Extramedullary relapse of acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation: incidence, risk factors and outcomes

Extramedullary relapse after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia is a contributor to post-transplant mortality but risk factors for, and outcomes of, this condition are not well characterized. We analyzed 257 consecutive patients undergoing allogeneic stem cell transplantation for acute myeloid leukemia at our institution to characterize extramedullary relapse, identify predictive variables and assess outcomes. The 5-year cumulative incidence of isolated extramedullary or bone marrow relapse was 9% and 29%, respectively. Extramedullary relapse occurred later than marrow relapse and most frequently involved skin and soft tissue. Factors predictive of extramedullary relapse after transplantation included previous extramedullary disease, French-American-British classification M4/M5 leukemia, high risk cytogenetics, and advanced disease status at the time of transplantation. Children were more likely than adults to develop extramedullary relapse, a finding probably explained by an overrepresentation of extramedullary disease prior to transplantation and M4/M5 leukemia in children. Acute graft-versus-host disease was not protective against relapse. Unlike medullary relapse, chronic graft-versus-host disease was not protective against extramedullary relapse. The survival rate after extramedullary relapse was 30% at 1 year and 12% at 2 years. Extramedullary relapse is a significant contributor to mortality after allogeneic transplantation for acute myeloid leukemia and appears to be resistant to the immunotherapeutic effect of allogeneic grafting. Effective strategies for patients with extramedullary relapse are needed to improve outcomes after transplantation.

Extramedullary relapse of acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation: incidence, risk factors and outcomes

Extramedullary relapse after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia is a contributor to post-transplant mortality but risk factors for, and outcomes of, this condition are not well characterized. We analyzed 257 consecutive patients undergoing allogeneic stem cell transplantation for acute myeloid leukemia at our institution to characterize extramedullary relapse, identify predictive variables and assess outcomes. The 5-year cumulative incidence of isolated extramedullary or bone marrow relapse was 9% and 29%, respectively. Extramedullary relapse occurred later than marrow relapse and most frequently involved skin and soft tissue. Factors predictive of extramedullary relapse after transplantation included previous extramedullary disease, French-American-British classification M4/M5 leukemia, high risk cytogenetics, and advanced disease status at the time of transplantation. Children were more likely than adults to develop extramedullary relapse, a finding probably explained by an overrepresentation of extramedullary disease prior to transplantation and M4/M5 leukemia in children. Acute graft-versus-host disease was not protective against relapse. Unlike medullary relapse, chronic graft-versus-host disease was not protective against extramedullary relapse. The survival rate after extramedullary relapse was 30% at 1 year and 12% at 2 years. Extramedullary relapse is a significant contributor to mortality after allogeneic transplantation for acute myeloid leukemia and appears to be resistant to the immunotherapeutic effect of allogeneic grafting. Effective strategies for patients with extramedullary relapse are needed to improve outcomes after transplantation.

Safety and efficacy of defibrotide for the treatment of severe hepatic veno-occlusive disease

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome, is a potentially life-threatening complication of chemotherapeutic conditioning used in preparation for hematopoietic stem-cell transplantation (SCT). VOD may occur in up to 62% of patients undergoing SCT, with onset generally within the first month after SCT. In severe cases, 100-day mortality is in excess of 80%. Current management consists of best supportive care, with no agents to date approved for treatment in the USA or the EU. Defibrotide, a polydisperse oligonucleotide, has been shown in phase II and III trials to improve complete response and survival in patients undergoing SCT with severe VOD. This article reviews our current understanding of VOD, and examines recent clinical findings on defibrotide for the treatment and prophylaxis of VOD.

TNF-inhibition with etanercept for graft-versus-host disease prevention in high-risk HCT: lower TNFR1 levels correlate with better outcomes

Graft-versus-host disease (GVHD) causes most non-relapse mortality (NRM) after alternative donor (unrelated and mismatched related) hematopoietic cell transplant (HCT). We previously showed that increases in day +7 TNF-receptor-1 (TNFR1) ratios (posttransplantation day +7/pretransplantation baseline) after myeloablative HCT correlate with outcomes including GVHD, NRM, and survival. Therefore, we conducted a phase II trial at 2 centers, testing whether the addition of the TNF-inhibitor etanercept (25 mg twice weekly from start of conditioning to day +56) to standard GVHD prophylaxis would lower TNFR1 levels, reduce GVHD rates, and improve NRM and survival. Patients underwent myeloablative HCT from a matched unrelated donor (URD; N = 71), 1-antigen mismatched URD (N = 26), or 1-antigen mismatched related donor (N = 3) using either total body irradiation (TBI)-based conditioning (N = 29) or non-TBI-based conditioning (N = 71). Compared to historical controls, the increase in posttransplantation day +7 TNFR1 ratios was not altered in patients who received TBI-based conditioning, but was 40% lower in patients receiving non-TBI-based conditioning. The latter group experienced relatively low rates of severe grade 3 to 4 GVHD (14%), 1-year NRM (16%), and high 1-year survival (69%). These findings suggest that (1) the effectiveness of TNF-inhibition with etanercept may depend on the conditioning regimen, and (2) attenuating the expected rise in TNFR1 levels early posttransplantation correlates with good outcomes.

Characterization of the metabolic phenotype of rapamycin-treated CD8+ T cells with augmented ability to generate long-lasting memory cells

Background

Cellular metabolism plays a critical role in regulating T cell responses and the development of memory T cells with long-term protections. However, the metabolic phenotype of antigen-activated T cells that are responsible for the generation of long-lived memory cells has not been characterized.

Design and Methods

Using lymphocytic choriomeningitis virus (LCMV) peptide gp33-specific CD8⁺ T cells derived from T cell receptor transgenic mice, we characterized the metabolic phenotype of proliferating T cells that were activated and expanded in vitro in the presence or absence of rapamycin, and determined the capability of these rapamycin-treated T cells to generate long-lived memory cells in vivo.

Results

Antigen-activated CD8⁺ T cells treated with rapamycin gave rise to 5-fold more long-lived memory T cells in vivo than untreated control T cells. In contrast to that control T cells only increased glycolysis, rapamycin-treated T cells upregulated both glycolysis and oxidative phosphorylation (OXPHOS). These rapamycin-treated T cells had greater ability than control T cells to survive withdrawal of either glucose or growth factors. Inhibition of OXPHOS by oligomycin significantly reduced the ability of rapamycin-treated T cells to survive growth factor withdrawal. This effect of OXPHOS inhibition was accompanied with mitochondrial hyperpolarization and elevation of reactive oxygen species that are known to be toxic to cells.

Conclusions

Our findings indicate that these rapamycin-treated T cells may represent a unique cell model for identifying nutrients and signals critical to regulating metabolism in both effector and memory T cells, and for the development of new methods to improve the efficacy of adoptive T cell cancer therapy.

Acute kidney injury in patients with systemic sclerosis participating in hematopoietic cell transplantation trials in the United States

Recipients of hematopoietic cell transplantation may be at risk for developing acute kidney injury (AKI), and this risk may be increased in patients who undergo transplantation for severe systemic sclerosis (SSc) due to underlying scleroderma renal disease. AKI after transplantation can increase treatment-related mortality. To better define these risks, we analyzed 91 patients with SSc who were enrolled in 3 clinical trials in the United States of autologous or allogeneic hematopoietic cell transplantation (HCT). Eleven (12%) of the 91 patients with SSc in these studies (8 undergoing autologous HCT, 1 undergoing allogeneic HCT, 1 pretransplantation, 1 given i.v. cyclophosphamide on a transplantation trial) experienced AKI, of whom 8 required dialysis and/or therapeutic plasma exchange. AKI injury in the 9 HCT recipients developed a median of 35 days (range, 0-90 days) after transplantation. Ten of 11 patients with AKI received angiotensin-converting enzyme inhibitor (ACE-I) therapy. The etiology of AKI was attributed to scleroderma renal crisis in 6 patients (including 2 with normotensive renal crisis), to AKI of uncertain etiology in 2 patients, and to AKI superimposed on scleroderma kidney disease in 3 patients. Eight of the 11 patients died, one each because of progression of SSc, multiorgan failure, gastrointestinal and pulmonary bleeding, pericardial tamponade and pulmonary complications, diffuse alveolar hemorrhage, pulmonary embolism, graft-versus-host disease, and malignancy. Limiting nephrotoxins, cautious use of corticosteroids, renal shielding during total body irradiation, strict control of blood pressure, and aggressive use of ACE-Is may be of importance in preventing renal complications after HCT for SSc.

Elafin is a biomarker of graft-versus-host disease of the skin

Graft-versus-host disease (GVHD), the major complication of allogeneic bone marrow transplantation, affects the skin, liver, and gastrointestinal tract. There are no plasma biomarkers specific for any acute GVHD target organ. We used a large-scale quantitative proteomic discovery procedure to identify biomarker candidates of skin GVHD and validated the lead candidate, elafin, with enzyme-linked immunosorbent assay in samples from 492 patients. Elafin was overexpressed in GVHD skin biopsies. Plasma concentrations of elafin were significantly higher at the onset of skin GVHD, correlated with the eventual maximum grade of GVHD, and were associated with a greater risk of death relative to other known risk factors (hazard ratio, 1.78). We conclude that elafin has significant diagnostic and prognostic value as a biomarker of skin GVHD.

In vitro enhancing oxidative phosphorylation by rapamycin in proliferative CD8+ T cells during antigenic priming augments the generation of long-lived memory T cells in vivo (101.11)

Oxidative phosphorylation is critical to the transition of effectors to memory T cells. However, whether increasing oxidative phosphorylation in proliferative CD8+ T cells during antigenic priming can augment memory T cell generation remains unknown. Using T cell receptor transgenic CD8+ T cells, we found that rapamycin significantly increased the oxidative phosphorylation in antigen-primed naïve CD8+ T cells in vitro without inhibiting their activation and proliferation. Augmented oxidative phosphorylation endowed the rapamycin-treated T cells great ability to survive after IL-2 withdrawal, whereas all the untreated control cells rapidly diminished. Rapamycin-treated CD8+ T cells expressed high levels of CD62L and CD127 but low levels of KLRG-1, PD-1 and IFN-γ. When adoptively transferred in vivo, CD8+ T cells derived from rapamycin-treated cultures generated 5-fold more memory T cells over a period of 6 months than control cells. These long-lived memory T cells had potent ability to produce IFN-γ and proliferate when reexposed to the specific antigen both in vivo and in vitro. These data indicate that augmentation of oxidative phosphorylation in T cells by rapamycin in vitro during antigenic priming dramatically increases both the number and quality of memory precursors, thereby enhancing the generation of long-lived memory T cells. Our findings may have significant implications in optimizing T cell properties to improve the efficacy of adoptive immunotherapy.

Frequency of CD4(+)CD25(hi)FOXP3(+) regulatory T cells has diagnostic and prognostic value as a biomarker for acute graft-versus-host-disease

The relationship between regulatory T cells (Tregs) and acute graft-versus-host disease (aGVHD) in clinical allogeneic bone marrow transplantation (BMT) recipients is not well established. We conducted a prospective analysis of peripheral blood Tregs as determined by the frequency of CD4(+)CD25(hi)FOXP3(+) lymphocytes in 215 BMT patients. Autologous BMT patients (N = 90) and allogeneic BMT patients without GVHD (N = 65) had similar Treg frequencies, whereas allogeneic patients with GVHD (N = 60) had Treg frequencies that were 40% less than those without GVHD. Treg frequencies decreased linearly with increasing grades of GVHD at onset, and correlated with eventual maximum grade of GVHD (P < .001). In addition, frequency of Tregs at onset of GVHD predicted the response to GVHD treatment (P = .003). Patients with Treg frequencies less than the median had higher nonrelapse mortality (NRM) than patients with Tregs greater than the median, but experienced equivalent relapse mortality, resulting in an inferior survival at 2 years (38% versus 63%, P = .03). Treg frequency may therefore have important prognostic value as a biomarker of aGVHD.

Identification of stem cell transcriptional programs normally expressed in embryonic and neural stem cells in alloreactive CD8+ T cells mediating graft-versus-host disease

A hallmark of graft-versus-host-disease (GVHD), a life-threatening complication after allogeneic hematopoietic stem cell transplantation, is the cytopathic injury of host tissues mediated by persistent alloreactive effector T cells (T(E)). However, the mechanisms that regulate the persistence of alloreactive T(E) during GVHD remain largely unknown. Using mouse GVHD models, we demonstrate that alloreactive CD8(+) T(E) rapidly diminished in vivo when adoptively transferred into irradiated secondary congenic recipient mice. In contrast, although alloreactive CD8(+) T(E) underwent massive apoptosis upon chronic exposure to alloantigens, they proliferated in vivo in secondary allogeneic recipients, persisted, and caused severe GVHD. Thus, the continuous proliferation of alloreactive CD8(+) T(E), which is mediated by alloantigenic stimuli rather than homeostatic factors, is critical to maintaining their persistence. Gene expression profile analysis revealed that although alloreactive CD8(+) T(E) increased the expression of genes associated with cell death, they activated a group of stem cell genes normally expressed in embryonic and neural stem cells. Most of these stem cell genes are associated with cell cycle regulation, DNA replication, chromatin modification, and transcription. One of these genes, Ezh2, which encodes a chromatin modifying enzyme, was abundantly expressed in CD8(+) T(E). Silencing Ezh2 significantly reduced the proliferation of alloantigen-activated CD8(+) T cells. Thus, these findings identify that a group of stem cell genes could play important roles in sustaining terminally differentiated alloreactive CD8(+) T(E) and may be therapeutic targets for controlling GVHD.

Phase II trial of combination therapy with bortezomib, pegylated liposomal doxorubicin, and dexamethasone in patients with newly diagnosed myeloma

PURPOSE

This single-center, open-label, phase II trial evaluated the bortezomib, pegylated liposomal doxorubicin (PLD), and dexamethasone combination regimen (VDD) as initial treatment for patients with newly diagnosed multiple myeloma (MM).

PATIENTS AND METHODS

Enrolled patients (N = 40) received up to six 3-week cycles of treatment with bortezomib 1.3 mg/m(2) intravenously (IV) on days 1, 4, 8, and 11; PLD 30 mg/m(2) IV on day 4; and dexamethasone 20 to 40 mg daily as specified in the study design. The primary end point was the complete/near-complete response (CR/nCR) rate after six cycles. Secondary end points included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). The impact of VDD on stem-cell mobilization and collection also was evaluated.

RESULTS

After six cycles, the ORR was 85.0% (CR/nCR, 37.5%; very good partial response [VGPR] or better, 57.5%). Patients who underwent stem-cell transplantation (SCT) after VDD (n = 30) experienced increased rates of VGPR or better (53.3% to 76.6% after SCT). Overall, 1-year PFS and OS rates were 92.5% and 97.5%, respectively. Those who achieved VGPR or better after treatment with VDD showed a significantly greater 1-year PFS versus those who achieved less than VGPR (100% v 82%, respectively; P = .03). Similar results were observed in patients who underwent SCT. Grades 3 or 4 hematologic toxicities occurred in < or = 10% of patients; grade 2 painful neuropathy occurred in 7.5%; and grade 3 palmar-plantar erythrodysesthesia occurred in 2.5%.

CONCLUSION

VDD is highly effective for initial treatment of MM followed by SCT in appropriate patients, and it has a reasonable safety profile. Achievement of VGPR or better with this initial therapy predicted longer PFS, regardless of the consolidation therapy given.

Graft-versus-Host Disease in Mini-transplant

Mini-transplant has been used popularly in recent years. The intensity of conditioning regimens is less in mini-transplant, thus the anti-tumor effect is mainly carried by an immunological reaction, called graft-versus-leukemia (GVL)/graft-versus-tumor (GVT) effect. Thus, graft-versus-host disease (GVHD) in mini-transplant has drawn much attention as a surrogate marker for GVL/GVT effect. However, as the regimen-related toxicity is less in mini-transplant, it is also true that GVHD is the single most worrisome adverse event after mini-transplant. As opposed to early predictions, the incidence and severity of GVHD after mini-transplant does not seem to be much different from the one after conventional stem cell transplant (CST). In addition, researchers find that host antigen presenting cells (APC) may play an important role in the development of GVHD, and thus the existence of donor-host chimerism may be critical. As a result, the theory regarding GVHD after mini-transplant is getting more confusing. A comprehensive understanding of GVHD after mini-transplant is necessary.

Mycobacterium chelonae necrotizing pneumonia after allogeneic hematopoietic stem cell transplant: report of clinical response to treatment with tigecycline

We present a case of progressive Mycobacterium chelonae ssp. chelonae necrotizing pneumonia after hematopoietic stem cell transplantation (HSCT) in the presence of chronic graft-versus-host disease. The patient failed to respond to standard combination therapy with multiple agents and developed resistance to most drugs over the course of treatment. Tigecycline, a new glycylcycline antimicrobial agent with in vitro activity against M. chelonae, was then used with a clinical response to treatment. To our knowledge, this is the first reported case demonstrating tigecycline to have a degree of clinical effectiveness to treat refractory pulmonary infection with M. chelonae in an HSCT recipient.

Reduced-intensity stem cell transplantation for hematological malignancies: current status and the future

Reduced-intensity stem cell transplantation (RIST) has opened a new era for hematopoietic stem cell transplantation (HSCT). It was developed based on the knowledge that graft-versus-tumor (GVT) effect is the main anti-tumor effect in allogeneic HSCT. Because RIST is associated with less morbidity and mortality, it can be applied to many patients who could not undergo conventional HSCT. Experiences in the last decade clarified many issues related to RIST. For example, graft-versus-host disease (GVHD) in RIST may differ in character compared to conventional HSCT. Also, it is now known that intensity of conditioning is important in disease control, and the optimal regimens may be different for each disease or for each disease status. There are still many unsolved questions, and large prospective randomized trials are necessary to resolve these.