimen (RR 3.4, 95% CI 1.7-6.9, P = 0.001); age > or =45 vs <45 yr (RR 2.5, 95% CI 1.4-4.5, P = 0.002) and diagnosis [other than chronic myeloid leukemia (CML) vs. CML] (RR 2.6, 95% CI 1.2-5.7 P = 0.02).

CONCLUSIONS

Our results indicate that the introduction of RIC allogeneic HSCT for patients at high risk for TRM (advanced age, prior HSCT and non-T-cell depletion) leads to a reduction in the TRM and improvement in the OS.

Nonmyeloablative stem cell transplantation: reduced-intensity conditioning for cancer immunotherapy—from bench to patient bedside

Despite major progress in treating hematologic malignancies and, to a lesser extent, metastatic solid tumors, much work remains ahead. With the anticancer potential of immunotherapy not yet fully exploited, patients with leukemia, malignant lymphoma, and other hematologic malignancies for which high-dose chemoradiotherapy is frequently recommended in conjunction with stem cell transplantation (SCT) can now benefit from the advantages of immunotherapy mediated by cytokines or alloreactive donor lymphocytes, while minimizing procedure-related toxicity and mortality. The feasibility of applying allogeneic cell-mediated immunotherapy in conjunction with allogeneic SCT following reduced-intensity conditioning, with minimal toxicity and no serious transplant-related complications, makes it possible to undertake such procedures on an outpatient basis as well as to offer an option for cure to elderly individuals and patients with less than optimal performance status. Being well tolerated, reduced-intensity transplants also offer a chance for cure to patients with otherwise resistant leukemia and malignant lymphoma who have relapsed after autologous SCT. Thus, the traditional obstacle of very high transplant-related toxicity and mortality due to multiorgan failure from cumulative toxicity of multiple anticancer agents and radiation therapy is overcome. Although immunotherapy mediated by allogeneic lymphocytes can be most effective, the immune potential of donor lymphocytes should be maximized by nonspecific or specific activation in vitro or in vivo, or both, for more effective eradication of resistant tumor cells, including in patients with bulky disease. More important is the challenge to target donor lymphocytes to the tumor and minimize their capacity to induce responses against normal host tissues, which frequently results in severe acute and chronic graft-versus-host disease (GVHD). Alternatively, donor lymphocytes should be eliminated as soon as tumor eradication is completed, or as soon as severe GVHD becomes prohibitive. Based on available experience, clinical application of innovative therapy, especially at the stage of minimal residual disease (MRD), may open new horizons for the treatment of malignancies considered until recently to be incurable. The feasibility of controlling cancer by targeted chemotherapy, best illustrated by the phenomenal activity of imatinib in patients with chronic myelogenous leukemia and, more recently, in gastrointestinal stromal tumors (including in patients fully resistant to all known anticancer agents) suggests that in the future, tumor-specific chemotherapy may represent the ultimate goal for achieving a stage of MRD with minimal multiorgan toxicity. Together, the combination of immunotherapy and targeted chemotherapy may provide the most logical approach for making real progress in controlling resistant hematologic malignancies and metastatic solid tumors.

Effective donor lymphohematopoietic reconstitution after haploidentical CD34+-selected hematopoietic stem cell transplantation in children with refractory severe aplastic anemia

Peritransplant toxicity and a delay in effective immune reconstitution have limited the utility of alternate donor transplantation for children with refractory severe aplastic anemia. We have assessed the effectiveness of infusing large numbers of highly purified haploidentical CD34+ cells after immunoablative conditioning in three patients who had failed intensive immunosuppression, lacked unrelated donors, and had active or recent serious infections. One patient rejected the first infusion, but engrafted after a second infusion from the same donor. This patient died 4 months after hematopoietic stem cell transplantation with no evidence of lymphoid reconstitution. Two patients experienced mixed chimerism requiring treatment with antibodies and/or donor lymphocyte infusion. Both currently survive more than 1 year after transplantation with normal blood counts, 100% donor engraftment, effective lymphoid reconstitution, and no chronic graft-versus-host disease. We observed functional thymopoiesis as measured by lymphocyte immunophenotyping, T cell receptor excision circles and T cell receptor Vbeta spectratyping complexity analysis. Further study is required to validate the initial promise of these preliminary observations.

Graft-versus-Host Disease, the Graft-versus-Leukemia Effect, and Mixed Chimerism following Nonmyeloablative Stem Cell Transplantation

Allogeneic bone marrow or blood stem cell transplantation represents an important therapeutic tool for the treatment of otherwise incurable cancer and a large spectrum of nonmalignant diseases. Until recently, bone marrow transplantation was used primarily to eliminate malignant, genetically abnormal, or otherwise deficient stem cells; hence, highly toxic myeloablative regimens were considered mandatory for the eradication of undesirable cells of host origin. Recent data suggest that high-dose chemoradiotherapy may be successively replaced by nonmyeloablative stem cell transplantation (NST), which represents a safer biologic tool that involves the induction of host-versus-graft transplantation tolerance. NST thus provides allogeneic donor lymphocytes with the capacity to induce immune-mediated graft-versus-malignancy effects, either against mismatched minor or major histocompatibility alloantigens or against tumor-specific or tumor-associated antigens expressed by tumor or other hematologic cells of host origin. The future goals of the wider and safer clinical application of NST for the treatment of a larger number of indications and larger numbers of patients in need depend, on the one hand, on the development of more effective and safer modalities for maximizing the antitumor potential of donor lymphocytes (T-cells as well as natural killer and natural killer T-cells). On the other hand, these goals depend on using more selective approaches for targeting anticancer effector cells to their target cells. Such changes will thus set the stage for smarter rather than stronger modalities for the treatment of malignant and life-threatening nonmalignant diseases.

Reduced-intensity allogeneic hematopoietic cell transplantation: Graft versus tumor effects with decreased toxicity

The potentially curative role of allogeneic hematopoietic cell transplantation (HCT) in neoplastic and non-neoplastic diseases is offset by the substantial risks of morbidity and mortality from complications of the intensive myeloablative and immunosuppressive preparative regimen. These regimen-related toxicities have restricted allogeneic HCT to young, otherwise healthy individuals without comorbid diseases. Pediatric patients undergoing conventional allogeneic HCT have lower procedure-related mortality but are at risk for non-fatal late effects of the high-dose pretransplant chemoradiotherapy, such as growth retardation, sterility and other endocrine dysfunction. Evaluation of reduced-intensity preparative regimens is the major focus of current clinical research in allogeneic HCT. Reduced-intensity HCT (RI-HCT) relies on the use of immunosuppressive but non-myeloablative agents that allow engraftment of donor cells, which provide adoptive allogeneic cellular immunotherapy and graft versus tumor (GVT) effects, with decreased regimen-related toxicities. Although the experience with RI-HCT in pediatric patients is very limited at this time, results in adults indicate that attenuated-dose preparative regimens allow older patients and those with organ dysfunction to undergo successful allogeneic HCT with acceptable morbidity and mortality. In adults, the potency of the allogeneic GVT effect varies among neoplastic diseases, with better results observed in patients with indolent hematological malignancies or renal cell carcinoma. The effectiveness of RI-HCT as treatment for children with hemoglobinopathies, chronic granulomatous disease and cellular immunodeficiencies is encouraging, and the role of reduced-intensity preparative regimens for allogeneic HCT in pediatric malignancies is under investigation.

Immunotherapy of hematologic malignancies and metastatic solid tumors in experimental animals and man

New approaches are needed for maximizing specific responses against tumor cells resistant to chemotherapy. While cytokine therapy may amplify natural resistance against minimal residual disease, more robust anti-leukemia reactivity can be provided by allogeneic bone marrow transplantation (BMT) in conjunction with myeloablative, hence hazardous, conditioning, at the cost of graft-versus-host disease (GVHD). Documentation of the capacity of donor lymphocyte infusion (DLI) given late post BMT, when patients were off immunosuppression, in early 1987, with successful reversal of relapse and cure of patients fully resistant to maximally tolerated doses of chemoradiotherapy, with many patients alive and well >10-15 years later, indicated two important facts. First, resistant tumors are unlikely to be cured with higher doses of chemoradiotherapy that may harm the patient but not eliminate all his clonogenic tumor cells. Second, that under condition of tolerance to donor alloantigens, DLI may provide a cure to otherwise resistant patients. These observations paved the road for clinical application of non-myeloablative stem cell transplantation (NST), in the early 90s, based on a two-step procedure, first involving induction of transplantation tolerance to donor alloantigens by engraftment of donor stem cells, following safe lymphoablative rather than myeloablative conditioning. Second, use of donor lymphocytes for elimination of residual tumor or otherwise abnormal hematopoietic cells by immune-mediated graft-versus-host effects inducible by mobilized blood stem cell allografts containing larger inocula of donor T cells, or supported by post-grafting DLI when patients were off immunosuppressive modalities.

Allogeneic stem cell transplant from HLA-identical sibling for chronic granulomatous disease and review of the literature

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by an abnormal function of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in the phagocytic cells, which results in an increased susceptibility to severe bacterial and fungal infections. We report on a 12-year-old boy with X-linked CGD who was successfully treated with allogeneic bone marrow transplantation from an HLA-identical sibling following a conditioning regimen consisting of busulphan (BU, 16 mg/kg) and cyclophosphamide (CY, 200 mg/kg). At >2 years from transplant, the boy is in excellent clinical and hematological condition with full chimerism. Our patient is the 24th case of CGD transplanted from an HLA-identical sibling. A review of the literature revealed that 20 of 24 CGD patients are alive and disease free 1-7 years after transplant. Most of these patients were conditioned with the BUCY combination, which should be considered the recommended regimen.

Long-term follow-up and prognosis of chronic granulomatous disease in Yugoslavia: is there a role for early bone marrow transplantation?

We report the long-term follow-up of 12 pediatric-aged patients with chronic granulomatous disease (CGD). The mean age at the onset of infections was 5 months with a median delay in diagnosis of 2.5 years. Bacille Calmette-Guérin lymphadenitis was the most common presenting infection (6) followed by suppurative lymphadenitis (4), liver abscess (1), or Salmonella sepsis (1). Prophylaxis with cotrimoxazole was recommended to all patients. During the mean follow-up of 10 years (range, 4-23 years) pneumonitis was the most prevalent infection (91%) followed by lymphadenitis (83%), aphtous stomatitis (58%), and liver abscesses (25%). Seven (58%) patients developed chronic lung disease due to grossly delayed diagnosis (3) or poor compliance with antimicrobial prophylaxis (4). Five (41%) patients died during the second decade of life of aspergillosis (3) or chronic lung disease (2). Probability of survival into the third decade of life was estimated to be only 19%. We argue that HLA-identical bone marrow transplantation (BMT), if possible, should be attempted at early age because of significant morbidity and mortality in adolescence. BMT also should be considered in patients who suffer severe infections despite antimicrobial prophylaxis or patients with evidence of chronic lung disease. Possibility of elective BMT from unrelated donors remains to be carefully evaluated.

Clinical developments in reduced intensity haematopoietic stem cell transplantation

Reduced intensity conditioning regimens prior to allogeneic haematopoietic stem cell transplantation (HSCT) were first described in the 1970s, and have developed rapidly over the past few years to become an important consideration as immunological therapy for patients with haematological and selected solid organ malignancies. This is especially the case for patients considered ineligible for conventional allogeneic HSCT due to age or medical contraindications. With the development of minimally toxic conditioning regimens, additional potential applications include the provision of normal haematopoietic repopulating cells to patients who have an inherited gene defect such as an haemoglobinopathy or an inborn error of metabolism. Intensive investigation in stem cell research promises to provide dramatic new insights into human biology, paving the way for new therapeutic approaches to malignant and inherited disorders.

Non-myeloablative hematopoietic cell transplant for treatment of nonmalignant disorders in children

Hematopoietic stem cell transplantation (HCT) may offer the only curative therapy for certain life-threatening immune deficiency disorders. Conventional HCT poses a risk to patients for severe morbidity, mortality, and late sequelae resulting from myeloablative preparative regimens. This review summarizes the development of nonmyeloablative regimens that have the potential to reduce both short- and long-term risks of HCT. Results of NM-HCT in a small number of patients indicate that this procedure may play an important role in treatment of life-threatening immune deficiencies.

Nonmyeloablative allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the most effective treatment for selected hematological malignancies. Its curative potential is largely mediated by an immune-mediated destruction of malignant cells by donor lymphocytes termed graft-versus-leukemia (GVL) effect. However, because of its toxicity, conventional allogeneic HSCT is restricted to younger and fitter patients. These observations led several groups to set up new (less toxic) transplant protocols (nonmyeloablative stem cell transplantation or NMSCT) based on a two-step approach: first, the use of immunosuppressive (but nonmyeloablative) preparative regimens providing sufficient immunosuppression to achieve engraftment of allogeneic hematopoietic stem cells and, in a second step, destruction of malignant cells by the GVL effect. Preliminary results showed that NMSCT were feasible with a relatively low transplant-related mortality (TRM), even in patients older than 65 years. In addition, strong antitumor responses were observed in several hematological malignancies as well as in some patients with renal cell carcinoma. After discussing the mechanisms and efficacy of the GVL effect as well as the rationale for NMSCT strategies, this article reviews the first results of ongoing clinical trials. Innovative modalities that may permit amplification of the GVL effect while minimizing the risk of GVHD are discussed. Because the benefits of NMSCT over alternative forms of treatment remain to be demonstrated, this strategy should be restricted to patients included in clinical trials.

Mobilization of allogeneic peripheral blood progenitor cells

It is possible to reliably obtain sufficient PBSC from most normal donors to perform allogeneic transplantation. The mobilization regimen, usually administration of a single daily dose of G-CSF at 7.5 to 10 micrograms/kg subcutaneously for 4 to 6 days, is tolerable with acceptable side effects. However, there is wide variability among individuals with respect to the extent of mobilization achieved by the regimen and the optimal timing of apheresis. Studies suggest that the likelihood of obtaining an adequate harvest of CD34+ cells, as defined locally may be enhanced by employing higher doses or different schedules of G-CSF, monitoring the mobilization and/or collection of PBPC, and using apheresis procedures processing 2 or more times blood volume. However, an optimal regimen for mobilization and harvesting for all donors has not yet been identified and a small percentage of donors may not mobilize adequately with G-CSF. Alternative regimens employing combinations of G-CSF and GM-CSF are available that may prove useful in such cases and novel cytokines that are even more effective than G-CSF in mobilizing stem cells are eagerly awaited. Based on currently available experience with normal donors, the short-term safety of G-CSF appears to be acceptable, however there exist several scenarios in which marrow harvesting may be preferable to G-CSF mobilization and apheresis collection of PBPC.

Nonmyeloablative hematopoietic cell transplant for treatment of immune deficiency

Hematopoietic stem cell transplantation (HCT) may offer the only curative therapy for certain life-threatening immune deficiency disorders. Conventional HCT poses a risk to patients for severe morbidity, mortality, and late sequelae resulting from myeloablative preparative regimens. This review summarizes the development of nonmyeloablative regimens that have the potential to reduce both short-and long-term risks of HCT. Results of NM-HCT in a small number of patients indicate that this procedure may play an important role in treating life-threatening immune deficiencies.

Nonmyeloablative transplantation in children. Current status and future prospects

Over the last few years a variety of conditioning regimens have been developed that allow allogeneic hematopoietic stem cell engraftment with significantly decreased transplant related-toxicity. While these reduced-intensity regimens have offered hope for patients with malignancies formerly not eligible for myeloablative transplantation due to excessive morbidity (older patients and patients with significant organ toxicity), the role of nonmyeloablative hematopoietic cell transplantation (NM-HCT) in children is unclear. A review of the available literature for pediatric and adult studies shows several malignancies in which approaches designed to limit long-term complications in children may be appropriate. In addition, NM-HCT may offer a safer approach for children with inherited disorders curable by marrow transplantation, such as immunodeficiencies, hemoglobinopathies, or storage diseases. Finally, use of this approach to establish partial donor chimerism may provide an immunologic platform that will allow specific cellular therapies, targeted gene therapy, or immunologic tolerance in solid organ transplantation.

Granulocyte function disorders: aspects of development, genetics and management

The field of phagocytic disorders has attained major biologic and clinical significance in the past 40 years. The development of exciting new techniques in molecular biology and the cellular physiology of signal transduction have made it possible to identify the genetic defects involved in many of these disorders. Moreover through immunopharmacologic intervention, bone marrow or peripheral or cord blood stem cell transplantation along with the prospect of gene therapy, we have begun attempts to at least partially correct genetic defects in cell development and activation pathways in the entire spectrum of phagocyte disorders. Carrier detection and prenatal diagnosis employing with chain reaction techniques or direct nucleotide sequencing in fetal blood have made these diseases potentially preventable or treatable in utero or shortly after birth.

Treatment of chronic granulomatous disease with nonmyeloablative conditioning and a T-cell-depleted hematopoietic allograft

BACKGROUND

The treatment of chronic granulomatous disease with conventional allogeneic hematopoietic stem-cell transplantation carries a high risk of serious complications and death. We investigated the feasibility of stem-cell transplantation without ablation of the recipient's bone marrow.

METHODS

Ten patients, five children and five adults, with chronic granulomatous disease underwent peripheral-blood stem-cell transplantation from an HLA-identical sibling. We used a nonmyeloablative conditioning regimen consisting of cyclophosphamide, fludarabine, and antithymocyte globulin. The allograft was depleted of T cells to reduce the risk of severe graft-versus-host disease. Donor lymphocytes were administered at intervals of 30 days or more after the transplantation to facilitate engraftment.

RESULTS

After a median follow-up of 17 months (range, 8 to 26), the proportion of donor neutrophils in the circulation in 8 of the 10 patients was 33 to 100 percent, a level that can be expected to provide normal host defense; in 6 the proportion was 100 percent. In two patients, graft rejection occurred. Acute graft-versus-host disease (grade II, III, or IV) developed in three of the four adult patients with engraftment, one of whom subsequently had chronic graft-versus-host disease. None of the five children had grade II, III, or IV acute graft-versus-host disease. During the follow-up period, four serious infections occurred among the patients who had engraftment. Three of the 10 recipients died. Preexisting granulomatous lesions resolved in the patients in whom transplantation was successful.

CONCLUSIONS

Nonmyeloablative conditioning followed by a T-cell-depleted hematopoietic stem-cell allograft is a feasible option for patients with chronic granulomatous disease, recurrent life-threatening infections, and an HLA-identical family donor.

Novel approaches to allogeneic stem cell therapy

Traditionally, allogeneic haematopoietic stem cell transplantation (SCT) has involved administration of myeloablative doses of chemotherapy and/or radiation that may cure many patients with haematologic diseases. The high morbidity and mortality associated with the intensive conditioning regimen limits allogeneic SCT to younger and healthier patients. However, it is now known that successful allogeneic SCT is dependent, at least in part, on the antitumour properties of the donor graft independent of the conditioning regimen. This potent 'graft versus tumour' (GVT) effect can now be exploited for clinical benefit. The best evidence of a direct GVT reaction comes from the use of donor leukocyte infusions (DLI). For many patients with relapsed leukaemia after allogeneic SCT, DLI re-establishes complete and durable remissions. This has suggested a novel approach to allogeneic cell therapy (ACT) using non-myeloablative, but immunosuppressive conditioning regimens to permit engraftment of allogeneic stem cells and lymphocytes. Engrafted donor cells would then provide GVT activity in the setting of reduced conditioning regimen toxicity. The ability to minimise toxicity and maximise the immunologic GVT effect will make allogeneic transplantation applicable to patients typically ineligible for conventional allogeneic SCT. Response rates with this strategy have been impressive, although toxicity related to graft versus host disease (GVHD) and other complications remains a concern. Current trials have involved heterogeneous groups of patients using various conditioning regimens. Many issues remain unsettled, including identification of the most appropriate tumour targets and definition of the most effective, least toxic conditioning regimen. In addition, the durability of response is unknown. Nevertheless, the use of non-myeloablative conditioning and ACT may provide a new paradigm for allogeneic cell transplantation and the immunotherapy of cancer.

Nonablative allogeneic hematopoietic stem cell transplantation

During the past few years there has been an explosion of knowledge in nonablative allogeneic stem cell transplantation. This approach to transplantation relies more on the creation of "immunologic space" for engraftment rather than the more traditional approach of creating "physical space" by the application of either intensive radiation or chemical therapy. Nonablative allogeneic stem cell transplantation holds the promise of allowing powerful alloimmune responses to eradicate disease processes while minimizing the initial treatment-related morbidity and mortality, and it appears to be the necessary enabling platform by which to apply allogeneic cellular therapy. Intuitively, this approach should broaden the eligibility for potentially curative allogeneic transplantation in various disease categories, reduce initial hospitalization costs, and at the same time have a positive impact on quality of life. We review the current published data relating to this approach including the underlying principles, the preparative regimen, disease indications, preliminary results in hematologic and solid malignancies, and certain correlative immunologic evaluations.

Successful stem cell transplantation following orthotopic liver transplantation from the same haploidentical family donor in a girl with hemophagocytic lymphohistiocytosis

The case of a 4-month-old girl with familial hemophagocytic lymphohistiocytosis is described. The patient underwent stem cell transplantation from her haploidentical mother 2 months after receiving a living-related liver transplant from the same donor for acute hepatic failure. Conditioning regimen consisted of 16 mg/kg busulfan, 200 mg/kg cyclophosphamide, 10 mg/kg thiothepa, and antithymocyte globulin. Myeloid engraftment occurred on day +10, but CD3+ cells of recipient origin remained. To convert the T-cell chimerism, the patient received donor lymphocyte infusion on day +43, and subsequently the allelic pattern changed to complete donor genotype on day +57. Four months after stem cell transplantation the patient is disease free, with complete donor chimerism in bone marrow and stable hepatic graft function without any immunosuppressive therapy.

Successful stem cell transplantation following orthotopic liver transplantation from the same haploidentical family donor in a girl with hemophagocytic lymphohistiocytosis

The case of a 4-month-old girl with familial hemophagocytic lymphohistiocytosis is described. The patient underwent stem cell transplantation from her haploidentical mother 2 months after receiving a living-related liver transplant from the same donor for acute hepatic failure. Conditioning regimen consisted of 16 mg/kg busulfan, 200 mg/kg cyclophosphamide, 10 mg/kg thiothepa, and antithymocyte globulin. Myeloid engraftment occurred on day +10, but CD3+ cells of recipient origin remained. To convert the T-cell chimerism, the patient received donor lymphocyte infusion on day +43, and subsequently the allelic pattern changed to complete donor genotype on day +57. Four months after stem cell transplantation the patient is disease free, with complete donor chimerism in bone marrow and stable hepatic graft function without any immunosuppressive therapy.

Stem-cell transplantation for inherited immunodeficiency disorders

For patients with well-characterized, rapidly fatal, nonmalignant immunodeficiency disorders, such as SCID, the decision to proceed with allogeneic SCT is clear-cut. For patients with many other disorders, this decision can be extremely difficult. Disorders such as LAD or CGD have a variable natural history. Each patient must be considered individually, with the risk for SCT-related morbidity and mortality carefully weighed against that of the underlying disease. Significant advances during the past 10 years have made SCT a much safer procedure. Use of nonmyeloablative conditioning regimens as a means of reducing toxicity of high-dose chemotherapy and irradiation hold great promise. Highly immunosuppressive, nonchemotherapeutic agents that inhibit graft rejection or GVHD by blocking the critical costimulatory component of the T-cell receptor-antigen interaction are beginning to emerge and may be ideal for SCT of nonmalignant diseases. Therefore, the risk-benefit equation must be reassessed each year as the severity of patients' disorders is better defined and techniques of SCT improve.

[Hereditary polymorphonuclear neutrophil deficiencies]

Rare hereditary deficiencies have been described which affect each functional stage of polymorphonuclear neutrophils. They almost invariably lead to recurrent acute infection. Among the abnormalities involving adhesion and motility, the following can be noted: the Buckley syndrome; and leucocyte type 1 and 2 adhesion deficiencies, respectively caused by a deficiency in membrane expression of beta 2 integrin CD11/CD18, and sialyl lewis X. Granulation system abnormalities include relatively non-symptomatic myeloperoxidase deficiency, specific granulation deficiency or the Chediak-Higashi syndrome with the presence of giant lysosomal granulations. Chronic or familial septic granulomatosis constitutes the main disease described due to the oxidative PMN burst connected with the functional impairment of one of the constituents of NADPH oxidase (with an incidence of one in 5.10(6) to one in 10(6) births) The transmission is X-linked, or autosomal recessive depending on the mutation. The antenatal detection of the X-linked component, gp91 phox, can be made in suspected carrier mothers. In addition to the standard treatment (Bactrim and Itraconazole), bone marrow transplantation may also be carried out, and in future gene therapy may be introduced.

Successful treatment of invasive aspergillosis in chronic granulomatous disease by granulocyte transfusions followed by peripheral blood stem cell transplantation

Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder characterized by impaired microbial killing and susceptibility to bacterial and fungal infections. Cure of the disease can be achieved by stem cell transplantation when performed early in its course, and before severe infections have developed. Invasive aspergillosis constitutes a very high risk for transplantation. We report a 4-year-old boy with X-linked CGD who underwent successful HLA-identical peripheral blood stem cell (PBSC) transplantation during invasive pulmonary aspergillosis and osteomyelitis of the left fourth rib, which was unresponsive to antifungal treatment. During the 2 months prior to the transplant he received G-CSF-mobilized granulocyte transfusions (GTX) from unrelated donors three times a week in addition to the antifungal treatment. This resulted in clinical improvement in his respiratory status. He also received GTX during the aplastic period after the conditioning regimen, until he had engrafted. Post-transplant superoxide generation test revealed that neutrophil function was within normal range. One year post transplant the CT scan showed almost complete clearance of the pulmonary infiltrates and a marked improvement in the osteomyelitic process. Based on other reports and our own experience, GTX can serve as important treatment in patients with CGD who have failed conventional anti-fungal treatment and for whom stem cell transplantation is the only chance for cure.

Fludarabine-based protocol for haploidentical peripheral blood stem cell transplantation in Hurler syndrome

To assess the feasibility of performing a haploidentical peripheral blood stem cell transplantation (PBSCT) in a child with Hurler syndrome after a novel conditioning regimen consisting of fludarabine monophosphate, anti-T-lymphocyte globulin, low-dose busulfan, and single-dose total body irradiation of 750 cGy. A 16-month old boy with Hurler syndrome underwent haploidentical PBSCT from his 3/6 HLA-matched sister. Pretransplant conditioning consisted of fludarabine (30 mg/m2 per day) from day -10 to day -5, busulfan (4 mg/kg per day) on days -7 and -6, rabbit anti-T-lymphocyte globulin (10 mg/kg per day) from day -4 to day -1, and total body irradiation of 750 cGy on day -1. In vitro T-cell depletion was carried out with rat antihuman CDw52 monoclonal antibody (Campath-1G). The fludarabine-based protocol was well-tolerated, with mild toxicity and no major transplant-related complications or graft-versus-host disease. Engraftment was complete and stable. Chimerism was 100% donor origin, as determined by restriction fragment length polymorphism. Cytogenetic and polymerase chain reaction-various number of tandem repeats (PCR-VNTR) analyses of peripheral blood and bone marrow showed 100% reconstitution with female donor cells. The patient underwent the transplant 30 months ago and is in good clinical condition, with normal counts, no signs of graft-versus-host disease, and no infectious episodes; neurologic signs have stabilized. Haploidentical PBSCT, T-cell-depleted by means of Campath-1G, may serve as a therapeutic alternative for patients with Hurler syndrome when a fully matched sibling is not available.