Endothelial chimerism in chronic sclerotic-type chronic graft-versus-host disease (GVHD) and GVHD-associated angiomatosis

Graft-versus-host disease-associated angiomatosis (GVHD-AA) is an uncommon manifestation of chronic GVHD consisting of friable vascular proliferations. Using fluorescence in situ hybridization, we demonstrate the presence of donor-derived endothelial cells within areas of GVHD-AA. This is the first documented occurrence of a benign neoplastic growth in relationship to a form of chronic GVHD.

An effective mobilization strategy for lymphoma patients after failed upfront mobilization with plerixafor

In an otherwise eligible patient, inadequate mobilization of PBSCs is a limiting factor to proceeding with an auto-ASCT. In such situations, plerixafor is commonly added to improve PBSC collection yields along with cytokine (G-CSF alone) or chemomobilization (chemotherapy+G-CSF). Individually, both strategies are proven to be safe and effective. Here we report six patients who underwent successful mobilization with combination chemomobilization plus plerixafor after upfront failure of cytokine mobilization plus plerixafor. The median CD34(+) cell yield after chemomobilization was 2.48 × 10(6)/kg (range 0.99-8.49) after receiving one to two doses of plerixafor. All patients subsequently underwent ASCT without major unforeseen toxicities and engrafted successfully. No significant delays in time to neutrophil recovery were observed. Our experience highlights the safety and effectiveness of chemomobilization with plerixafor after G-CSF plus plerixafor (G+P) failure and suggests this is a viable salvage strategy after initial failed G+P mobilization.

Association of pre-transplantation positron emission tomography/computed tomography and outcome in mantle cell lymphoma

Positron emission tomography/computed tomography (PET/CT)-positive findings before autologous SCT (auto-SCT) are associated with inferior PFS and OS in patients with relapsed Hodgkin's and diffuse large B-cell lymphoma. We classified pre-transplant PET/CT performed before auto-SCT as positive or negative to evaluate the impact of pre-transplant PET/CT in mantle cell lymphoma (MCL). In 29 patients, 17 were PET/CT(-) and 12 were PET/CT(+). PET/CT(+) patients were younger (P=0.04), had lower MCL International Prognostic Index (MIPI, P=0.04) scores, but increased bulky adenopathy >5 cm (45% vs 13%, P=0.09). With a median follow-up of 27 months (range: 5-55 months), 7 patients relapsed (4 in the PET/CT(-) group and 3 in the PET/CT(+) group) with 2 deaths in the PET/CT(+) group without a documented relapse. The estimated 2-year PFS was 64% (95% confidence interval (CI): 0.30-0.85) vs 87% (95% CI: 0.57-0.97) in PET/CT(+) and PET/CT(-) patients, respectively (P=0.054). OS was significantly decreased in PET/CT(+) patients (P=0.007), with 2-year estimates of 60% (95% CI: 0.23-0.84) vs 100% in PET/CT(-) patients. A positive pre-transplant PET/CT is associated with a poor prognosis in patients with MCL. Additional factors may impact the prognostic value of PET/CT, as several PET/CT(+) patients remain in remission.

How we approach patient evaluation for hematopoietic stem cell transplantation

The evaluation of patients for hematopoietic stem cell transplantation is a complex process. The decision to recommend transplantation is not simply dependent on patient diagnosis; instead it is a specialized analytic decision process intricately dependent on a number of variables including patient age, performance status, medical comorbidities, family support structure, socioeconomic viability and motivation to participate in self-care, to name a few. The process of pre-transplant patient evaluation has substantial variability across different transplant centers, owing to lack of formal published guidelines. This review summarizes the process of pre-transplant patient evaluation and workup, and aims to describe components of a well-organized and evidenced-based patient selection process for SCT.

Pulmonary Nocardia and Aspergillus co-infection in a patient with chronic graft-versus-host disease

Immunosuppression and chronic graft-versus-host disease (GVHD) are major risk factors for the development of invasive pulmonary aspergillosis in bone marrow transplant patients. Although nocardial infections are well described in hematopoietic stem cell transplantation (HSCT) recipients, little information is available about the incidence of nocardiosis in patients with chronic GVHD after HSCT. Coexistence of invasive pulmonary aspergillosis and nocardiosis following non-myeloablative HSCT has not been reported previously. With the increasing use of pentostatin in the treatment of chronic GVHD in future and other nucleoside analogues as preparative regimens in patients undergoing reduced-intensity conditioning transplantation, the possibility of co-infection with rare organisms should be kept in mind while assessing at-risk patients.

Mobilizing stem cells from normal donors: is it possible to improve upon G-CSF?

Currently, granulocyte colony stimulating factor (G-CSF) remains the standard mobilizing agent for peripheral blood stem cell (PBSC) donors, allowing the safe collection of adequate PBSCs from the vast majority of donors. However, G-CSF mobilization can be associated with some significant side effects and requires a multi-day dosing regimen. The other cytokine approved for stem cell mobilization, granulocyte-macrophage colony stimulating factor (GM-CSF), alters graft composition and may reduce the development of graft-versus-host disease, but a significant minority of donors fails to provide sufficient CD34+ cells with GM-CSF and some experience unacceptable toxicity. AMD3100 is a promising new mobilizing agent, which may have several advantages over G-CSF for donor mobilization. As it is a direct antagonist of the interaction between the chemokine stromal-derived factor-1 and its receptor CXCR4, AMD3100 mobilizes PBSCs within hours rather than days. It is also well tolerated, with no significant side effects reported in any of the clinical trials to date. Studies of autologous and allogeneic transplantation of AMD3100 mobilized grafts have demonstrated prompt and stable engraftment. Here, we review the current state of stem cell mobilization in normal donors and discuss novel strategies for donor stem cell mobilization.

Hematologic malignancies developing in previously healthy individuals who received hematopoietic growth factors: Implications for use of colony stimulating factors in healthy volunteers participating in early phase clinical studies and in healthy blood product donors

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Background: Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHu-MGDF aka MGDF) and recombinant granulocyte colony stimulating factor (G-CSF) promote the maturation of hematopoietic progenitor cells. Healthy volunteers/donors have received MGDF in phase I/II clinical trials and G-CSF in allogeneic peripheral blood stem cell transplantation procedures. Herein, we review clinical findings for five previously healthy volunteers/donors who developed hematologic malignancies after the use of MGDF or G-CSF. Methods: Clinical information related to hematologic malignancies were reviewed for three volunteers who had participated in a phase I/II clinical trial with MGDF and two donors who underwent G-CSF mobilized peripheral blood stem cell harvesting procedures for sibling allogeneic stem cell transplantation for acute leukemia. Results: Mantle cell, diffuse large B-cell lymphoma, and chronic lymphocytic leukemia were diagnosed three to five years after exposure among three volunteers who received MGDF. For one of these patients, autoimmune thrombocytopenia and antibodies to MGDF that cross-reacted with endogenous thrombopoietin had developed shortly after MGDF administration and persisted until lymphoma chemotherapy was administered. Following chemotherapy, all three achieved complete remission, although one patient subsequently relapsed. Acute myelogenous leukemia was diagnosed four to five years after exposure in two donors who underwent G-CSF primed stem cell harvests prior to their siblings’ allogeneic stem cell transplantation. Following intensive chemotherapy, one of these patients died from acute leukemia and the second is now in complete remission. Conclusion: Controversy exists over the appropriateness of administering hematopoietic growth factors to healthy individuals. While a causal relationship with hematologic malignancies is uncertain, long-term follow-up among healthy individuals who receive hematopoietic growth factors is needed.

No significant financial relationships to disclose.

Once daily ganciclovir as initial pre-emptive therapy delayed until threshold CMV load ⩾10000 copies/ml: a safe and effective strategy for allogeneic stem cell transplant patients

Quantitative polymerase chain reaction (QPCR) for cytomegalovirus (CMV) is emerging as the preferred screening method for detection of CMV viremia in patients following allogeneic bone marrow and peripheral blood stem cell transplant. However, there are currently no universally accepted QPCR treatment thresholds at which to start pre-emptive therapy. We report here results of a pre-emptive therapy strategy using ganciclovir (GCV) 5 mg/kg initiated once daily (ODG) delayed till a threshold CMV load of > or =10 000 copies/ml whole blood in clinically stable patients. Sixty-nine at risk patients underwent allogeneic stem cell transplant. 48/69 (70%) patients had an initial episode of CMV viremia. 5/48 (10%) cleared viremia without requiring treatment. 28/43 (65%) patients requiring treatment initiated treatment with ODG. 17/28 (61%) patients successfully cleared CMV viremia on ODG, 10/28 (36%) patients required dose escalation to twice daily GCV for increasing viral loads. There were two cases of CMV disease (colitis) and no deaths due to CMV disease in patients initiating treatment with ODG. We conclude delaying pre-emptive therapy with ODG until whole blood QPCR> or =10 000 copies/ml is a safe and effective strategy for CMV viremia after allogeneic stem cell transplant in clinically stable patients.

Reduced risk of acute GVHD following mobilization of HLA-identical sibling donors with GM-CSF alone

We retrospectively reviewed the results of transplanting peripheral blood progenitor cell (PBPC) allografts from HLA-matched sibling donors mobilized using various hematopoietic cytokines. Patients had received allografts mobilized with Granulocyte colony-stimulating factor (G-CSF) (G, N = 65) alone, G plus Granulocyte-macrophage colony stimulating factor (GM-CSF) (G/GM, N = 70), or GM-CSF alone at 10 or 15 microg/kg/day (GM, N = 10 at 10 microg/kg/day and 21 at 15 microg/kg/day). The CD34+ and CD3+ cell content of grafts were significantly lower following GM alone compared to G alone (P < 0.001 and 0.04, respectively). Nonhematopoietic toxicity observed in donors precluded dose escalation of GM-CSF beyond 10 microg/kg/day. Hematopoietic recovery was similar among all three groups. Grades II-IV acute graft-versus-host disease (GVHD) was observed in only 13% of patients in the GM alone group compared to 49 and 69% in the G alone or G/GM groups, respectively (P < 0.001). In a multivariate analysis, receipt of PBPC mobilized with GM alone was associated with a lower risk of grades II-IV acute GVHD (hazard ratio 0.21; 95% CI 0.073, 0.58) compared to G alone or G/GM. There were no differences in relapse risk or overall survival among the groups. Donor PBPC grafts mobilized with GM-CSF alone result in prompt hematopoietic engraftment despite lower CD34+ cell doses and may reduce the risk of grades II-IV acute GVHD following HLA-matched PBPC transplantation.

Low-dose short-course intravenous ganciclovir as pre-emptive therapy for CMV viremia post allo-PBSC transplantation

In contrast to allogeneic bone marrow transplantation (allo-BMT), there is a paucity of data on cytomegalovirus (CMV) infection and preemptive therapy (PT) strategies following allogeneic peripheral blood stem cell (allo-PBSC) transplantation. We report here on the patterns of CMV infection in a cohort of 225 patients following sibling donor allo-PBSC transplantation. In an attempt to reduce neutropenia, we used intravenous low-dose short-course (LDSC) ganciclovir (GCV) 5 mg/kg once daily for 21 days as preemptive therapy. A total of 165 recipient-donor pairs were CMV seropositive. An initial episode of viremia (detected by shell vial/tube culture) occurred in 75/165 (45%) at a median of day +35 (17-445) post allo-PBSC. In all, 58 patients received PT with LDSC GCV. Among 58, 55 (94%) completed the 21-day course of PT. A second episode of viremia occurred in 19/58 (33%) at day+80 (50-174) and a third episode in 5/58 (9%) at day+134 (103-218). Among patients receiving LDSC GCV, 5/58(9%) developed disease (four pneumonia, one colitis) at day+211 (63-487). No patient on LDSC GCV exhibited a decline in their ANC below 500/microl and none required growth factors. LDSC GCV is extremely well tolerated and cost-effective as PT for CMV viremia following allo-PBSC transplantation.

Clinical application of hematopoietic progenitor cell expansion: current status and future prospects

In the past decade, we have witnessed significant advances in ex vivo hematopoietic stem cell culture expansion, progressing to the point where clinical trials are being designed and conducted. Preclinical milestone investigations provided data to enable expansion of portions of hematopoietic grafts in a clinical setting, indicating safety and feasibility of this approach. Data derived from current clinical trials indicate successful reconstitution of hematopoiesis after myeloablative chemoradiotherapy using infusion of ex vivo-expanded perfusion cultures. Future avenues of exploration will focus upon refining preclinical and clinical studies in which cocktails of available cytokines, novel molecules and sophisticated expansion systems will explore expansion of blood, marrow and umbilical cord blood cells.

Mesenchymal stem cells: stealth and suppression

Human post-natal bone marrow contains mesenchymal stem cells (MSCs), which are capable of giving rise to multiple mesenchymal cell lineages. Large quantities of human MSCs can be readily obtained following a simple bone marrow aspiration procedure and subsequent expansion over a million-fold in culture. This extensive capacity for clinical scale expansion in vitro has facilitated the development of preclinical models as well as clinical studies designed to assess the safety, feasibility, and efficacy of transplanting allogeneic MSCs for a variety of indications. This review focuses on the rationale for performing clinical studies of MSC transplantation and will discuss the potential role that MSCs may have in the field of hematopoietic stem cell transplantation as well as for the repair or regeneration of bone, cartilage, and cardiac tissues.

Fludarabine and melphalan-based conditioning for patients with advanced hematological malignancies relapsing after a previous hematopoietic stem cell transplant

Severe regimen-related toxicity often complicates second transplant procedures performed in patients with hematological malignancies that have relapsed after an initial hematopoietic stem cell (HSC) transplant. Therefore, we studied the safety and efficacy of a reduced-intensity fludarabine and melphalan based conditioning regimen in 11 patients who had relapsed following an autologous (n = 7) or allogeneic (n = 4) HSC transplant. All patients received allogeneic peripheral blood HSC from either an HLA-identical (n = 7) or an HLA-mismatched (n = 4) relative. Diagnoses included AML (n = 9), ALL (n = 1), or Hodgkin's disease (n = 1). Only one patient was in complete remission at the time of second transplant. The median interval between first transplant and relapse was 163 days (range 58-1885). Recipients of HLA-mismatched transplants received antithymocyte globulin in addition to fludarabine and melphalan as part of the conditioning regimen. All 11 patients received acute GVHD prophylaxis consisting of tacrolimus and methotrexate. Ten of 11 patients achieved hematopoietic engraftment with a median time to absolute neutrophil count >0.5 x 10(9)/l and to platelet count of >20 x 10(9)/l of 14 and 19 days, respectively. All engrafting patients achieved 100% donor chimerism on initial analysis, except for one with persistent leukemia at day +19. Two patients experienced grade 3 regimen-related toxicity, manifesting as acute renal failure. Acute GVHD grades 2-4 occurred in two recipients and chronic GVHD in four. The 100-day mortality from all causes was 36%. Ten of 11 patients (91%) died a median of 140 days (range 9-996) after the second transplant. The causes of death included relapse (n = 5), sepsis (n = 4), and idiopathic pneumonia syndrome (n = 1). One patient with AML survives in remission at 880 days post-transplant. We conclude that fludarabine- and melphalan-based conditioning promotes full donor chimerism, even following HLA-mismatched transplants. However, the regimen may be more beneficial when applied to patients undergoing allogeneic HSC transplantation earlier in their disease course.

Baboon mesenchymal stem cells can be genetically modified to secrete human erythropoietin in vivo

Human mesenchymal stem cells (MSCs) are capable of differentiating into multiple mesenchymal lineages including chondrocytes, osteocytes, adipocytes, and marrow stromal cells. Using a nonhuman primate model, we evaluated nonhuman primate MSCs as targets for gene therapy. Baboon MSCs (bMSCs) cultured from bone marrow aspirates appeared as a homogeneous population of spindle-shaped cells. bMSCs were capable of differentiating into adipocytes and osteocytes in vitro and chondrocytes in vivo. bMSCs were genetically modified with a bicistronic vector encoding the human erythropoietin (hEPO) gene and the green fluorescent protein (GFP) gene. Transduction efficiencies ranged from 72 to 99% after incubation of MSCs with retroviral supernatant. Transduced cells produced from 1.83 x 10(5) to 7.12 x 10(5) mIU of hEPO per 10(6) cells per 24 hr in vitro before implantation. To determine the capacity of bMSCs to express hEPO in vivo, transduced bMSCs were injected intramuscularly in NOD/SCID mice. In a separate experiment, transduced bMSCs were loaded into immunoisolatory devices (IIDs) and surgically implanted into either autologous or allogeneic baboon recipients. Human EPO was detected in the serum of NOD/SCID mice for up to 28 days and in the serum of five baboons for between 9 and 137 days. NOD/SCID mice experienced sharp rises in hematocrit after intramuscular injection of hEPO-transduced bMSCs. The baboon that expressed hEPO for 137 days experienced a statistically significant (p < 0.04) rise in its hematocrit. These data demonstrate that nonhuman primate MSCs can be engineered to deliver a secreted and biologically active gene product. Therefore, human MSCs may be an effective target for future human gene therapy trials.

The relative quiescence of hematopoietic stem cells in nonhuman primates

Quiescence has been thought to be required for the retention of the full biological potential of pluripotent hematopoietic stem cells (PHSCs). This hypothesis has been challenged recently by the observation that all murine PHSCs cycle continuously and constantly contribute to steady-state blood cell production. It was asked whether these observations could be extrapolated to describe hematopoiesis in higher mammals. In this series of experiments, the replicative history of PHSCs was examined in baboons by continuously administering bromodeoxyuridine (BrdU) for more than 85 weeks. The results indicate that under steady-state conditions, PHSCs remain largely quiescent but do cycle, albeit at a far lower rate than previously reported for rodent PHSCs. BrdU-labeled cycling PHSCs and progenitor cells were shown to have an extensive proliferative capacity and to contribute to blood cell production for prolonged periods of time. The proportion of PHSCs entering cell cycle could, however, be rapidly increased by the in vivo administration of granulocyte-colony stimulating factor. These data indicate that during steady-state hematopoiesis, baboon PHSCs require prolonged periods of time to cycle and that the proportion of PHSCs in cycle is not fixed but can be altered by external stimuli. The relative quiescence of PHSCs observed in this nonhuman primate model, in contrast to murine PHSCs, might explain the current barriers to genetic modification and ex vivo expansion of human PHSCs.

Mesenchymal stem cells are capable of homing to the bone marrow of non-human primates following systemic infusion

OBJECTIVE

The human bone marrow contains mesenchymal stem cells capable of differentiating along multiple mesenchymal cell lineages. Using a non-human primate model, we sought to determine whether the systemic infusion of baboon-derived mesenchymal stem cells was associated with toxicity and whether these cells were capable of homing to and persisting within the bone marrow.

MATERIALS AND METHODS

Five baboons (Papio anubis) were administered lethal irradiation followed by intravenous autologous hematopoietic progenitor cells combined with either autologous (n = 3) or allogeneic (n = 2) mesenchymal stem cells that had been expanded in culture. In four of these baboons, the mesenchymal stem cells were genetically modified with a retroviral vector encoding either the enhanced green fluorescent protein gene (n = 3) or the human placental alkaline phosphatase gene (n = 1) for tracking purposes. A sixth animal received only intravenous gene marked autologous mesenchymal stem cells but no hematopoietic stem cells or conditioning irradiation.

RESULTS

Following culture, baboon mesenchymal stem cells appeared morphologically as a homogeneous population of spindle-shaped cells that were identified by the monoclonal antibodies SH-3 and SH-4. These cells did not express the hematopoietic markers CD34 or CD45. Baboon mesenchymal stem cells isolated from primary culture were capable of differentiating along both adipogenic and osteogenic lineages. There was no acute or chronic toxicity associated with the intravenous infusion of mesenchymal stem cells. In all five recipients of gene marked mesenchymal stem cells, transgene was detected in post-transplant bone marrow biopsies. In two animals receiving autologous mesenchymal stem cells, including the one non-conditioned recipient, transgene could be detected over 1 year following infusion. In one recipient of allogeneic gene marked mesenchymal stem cells, transgene was detected in the bone marrow at 76 days following infusion.

CONCLUSION

These data demonstrate that baboon mesenchymal stem cells: 1) are not associated with significant toxicity when administered intravenously, 2) are capable of homing to the bone marrow following intravenous infusion, and 3) have the capacity to establish residence within the bone marrow for an extended duration following systemic administration.

Role of mesenchymal stem cells in hematopoietic stem cell transplantation

Within the bone marrow stroma are multipotential cells which are capable of differentiation into a number of mesenchymal cell lineages. These cells, termed mesenchymal stem cells, have recently been identified and characterized in humans. Many studies indicate that the bone marrow stroma is damaged following bone marrow transplantation. Since the marrow stroma is critical for the maintenance of hematopoiesis, its ability to support hematopoiesis following stem cell transplantation may be impaired. Animal models suggest that the transplantation of healthy stromal elements, including mesenchymal stem cells, may enhance the ability of the bone marrow microenvironment to support hematopoiesis after stem cell transplantation. Here the authors review recent data that suggest that mesenchymal stem cells may possess therapeutic value not only for the repair of damaged mesenchymal tissues following hematopoietic stem cell transplantation, but also as potential vectors for the delivery of corrective genes.

Phase III study comparing methotrexate and tacrolimus (prograf, FK506) with methotrexate and cyclosporine for graft-versus-host disease prophylaxis after HLA-identical sibling bone marrow transplantation

We report the results of a phase III open-label, randomized, multicenter trial comparing tacrolimus/methotrexate to cyclosporine/methotrexate for graft-versus-host disease (GVHD) prophylaxis after HLA-identical sibling marrow transplantation in patients with hematologic malignancy. The primary objective of this study was to compare the incidence of moderate to severe (grade II-IV) acute GVHD. Secondary objectives were to compare the relapse rate, disease-free survival, overall survival, and the incidence of chronic GVHD. Patients were stratified according to age (<40 v >/=40) and for male recipients of a marrow graft from an alloimmunized female. There was a significantly greater proportion of patients with advanced disease randomized to tacrolimus arm (P = . 02). The incidence of grade II-IV acute GVHD was significantly lower in patients who received tacrolimus than patients in the cyclosporine group (31.9% and 44.4%, respectively; P = .01). The incidence of grade III-IV acute GVHD was similar, 17.1% in cyclosporine group and 13.3% in the tacrolimus group. There was no difference in the incidence of chronic GVHD between the tacrolimus and the cyclosporine group (55.9% and 49.4%, respectively; P = .8). However, there was a significantly higher proportion of patients in the cyclosporine group who had clinical extensive chronic GVHD (P = . 03). The relapse rates of the two groups were similar. The patients in the cyclosporine arm had a significantly better 2-year disease-free survival and overall survival than patients in the tacrolimus arm, 50.4% versus 40.5% (P = .01) and 57.2% versus 46.9% (P = .02), respectively. The significant difference in the overall and disease-free survival was largely the result of the patients with advanced disease, 24.8% with tacrolimus versus 41.7% with cyclosporine (P = .006) and 20.4% with tacrolimus versus 28% with cyclosporine (P = .007), respectively. There was a higher frequency of deaths from regimen-related toxicity in patients with advanced disease who received tacrolimus. There was no difference in the disease-free and overall survival in patients with nonadvanced disease. These results show the superiority of tacrolimus/methotrexate over cyclosporine/methotrexate in the prevention of grade II-IV acute GVHD with no difference in disease-free or overall survival in patients with nonadvanced disease. The survival disadvantage in advanced disease patients receiving tacrolimus warrants further investigation.

Lack of interaction between tacrolimus (FK506) and methotrexate in bone marrow transplant recipients

Tacrolimus (FK506) is a macrolide lactone effective in the control of graft-versus-host disease (GVHD). An interaction between high-dose methotrexate and a macrolide antibiotic (pristinamycin) leading to prolonged methotrexate exposure has been described. Because a randomized prospective trial comparing tacrolimus with cyclosporine (both in combination with methotrexate) following allogeneic BMT showed the tacrolimus plus methotrexate regimen to be more effective in prevention of GVHD, we assessed methotrexate pharmacokinetics in a subgroup of the participants of this trial to evaluate the possibility that an interaction of FK506 and methotrexate was the explanation for the clinical findings. Mean and median methotrexate levels at various time-points after the day 1 and 6 methotrexate doses were comparable in the tacrolimus and cyclosporine cohorts and were elevated in only three of 70 study patients. Area under the curve (AUC) concentrations were also similar after the day 1 and 6 methotrexate doses. Thus, no significant interaction between tacrolimus and methotrexate is apparent and the differences in efficacy between tacrolimus and cyclosporine are unlikely to be attributable to pharmacologic interactions with methotrexate.

The outcome of unrelated donor bone marrow transplantation in patients with hematologic malignancies using tacrolimus (FK506) and low dose methotrexate for graft-versus-host disease prophylaxis

Initial studies of FK506 combined with methotrexate (MTX) in patients receiving unrelated donor BMT have demonstrated a possible-decrease in the incidence of severe GVHD but high rates of severe stomatitis and nephrotoxicity. With this background, we undertook a pilot study evaluating FK506 in combination with a lower than usual dose of MTX in an attempt to improve the tolerability of this immunoprophylaxis regimen. Between July 1993 and October 1994, 26 consecutive adults receiving unrelated donor BMT at Emory University Hospital were enrolled on this study. All patients received FK506 intravenously at an initial dose of 0.03 mg/kg/day beginning day -1 and continuing until oral FK506 was tolerated. Patients also received MTX intravenously at 5 mg/m2 on days 1, 3, 6, and 11. The preparative regimen administered to all but one patient included cyclophosphamide at 200 mg/kg over 4 days followed by total body irradiation (TBI) at 1400 cGy in twice daily fractions over 4 days. The median age of patients was 31 years (range: 19 to 52). Sixteen donor/recipient pairs were matched for HLA-A, -B, and -DR by serology and molecular typing. Ten paris were minor mismatches at either class I or class II. Twenty-two of 26 patients (85%) completed four doses of MTX on schedule. Nephrotoxicity was the most common adverse event associated with the administration of FK506: 88% of patients experienced a doubling of their serum creatinine. One patient died of central nervous system hemorrhage prior to engraftment. Twenty-four of the remaining 25 patients (96%) engrafted. Fourteen of 24 patients (50%) evaluable developed grades 2-4 acute GVHD. The rate of severe (grades 3-4) acute GVHD was 25%. Chronic GVHD developed in 11 of 20 (55%) evaluable patients. At a median follow-up of 461 days, 14 patients (54%) are alive. All are relapse-free with a median Karnofsky performance status of 90% (range: 70-100%). The cumulative probability of 2-year disease-free survival is 50% (95% confidence interval [CI]: 0.33 to 0.77); for low risk patients 67% (95% CI: 0.47 to 0.95) and for high risk patients 23% (95% CI: 0.049 to 1.00). These preliminary data indicate that FK506-based immunosuppression following unrelated donor BMT is effective in preventing severe acute GVHD and warrants comparison to CSA-based regimens.

Allogeneic bone marrow transplantation with matched unrelated donors for patients with hematologic malignancies using a preparative regimen of high-dose cyclophosphamide and fractionated total body irradiation

Allogeneic bone marrow transplantation (BMT) from an HLA-identical sibling donor is effective therapy for patients with bone marrow failure states and those with hematologic malignancies. However, only a minority of them will have an HLA-identical sibling donor; unrelated donors, matched or partially mismatched, have been used successfully for patients lacking a related donor. Even though results with allogeneic transplants using unrelated donors are encouraging, the incidence of complications including graft-versus-host disease (GVHD) and graft rejection or late graft failure is increased compared to identical sibling transplants. The combination of cyclophosphamide and total body irradiation (TBI) has been used as an effective preparative regimen for allogeneic transplants, however, the total dosage and dosing schedule of both the cyclophosphamide and TBI has varied significantly among studies. To decrease the rate of graft rejection and late graft failure with volunteer donors, we evaluated a preparative regimen of high-dose cyclophosphamide (200 mg/kg over 4 consecutive days, days -8, -7, -6, -5) followed by fractionated TBI (1400 cGy administered in eight fractions over 4 days, days -4, -3, -2, -1). GVHD prophylaxis included FK506 and methotrexate. From July 1993 to January 1996, 43 adult patients, median age 38 years (range 18-58 years), were treated with this preparative regimen. Seventeen patients had low-risk disease and 26 had high-risk disease. Thirty-one donor/recipient pairs were matched for HLA-A, -B, and -DR by serology and molecular typing. Seven additional pairs were minor mismatched at the HLA-A or HLA-B loci. Four other donor/recipient pairs were HLA-A,-B, and -DR identical by serology but allele mismatched at either DRB1 or DQB. Forty patients were evaluable for myeloid engraftment. Engraftment occurred in all 40 patients at a median of 19 days. There were no cases of graft rejection or late graft failure. Nephrotoxicity was the primary adverse event with 26 patients (60%) experiencing a doubling of their creatinine. Hepatic veno-occlusive disease occurred in seven patients, six of whom had high-risk disease. All patients who had relapsed or refractory disease prior to BMT achieved a complete remission following BMT. Six patients transplanted for high-risk disease relapsed a median of 377 days post-BMT. None of the patients with low-risk disease have relapsed following transplant; the Kaplan-Meier survival for those patients with low-risk disease is 62% and 37% for those patients transplanted with high-risk disease (P = 0.0129). The median Karnofsky performance status is 100% (range 70-100%). Therefore, a preparative regimen of high-dose cyclophosphamide and fractionated TBI is an acceptable regimen for patients receiving an allograft from unrelated donors.

Successful engraftment after primary graft failure in aplastic anemia using G-CSF mobilized peripheral stem cell transfusions

A 19-year-old male underwent allogeneic BMT for severe aplastic anaemia (SAA) from his HLA- and blood group-identical sister. He was conditioned with cyclophosphamide (CY) and single fraction total lymphoid irradiation (TLI). GVHD prophylaxis consisted of FK506 and a short course of methotrexate. The patient failed to achieve durable trilineage hematopoietic engraftment. There was no significant myeloid response to GM-CSF or G-CSF. Evaluation of FACS-sorted peripheral T cells from the patient by fluorescence in situ hybridization (FISH) revealed mixed chimerism (44% host origin). Fifty-three days after the first BMT, he was treated with G-CSF primed, unmanipulated PBSC transfusions (5.28 x 10(8)/kg mononuclear, 4.28 x 10(6)/kg CD34+, 292.51 x 10(6)/kg CD3+ cells) from his original donor without reconditioning. FK506 was continued at the same dose. Neutrophil recovery to 0.5 x 10(9)/l and platelet engraftment to 20 x 10(9)/l was achieved 11 and 27 days following the first dose of allogeneic PBSC transfusion, respectively. On day 23 a repeat FISH on the patient's sorted peripheral T lymphocytes revealed 91% donor origin T cells. The patient is currently well with a stable engraftment 6 months following allogeneic PBSC transfusion, with no signs of acute of chronic GVHD.

Tacrolimus (FK506)-induced cerebral blindness following bone marrow transplantation

Three patients who developed acute onset of cerebral blindness within 5-47 days of BMT using tacrolimus (FK506) as primary GVHD prophylaxis are described. This syndrome has been described with the use of cyclosporin A (CsA) and FK506 in solid organ transplant recipients. CsA-induced cerebral blindness has also been noted in BMT recipients but to date there have been no reports of this complication in BMT patients receiving FK506. We have noted a striking similarity in the clinical and radiographic presentations between these patients and those with CsA-associated cerebral blindness. Reversibility within 1-2 weeks of onset and the potential for substitution of CsA for FK506 in these patients is described.

Minimal toxicity and mortality in high-risk breast cancer patients receiving high-dose cyclophosphamide, thiotepa, and carboplatin plus autologous marrow/stem-cell transplantation and comprehensive supportive care

PURPOSE

To assess the clinical toxicity and outcome associated with a comprehensive supportive care approach in poor-risk breast cancer (BrCA) patients with high-dose chemotherapy (HDC).

PATIENTS AND METHODS

One hundred twenty-five consecutive patients with stages II, III or metastatic breast cancer received HDC between February 1992 and June 1994. Recipients received 4 days of continuous infusion of cyclophosphamide 1.5 g/m2/d, thiotepa 125 mg/m2/d, and carboplatin 200 mg/m2/d followed by infusion of bone marrow or peripheral-blood stem cells (PBSC) and recombinant human growth factor (rhu-GF) support. Patients received similar supportive care that included administration of prophylactic antibiotics, management of neutropenic fevers, and transfusion support.

RESULTS

There were 38 women with stage II or III (27 patients with > or = 10 lymph nodes), four with stage IIIB, and 83 with metastatic breast cancer. The median age was 44 years (range, 27 to 61). Grade II or greater nonhematologic toxicities included diarrhea (66%), stomatitis (33%), hepatic venoocclusive disease (VOD) (5%), and pulmonary toxicity (4%). Myeloid and platelet engraftment was comparable between bone marrow and PBSC recipients (P > .1). Infectious complications were rare and consisted of gram-negative bacteremia (1.6%), gram-positive bacteremia (1.6%), fungemia (1.6%), and documented or suspected aspergillosis infection (3%). There was one treatment-related death secondary to severe VOD.

CONCLUSION

A comprehensive supportive care approach was associated with a low treatment-related mortality rate of less than 1%. With the observed reduction in treatment-related mortality, it is reasonable to evaluate the efficacy of HDC in women with less than 10 positive nodes and stage II disease in well-designed clinical trials.

Association of busulfan area under the curve with veno-occlusive disease following BMT

Busulfan pharmacokinetics, specifically area under the concentration curve (AUC), have been correlated with the occurrence of veno-occlusive disease (VOD) following BMT. To evaluate the risk of VOD, we studied 66 patients who received pharmacotherapeutically monitored busulfan regimens in combination with CY, etoposide (VP16) and/or Ara-C in preparation for BMT. These patients received a total of 16 doses of busulfan dosed as 1 mg/kg/dose q 6 h beginning at 09.00 (n = 39), 18.00 (n = 2), 21.00 (n = 1) or 24.00 (n = 24) h. With the first dose, blood samples were obtained at baseline, every 15-30 min for 2 h, then every 1-2 h for 4 h. Blood was analyzed for busulfan concentration by high performance liquid chromatography and AUC calculated by the trapezoidal rule. Seventeen patients (25.8%) were not evaluable for AUC calculation due to slow absorption and/or elimination: 13 of 27 (48.1%) received the first dose between 18.00-24.00 vs four of 39 (10.2%) patients who received the first dose at 09.00 (P < 0.001). Eighteen of 51 (35.3%) evaluable patients had an AUC > 1500 mumol x min/l; 10 of whom received doses reduced proportionally to achieve an AUC = 1200 mumol x min/l starting with the 10th to 15th dose. Six of 18 (33.3%) patients with an initial AUC > 1500 mumol x min/l developed VOD vs one of 33 (3.0%) patients with an initial AUC < 1500 mumol x min/l (relative risk = 11.1; P = 0.0056). Other pharmacokinetic parameters, age, gender, type of BMT, previous therapy or pre-transplant liver function tests were not predictive of VOD. A higher incidence of VOD occurred in patients receiving BUCY (4 of 10) compared to those receiving BUCYAra-C (1 of 18) or BUCYVP16 (7 of 38), which could not be attributed to increased busulfan exposure in the BUCY patients. Routine pharmacotherapeutic monitoring of busulfan is recommended with further study to evaluate the impact of earlier and greater overall dose reduction in patients with high initial busulfan exposures.

Thrombotic thrombocytopenic purpura associated with FK506 following bone marrow transplantation

Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) have been observed after bone marrow transplantation (BMT), typically occurring 1-6 months following BMT. We describe two patients who developed TTP very early after BMT while receiving intravenous FK506. They were treated with platelet support and plasma exchange (PE) using either fresh frozen plasma (FFP) or cryosupernatant fraction of plasma (CFP), resulting in remission of TTP activity.

Early detection of human cytomegalovirus viremia in bone marrow transplant recipients by DNA amplification

Surveillance blood cultures for human cytomegalovirus (HCMV) are commonly used to identify the bone marrow transplant (BMT) recipients with the highest risk of serious HCMV disease and for whom early interventional ganciclovir therapy would be beneficial. We monitored 36 allogeneic BMT recipients weekly for the presence of HCMV in the blood from 0 to 100 days posttransplantation. Viable HCMV in leukocytes (WBC) was detected by shell vial and tube culture methods. HCMV DNA in WBC and plasma was detected by PCR and DNA hybridization using primers and a probe from the EcoRI fragment D region of HCMV AD169. A uracil-N-glycosylase-dUTP PCR protocol was used to prevent false-positive results due to amplicon carryover. Seventeen patients had multiple consecutive positive samples containing HCMV DNA in plasma or WBC. In 14 of 17 patients, HCMV was also detected by blood culture. HCMV DNA was detected sporadically in six patients, none of whom had positive cultures. One patient had HCMV viremia detected by WBC culture only. The remaining 12 patients had no positive PCR assays or blood cultures. For the patients with positive blood cultures, PCR detection of HCMV DNA in plasma preceded detection of HCMV in culture by a mean of 8 days and detection in WBC preceded detection in culture by 6 days. HCMV disease (interstitial pneumonia) was documented for two patients with viremia (blood culture and PCR positive) and one patient without viremia (blood culture and PCR negative). The earlier recognition of high-risk patients provided by detection of HCMV DNA in plasma or WBC may improve the efficacy of early interventional antiviral therapy.

The paranasal sinuses of patients with acute graft-versus-host disease

PURPOSE

To determine whether patients who have acute graft-versus-host disease (AGVHD), are more likely to have radiographically abnormal paranasal sinuses after bone marrow transplantation than patients without AGVHD.

METHODS

This retrospective case-control study population comprised 45 adult allogeneic or matched unrelated donor patients who underwent bone marrow transplantation. Twenty-eight patients had AGVHD, and 17 patients did not. All patients had paranasal sinus imaging with either CT or plain films for evaluation of possible sinusitis after bone marrow transplantation. The severity of radiographic changes was measured with an objective scoring system based on mucosal findings.

RESULTS

An odds ratio revealed no association between AGVHD and the presence of radiographically abnormal sinuses.

CONCLUSION

The diagnosis of AGVHD should not complicate the radiographic evaluation of acute sinusitis after bone marrow transplantation.

Acute leukemia in adults: recent developments in diagnosis and treatment

Major advances in the diagnosis, classification, and treatment of adult acute leukemias have resulted in significant increases in the number of complete remissions and long-term disease-free survivors. Despite these improvements, most adult patients with acute leukemias still eventually die from their disease or complications of its treatment. New experimental and clinical approaches used to diagnose, monitor, and treat these diseases hold promise for further increased cure rates in the future. This article reviews the classification, immunobiology, cytogenetics, diagnosis, and treatment of adult acute leukemias and describes new directions being taken toward their cure.

Viral infections in severely immunocompromised cancer patients

Immunocompromised cancer patients are susceptible to infection by many viral pathogens. The most serious morbidity results from active infection by members of the herpes virus family. Reactivation of latent virus occurs as a sequela of cytotoxic therapy and deficiency of cell-mediated immunity, especially cytotoxic responses, the major host protective defense. Herpes simplex virus and varicella zoster virus infections are problematic in patients with all types of cancer; cytomegalovirus infections cause life-threatening morbidity in bone marrow transplant patients. Several antiviral agents are highly active against these pathogens and different strategies of using them have resulted in reduced morbidity and mortality. Ultimately, the resolution of these infections is dependent on the control of the malignancy and the ability of the patient to mount an adequate immune response.

New preparative regimens with diaziquone or cytarabine in combination with busulfan and cyclophosphamide

Preparative regimens used prior to bone marrow transplantation (BMT) in patients with malignancies must mediate engraftment and eradicate malignant cells without producing significant extramedullary toxicities. The first agents to be tested in BMT preparative regimens, total body irradiation (TBI) and cyclophosphamide (Cy), were ineffective as single agents, but resulted in long-term disease-free survival in some leukemic patients when combined. However, Cy/TBI regimens are associated with significant acute and chronic toxicities as well as technical constraints involving the administration of radiation. Accordingly, a nonradiation-based regimen consisting of Cy and busulfan (Bu) was developed. Regimens using either a 4-day course (BuCy4) or a 2-day course (BuCy2) of Cy have been shown to have significant antileukemic effects. In general, however, BuCy regimens do not appear to result in greater antileukemic activity or lower treatment-related toxicity than Cy/TBI regimens. New preparative regimens are currently being developed to lower the incidence of disease recurrence after BMT. One such regimen consists of BuCy plus etoposide. At our institution, we are currently testing the efficacy and toxicity of regimens in which cytarabine or diaziquone are administered in combination with Bu and Cy. It is hoped that these new preparative regimens will enhance the antileukemic effects of BMT without significantly increasing treatment-related toxicity.

A pilot study of prophylactic aerosolized amphotericin B in patients at risk for prolonged neutropenia

Invasive aspergillosis continues to be a significant cause of morbidity and mortality in patients with prolonged neutropenia. We performed a phase I trial of escalating doses of aerosolized amphotericin B given by a face mask nebulizer system with a disposable bacterial exhale filter. Five, 10, 15, and 20 mg of drug were dissolved in sterile water and inhaled over 10 to 15 minutes twice daily. Tolerance was studied in 26 patients (18 transplant recipients, and 8 leukemia patients). No side effects were observed at any dose level. Prophylactic treatment ended for 14 patients (54%) when intravenous (IV) amphotericin B was begun empirically for antifungal coverage following fevers. Eleven patients (43%) continued inhaled amphotericin B until blood counts recovered. One patient was taken off study when she developed cardiogenic pulmonary edema. No patient developed clinically suspicious or pathologically documented infection with invasive aspergillosis. Prophylactic aerosolized amphotericin B is well tolerated at 5, 10, 15, and 20 mg twice daily dosing. In addition, prophylactic aerosolized amphotericin B does not appear to sensitize patients to the subsequent use of IV amphotericin B. Although this study suggests that prophylactic inhaled amphotericin B is well tolerated and effective, a large scale controlled trial is needed.

Bronchiolitis obliterans organizing pneumonia as a complication of allogeneic bone marrow transplantation

We report a patient who underwent two allogeneic bone marrow transplants for chronic myelogenous leukemia, initially in 1984 and again after relapse in 1990, who developed an identical pulmonary syndrome at a similar interval following each transplant. The patient presented with a non-productive cough, bilateral inspiratory crackles, and multiple patchy infiltrates on chest X-ray. Pulmonary function testing revealed a restrictive abnormality but no obstructive defects. The appearance of this pulmonary disorder after each transplant coincided with the development of chronic graft-versus-host disease. In both instances, this pulmonary syndrome completely reversed with corticosteroid therapy. The patient's chest computed tomographic scan and lung biopsy specimens were consistent with the diagnosis of bronchiolitis obliterans with organizing pneumonia (BOOP). While bronchiolitis obliterans has been reported following allogeneic transplant, BOOP has not previously been reported in this setting.

Chemotherapeutic and biologic radiation enhancement

The main objectives of concomitant chemoradiotherapy are to increase local tumor control, decrease the incidence of distant metastases, and improve survival. In addition, concomitant therapy may reduce long-term cancer therapy morbidity either by reducing the need for radical surgery or by permitting the use of lower radiation doses. This article briefly summarizes the rationale for concomitant chemoradiotherapy and summarizes the most recent clinical experience for selected solid tumors. In addition, recent data that suggest additive or synergistic interaction between radiation and certain biologic response modifiers such as tumor necrosis factor and interferon are reviewed.