Minoo Battiwalla

Prevention and Early Treatment of Invasive Fungal Infection in Patients with Cancer and Neutropenia and in Stem Cell Transplant Recipients in the Era of Newer Broad-Spectrum Antifungal Agents and Diagnostic Adjuncts

Invasive fungal infection (IFI) is a leading cause of infection-related mortality among patients with cancer and prolonged neutropenia and among allogeneic hematopoietic stem cell transplant recipients with graft-versus-host disease. Invasive candidiasis was the principal IFI in the period predating fluconazole prophylaxis, whereas today, invasive aspergillosis and other mold infections cause the majority of deaths from fungal infection in this patient population. The changing epidemiology of IFI, in addition to advances made in antifungal therapeutics and early diagnosis of IFI, warrant a reevaluation of earlier strategies aimed at prevention and early treatment of IFI that were developed several years ago. Here, we propose that persistent neutropenic fever is nonspecific for an IFI and should not be used as the sole criterion for empirical modification in the antifungal regimen in a patient receiving mold-active prophylaxis. We explore the potential benefits and gaps in knowledge associated with employing chest CT scans and laboratory markers as diagnostic adjuncts for IFI. Finally, we discuss the implications of newer antifungal agents and diagnostic adjuncts in the design of future clinical trials to evaluate prophylaxis and early prevention strategies.

Mesenchymal Stem Cells in Hematopoietic Stem Cell Transplantation

Mesenchymal stromal/stem cells (MSC) of bone marrow (BM) origin not only provide the supportive microenvironmental niche for hematopoietic stem cells (HSC) but are capable of differentiating into various cell types of mesenchymal origin, such as bone, fat and cartilage. In vitro and in vivo data suggest that MSC have low inherent immunogenicity, modulate/suppress immunologic responses through interactions with immune cells, and home to damaged tissues to participate in regeneration processes through their diverse biologic properties. MSC derived from BM are being evaluated for a wide range of clinical applications, including disorders as diverse as myocardial infarction and newly diagnosed diabetes mellitus type 1. However, their use in HSC transplantation, either for enhancement of hematopoietic engraftment or for treatment/prevention of graft-versus-host disease, is far ahead of other indications. Ease of isolation and ex vivo expansion of MSC, combined with their intriguing immunomodulatory properties and their impressive record of safety in a wide variety of clinical trials, make these cells promising candidates for further investigation.

Increasing Incidence of Chronic Graft-versus-Host Disease in Allogeneic Transplantation: A Report from the Center for International Blood and Marrow Transplant Research

Although transplant practices have changed over the last decades, no information is available on trends in incidence and outcome of chronic graft-versus-host disease (cGVHD) over time. This study used the central database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to describe time trends for cGVHD incidence, nonrelapse mortality, and risk factors for cGVHD. The 12-year period was divided into 3 intervals, 1995 to 1999, 2000 to 2003, and 2004 to 2007, and included 26,563 patients with acute leukemia, chronic myeloid leukemia, and myelodysplastic syndrome. Multivariate analysis showed an increased incidence of cGVHD in more recent years (odds ratio = 1.19, P < .0001), and this trend was still seen when adjusting for donor type, graft type, or conditioning intensity. In patients with cGVHD, nonrelapse mortality has decreased over time, but at 5 years there were no significant differences among different time periods. Risk factors for cGVHD were in line with previous studies. This is the first comprehensive characterization of the trends in cGVHD incidence and underscores the mounting need for addressing this major late complication of transplantation in future research.

Relapse after allogeneic stem cell transplantation.

Since allogeneic stem cell transplantation (SCT) represents an intensive curative treatment for high-risk malignancies, its failure to prevent relapse leaves few options for successful salvage treatment. While many patients have a high early mortality from relapse, some respond and have sustained remissions, and a minority has a second chance of cure with appropriate therapy. The prognosis for relapsed hematological malignancies after SCT depends on four factors: the time elapsed from SCT to relapse (with relapses occurring within 6 months having the worst prognosis), the disease type (with chronic leukemias and some lymphomas having a second possibility of cure with further treatment), the disease burden and site of relapse (with better treatment success if disease is treated early), and the conditions of the first transplant (with superior outcome for patients where there is an opportunity to increase either the alloimmune effect, the specificity of the antileukemia effect with targeted agents or the intensity of the conditioning in a second transplant). These features direct treatments toward either modified second transplants, chemotherapy, targeted antileukemia therapy, immunotherapy or palliative care.

Early cytomegalovirus reactivation remains associated with increased transplant-related mortality in the current era: a CIBMTR analysis

Single-center studies have reported an association between early (before day 100) cytomegalovirus (CMV) reactivation and decreased incidence of relapse for acute myeloid leukemia (AML) following allogeneic hematopoietic cell transplantation. To substantiate these preliminary findings, the Center for International Blood and Marrow Transplant Research (CIBMTR) Database was interrogated to analyze the impact of CMV reactivation on hematologic disease relapse in the current era. Data from 9469 patients transplanted with bone marrow or peripheral blood between 2003 and 2010 were analyzed according to 4 disease categories: AML (n = 5310); acute lymphoblastic leukemia (ALL, n = 1883); chronic myeloid leukemia (CML, n = 1079); and myelodysplastic syndrome (MDS, n = 1197). Median time to initial CMV reactivation was 41 days (range, 1-362 days). CMV reactivation had no preventive effect on hematologic disease relapse irrespective of diagnosis. Moreover, CMV reactivation was associated with higher nonrelapse mortality [relative risk [RR] among disease categories ranged from 1.61 to 1.95 and P values from .0002 to <.0001; 95% confidence interval [CI], 1.14-2.61). As a result, CMV reactivation was associated with lower overall survival for AML (RR = 1.27; 95% CI, 1.17-1.38; P <.0001), ALL (RR = 1.46; 95% CI, 1.25-1.71; P <.0001), CML (RR = 1.49; 95% CI, 1.19-1.88; P = .0005), and MDS (RR = 1.31; 95% CI, 1.09-1.57; P = .003). In conclusion, CMV reactivation continues to remain a risk factor for poor posttransplant outcomes and does not seem to confer protection against hematologic disease relapse.

Leflunomide failure to control recurrent cytomegalovirus infection in the setting of renal failure after allogeneic stem cell transplantation.

Abstract: Cytomegalovirus (CMV) reactivation is common in the allogeneic stem cell transplant setting but the incidence of CMV organ disease and mortality has been dramatically reduced by prophylactic or preemptive antiviral therapy. We report the case of a CMV‐seropositive 46‐year‐old man with non‐Hodgkins lymphoma who underwent an unrelated allogeneic stem cell transplant from a CMV‐seronegative HLA‐matched unrelated donor. CMV encephalitis and colitis developed that was refractory to single‐agent therapy. The CMV isolate demonstrated genotypic resistance to both ganciclovir and foscarnet. CMV disease was controlled by prolonged combination ganciclovir and cidofovir therapy, but severe renal dysfunction developed. Leflunomide was selected as a last resort to avoid the nephrotoxicity of cidofovir. CMV antigenemia rapidly increased following leflunomide administration, necessitating discontinuing this agent and resuming prior antiviral therapy. The pharmacokinetics of leflunomide in the setting of renal insufficiency is presented. Options for salvage therapy in refractory CMV disease in allogeneic stem cell transplant recipients are briefly reviewed.

Identification of a permissible HLA mismatch in hematopoietic stem cell transplantation

In subjects mismatched in the HLA alleles C*03:03/C*03:04 no allogeneic cytotoxic T-lymphocyte responses are detected in vitro. Hematopoietic stem cell transplantation (HSCT) with unrelated donors (UDs) showed no association between the HLA-C allele mismatches (CAMMs) and adverse outcomes; antigen mismatches at this and mismatches other HLA loci are deleterious. The absence of effect of the CAMM may have resulted from the predominance of the mismatch C*03:03/C*03:04. Patients with hematologic malignancies receiving UD HSCT matched in 8/8 and 7/8 HLA alleles were examined. Transplants mismatched in HLA-C antigens or mismatched in HLA-A, -B, or -DRB1 presented significant differences (P < .0001) in mortality (hazard ratio [HR] = 1.37, 1.30), disease-free survival (HR = 1.33, 1.27), treatment-related mortality (HR = 1.54, 1.54), and grade 3-4 acute graft-versus-host disease (HR = 1.49, 1.77) compared with the 8/8 group; transplants mismatched in other CAMMs had similar outcomes with HR ranging from 1.34 to 172 for these endpoints. The C*03:03/C*03:04 mismatched and the 8/8 matched groups had identical outcomes (HR ranging from 0.96-1.05). The previous finding that CAMMs do not associate with adverse outcomes is explained by the predominance (69%) of the mismatch C*03:03/03:04 in this group that is better tolerated than other HLA mismatches.

CMV reactivation is associated with a lower incidence of relapse after allo-SCT for CML

Preemptive therapy at CMV reactivation has diminished post-transplant CMV mortality. Furthermore, recent studies suggest a favorable ‘virus-versus-leukemia’ effect from reactivating CMV, reducing relapse of AML after SCT. We studied the relationship of CMV reactivation with leukemic relapse in 110 patients with CML receiving HLA-identical sibling SCT between 1993 and 2008. Of these, 79 (72%) were in chronic phase, 5 in second chronic phase, 17 in accelerated phase and 9 in blast phase. A total of 97 patients (88%) received a myeloablative conditioning regimen, 97 received 4-log ex vivo T cell-depleted grafts and 13 received T-replete grafts. CMV reactivation before day 100 was observed in 72 patients (65.5%). At a median follow-up of 6.2 years, CMV reactivation < day 100 as a time-dependent covariate was an independent factor associated with decreased relapse. We conclude that CMV reactivation may contribute to a beneficial GVL effect in CML transplant recipients.

Proceedings from the National Cancer Institute’s Second International Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation: Part III. Prevention and Treatment of Relapse after Allogeneic Transplantation

In the Second Annual National Cancer Institutes Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation, the Scientific/Educational Session on the Prevention and Treatment of Relapse after Allogeneic Transplantation highlighted progress in developing new therapeutic approaches since the first relapse workshop. Recent insights that might provide a basis for the development of novel, practical clinical trials were emphasized, including utilization of newer agents, optimization of donor lymphocyte infusion (DLI), and investigation of novel cellular therapies. Dr. de Lima discussed pre-emptive and maintenance strategies to prevent relapse after transplantation, for example, recent promising results suggestive of enhanced graft-versus-tumor activity with hypomethylating agents. Dr. Schmid provided an overview of adjunctive strategies to improve cell therapy for relapse, including cytoreduction before DLI, combination of targeted agents with DLI, and considerations in use of second transplantations. Dr. Porter addressed strategies to enhance T cell function, including ex vivo activated T cells and T cell engineering, and immunomodulatory approaches to enhance T cell function in vivo, including exogenous cytokines and modulation of costimulatory pathways.

Amino acid substitution at peptide-binding pockets of HLA class I molecules increases risk of severe acute GVHD and mortality

HLA disparity has a negative impact on the outcomes of hematopoietic cell transplantation (HCT). We studied the independent impact of amino acid substitution (AAS) at peptide-binding positions 9, 99, 116, and 156, and killer immunoglobulin-like receptor binding position 77 of HLA-A, B, or C, on the risks for grade 3-4 acute graft-versus-host disease (GVHD), chronic GVHD, treatment-related mortality (TRM), relapse, and overall survival. In multivariate analysis, a mismatch at HLA-C position 116 was associated with increased risk for severe acute GVHD (hazard ratio [HR] = 1.45, 95% confidence interval [CI] = 1.15-1.82, P = .0016). Mismatch at HLA-C position 99 was associated with increased transplant-related mortality (HR = 1.37, 95% CI = 1.1-1.69, P = .0038). Mismatch at HLA-B position 9 was associated with increased chronic GVHD (HR = 2.28, 95% CI = 1.36-3.82, P = .0018). No AAS were significantly associated with outcome at HLA-A. Specific AAS pair combinations with a frequency >30 were tested for association with HCT outcomes. Cysteine to tyrosine substitution at position 99 of HLA-C was associated with increased TRM (HR = 1.78, 95% = CI 1.27-2.51, P = .0009). These results demonstrate that donor-recipient mismatch for certain peptide-binding residues of the HLA class I molecule is associated with increased risk for acute and chronic GVHD and death.