Hematopoietic cell transplantation in older patients with hematologic malignancies: replacing high-dose cytotoxic therapy with graft-versus-tumor effects

Comparison of ARF after myeloablative and nonmyeloablative hematopoietic cell transplantation

BACKGROUND

Acute renal failure (ARF) occurs with significant frequency after myeloablative and nonmyeloablative allogeneic hematopoietic cell transplantation (HCT). Myeloablative (conventional) HCT is the standard of care for cure of various malignant disorders. The newer modality of nonmyeloablative ("mini-allo") HCT is reserved for patients with advanced age and comorbidities who are ineligible for myeloablative HCT. The present study compares the incidence of ARF between patients undergoing concurrent myeloablative and nonmyeloablative HCT in the same period at the same institution.

METHODS

This retrospective cohort study from 1997 to 2003 compares 140 myeloablative and 129 nonmyeloablative patients from the Fred Hutchinson Cancer Research Center. Severity of ARF was classified into 4 grades based on the increase in serum creatinine levels in the first 100 days after HCT. Mortality was studied at 100 days and 1 year.

RESULTS

Nonmyeloablative patients were significantly older and had greater pretransplantation comorbidity at baseline. Despite this, patients undergoing myeloablative HCT had a greater incidence of severe ARF (grades 2 and 3, 73% versus 47%; P < 0.001). The incidence of dialysis also was 4-fold greater (12% versus 3%; P < 0.001) in the myeloablative than nonmyeloablative group. On multivariate analysis after controlling for baseline characteristics, myeloablative HCT was associated with a 4.8-fold greater incidence of ARF compared with nonmyeloablative HCT. Nonrelapse mortality also was greater in the myeloablative group at 100 days and 1 year.

CONCLUSION

The incidence and severity of ARF, as well as nonrelapse mortality, occurring after nonmyeloablative HCT is significantly lower compared with myeloablative HCT.

Advances in the diagnosis and treatment of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a low-grade B-lineage lymphoid malignancy, which is often not treated until patients become symptomatic or develop signs of rapid progression. Even in this setting, treatment is non-curative and is directed at reducing the symptoms from an increasing disease burden. Newer treatment regimens incorporating purine nucleoside analogs have increased the rate of successful remission induction in CLL patients. Recent combination chemoimmunotherapy regimens have produced frequent complete molecular remissions, and early evidence suggests this may result in an improved long-term survival. Allogeneic hematopoietic cell transplantation is the only curative therapy for CLL but is infrequently used due to the older age of most patients, although reduced intensity conditioning regimens have reduced the toxicity of allogeneic transplantation. This review will summarize recent advances in the management of CLL, including prognostic factors, combination chemotherapy including nucleoside analogs and monoclonal antibodies, and reduced intensity allogeneic transplant conditioning regimens.

Allogeneic peripheral blood stem cell graft composition affects early T-cell chimaerism and later clinical outcomes after non-myeloablative conditioning

We have studied the influence of cell subsets [CD34, CD3, CD4, CD8, CD14, CD20, natural killer (NK; CD3(-)/CD56(+)), NKT (CD3(+)/CD56(+)), DC1, and DC2 cells] of granulocyte colony-stimulating factor mobilized peripheral blood stem cells (PBSC) on early T-cell chimaerism and later clinical outcomes in 125 patients with haematological malignancies who received human leucocyte antigen (HLA)-matched related grafts after non-myeloablative conditioning. Conditioning consisted of 2 Gy total body irradiation (TBI) alone (n = 28), or 2 Gy TBI preceded by either 90 mg/m(2) fludarabine (n = 62) or planned autologous haematopoietic cell transplantation (HCT) (n = 35). Post-transplant immunosuppression included mycophenolate mofetil and ciclosporin. Multivariate analysis showed that higher numbers of grafted NK cells predicted higher early T-cell chimaerism (P = 0.03), while higher numbers of B cells were associated with better clinical outcomes and a higher risk for chronic graft-versus-host disease (P = 0.05). Higher numbers of CD14(+) cells were associated with worse overall survival (P = 0.03), while higher numbers of CD34(+) cells showed better survival (P = 0.03). The addition of fludarabine or autologous HCT predicted higher early T-cell chimaerism (P = 0.001), while advanced donor age predicted lower chimaerism (P < or = 0.02). Patients with aggressive diseases were at higher risk for relapse/disease progression, and shorter progression-free and overall survival (P < 0.01). These results suggest that the dosing of certain cellular subsets of PBSC products can influence important outcomes post-HCT after non-myeloablative conditioning.

Management of paraproteinemic renal disease

PURPOSE OF REVIEW

Paraproteinemic renal diseases comprise a group of renal disorders that are difficult to manage, in part because of subtleties in the clinical presentation and confusion regarding diagnosis and appropriate therapy. Often, nephrologists make the diagnosis of the underlying plasma cell dyscrasia following renal biopsy. This review seeks to provide a greater understanding of the mechanism of disease and recent approaches to the management of patients who have AL-amyloidosis, monoclonal light-chain and light and heavy-chain deposition disease [termed ML(H)CDD], and cast nephropathy. All three renal lesions are caused by deposition of immunoglobulin light chains. This review seeks to provide a greater understanding of the mechanism of disease and recent approaches to the management of these patients.

RECENT FINDINGS

The immunoglobulin light chain takes the center stage in the pathogenesis of AL-amyloidosis, ML(H)CDD and cast nephropathy. Modifications in the variable domain are responsible for the affinity of the light chain for a given segment of the nephron and the subsequent toxic manifestations. Therapy aimed at eradicating the offending clone of plasma cells that secrete the monoclonal light chain should be beneficial, but this hypothesis lacks confirmation. Four nonrandomized studies have now demonstrated clinical benefit, including return of renal function, of high-dose chemotherapy with autologous stem cell transplantation (HDT/SCT) in the treatment of patients who have AL-amyloidosis or ML(H)CDD.

SUMMARY

While randomized trials are lacking, the data support the clinical efficacy of more aggressive treatments designed to reduce the plasma cell clone responsible for these renal disorders.

Transmission of donor illness by stem cell transplantation: should screening be different in older donors?

With increasing donor age, the potential of transmitting diseases from donor to recipient reaches new dimensions. Potentially transmittable diseases from donors include infections, congenital disorders, and acquired illnesses like autoimmune diseases or malignancies of hematological or nonhematological origin. While established nonmalignant or malignant diseases might be easy to discover, early-stage hematological diseases like CML, light-chain multiple myelomas, aleukemic leukemias, occult myelodysplastic syndromes and other malignant and nonmalignant diseases might not be detectable by routine screening but only by invasive, new and/or expensive diagnostic tests. In the following article, we propose recommendations for donor work-up, taking into consideration the age of the donors. In contrast to blood transfusions, stem cells from donors with abnormal findings might still be acceptable for HCT, when no other options are available and life expectancy is limited. This issue is discussed in detail in relation to the available donor and stem cell source. Finally, the recommendations presented here aim at harmonized worldwide work-up for donors to insure high standard quality.

Reduced-intensity conditioning followed by allografting of CD34-selected stem cells and ?106/kg T cells may have an adverse effect on transplant-related mortality

In patients undergoing allogeneic peripheral blood stem cell (PBSC) transplantation after reduced-intensity conditioning (RIC), graft-versus-host disease (GVHD) represents a major cause of morbidity and mortality. T-cell depletion (TCD) prevents GVHD but carries potential risks of graft failure, opportunistic infections, and disease relapse. We explored ex vivo TCD of stem cell allografts that were administered after RIC treatment. Thirteen high-risk patients with hematological malignancies were treated with a fludarabine/melphalan-based RIC regimen followed by transplantation of immunomagnetically selected CD34(+) PBSC from HLA-identical sibling or matched unrelated donors. Patients were sequentially enrolled in two cohorts: group A (n=6) received antithymocyte globulin (ATG) during conditioning and 10(5) donor T cells/kg at transplantation, while group B (n=7) received 10(6) donor T cells/kg without ATG pretreatment. Primary graft failure occurred in two patients of group A and in one patient of group B. Complete donor chimerism persisting more than 1 year was achieved in two cases per cohort. Acute grade II to IV or chronic extensive GVHD were observed in a total of six patients (group A, 2; group B, 4). Procedure-related deaths were mainly due to severe pneumonia occurring in two patients of group A and in five patients of group B. These results suggest that CD34 selection of reduced-intensity PBSC allografts may cause adverse effects upon specific antimicrobial immunity which can lead to fatal infections, particularly in high-risk patients. In our study, simultaneous add-back of < or =10(6)/kg donor T cells was unable to compensate for this deficiency.

Mycophenolate mofetil and cyclosporine for graft-versus-host disease prophylaxis following reduced intensity conditioning allogeneic stem cell transplantation

The use of reduced intensity conditioning (RIC) regimens for allogeneic stem cell transplantation (allo-SCT) can result in a significant decrease in early procedure-related toxicity in patients not eligible for standard myeloablative regimens. However, acute graft-versus-host disease (aGVHD) remains a matter of concern after RIC allo-SCT, and its incidence might be expected to be higher in elderly and high-risk patients. This report investigated mycophenolate mofetil (MMF) and cyclosporin A (CsA) combination (n=14) in comparison to CsA alone (n=20) for GVHD prophylaxis in cancer patients aged over 50 years (27 haematological malignancies and seven solid tumours) receiving an HLA-identical sibling antithymocyte-globulin (ATG)-based RIC allo-SCT. Baseline demographic characteristics and risk factors for aGVHD were comparable between both groups. Although MMF administration was not associated with any significant toxicity, the cumulative incidence of any form of GVHD was comparable between both groups (cumulative incidence of grade II-IV aGVHD, 50% (95% CI, 28-72%) for CsA alone, as compared to 64% (95% CI, 39-89%) to CsA and MMF, P=NS), suggesting that adjunction of MMF to CsA is feasible, but does not translate towards a significant reduction of aGVHD, at least in the context ATG-based RIC allo-SCT.

Incidence of invasive aspergillosis after allogeneic hematopoietic stem cell transplantation with a reduced-intensity regimen compared with transplantation with a conventional regimen

To evaluate the clinical characteristics of invasive aspergillosis (IA) after reduced-intensity stem cell transplantation (RIST) compared with those after conventional stem cell transplantation (CST), we examined the medical records of 486 CST and 178 RIST recipients. The overall incidence of IA after allogeneic transplantation was 35 (5.3%) of 664, which gave a 3-year cumulative incidence of 5.6%. The estimated 3-year incidence of IA in CST and RIST was 4.5% and 8.2% (P = .045), respectively, but the mortality rates were similar (76% and 86%). The median onset of IA after RIST (day 127) occurred significantly later than that after CST (day 97). A multivariate analysis revealed that IA was associated with age older than 50 years (relative risk, 2.12; 95% confidence interval, 1.08-4.17; P = .03) and the presence of acute and/or chronic GVHD (relative risk, 6.2; 95% confidence interval, 2.4-16.4; P = .0002). IA remains an important complication after allogeneic transplantation, regardless of the type of conditioning regimen.

Chimerism studies in HLA-identical nonmyeloablative hematopoietic stem cell transplantation point to the donor CD8(+) T-cell count on day + 14 as a predictor of acute graft-versus-host disease

Chimerism analysis of hematopoietic cells has emerged as an essential tool in nonmyeloablative hematopoietic stem cell transplantation. We have investigated the development of donor chimerism in granulocytes and CD4(+) and CD8(+) T cells in blood and bone marrow of 24 patients with hematologic malignancies who received HLA-identical sibling peripheral blood stem cell grafts after conditioning with fludarabine and 2 Gy of total body irradiation. The T-cell chimerism of blood and bone marrow was tightly correlated. Complete donor chimerism was reached earlier in the granulocytes than in the T cells. Mixed T-cell chimerism was common at the time of onset of acute graft-versus-host disease (aGVHD), and both CD4(+) and CD8(+) donor T-cell chimerism increased with the occurrence of aGVHD grades II to IV (P =.0002 and P =.019, respectively). The rate of disappearance of recipient CD8(+) T cells was faster in patients with aGVHD grades II to IV than in patients without clinically significant aGVHD (P =.016). This observation indicates a role of graft-versus-lymphohematopoietic tissue reactions in creating complete donor T-cell chimerism. A donor CD8(+) T-cell count above the median on day +14 increased the risk of subsequent development of aGVHD grades II to IV (P =.003).

Nonmyeloablative allogeneic stem cell transplantation in metastatic renal cell carcinoma: a new therapeutic option or just a clinical experiment?

Nonmyeloablative stem cell transplantation (NST) and donor lymphocyte infusions (DLI) are currently under clinical investigation as an innovative therapeutic option for patients with metastatic renal cell carcinoma (RCC). The underlying concept, adopted from patients with hematologic malignancies, aims at a reduction of conditioning toxicity and exploits the graft versus malignancy effect of donor T-lymphocytes after transplantation. Clinical data from more than 100 patients treated worldwide have been published so far. The data provide evidence that NST is feasible with a very low rate of engraftment failure. Objective remissions in these heterogenous studies were observed in 23% of the patients overall. Remissions after NST developed only after complete engraftment of donor lymphoid cells had occurred. Objective responses were almost always accompanied by graft versus host disease (GvHD) after withdrawal of immunosuppression and/or DLI. GvHD and infections were the main contributors to a substantial transplant related morbidity and mortality, the major drawback of allogeneic stem cell transplantation. Therefore, clinical studies are necessary to further investigate and improve the selection of patients with metastatic RCC or other solid tumors for NST and to reduce post-transplant complications. This article reviews the results, side effects and potential future developments of NST in the treatment of solid tumors.

The influence of human platelet antigen match on the success of allogeneic peripheral blood progenitor cell transplantation following a reduced-intensity conditioning regimen

BACKGROUND

Allogeneic transplantation in elderly patients requires a dose-reduced conditioning regimen. Owing to reduced-intensity conditioning, host- and donor-type immune responses may affect the early posttransplant period, whereas only later on donor-derived reactions may ensue. Mismatches in the HLA system are known to be detrimental for the outcome of transplantation. Mismatches between donor and recipient for human platelet antigens (HPAs) may also affect the success of transplantation owing to serving as minor histocompatibility antigens and therefore rendering recipients at risk for graft-versus-host disease (GVHD) or graft rejection and inhibition of thrombopoiesis attributed to platelet (PLT) antibodies.

PATIENTS AND METHODS

Therefore, the occurrence of GVHD, incidence of relapse, need of PLT support, and outcome by analysis of 45 donor-recipient pairs for HPA-1, -2, -3, and -5 allotypes and screening for PLT antibodies were evaluated before transplantation and again 1 year thereafter.

RESULTS

Mismatches within the HPA system were not associated with an increased occurrence of transplant-related mortality or GVHD, the onset of thrombopoiesis, the frequency of PLT transfusions, or the incidence of relapse. Neither were settings of homozygous donors versus heterozygous recipients (graft-vs.-host direction) nor homozygous recipients versus heterozygous donors (host-vs.-graft direction) associated with any adverse effects on the outcome of the transplantation.

CONCLUSION

Thus, the HPA match does not affect the outcome of transplantation after reduced-intensity conditioning.

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.

Reduced-intensity allogeneic hematopoietic stem-cell transplantation as an immunotherapy for metastatic colorectal cancer

BACKGROUND

Allogeneic stem-cell transplantation (allo-SCT) can induce curative graft-versus-leukemia reactions for hematologic malignancies through allogeneic immunity. Because the gastrointestinal tract is a target of graft-versus-host disease (GvHD), colorectal cancer might be a candidate for allo-SCT.

METHODS

Four patients with metastatic colorectal cancer underwent reduced-intensity stem-cell transplantation (RIST) in the National Cancer Center Hospital between July 2002 and February 2003. Three patients received transplants from an human leukocyte antigen (HLA)-identical related donor, and the remaining patient received selected CD34-positive cells from a two-loci HLA-mismatched donor. The basis of preparative regimen was busulfan 4 mg/kg for 2 days and fludarabine 25 mg/kg for 6 days.

RESULTS

All the patients tolerated the preparative regimen and achieved engraftment without significant toxicities. All developed acute or chronic GvHD. Although serum levels of CA19-9 and carcinoembryonic antigen were transiently elevated after RIST in all the patients, the levels subsequently decreased below the levels from before RIST in all but one patient. Three had measurable lesions before RIST, one achieved partial response, and the others stable disease, which was durable for 120 and 60 days. Three patients died; the causes of death were progressive disease, GvHD, and accident. Postmortem examination was obtained for two patients; in one patient, the peritoneal metastatic lesions macroscopically disappeared, and in the other patient, the supraclavicular lymph node disappeared while the other measurable lesions remained stable.

CONCLUSIONS

All the patients showed some evidence suggesting the presence of a graft-versus-tumor effect for colorectal cancer, which should be confirmed in a future prospective trial.

Pulmonary function testing prior to hematopoietic stem cell transplantation

The pretransplant pulmonary function test plays an important role in the management of noninfectious pulmonary complications after hematopoietic stem cell transplantation (HCT). Although these tests are widely used as standard preoperative assessments in the nontransplant population, common conditions associated with the HCT patient requires that particular attention be given to interpretation of pulmonary function testing (PFT) results, such as comparison of serial pulmonary function tests and evaluation of the diffusion capacity. Although their utility in helping to predict the likelihood of developing post transplant pulmonary complications and mortality is not well established, current data indicate that pretransplant PFTs are important as a reference for the interpretation of post transplant PFTs and for identifying patients at high risk for developing pulmonary complications and/or mortality after HCT. Future studies of pretransplant pulmonary function should consider the advances in HCT, so that pretransplant PFTs will become a useful tool in pretransplant risk assessment and help the transplant oncologist to determine the most appropriate conditioning regimen for a patient with compromised lung function.

Aspergillus infections in transplant recipients

Aspergillus infections are occurring with an increasing frequency in transplant recipients. Notable changes in the epidemiologic characteristics of this infection have occurred; these include a change in risk factors and later onset of infection. Management of invasive aspergillosis continues to be challenging, and the mortality rate, despite the use of newer antifungal agents, remains unacceptably high. Performing molecular studies to discern new targets for antifungal activity, identifying signaling pathways that may be amenable to immunologic interventions, assessing combination regimens of antifungal agents or combining antifungal agents with modulation of the host defense mechanisms, and devising diagnostic assays that can rapidly and reliably diagnose infections represent areas for future investigations that may lead to further improvement in outcomes.

Low-intensity allogeneic hematopoietic stem cell transplantation for myeloid malignancies: separating graft-versus-leukemia effects from graft-versus-host disease

PURPOSE OF REVIEW

Over the past several years, significant advances in allogeneic hematopoietic cell transplantation (HCT), specifically the development of nonablative and reduced-intensity conditioning regimens, have enabled the extension of transplantation to include older or medically infirm patients with myeloid malignancies. The regimens rely largely on graft-versus-leukemia effects rather than high-dose therapy to eliminate malignant cells. Studies have demonstrated that the regimens allow sustained engraftment with relatively low transplant-related mortality. However, conclusions regarding the ultimate efficacy of these regimens for myeloid malignancies have been limited, given the small numbers of patients who have had transplants so far. This review summarizes recent studies of nonablative or reduced-intensity regimens for patients with myeloid malignancies (acute and chronic myelogenous leukemia, myelodysplastic syndrome, and myeloproliferative disorders). In addition, this review evaluates what is currently known regarding the association of graft-versus-leukemia responses and graft-versus-host disease (GVHD). When possible, graft-versus-leukemia responses are highlighted in the articles discussed.

RECENT FINDINGS

This review covers six articles and four abstracts that have been published since September 2003 on patients with myeloid malignancies who received HCT following nonmyeloablative or reduced-intensity conditioning. Due to the heterogeneity of the conditioning and GVHD prophylaxis regimens, direct comparisons between studies are difficult. However, these studies have demonstrated encouraging overall survivals (30 to 74%), disease-free/event-free or progression-free survivals (19 to 62%), and nonrelapse mortalities (15 to 55%). In addition, these studies demonstrated evidence for graft-versus-leukemia responses. However, relapse and progressive disease continued to be problems, particularly in patients with large tumor burdens at time of HCT.

SUMMARY

Over the past 10 years, significant advances have been made in the field of transplantation. Nonmyeloablative and reduced-intensity HCT have promised patients with hematologic and nonhematologic malignancies potential cures. However, disease relapse and nonrelapse mortality, mainly from GVHD and its therapy, continue to be problems. Future studies are needed to increase our understanding of GVHD and graft-versus-leukemia responses, which will greatly improve outcome. In addition, a better understanding of minor histocompatibility antigens may lead to more targeted immunotherapy and enhance the precision and success of transplantation.

Reduced-Intensity Conditioning Regimens for Hematologic Malignancies: What Have We Learned over the Last 10 Years?

Reduced-intensity conditioning (RIC) regimens have been investigated for more than 10 years as an alternative to traditional myeloablative conditioning regimens. RIC regimens are being commonly used in older patients as well as in disorders in which traditional myeloablative conditioning regimens are associated with high rates of non-relapse mortality. Hodgkin disease, myeloma, and low-grade lymphoid malignancies have been the diseases most impacted by RIC regimens. RIC regimens have also been shown to be safe and effective in older patients as well as patients with co-morbidities, although patients with chemorefractory disease still have high relapse rates and poor outcomes. Patients with chemosensitive disease have outcomes similar to those obtained with conventional ablative therapies, and thus comparative trials are warranted. RIC regimens are associated with lower rates of severe toxicity and non-relapse mortality; however, infections, graft-versus-host disease, and relapse of primary disease remain the most common obstacles to a successful outcome. The impact on survival and the relative benefits of RIC allografting compared with traditional conditioning regimens or alternative therapy remain to be defined. Incorporating targeted therapies as part of the conditioning regimens or as maintenance therapies is currently being explored to reduce relapse rates without increasing toxicity.

Transplantation of hematopoietic stem cells from the peripheral blood

Hematopoietic stem cells can be collected from the peripheral blood. These hematopoietic stem cells (HSC), or better progenitor cells, are mostly expressed as the percentage of cells than react with CD34 antibodies or that form colonies in semi-solid medium (CFU-GM). Under steady-state conditions the number of HSC is much lower in peripheral blood than in bone marrow. Mobilization with chemotherapy and/or growth factors may lead to a concentration of HSC in the peripheral blood that equals or exceeds the concentration in bone marrow. Transplantation of HSC from the peripheral blood results in faster hematologic recovery than HSC from bone marrow. This decreases the risk of infection and the need for blood-product support. For autologous stem-cell transplantation (SCT), the use of peripheral blood cells has completely replaced the use of bone marrow. For allogeneic SCT, on the other hand, the situation is more complex. Since peripheral blood contains more T-lymphocytes than bone marrow, the use of HSC from the peripheral blood increases the risk of graft-versus-host disease after allogeneic SCT. For patients with goodrisk leukemia, bone marrow is still preferred, but for patients with high-risk disease, peripheral blood SCT has become the therapy of choice.

Low dose total body irradiation followed by allogeneic lymphocyte infusion for refractory hematologic malignancy--an updated review

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy and radiotherapy used in conventional myeloablative conditioning regimens may lead to severe toxicity. In our initial study, we treated 25 patients with refractory cancers with 100 cGy total body irradiation (TBI) followed by allogeneic, non mobilized peripheral blood cells. Eighteen patients received sibling and 7 patients received unrelated cord blood stem cells. None of the 13 patients with solid tumors achieved donor chimerism or had a sustained response. Twelve patients with hematologic malignancies were treated, 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers, and 2 are long-term survivors. The development of chimerism correlated with total previous myelotoxic chemotherapy (p < 0.001). This technique is now being extended into the haploidentical setting.

Outcomes after alemtuzumab-containing reduced-intensity allogeneic transplantation regimen for relapsed and refractory non-Hodgkin lymphoma

We report the outcomes after reduced-intensity conditioning allogeneic stem cell transplantation (RIT) for non-Hodgkin lymphoma (NHL) in 88 patients (low-grade NHL [LG-NHL], n = 41; high-grade NHL [HG-NHL], n = 37; mantle cell lymphoma [MCL], n = 10). Thirty-seven patients had previously received autografts, and 21 were in complete remission (CR) at transplantation. Conditioning therapy consisted of alemtuzumab, fludarabine, and melphalan. Sixty-five patients received peripheral blood stem cells (PBSCs) from HLA-identical siblings, and 23 received bone marrow (BM) from matched unrelated donors. Prophylaxis for graft-versus-host disease (GVHD) consisted of cyclosporin A. Grade III-IV acute GVHD developed in 4 patients, and chronic GVHD developed in 6 patients. With a median follow-up of 36 months (range, 18-60 months), the actuarial overall survival (OS) rates at 3 years were 34% for HG-NHL, 60% for MCL, and 73% for LG-NHL (P &lt; .001). The 100-day and 3-year transplant-related mortality (TRM) rates for patients with LG-NHL were 2% and 11%, respectively, and were better (P = .01) than they were for patients with HG-NHL (27% and 38%, respectively). The actuarial current progression-free survival (PFS) rate at 3 years, including the rate for patients who achieved remission after donor lymphocyte infusion (DLI) for progression, was 65% for LG-NHL, 50% for MCL, and 34% for HG-NHL (P = .002). Twenty-one patients underwent DLI for matched related donor (MD)-persistent disease or relapse, and 15 underwent DLI for mixed hematopoietic chimerism. Patients who experienced relapses of LG-NHL and chronic lymphocytic leukemia (CLL) achieved excellent PFS with extremely low TRM and GVHD, even when matched related donors were unavailable. (Blood. 2004;104:3865-3871)

Indium-111-labelled donor-lymphocyte infusion by way of hepatic artery and radio-frequency ablation against liver metastases of renal and colon carcinoma after allogeneic hematopoietic stem-cell transplantation

BACKGROUND

In patients with metastatic solid cancer, antitumor effects occur after allogeneic stem-cell transplantation (SCT). However, this treatment is not as effective in the liver as against pulmonary and lymph-node metastases. To intensify the effect of donor-lymphocyte infusions (DLI) against liver metastases, intra-arterial (IA) cell injection by way of the hepatic artery (HA) can be used.

METHODS

To trace infused cells, three patients with colorectal, three with renal, and one with breast carcinoma were treated with Indium-111 (111-In)-oxinate-labeled lymphocytes. Four patients received the DLI IA, all after radio-frequency ablation (RFA) of liver metastases. Three patients with other metastases received 111-In DLI intravenously (IV). One of them had RFA before SCT.

RESULTS

Localization of the IA 111-In DLI activity on scintigrams homed to the liver. After IA injection, the liver to sternum ratio of radioactivity was higher compared with IV injection. Cells (CD3+, 19+, and 56+) of donor origin in biopsies of liver metastasis in two patients treated with IA injection increased to 80% to 100%. Two of four patients treated using the IA DLI showed stable size and number of liver metastases for 5 and 21 months, respectively. Both are alive 18 and 34 months after SCT. Two of three patients receiving DLI IV are doing well, with a stable metastatic disease or still without metastases 21 and 20 months after cell infusions (26 and 34 months after SCT), respectively. Three patients died because of progressive disease.

CONCLUSION

When infused by way of the HA, 111-In-labeled lymphocytes home to the liver and its metastases. The liver metastasis infiltrating cells of donor origin increased. DLI by way of the HA combined with RFA may be used to treat liver metastases after SCT.

Use of cyclosporine in hematopoietic cell transplantation

Early attempts to perform successful allogeneic hematopoietic stem cell transplants were plagued by graft rejection and graft-versus-host disease, leading many investigators to lose hope that bone marrow transplantation could ever become a useful therapeutic approach in clinical medicine. Although many subsequent discoveries contributed to the successful transformation of this area of research into lifesaving therapy, there can be no doubt that the discovery of cyclosporine (CsA) constituted one of the major advances. Even today, more than 25 years after the first description of its use in humans, CsA remains one of the cornerstones of therapy for the majority of patients undergoing allogeneic hematopoietic cell transplantation (HCT). In this review we will recount the events that have established CsA as a foundation of HCT.

Factors affecting engraftment of allogeneic hematopoietic stem cells after reduced-intensity conditioning

Several factors influence the engraftment of allogeneic hematopoietic stem cells (HSC). Recently, there has been increased utilization of transplant-conditioning regimens that use reduced doses of chemotherapy and radiation that are considered to be non-myeloablative. These non-myeloablative (or reduced-intensity) allogeneic HSC transplants (RIST) decrease early post-transplant complications, but they are associated with higher incidences of mixed chimerism and graft rejection compared with transplantation after myeloablative condition-ing. RIST provides a unique opportunity to study allogeneic HSC engraftment. In particular, host immune status and stem cell graft composition have emerged as important factors affecting engraftment after RIST Based on these observations, it has been hypothesized that conditioning regimens and allograft composition can be tailored to an individual patients immune and disease status prior to transplant.

Allogenic stem cell transplantation for nonmalignant disorders using matched unrelated donors

We here report 25 patients with nonmalignant disorders, ie, severe aplastic anemia (SAA, n = 12) or inborn errors of metabolism (IEM, n = 13), who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated high-resolution typed HLA-A, -B, and -DRbeta1 identical donors. One patient had an HLA-B subtype-mismatched donor. Conditioning for SAA mainly consisted of cyclophosphamide and total body irradiation, and that for IEM consisted of busulfan and cyclophosphamide. All patients received antithymocyte globulin during conditioning. After HSCT, they were given cyclosporine combined with methotrexate for immunosuppression. Two patients rejected their grafts: 1 died of pneumonia, and the other was successfully regrafted. The cumulative incidence of acute graft-versus-host disease grades II to IV was 24%, whereas chronic graft-versus-host disease occurred in 21%. The 5-year survival rates were 83% in the SAA group and 85% in those with IEM. We conclude that HSCT with HLA-A, -B, and -DRbeta1 genomically matched unrelated donors in combination with antithymocyte globulin in the conditioning regimen gives encouraging results in patients with SAA or IEM.

Radiation dose determines the degree of myeloid engraftment after nonmyeloablative stem cell transplantation

A multivariate analysis of 121 dogs conditioned with 200, 100, or 50 cGy of total body irradiation (TBI) followed by hematopoietic stem cell transplantation from matched littermates showed that TBI dose was the only factor examined that was statistically significantly associated with the percentage of donor myeloid engraftment in stable long-term chimeras ( P = .008). To understand the direct effects of low-dose irradiation on hematopoietic stem/progenitor cells, nonirradiated and irradiated human CD34 + cells were evaluated for competitive repopulating ability in nonobese diabetic/severe combined immunodeficiency beta2m -/- mice. As expected, the results showed a radiation dose-dependent loss of competitive repopulating ability. Flow cytometric analysis indicated that, within a viable cell gate, there was reduced expression of P-selectin glycoprotein ligand-1 and L selectin on irradiated compared with nonirradiated CD34 + cells; this suggests that irradiated stem/progenitor cells may be compromised in their ability to home to or interact with the marrow microenvironment. However, the CD34 + /P-selectin glycoprotein ligand-1 dim cells also showed activation of caspase-3, indicating that they were destined to die. These results suggest that the TBI dose determines the degree of myeloid engraftment by compromising the resident stem/progenitor cell compartment.

Engraftment and survival following reduced-intensity allogeneic peripheral blood hematopoietic cell transplantation is affected by CD8+ T-cell dose

The influence of graft composition on clinical outcomes after reduced-intensity conditioning is not well-characterized. In this report we prospectively enumerated CD34+, CD3+, CD4+, and CD8+ cell doses in granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell (G-PBMC) allografts in 63 patients who received transplants following non-myeloablative conditioning with total body irradiation 200 cGy plus fludarabine as treatment for malignant diseases. Donors were HLA-identical siblings (n = 38) or HLA-matched unrelated individuals (n = 25). By univariate analyses G-PBMC CD8+ T-cell dose in at least the 50th percentile favorably correlated with full donor blood T-cell chimerism (P = .03), freedom from progression (P = .001), and overall survival (P = .01). No G-PBMC cell dose influenced grade II to IV acute or extensive chronic graft-versus-host disease. In multivariate analysis only G-PBMC CD8+ T-cell dose (P = .003; RR = 0.2, 95% CI = 0.1-0.6) was associated with improved freedom from progression. Infusion of low G-PBMC CD8+ T-cell dose for reduced-intensity allografting may adversely affect T-cell engraftment and survival outcome.

Serious graft-versus-host disease after hematopoietic cell transplantation following nonmyeloablative conditioning

The efficacy of allogeneic hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning depends on the balance between the desirable antineoplastic effects of donor cells weighed against the undesirable morbidity of graft-versus-host disease (GVHD). Development of serious acute or chronic GVHD was analyzed retrospectively in 171 consecutive patients, who had related or unrelated nonmyeloablative HCT for hematologic malignancies. GVHD was defined as serious when it resulted in (1) death, (2) disability, (3) three or more major infections in 1 year, (4) prolonged hospitalization or (5) suicide or hospitalization for suicidal ideation. According to this definition, 43 of 171 (25%) patients developed serious GVHD with a median follow-up of 30 (range, 12-65) months. The incidence of serious GVHD was similar after related and unrelated HCT. Among the 43 patients with serious GVHD, 20 had grade III-IV acute GVHD, and 30 had extensive chronic GVHD. Among the 171 patients, seven had grade III acute GVHD and 84 had extensive chronic GVHD that did not meet criteria for serious GVHD. Assessment of serious GVHD provides additional useful information to acute GVHD grades and classification of limited and extensive chronic GVHD in describing the overall risk and impact complications caused by donor cells.

Reduced-intensity stem cell transplantation from an HLA-identical sibling donor in patients with myeloid malignancies

The purpose of this study was to evaluate the feasibility and efficacy of allogeneic hematopoietic stem cell transplantation with a reduced-intensity regimen (RIST) in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). In all, 36 patients (median age 55 years) underwent RIST from an HLA-matched related donor between September 1999 and December 2002. The diagnoses included AML (n=14), leukemia evolving from MDS (n=10), and MDS (refractory anemia with excess blasts n=6, refractory anemia n=6). The RIST regimen consisted of purine analog (cladribine or fludarabine)/busulfan, with or without antithymocyte globulin. The regimen was well tolerated, and 34 patients achieved durable engraftment and most achieved remission after RIST. A total of 17 patients developed grade II-IV acute GVHD, and 27 developed chronic GVHD. Eight patients relapsed, and five of them received antithymocyte globulin (ATG) as part of the preparative regimen. A total of 12 patients died (four disease progression, six transplantation-related complications, and two others). Estimated 1-year disease-free survival (DFS) in low- and high-risk groups was 85 and 64%, respectively. We conclude that RIST can be performed safely in elderly patients with myeloid malignancies, and has therapeutic potential for those who fail conventional chemotherapy. In view of the significant association between GVHD or ATG and DFS, defined management of GVHD following RIST should become a major target of clinical research.

A novel reduced intensity regimen for allogeneic hematopoietic stem cell transplantation associated with a reduced incidence of graft-versus-host disease

SUMMARY

In all, 55 patients at high risk or ineligible for a conventional allogeneic hematopoietic stem cell transplant (HSCT) received a regimen consisting of extracorporeal photopheresis, pentostatin, and reduced dose total body irradiation. The median age was 49 years (18-70 years); 44 received a sibling and 11 an unrelated HSCT; 44% were over the age of 50 years and 31% had undergone a prior HSCT. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate. Full donor chimerism was documented in 98% by day +100. The 1000-day nonrelapse mortality was 11%. The median follow-up is 502 days (154-1104 days). The 1- and 2-year overall survival (OS) and event-free survival (EFS) are 67, 58 and 55%, and 47%, respectively. Patients who had not received a prior HSCT or had less than three prior chemotherapy regimens had a 71% OS and 67% EFS at 1 year. Greater than grade II aGVHD developed in 9% and chronic GVHD (cGVHD) in 43%, and extensive in 12% and limited in 31%. Of the patients, 86% who engrafted had a disease response, 72% had complete and 14% partial responses. This novel reduced intensity preparative regimen was well tolerated and associated with a low incidence of transplant-related mortality and serious acute and cGVHD.

Hematopoietic stem-cell transplantation from unrelated donors in elderly patients (age>55 years) with hematologic malignancies: older age is no longer a contraindication when using reduced intensity conditioning

Allogeneic stem cell transplantation (SCT) is a potentially curative approach for patients with hematological malignancies. Reduced-intensity conditioning regimens allow SCT in elderly patients; however, there are only limited data on the feasibility and outcomes of unrelated donor SCT in these patients. In this study, we analyzed, retrospectively, data of 36 patients with various hematological malignancies and median age 58 years (range, 55-66), who were given unrelated donor SCT after reduced-intensity conditioning. The preparative regimen consisted of fludarabine combined with oral busulfan (8 mg/kg, n=8), intravenous busulfan (6.4 mg/kg, n=11), treosulfan (30 g/m(2), n=5) or melphalan (100-150 mg/m(2), n=12). Patients were also given serotherapy, ATG (n=32), or alemtuzumab (n=4). The probabilities of overall survival, disease-free survival, and nonrelapse mortality at 1 year after SCT were 52, 43, and 39%, respectively. Acute graft-versus-host disease (GVHD) grade II-IV and chronic GVHD occurred in 31 and 45%, respectively. Multivariable analysis determined that survival rates were higher in patients with chemosensitive disease (HR 4.5), and patients conditioned with intravenous busulfan or treosulfan (HR 3.9). Unrelated donor SCT is feasible in elderly patients, with outcomes that are similar to younger patients. Favorable outcome was observed in patients with myeloid malignancies, and those transplanted in remission and early in the course of disease. Age alone should not be considered a contraindication to unrelated donor SCT.

Targeted pretransplant host lymphocyte depletion prior to T-cell depleted reduced-intensity allogeneic stem cell transplantation

Mixed chimaerism and graft rejection are higher after reduced-intensity allogeneic stem cell transplantation (RIST) with T-cell depleted (TCD) allografts. As host immune status before RIST affects engraftment, we hypothesized that targeted depletion of host lymphocytes prior to RIST would abrogate graft rejection and promote donor chimaerism. Lymphocyte-depleting chemotherapy was administered at conventional doses to subjects prior to RIST with the intent of decreasing CD4(+) counts to <0.05 x 10(9)cells/l. Subjects (n = 18) then received reduced-intensity conditioning followed by ex vivo TCD human leucocyte antigen-matched sibling allografts. All evaluable patients (n = 17) were engrafted; there were no late graft failures. At day +28 post-RIST, 12 patients showed complete donor chimaerism. Mixed chimaerism in the remaining five patients was associated with higher numbers of circulating host CD3(+) cells (P = 0.0032) after lymphocyte-depleting chemotherapy and was preferentially observed in T lymphoid rather than myeloid cells. Full donor chimaerism was achieved in all patients after planned donor lymphocyte infusions. These data reflect the importance of host immune status prior to RIST and suggest that targeted host lymphocyte depletion facilitates the engraftment of TCD allografts. Targeted lymphocyte depletion may permit an individualized approach to conditioning based on host immune status prior to RIST.

Unrelated Cord Blood Transplantation with a Reduced-Intensity Conditioning Regimen following Autologous Transplantation for Multiple Myeloma

Two patients, 51- and 45-year-old men with stage III immunoglobulin G multiple myeloma, achieved partial and complete remissions, respectively, after conventional chemotherapy. They both received high-dose melphalan (200 mg/m2) with autologous stem cell transplantation (ASCT). Eighty-four and 78 days after ASCT, the patients underwent unrelated cord blood transplantation (CBT) following treatment with total-body irradiation (2 Gy), fludarabine (90 mg/m2), and melphalan (140 mg/m2). Neutrophil engraftment was attained on day +27 in patient 1 and day +15 in patient 2. Full donor chimerism of the marrow cells was confirmed. Regimen-related toxicity in both patients remained within grade I. Grades I and II acute graft-versus-host disease (GVHD) occurred in patients I and 2, respectively, but improved without steroid therapy. Both patients developed limited chronic GVHD of the skin but needed no treatment. The serum paraprotein level in patient 1 decreased further after ASCT and CBT but remained at minimally detectable levels. The serum and urine paraprotein levels in patient 2 remained below detectable limits. These results suggested that CBT with a reduced-intensity conditioning regimen after high-dose chemotherapy with ASCT is a new promising approach for the treatment of multiple myeloma.

How and when should we monitor chimerism after allogeneic stem cell transplantation?

SUMMARY

Chimerism analysis has become an important tool for the peri-transplant surveillance of engraftment. It offers the possibility to realize impending graft rejection and can serve as an indicator for the recurrence of the underlying malignant or nonmalignant disease. Most recently, these investigations have become the basis for treatment intervention, for example, to avoid graft rejection, to maintain engraftment and to treat imminent relapse by pre-emptive immunotherapy. This invited review focuses on the clinical implications of characterization of hematopoietic chimerism in stem cell transplantation.

Kinetics of in vivo elimination of suicide gene-expressing T cells affects engraftment, graft-versus-host disease, and graft-versus-leukemia after allogeneic bone marrow transplantation

Suicide gene therapy is one approach being evaluated for the control of graft-vs-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). We recently constructed a novel chimeric suicide gene in which the entire coding region of HSV thymidine kinase (HSV-tk) was fused in-frame to the extracellular and transmembrane domains of human CD34 (DeltaCD34-tk). DeltaCD34-tk is an attractive candidate as a suicide gene in man because of the ensured expression of HSV-tk in all selected cells and the ability to rapidly and efficiently purify gene-modified cells using clinically approved CD34 immunoselection techniques. In this study we assessed the efficacy of the DeltaCD34-tk suicide gene in the absence of extended ex vivo manipulation by generating transgenic animals that express DeltaCD34-tk in the peripheral and thymic T cell compartments using the CD2 locus control region. We found that DeltaCD34-tk-expressing T cells could be purified to near homogeneity by CD34 immunoselection and selectively eliminated ex vivo and in vivo when exposed to low concentrations of GCV. The optimal time to administer GCV after allogeneic BMT with DeltaCD34-tk-expressing transgenic T cells was dependent on the intensity of the conditioning regimen, the leukemic status of the recipient, and the dose and timing of T cell infusion. Importantly, we used a controlled graft-vs-host reaction to promote alloengraftment in sublethally irradiated mice and provide a graft-vs-leukemia effect in recipients administered a delayed infusion of DeltaCD34-tk-expressing T cells. This murine model demonstrates the potential usefulness of DeltaCD34-tk-expressing T cells to control GVHD, promote alloengraftment, and provide a graft-vs-leukemia effect in man.

Autologous/syngeneic stem cell transplantation to treat refractory GvHD

Severe graft-versus-host disease (GvHD) refractory to corticosteroids responds poorly to experimental treatment and is often fatal. Attempts have been made to 'rescue' such patients by transfusing autologous cells in order to ablate the lymphoid component of the graft or to introduce regulatory cells capable of suppressing the GvHD. Here, we report details of eight patients with severe grade III-IV acute GvHD (n=7) or extensive chronic GvHD (n=1) who after failing a median of four lines of treatment were then treated with either autologous or syngeneic nucleated cell transfusions. Patients received standard conditioning (n=3), low intensity (n=2) or no conditioning (n=3) before the rescue procedure. In four of the five patients who received some form of conditioning, mixed chimerism or complete recipient hematopoiesis was restored. The GvHD resolved in four patients, of whom one died subsequently of multiorgan failure and two died of leukemia; one is still alive. A fifth patient had transient improvement in GvHD, which recurred when the corticosteroids were reduced. Three patients obtained no benefit from the procedure. We conclude that 'rescue' by transfusion of autologous or syngeneic nucleated cells may be valuable to treat severe refractory GvHD; the best approach to conditioning remains to be defined.

CD34+ cell dose, conditioning regimen and prior chemotherapy: factors with significant impact on the early kinetics of donor chimerism after allogeneic hematopoietic cell transplantation

The aim of this study was to define factors that significantly influence the early kinetics of donor chimerism after transplantation. In a retrospective study, the percentage of donor chimerism in peripheral blood measured with sex-chromosome-specific probes and fluorescence-in situ hybridization was analyzed in 184 recipients of allogeneic hematopoietic cells between days 1 and 30. Using a generalized linear model for longitudinal observations, the dose of CD34+ cells infused had a significant impact on the slope of donor chimerism. In multivariate analysis, cell doses of 2-8 x 10(6)/kg (P=0.001) and <2 x 10(6) CD34+ cells/kg (P<0.0001) were associated with slower increase of donor chimerism compared to >8.0 x 10(6) CD34+ cells/kg. In addition, fludarabine-based reduced-intensity conditioning resulted in a significant delay of donor cell increase compared to standard conditioning therapy (P=0.0001). The application of chemotherapy before the start of conditioning (P=0.0003) and the use of antithymocyte globulin (P=0.003) were associated with a faster increase of donor chimerism. The factors identified in this study can be used to predict the kinetics of early donor chimerism for an individual patient.

Reduced-intensity conditioning using TBI (8 Gy), fludarabine, cyclophosphamide and ATG in elderly CML patients provides excellent results especially when performed in the early course of the disease

Allogeneic bone marrow or stem cell transplantation is a curative therapeutic option for chronic myelogenous leukemia. In order to decrease the toxicity of the procedure, the dosage of total body irradiation was reduced from 12 to 8 Gy and subsequently the dose of cyclophosphamide from 120 to 80 mg/kg. The purine analogue fludarabine, ATG, cyclosporine A and a short course of methotrexate were given for immune suppression. So far, 35 elderly CML patients with sibling and unrelated donors have been transplanted. Transplant-related mortality at day + 100 was 11%. After engraftment, all patients achieved a complete cytogenetic remission. Relapse occurred in 14% of the patients. The risk of relapse was significantly higher in those patients transplanted in second chronic or accelerated phase (P = 0.048). After a median follow-up of 30 months (range 12-62), 63% of the patients are alive. Those patients transplanted within the first year from diagnosis had an overall survival of 79% (P = 0.049), emphasizing the benefit of early transplantation. Stepwise reduction of conditioning intensity resulted in stable engraftment, low relapse rates and encouraging overall survival in this high-risk patient group.

Graft-versus-leukemia activity may overcome therapeutic resistance of chronic lymphocytic leukemia with unmutated immunoglobulin variable heavy-chain gene status: implications of minimal residual disease measurement with quantitative PCR

The aim of this study was to investigate if graft-versus-leukemia (GVL) activity conferred by allogeneic stem cell transplantation (allo-SCT) is effective in chronic lymphocytic leukemia (CLL) with unmutated VH gene status. The kinetics of residual disease (MRD) were measured by quantitative allele-specific immunoglobulin heavy chain (IgH) polymerase chain reaction (PCR) in 9 patients after nonmyeloablative allo-SCT for unmutated CLL. Despite an only modest decrease in the early posttransplantation phase, MRD became undetectable in 7 of 9 patients (78%) from day +100 onwards subsequent to chronic graft-versus-host disease or donor lymphocyte infusions. With a median follow-up of 25 months (range, 14-37 months), these 7 patients remain in continuous clinical and molecular remission. In contrast, PCR negativity was achieved in only 6 of 26 control patients (23%) after autologous SCT for unmutated CLL and it was not durable. Taken together, this study shows for the first time that GVL-mediated immunotherapy might be effective in CLL with unmutated VH.

A Comparison of Nonmyeloablative and Reduced-Intensity Conditioning for Allogeneic Stem-Cell Transplantation

BACKGROUND

Nonmyeloablative (NM) conditioning and reduced-intensity conditioning (RIC) are increasingly used for allogeneic hematopoietic stem-cell transplantation. Such regimens have not been compared.

METHODS

The primary endpoint was graft-versus-host disease (GVHD). Secondary endpoints included transfusions, engraftment, and transplant-related mortality (TRM). NM conditioning (n=24) consisted of fludarabine and 2-Gy total-body irradiation followed by immunosuppression with cyclosporine A (CsA) combined with mycophenolate mofetil (MMF). The RIC (n=34) protocol consisted of fludarabine combined with busulfan or cyclophosphamide, antithymocyte globulin, and posttransplant immunosuppression CsA plus methotrexate. Diagnoses included hematologic malignancies and solid tumors. Donors were 34 human leukocyte antigen-identical siblings and 24 unrelated donors. Chimerism was analyzed by polymerase chain reaction of minisatellites.

RESULTS

Graft failure occurred in 6 of 24 in the NM group and in 1 of 34 in the RIC group, which was a significant difference (odds ratio [OR], 22.6; P=0.02). The NM group also had less leukopenia and required fewer erythrocyte and platelet transfusions than the RIC group. The time to and proportion of CD3, CD19, and CD45 donor chimerism were similar in both groups. The cumulative incidence of grades II to IV acute GVHD was higher in the NM group (59% vs. 12%; OR, 26.9; P<0.001), but we found no difference in the cumulative incidence of chronic GVHD (41% vs. 61%). TRM was 42% in the NM group and 20% in the RIC patients (relative hazard, 11.6; P=0.03).

CONCLUSIONS

NM conditioning with posttransplant immunosuppression using CsA and MMF resulted in less leukopenia and fewer transfusions, but resulted in more cases of graft failure, acute GVHD, and TRM than in RIC patients.

Incidence and outcome of adenovirus disease in transplant recipients after reduced-intensity conditioning with alemtuzumab

Adenoviruses are emerging as a major cause of infectious complications after allogeneic transplantation. We evaluated the incidence and outcome of symptomatic adenovirus infection or adenovirus disease after alemtuzumab-based reduced-intensity conditioning in 86 consecutive patients. The overall probability of adenovirus disease was 18.4% (11/86 patients). Five patients died of progressive adenovirus disease, and this was the most important infectious cause of mortality in this cohort. The probability of nonrelapse mortality was 49% in patients with adenovirus disease compared with 25.5% in those without (P=.007). The severity of lymphocytopenia and continuation of immunosuppressive therapy were the most important risk factors for progressive adenovirus disease and death. In contrast, patients who were not receiving immunosuppressive therapy or had had it reduced or withdrawn cleared the virus. We also detected a correlation between the lack of preemptive anti-cytomegalovirus (CMV) therapy for CMV reactivation and the risk of progressive adenovirus disease (P=.05). Our findings highlight the emergence of adenovirus as an important posttransplantation pathogen even after reduced-intensity conditioning and demonstrate the effect of the severity of lymphocytopenia, anti-CMV prophylaxis, and immunosuppressive therapy on the outcome of adenovirus disease.

Treatment of CML in pediatric patients: should imatinib mesylate (STI-571, Gleevec) or allogeneic hematopoietic cell transplant be front-line therapy?

BACKGROUND

Long-term survival of pediatric patients with chronic myelogenous leukemia (CML) receiving myeloablative hematopoietic stem cell transplantation from fully-matched related and unrelated donors has been reported between 60 and 75%, but is associated with significant morbidity. Imatinib mesylate (STI-571, Gleevec) and reduced intensity conditioning stem cell transplantation (RIC) are two promising new tools that offer potential for decreasing therapy associated morbidity for patients with CML.

RESULTS

Large trials have shown significant responses in chronic phase patients treated with imatinib and reasonable but short-lived responses in advanced phase CML. Data from adult studies is beginning to define populations likely to progress or have prolonged responses to imatinib, and some adult treatment paradigms are moving toward reserving transplantation until patients are at risk of failure with imatinib. Early trials of RIC transplantation in CML show decreased transplant related morbidity with efficacy similar to conventional transplantation, but the approach has yet to be verified in phase III studies. Data in pediatric patients with imatinib and RIC transplantation is limited.

CONCLUSIONS

Studies with imatinib are underway in pediatrics, but whether pediatric dosing schemes will lead to outcomes similar to adults is unknown. Because HLA-matched myeloablative transplantation offers a high rate of cure in the pediatric population, clinical studies assessing the role of imatinib mesylate and RIC transplantation should be planned carefully in order to avoid sub-optimal outcomes.

Successful Treatment of Tacrolimus (FK506)-Related Leukoencephalopathy with Cerebral Hemorrhage in a Patient Who Underwent Nonmyeloablative Stem Cell Transplantation

A 46-year-old woman with Hodgkin's disease who underwent nonmyeloablative allogeneic stem cell transplantation developed cortical blindness, seizures, and left hemiparesis on day 100 while receiving tacrolimus (FK506) and prednisone for the treatment of graft-versus-host disease (GVHD). Magnetic resonance imaging revealed multiple changes, mainly in the bilateral occipital lobes, suggesting FK506-related leukoencephalopathy. These abnormalities improved after discontinuation of FK506. However, 3 days after the episode, cerebral hemorrhage in the left occipital lobe with perforation to the left subdural space occurred. Although FK506-induced leukoencephalopathy with cerebral hemorrhage is considered the more severe form of such leukoencephalopathy, the patient's neurological symptoms almost completely resolved and radiographic findings improved after discontinuation of FK506, tapering of methylprednisolone, and initiation of mycophenolate mofetil. FK506-related leukoencephalopathy is a rare complication after allogeneic stem cell transplantation. Although the symptoms usually subside after discontinuation of FK506, therapeutic intervention in many cases may result in severe complications, including GVHD and vascular disease. We consider it important to use immunosuppressive agents without vascular endothelial toxicity for preventing the development of fatal GVHD after discontinuation of FK506.

Hematopoietic stem cell transplantation for β-thalassemia major: Experience in south of Iran

INTRODUCTION

Allogeneic stem cell transplantation as a curative treatment for thalassemia major was established in Shiraz in 1993. In this article we describe our results of 10 years experience with allogeneic bone marrow transplantation for thalassemia major.

METHODS

From June 1993 to January 2003, 112 cases of beta-thalassemia major underwent allogeneic marrow transplantation from HLA-identical or one antigen-mismatched related donors. Conditioning chemotherapy included busulfan (14 to 15 mg/kg), cyclophosphamide (200 mg/kg), and antithymocyte globulin (ATG; 40 mg/kg). Prophylaxis for graft-versus-host disease consisted of cyclosporine, prednisolone, and methotrexate.

RESULTS

One hundred twelve patients with a diagnosis of beta-thalassemia major underwent allogeneic marrow transplantation during this period. The mean age of the patients was 9.5 years with the range of 2 to 20 years. The distribution of cases according to the Lucarelli classification were: 27 cases class I, 38 cases class II, and 47 cases class III. Eighty-seven of 112 patients (77.6%) with diagnosis of beta-thalassemia major are living with full engraftment at a median follow-up of 6 years (range 2 to 119 months).

CONCLUSION

Allogeneic bone marrow transplantation has changed the outcome of disease dramatically. According to our results stem cell transplantation is the treatment of choice for class I and II (Lucarelli risk groups). Also, we recommend transplantation as a curative method for treatment of class III beta-thalassemic patients.