[Show abstract][Hide abstract] ABSTRACT: A 12-year-old boy with refractory acute lymphoblastic leukemia received a haploidentical transplant from his mother. As prophylaxis for EBV, CMV and adenovirus, he received ex-vivo expanded virus-specific donor T cells 3.5 months after transplant. Four weeks later leukemic blasts bearing the E2A deletion, identified by FISH, appeared transiently in the blood followed by a FISH negative hematological remission, which was sustained until a testicular relapse 3.5 months later. Clearance of the circulating leukemic cells coincided with a marked increase in circulating virus specific T cells. The virus-specific cytotoxic T-cell (CTL) line showed strong polyfunctional reactivity with the patient's leukemic cells but not PHA blasts, suggesting that virus-specific CTL lines may have clinically significant anti-leukemia activity.Molecular Therapy (2014); doi:10.1038/mt.2014.192.
[Show abstract][Hide abstract] ABSTRACT: Biomarkers have the potential to improve diagnosis and prognosis, facilitate targeted treatment, and reduce health care costs. Thus, there is great hope that biomarkers will be integrated in all clinical decisions in the near future. A decade ago, the biomarker field was launched with great enthusiasm because mass spectrometry revealed that blood contains a rich library of candidate biomarkers. However, biomarker research has not yet delivered on its promise due to several limitations: (i) improper sample handling and tracking as well as limited sample availability in the pediatric population, (ii) omission of appropriate controls in original study designs, (iii) lability and low abundance of interesting biomarkers in blood, and (iv) the inability to mechanistically tie biomarker presence to disease biology. These limitations as well as successful strategies to overcome them are discussed in this review. Several advances in biomarker discovery and validation have been made in hematopoietic stem cell transplantation, the current most effective tumor immunotherapy, and these could serve as examples for other conditions. This review provides fresh optimism that biomarkers clinically relevant in pediatrics are closer to being realized based on: (i) a uniform protocol for low-volume blood collection and preservation, (ii) inclusion of well-controlled independent cohorts, (iii) novel technologies and instrumentation with low analytical sensitivity, and (iv) integrated animal models for exploring potential biomarkers and targeted therapies.This article is protected by copyright. All rights reserved
[Show abstract][Hide abstract] ABSTRACT: Mucolipidosis type II (MLII), or I-Cell Disease, is a rare, but severe disorder affecting localization of enzymes to the lysosome, generally resulting in death before the 10(th) birthday. Although hematopoietic stem cell transplant (HSCT) has been used to successfully treat some lysosomal storage diseases, there have been only two case reports in the use of HSCT to treat MLII. For the first time, we describe the combined international experience in the use of HSCT for MLII in 22 patients. Although 95% of the patients engrafted, the overall survival was low with only 6 patients (27%) alive at last follow-up. The most common cause of death post-transplant was cardiovascular complications, most likely due to disease progression. Survivors were globally delayed in development, and often required complex medical support such as gastrostomy tubes for nutrition, and tracheostomy with mechanical ventilation. Although HSCT has demonstrated efficacy in treating some lysosomal storage disorders, the neurologic outcome and survival for patents with MLII were poor. Therefore new medical and cellular therapies should be sought for these patients.
Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 07/2014; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It remains difficult to treat the multiplicity of distinct viral infections that afflict immunocompromised patients. Adoptive transfer of virus-specific T cells (VSTs) can be safe and effective, but such cells have been complex to prepare and limited in antiviral range. We now demonstrate the feasibility and clinical utility of rapidly generated single-culture VSTs that recognize 12 immunogenic antigens from five viruses (Epstein-Barr virus, adenovirus, cytomegalovirus, BK virus, and human herpesvirus 6) that frequently cause disease in immunocompromised patients. When administered to 11 recipients of allogeneic transplants, 8 of whom had up to four active infections with the targeted viruses, these VSTs proved safe in all subjects and produced an overall 94% virological and clinical response rate that was sustained long-term.
Science translational medicine 06/2014; 6(242):242ra83. · 14.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adoptive transfer of donor-derived T lymphocytes expressing a safety switch may promote immune reconstitution in patients undergoing haploidentical hematopoietic stem cell transplant (haplo-HSCT) without the risk of uncontrolled graft versus host disease (GvHD). Thus patients who develop GvHD after infusion of allodepleted donor-derived T cells expressing an inducible human caspase-9 (iC9) had their disease effectively controlled by a single administration of a small molecule drug (AP1903) that dimerizes and activates the iC9 transgene. We now report the long term follow-up of 10 patients infused with such safety switch-modified T cells. We find long-term persistence of iC9-modified (iC9-T) T cells in vivo in the absence of emerging oligoclonality, and a robust immunologic benefit, mediated initially by the infused cells themselves, and subsequently by an apparently accelerated reconstitution of endogenous naïve T lymphocytes. As a consequence, these patients have immediate and sustained protection from major pathogens including cytomegalovirus, adenovirus, BK virus and Epstein-Barr virus in the absence of acute or chronic GvHD, supporting the beneficial effects of this approach to immune reconstitution after haplo-HSCT. This study is registered at www.clinicaltrials.gov as NCT00710892.
[Show abstract][Hide abstract] ABSTRACT: SIRS is a rare systemic inflammatory response associated with fever, tachycardia, profound hypotension and respiratory distress that has been reported in cancer patients receiving T cells genetically modified with chimeric antigen receptors to retarget their specificity to tumor associated antigens. The syndrome usually occurs following significant in vivo expansion of the infused cells and has been associated with tumor destruction/lysis. Analysis of patient plasma has shown elevated cytokine levels, and resolution of symptoms has been reported after administration of steroids and/or antibodies such as anti-TNF and anti-IL6 receptor that interfere with cytokine responses.To date SIRS has not been reported in subjects receiving genetically unmodified T-cells with native receptors directed to tumor antigens, in which more physiological control of T cell activation and expansion may occur. Here, however, we report a patient with bulky refractory EBV-associated lymphoma who developed this syndrome two weeks after receiving T cells directed to EBV antigens through their native receptors. She was treated with steroids and Etanercept with rapid resolution of symptoms. SIRS may therefore occur even when T cells recognize antigens physiologically through their "wild-type" native receptors, and should be acknowledged as a potential complication of this therapyMolecular Therapy (2014); doi:10.1038/mt.2014.48.
[Show abstract][Hide abstract] ABSTRACT: Graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (alloSCT) has been associated with low numbers of circulating CD4+CD25+FoxP3+ regulatory T-cells(Tregs). Because Tregs express high levels of the IL-2 receptor, they may selectively expand in vivo in response to doses of IL-2 insufficient to stimulate T-effector T-cell populations, thereby preventing GvHD.
We prospectively evaluated the effects of ultra low-dose (ULD) IL-2 injections on Treg recovery in pediatric patients after alloSCT and compared this recovery with Treg reconstitution post alloSCT in patients without IL-2. Sixteen recipients of related(n=12) or unrelated(n=4) donor grafts received ULD-IL-2 post HSCT (100,000-200,000 IU/m2 3xweekly), starting <day30 and continuing for 6-12weeks.
No grade 3/4 toxicities were associated with ULD-IL-2. CD4+CD25+FoxP3+ Tregs increased from a mean of 4.8%(range, 0-11.0%) pre IL-2 to 11.1%(range,1.2-31.1%) following therapy, with the greatest change occurring in the recipients of MRD transplants. No IL-2 patients developed grade II-IV aGvHD, compared to 4/33(12%) of the comparator group who did not receive IL-2. IL-2 recipients retained T-cells reactive to viral and leukemia antigens, and in the MRD recipients, only 2/13(15%) of the IL-2 patients developed viral infections versus 63% of the comparator group (p=0.022).
Hence, ULD-IL-2 is well-tolerated, expands a Treg population in vivo, and may be associated with a lower incidence of viral infections and GvHD.
Clinical Cancer Research 02/2014; · 8.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human phosphoglucomutase 3 (PGM3) catalyzes the conversion of N-acetyl-glucosamine (GlcNAc)-6-phosphate into GlcNAc-1-phosphate during the synthesis of uridine diphosphate (UDP)-GlcNAc, a sugar nucleotide critical to multiple glycosylation pathways. We identified three unrelated children with recurrent infections, congenital leukopenia including neutropenia, B and T cell lymphopenia, and progression to bone marrow failure. Whole-exome sequencing demonstrated deleterious mutations in PGM3 in all three subjects, delineating their disease to be due to an unsuspected congenital disorder of glycosylation (CDG). Functional studies of the disease-associated PGM3 variants in E. coli cells demonstrated reduced PGM3 activity for all mutants tested. Two of the three children had skeletal anomalies resembling Desbuquois dysplasia: short stature, brachydactyly, dysmorphic facial features, and intellectual disability. However, these additional features were absent in the third child, showing the clinical variability of the disease. Two children received hematopoietic stem cell transplantation of cord blood and bone marrow from matched related donors; both had successful engraftment and correction of neutropenia and lymphopenia. We define PGM3-CDG as a treatable immunodeficiency, document the power of whole-exome sequencing in gene discoveries for rare disorders, and illustrate the utility of genomic analyses in studying combined and variable phenotypes.
[Show abstract][Hide abstract] ABSTRACT: Autologous T cells expressing a CD19-specific chimeric antigen receptor (CD19.CAR) are active against B-cell malignancies, but it is unknown if allogeneic CD19.CAR T cells are safe or effective. After allogeneic hematopoietic stem cell transplantation (HSCT), infused donor-derived virus-specific T cells (VSTs) expand in vivo, persist long-term and have anti-viral activity without inducing graft versus host disease; therefore, we determined whether donor VSTs, engineered to express CD19.CAR, retained the characteristics of non manipulated allogeneic VSTs whilst gaining anti-tumor activity. We treated 8 patients with allogeneic (donor-derived) CD19.CAR-VSTs, 3 months to 13 years after HSCT. There were no infusion-related toxicities. VSTs persisted a median of 8 weeks in blood and up to 9 weeks at disease sites. Objective anti-tumor activity was evident in 2/6 patients with relapsed disease during the period of CD19.CAR-VST persistence, while two patients who received cells while in remission remain disease-free. In two of three patients with viral reactivation, donor CD19.CAR-VSTs expanded concomitantly with VSTs. Hence, CD19.CAR-VSTs have anti-tumor activity, and, since their number may be increased in the presence of viral stimuli, earlier treatment post HSCT (when lymphodepletion is greater and the incidence of viral infection higher) or planned vaccination with viral antigens may enhance disease control. This study is registered at ClinicalTrials.gov, identifier: NCT00840853.
[Show abstract][Hide abstract] ABSTRACT: Adoptive transfer of virus-specific T-cells can prevent and treat serious infections with Epstein-Barr virus (EBV), cytomegalovirus (CMV), and adenovirus (Adv) after allogeneic hematopoietic stem cell transplant. It has, however, proved difficult to make this approach widely available since infectious virus and viral vectors are required for T-cell activation, followed by an intensive and prolonged culture period extending over several months. We now show that T cells targeting a range of viral antigens derived from EBV, CMV, and Adv can be reproducibly generated in a single culture over a 2-3 week period, using methods that exclude all viral components and employ a much-simplified culture technology. When administered to recipients of haploidentical (n=5), matched unrelated (n=3), mismatched unrelated (n=1) or matched related (n=1) transplants with active CMV (n=3), Adv (n=1), EBV (n=2), EBV+Adv (n=2) or CMV+Adv (n=2) infections, the cells produced complete virological responses in 80%, including all patients with dual infections. In each case a decrease in viral load correlated with an increase in the frequency of T-cells directed against the infecting virus(es); both immediate and delayed toxicities were absent. This approach should increase both the feasibility and applicability of T-cell therapy. The trial was registered at http://www.clinicaltrials.gov as NCT01070797.Molecular Therapy (2013); doi:10.1038/mt.2013.151.
[Show abstract][Hide abstract] ABSTRACT: Chronic granulomatous disease (CGD) patients are highly susceptible to invasive aspergillosis and may benefit from aspergillus-specific T cell immunotherapy, which has shown promise in treating those with known T cell defects like hematopoietic stem cell transplant (HSCT) recipients. But whether such T cell defects contribute to increased risks for aspergillus infection in CGD is unclear. Hence, we set out to characterize the aspergillus-specific T cell response in CGD. We showed in murine CGD models and in patients with CGD that the CD4+ T cell responses to aspergillus were unimpaired: aspergillus-specific T cell frequencies were even elevated in CGD mice (p<0.01) and humans (p=0.02), compared to their healthy counterparts. CD4-depleted murine models suggested that the role of T cells may be redundant since resistance to aspergillus infection was conserved in CD4+ T cell-depleted mice, similar to wildtype animals. In contrast, mice depleted of neutrophils alone or neutrophils and CD4+ T cells developed clinical and pathologic evidence of pulmonary aspergillosis and increased mortality (p<0.05 compared to non-depleted animals). Our findings that T cells in CGD have a robust aspergillus CD4+ T cell response suggest that CD4+ T cell-based immunotherapy for this disease is unlikely to be beneficial.
[Show abstract][Hide abstract] ABSTRACT: We describe outcomes after allogeneic transplantation in 34 patients with dyskeratosis congenita transplanted between 1981 and 2009. The median age at transplantation was 13 years (range 2 - 35). Approximately 50% of transplants were from related donors. Bone marrow was the predominant source of stem cells (n=24/34). The day-28 probability of neutrophil recovery was 73% and the day-100 platelet recovery was 72%. The day-100 probability of grade II-IV acute GVHD and the 3-year probability of chronic GVHD were 24% and 37%, respectively. The 10-year probability of survival was 30%; 14 patients were alive at last follow-up. Ten deaths occurred within 4 months from transplantation due to graft failure (n=6) or other transplant-related complications; 9 of these patients had been transplanted from mismatched related or from unrelated donors. Another 10 deaths occurred after 4 months; 6 of them occurred more than 5 years from transplantation, 4 of these were attributed to pulmonary failure. Transplant-regimen intensity and transplants from mismatched related or unrelated donors were associated with early mortality. Transplantation of grafts from HLA-matched siblings with cyclophosphamide-containing non-radiation regimens was associated with early low toxicity. Late mortality was attributed mainly to pulmonary complications and likely related to the underlying disease.
Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 06/2013; · 3.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rothia mucilaginosa is a gram-positive coccus that poses a diagnostic challenge and often requires DNA pyrosequencing for diagnosis as it can be easily mistaken for coagulase-negative staphylococci on initial culture results. While it is often times normal human oral and upper respiratory tract microbiota, it can be a virulent pathogen in immunocompromised patients. Most commonly, it causes bacteremia (catheter and non-catheter related) and meningitis in these patients. Our objective was to report the incidence of R. mucilaginosa infections in neutropenic children with hematological malignancies or following hematopoietic stem cell transplantation at a major children's hospital. We report 11 patients in this cohort who developed clinically significant R. mucilaginosa infections, including three deaths directly attributable to this microorganism. Three patients developed significant neurological involvement, accounting for two of the deaths, and one patient died of disseminated infection. Except for one, all patients had severe neutropenia, central line catheters, and mucosal breakdown at the time of infection. Patients who succumbed never achieved neutrophil recovery. In conclusion, R. mucilaginosa can lead to life-threatening infections in immunocompromised hosts, especially in profoundly neutropenic patients.
Pediatric Hematology and Oncology 05/2013; · 0.90 Impact Factor