[Show abstract][Hide abstract] ABSTRACT: Omenn syndrome is a primary immunodeficiency disorder, featuring susceptibility to infections and autoreactive T cells and resulting from defective genomic rearrangement of genes for the T cell and B cell receptors. The most frequent etiologies are hypomorphic mutations in "non-core" regions of the Rag1 or Rag2 genes, the protein products of which are critical members of the cellular apparatus for V(D)J recombination. In this report, we describe an infant with Omenn syndrome with a previously unreported termination mutation (p.R142) in Rag1 on one allele and a partially characterized substitution mutation (p.V779M) in a "core" region of the other Rag1 allele. Using a cellular recombination assay, we found that while the p.R142 mutation completely abolished V(D)J recombination activity, the p.V779M mutation conferred a severe, but not total, loss of V(D)J recombination activity. The recombination defect of the V779 mutant was not due to overall misfolding of Rag1, however, as this mutant supported wild-type levels of V(D)J cleavage. These findings provide insight into the role of this poorly understood region of Rag1 and support the role of Rag1 in a post-cleavage stage of recombination.
[Show abstract][Hide abstract] ABSTRACT: Background:
The Primary Immune Deficiency Treatment Consortium was formed to analyze the results of hematopoietic-cell transplantation in children with severe combined immunodeficiency (SCID) and other primary immunodeficiencies. Factors associated with a good transplantation outcome need to be identified in order to design safer and more effective curative therapy, particularly for children with SCID diagnosed at birth.
We collected data retrospectively from 240 infants with SCID who had received transplants at 25 centers during a 10-year period (2000 through 2009).
Survival at 5 years, freedom from immunoglobulin substitution, and CD3+ T-cell and IgA recovery were more likely among recipients of grafts from matched sibling donors than among recipients of grafts from alternative donors. However, the survival rate was high regardless of donor type among infants who received transplants at 3.5 months of age or younger (94%) and among older infants without prior infection (90%) or with infection that had resolved (82%). Among actively infected infants without a matched sibling donor, survival was best among recipients of haploidentical T-cell-depleted transplants in the absence of any pretransplantation conditioning. Among survivors, reduced-intensity or myeloablative pretransplantation conditioning was associated with an increased likelihood of a CD3+ T-cell count of more than 1000 per cubic millimeter, freedom from immunoglobulin substitution, and IgA recovery but did not significantly affect CD4+ T-cell recovery or recovery of phytohemagglutinin-induced T-cell proliferation. The genetic subtype of SCID affected the quality of CD3+ T-cell recovery but not survival.
Transplants from donors other than matched siblings were associated with excellent survival among infants with SCID identified before the onset of infection. All available graft sources are expected to lead to excellent survival among asymptomatic infants. (Funded by the National Institute of Allergy and Infectious Diseases and others.).
No preview · Article · Jul 2014 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: Cord blood transplantation (CBT) is a known risk factor for human herpesvirus-6 (HHV-6) infection. We analyzed the nature of HHV-6 infections in 125 double-unit CBT recipients (median age 42 years) transplanted for hematologic malignancies with calcineurin-inhibitor/ mycophenolate mofetil prophylaxis and no anti-thymocyte globulin (ATG). One-hundred and seventeen (94%) patients reactivated HHV-6 by quantitative plasma PCR (median peak 7,600 copies/mL, range 100-160,000) at a median of 20 days (range 10-59) after transplantation. HHV-6 encephalitis occurred in 2 patients (1.6%), of whom one died and the other recovered with therapy. There was no association between high level HHV-6 viremia (> 10,000 or > 25,000 copies/mL) and age, diagnosis, conditioning intensity, or dominant unit characteristics, or between high level viremia and transplant outcomes (engraftment, cytomegalovirus reactivation, day 100 grade II-IV acute graft-versus-host disease, day 100 transplant-related mortality, or 1-year disease-free survival). HHV-6 therapy delayed the onset of cytomegalovirus reactivation. Interestingly, HHV-6 resolution was observed in untreated patients, and resolution of viremia correlated with absolute lymphocyte count recovery. We observed a low incidence of encephalitis and no association with CBT outcomes. Our data suggests therapy in uncomplicated viremia may not be warranted. However, further investigation of the risk-benefit of HHV-6 viremia treatment and standardization of PCR testing is required.
Preview · Article · Feb 2014 · Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: The Primary Immune Deficiency Treatment Consortium (PIDTC) is a network of 33 centers in North America that study the treatment of rare and severe primary immunodeficiency diseases. Current protocols address the natural history of patients treated for severe combined immunodeficiency (SCID), Wiskott-Aldrich syndrome, and chronic granulomatous disease through retrospective, prospective, and cross-sectional studies. The PIDTC additionally seeks to encourage training of junior investigators, establish partnerships with European and other International colleagues, work with patient advocacy groups to promote community awareness, and conduct pilot demonstration projects. Future goals include the conduct of prospective treatment studies to determine optimal therapies for primary immunodeficiency diseases. To date, the PIDTC has funded 2 pilot projects: newborn screening for SCID in Navajo Native Americans and B-cell reconstitution in patients with SCID after hematopoietic stem cell transplantation. Ten junior investigators have received grant awards. The PIDTC Annual Scientific Workshop has brought together consortium members, outside speakers, patient advocacy groups, and young investigators and trainees to report progress of the protocols and discuss common interests and goals, including new scientific developments and future directions of clinical research. Here we report the progress of the PIDTC to date, highlights of the first 2 PIDTC workshops, and consideration of future consortium objectives.
Full-text · Article · Oct 2013 · The Journal of allergy and clinical immunology
[Show abstract][Hide abstract] ABSTRACT: Dyskeratosis congenita (DC) is a heterogeneous inherited bone marrow failure and cancer predisposition syndrome in which germline mutations in telomere biology genes account for approximately one-half of known families. Hoyeraal Hreidarsson syndrome (HH) is a clinically severe variant of DC in which patients also have cerebellar hypoplasia and may present with severe immunodeficiency and enteropathy. We discovered a germline autosomal recessive mutation in RTEL1, a helicase with critical telomeric functions, in two unrelated families of Ashkenazi Jewish (AJ) ancestry. The affected individuals in these families are homozygous for the same mutation, R1264H, which affects three isoforms of RTEL1. Each parent was a heterozygous carrier of one mutant allele. Patient-derived cell lines revealed evidence of telomere dysfunction, including significantly decreased telomere length, telomere length heterogeneity, and the presence of extra-chromosomal circular telomeric DNA. In addition, RTEL1 mutant cells exhibited enhanced sensitivity to the interstrand cross-linking agent mitomycin C. The molecular data and the patterns of inheritance are consistent with a hypomorphic mutation in RTEL1 as the underlying basis of the clinical and cellular phenotypes. This study further implicates RTEL1 in the etiology of DC/HH and immunodeficiency, and identifies the first known homozygous autosomal recessive disease-associated mutation in RTEL1.
[Show abstract][Hide abstract] ABSTRACT: The Primary Immune Deficiency Treatment Consortium (PIDTC) consists of 33 centers in North America. We hypothesized that the analysis of uniform data on patients with severe combined immunodeficiency (SCID) enrolled in a prospective protocol will identify variables that contribute to optimal outcomes following treatment. We report baseline clinical, immunologic, and genetic features of the first 50 patients enrolled, and the initial therapies administered, reflecting current practice in the diagnosis and treatment of both typical (n = 37) and atypical forms (n = 13) of SCID. From August 2010 to May 2012, patients with suspected SCID underwent evaluation and therapy per local center practices. Diagnostic information was reviewed by the PIDTC eligibility review panel, and hematopoietic cell transplantation (HCT) details were obtained from the Center for International Blood and Marrow Transplant Research. Most patients (92 %) had mutations in a known SCID gene. Half of the patients were diagnosed by newborn screening or family history, were younger than those diagnosed by clinical signs (median 15 vs. 181 days; P = <0.0001), and went to HCT at a median of 67 days vs. 214 days of life (P = <0.0001). Most patients (92 %) were treated with HCT within 1-2 months of diagnosis. Three patients were treated with gene therapy and 1 with enzyme replacement. The PIDTC plans to enroll over 250 such patients and analyze short and long-term outcomes for factors beneficial or deleterious to survival, clinical outcome, and T- and B-cell reconstitution, and which biomarkers are predictive of these outcomes.
No preview · Article · Jul 2013 · Journal of Clinical Immunology
[Show abstract][Hide abstract] ABSTRACT: Adenovirus (ADV) is an important cause of viral mortality in hematopoietic stem cell transplantation (HSCT). Recipients of T cell–depleted (TCD) HSCT are at increased risk for viral infections. We compared the rates and outcomes of ADV viremia and disease between TCD and conventional (CONV) HSCT at our institution. This was an observational study of 624 adult and pediatric recipients of myeloablative HSCT at Memorial Sloan-Kettering Cancer Center between January 1, 2006, and March 11, 2011. Viral cultures and ADV PCR were ordered as clinically indicated. ADV viremia by quantitative PCR assay was defined as 1 or more positive values ≥1,000 copies/mL or 2 or more consecutive positive values. Competing-risk regression analyses were used to identify predictors for ADV viremia. ADV viremia at 1 year after HSCT occurred in 8% of TCD HSCT recipients and in 4.0% of CONV HSCT recipients (P = .041). Among the TCD recipients, ADV viremia was seen in 15% of children, compared with 5% of adults (P = .008). Young age (hazard ratio [HR], 3.0; P < .001) and acute graft-versus-host disease (GVHD) (HR, 3.2; P = .001) were identified as risk factors for ADV viremia. ADV viremia was predictive of mortality (HR, 6.0; P < .001). ADV disease developed in 3.5% of TCD HSCT recipients and in 0.4% of CONV HSCT recipients (P = .022), with an attributable mortality of 27%. Among TCD HSCY recipients, grade II to IV GVHD was a risk factor for ADV disease (HR, 13; P < .001), but age was not. More than 90% of the cases of ADV disease involved a viral load of ≥10,000 copies/mL. Rates of ADV disease were 10-fold greater in TCD HSCT recipients compared with CONV HSCT recipients, predominantly in patients who developed acute GVHD. The benefit of preemptive therapy for an ADV viral load ≥10,000 copies/mL for preventing ADV disease in TCD HSCT recipients should be evaluated in prospective clinical trials.
No preview · Article · Mar 2013 · Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: Manifestations and risk factors of graft-versus-host disease (GVHD) after double-unit cord blood transplantation (DCBT) are not firmly established. We evaluated 115 DCBT recipients (median age 37 years) transplanted for hematologic malignancies with myeloablative or non-myeloablative conditioning and calcineurin-inhibitor/ mycophenolate mofetil immunosuppression. Incidences of day 180 grade II-IV and III-IV acute GVHD (aGVHD) were 53% (95%CI: 44-62) and 23% (95%CI: 15-31), respectively, with a median onset of 40 days (range 14-169). Eighty percent of patients with grade II-IV aGVHD had gut involvement, and 79% and 85% had day 28 treatment responses to systemic corticosteroids or budesonide, respectively. Of 89 engrafted patients cancer-free at day 100, 54% subsequently had active GVHD with 79% of those affected having persistent or recurrent aGVHD or overlap syndrome, whereas late GVHD in the form of classical chronic GVHD was uncommon. Notably, grade III-IV aGVHD incidence was lower if the engrafting unit human leukocyte antigen (HLA)-A,-B,-DRB1 allele match was > 4/6 to the recipient (HR 0.385, p = 0.031), whereas engrafting unit infused nucleated cell dose and unit-unit HLA-match were not significant. GVHD after DCBT was common in our study, predominantly affected the gut, had a high therapy response, and late GVHD frequently had acute features. Our findings support the consideration of HLA- A,-B,-DRB1 allele donor-recipient (but not unit-unit) HLA-match in unit selection, a practice change in the field. Moreover, new prophylaxis strategies that target the gastrointestinal tract are needed.
Preview · Article · Feb 2013 · Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: MHC Class II deficiency is a rare primary immunodeficiency disease characterized by absent HLA Class II expression resulting in CD4 lymphopenia, lack of Ag-specific responses and recurrent infection. Without successful allogeneic SCT, most children succumb to infection within the first decade of life. To date, alternative donor transplants for this disorder have been inferior to SCT for other forms of combined immunodeficiency disease due to an increased incidence of graft rejection, GVHD and death from infections generally acquired before haematopoietic cell transplantation. This study details the transplant outcome of 16 affected children consecutively transplanted at four centers since 1990, 8 of whom required mechanical ventilation pretransplant. Stem cells were derived from an HLA-mismatched family member (n=10), an HLA-matched unrelated adult donor (n=4), or an unrelated cord blood donor (n=2). Graft failure occurred in five children, all of whom underwent a second SCT. Six patients developed acute GVHD although no patient developed chronic GVHD after primary transplantation. CD4 T-cell reconstitution remained below the normal range for age, suggesting defective thymopoiesis after allo-SCT. Nonetheless, 69% of children survive without GVHD at a median follow-up of 5.7 years, indicating improved outcomes compared with previous studies.
Full-text · Article · Sep 2012 · Bone Marrow Transplantation
[Show abstract][Hide abstract] ABSTRACT: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease in children. The most significant clinical features of PNH include: bone marrow failure, intravascular hemolysis, and thrombosis. To further characterize the clinical presentation and outcome to treatment we performed a retrospective analysis of pediatric patients with PNH.
We reviewed the medical records of 12 consecutive pediatric patients with PNH diagnosed at our institution from 1992 to 2010.
Presenting clinical symptoms included: bone marrow failure (N = 10); gross hemoglobinuria with isolated red cell anemia (N = 1); and jaundice, hepatitis, and isolated thrombocytopenia (N = 1). Immunosuppressive therapy was the initial treatment for 8 patients. Five patients had myelodysplastic features without developing excessive blasts or leukemic transformation. Thrombosis occurred in 6 patients. Five patients underwent hematopoietic stem cell transplant (HSCT) of whom 3 patients are alive and disease-free. Three patients received anti-complement therapy with eculizumab. Two patients died following complications related to thrombosis and 2 patients are transfusion independent with stable disease.
This report highlights a high rate of bone marrow failure along with a low rate of hemoglobinuria at presentation, a high rate of thrombosis, and for some patients the spontaneous resolution of myelodysplastic features. Delay in diagnosis is common and we recommend appropriate PNH testing in all patients with AA, MDS, unexplained Coombs-negative hemolysis, or thrombosis. While HSCT remains the only curative option the high prevalence of hemolysis and thrombosis should warrant the consideration of early treatment with anti-complement therapy.
No preview · Article · Sep 2012 · Pediatric Blood & Cancer
[Show abstract][Hide abstract] ABSTRACT: Over 40 000 hematopoietic cell transplantations (HCT) are performed worldwide each year, increasing the number of transplant survivors returning to school, the work place and overseas travel. Outbreaks of measles and mumps in immunocompetent individuals and the increased morbidity associated with primary varicella and shingles in older individuals highlight the need for effective vaccination of these vulnerable patients. In current post-HCT vaccination guidelines, only the measles, mumps and rubella vaccine (MMR) and the live-attenuated varicella vaccine (LAVV) designed to prevent primary varicella in varicella zoster seronegative individuals are permissible post HCT and only in select patient groups. All other vaccines, including the shingles vaccines, are contraindicated post HCT. Current data, primarily in pediatric HCT recipients, demonstrate a 60-70% response following a single MMR or LAVV. A two-dose schedule increases the seroconversion rate following these vaccines. This review will highlight published studies on the immunogenicity of MMR and the LAVV, areas in which data on these vaccines are lacking, the criteria for their use in patients transplanted at our center and potential studies to answer questions posed by the growing number of transplant survivors and their physicians on how to safely administer live-attenuated viral vaccines.Bone Marrow Transplantation advance online publication, 13 August 2012; doi:10.1038/bmt.2012.141.
No preview · Article · Aug 2012 · Bone marrow transplantation