Matched unrelated bone marrow transplantation for combined immunodeficiency

Hematopoietic Stem Cell Transplantation for Children With Inborn Errors of Immunity

This is a retrospective analysis of clinical characteristics of children with inborn errors of immunity who underwent hematopoietic stem cell transplant (HSCT). Although the mean age at diagnosis was 24.4 months, it was 51.9 months at HSCT. There is an urgent need to improve awareness, expand donor registries and initiate newborn screening for inborn errors or immunity.

Considerations in Preparative Regimen Selection to Minimize Rejection in Pediatric Hematopoietic Transplantation in Non-Malignant Diseases

The variables that influence the selection of a preparative regimen for a pediatric hematopoietic stem cell transplant procedure encompasses many issues. When one considers this procedure for non-malignant diseases, components in a preparative regimen that were historically developed to reduce malignant tumor burden may be unnecessary. The primary goal of the procedure in this instance becomes engraftment with the establishment of normal hematopoiesis and a normal immune system. Overcoming rejection becomes the primary priority, but pursuit of this goal cannot neglect organ toxicity, or post-transplant morbidity such as graft-versus-host disease or life threatening infections. With the improvements in supportive care, newborn screening techniques for early disease detection, and the expansion of viable donor sources, we have reached a stage where hematopoietic stem cell transplantation can be considered for virtually any patient with a hematopoietic based disease. Advancing preparative regiments that minimize rejection and transplant related toxicity will thus dictate to what extent this medical technology is fully utilized. This mini-review will provide an overview of the origins of conditioning regimens for transplantation and how agents and techniques have evolved to make hematopoietic stem cell transplantation a viable option for children with non-malignant diseases of the hematopoietic system. We will summarize the current state of this facet of the transplant procedure and describe the considerations that come into play in selecting a particular preparative regimen. Decisions within this realm must tailor the treatment to the primary disease condition to ideally achieve an optimal outcome. Finally, we will project forward where advances are needed to overcome the persistent engraftment obstacles that currently limit the utilization of transplantation for haematopoietically based diseases in children.

Allogeneic hematopoietic stem cell transplantation in two brothers with DNA ligase IV deficiency: a case report and review of the literature

BACKGROUND

DNA ligase IV deficiency is a rare autosomal recessive disorder caused by hypomorphic mutations in the DNA ligase IV (LIG4) gene. DNA ligase IV is an essential protein for the development of a healthy immune system as well as for the protection of genomic integrity. Apart from typical stigmata, patients with DNA ligase IV deficiency are characterized by progressive bone marrow failure and a predisposition to malignancy. To our knowledge this reported case is the first description of two brothers with ligase IV deficiency who are treated with different hematopoietic stem cell transplantation (HSCT) regimens resulting in vastly divergent outcomes.

CASE PRESENTATION

The cases of two brothers suffering from severe recurrent infections and growth retardation are described. The laboratory findings showed pancytopenia with significant lymphopenia. The two boys were diagnosed with DNA ligase IV deficiency, associated with severe combined immunodeficiency (SCID). Both patients received HSCT from two different matched unrelated donors (MUD) at the age of 33 and 18 months. The older brother succumbed post-transplant due to fatal side-effects 143 days after allogeneic HSCT. The younger brother - conditioned with a different regimen - received a T cell depleted graft 4 months later. No severe side-effects occurred, neither post-transplant nor in the following years. Ten years after HSCT the patient is well off, living a normal life and attending a regular high school. His immune system is fully reconstituted, resulting in a maximum of T cell receptor (TCR) diversity, which is a prerequisite for immune competence. However, he still suffers from microcephaly, dwarfism and dystrophy.

CONCLUSIONS

This case report gives an example of a successful HSCT as a treatment option in a genetic disorder such as ligase IV deficiency, using a rather mild conditioning regimen. Further studies are required to determine the viability and efficacy of this treatment option.

Long-Term Outcomes of Hematopoietic Stem Cell Transplantation for ZAP70 Deficiency

ZAP70 deficiency is a rare T + B + NK+ combined immunodeficiency with limited outcome data to help guide decisions around hematopoietic stem cell transplant (HSCT). We sought to understand the long-term clinical and immunologic outcomes of both conditioned and unconditioned HSCT for ZAP70 deficiency following transplant from a variety of graft sources. We performed a retrospective, single center review of all cases of HSCT for genetically confirmed ZAP70 deficiency since 1992. At a median of 13.5-year post-HSCT, 8/8 (100 %) patients are alive. Three received unconditioned bone marrow transplants from human leukocyte antigen (HLA)-matched siblings and achieved stable mixed donor-recipient T cell chimerism but low B cell (4-9 %) and absent to near-absent myeloid donor engraftment. Despite this, all three have normal immunoglobulin levels, have developed specific protective antibody responses to post-HSCT vaccinations, and have discontinued immunoglobulin replacement. Five patients received myeloablative conditioning (three T cell-depleted haploidentical and two unrelated cord blood) and have full donor chimerism for T and B cells and myeloid lineages. One patient experienced primary graft failure after serotherapy only. CD8 T cell count is normal in 5/8, high in 1/8, and low in 2/8. Infectious complications in 5/5 and autoimmune thrombocytopenia in one patient resolved post-HSCT. Mitogen proliferation to phytohemagglutinin was normal after HSCT in 8/8 patients. In total, seven have discontinued immunoglobulin replacement. In conclusion, HSCT using a variety of graft sources and approaches, including unconditioned matched sibling donor transplant, is a life-saving therapy for ZAP70 deficiency, providing excellent long-term immune function and resolution of clinical problems.

Isolation protocol for patients with severe combined immune deficiency

Infants with severe combined immune deficiency (SCID) typically present in the first few months of life with severe, recurrent, opportunistic infections, and without definitive treatment the condition is invariably fatal (Gaspar et al. 2013). Many centres believe that protective isolation is required for treatment of SCID patients once diagnosed, and the isolation protocol varies across institutions. This paper describes the isolation protocol for SCID requiring hematopoietic stem cell transplant (HSCT) that has been utilized at our institution for over the last 25 years. We believe that the profound immunodeficiency in SCID patients warrants a more restrictive treatment to limit the morbidity and mortality associated with HSCT. With this protocol, we have seen a very low infection rate in and have a very good survival rate for our SCID population.

Hematopoietic Stem Cell Transplantation for Severe Combined Immunodeficiency

Hematopoietic stem cell transplantation (HSCT) is an effective approach for the treatment of severe combined immunodeficiency (SCID). However, SCID is not a homogeneous disease, and the treatment required for successful transplantation varies significantly between SCID subtypes and the degree of HLA mismatch between the best available donor and the patient. Recent studies are beginning to more clearly define this heterogeneity and how outcomes may vary. With a more detailed understanding of SCID, new approaches can be developed to maximize immune reconstitution, while minimizing acute and long-term toxicities associated with chemotherapy conditioning.

Hematopoietic stem cell transplantation for CD3δ deficiency

BACKGROUND

CD3δ deficiency is a fatal form of severe combined immunodeficiency that can be cured by hematopoietic stem cell transplantation (HSCT). The presence of a thymus loaded with T-cell progenitors in patients with CD3δ deficiency may require special considerations in choosing the regimen of conditioning and the type of HSCT.

OBJECTIVES

To study the outcome of CD3δ deficiency by using various modalities of stem cell transplantation.

METHODS

We analyzed data on 13 patients with CD3δ deficiency who underwent HSCT in 7 centers. HSCT was performed by using different sources of donor stem cells as well as various conditioning regimens.

RESULTS

One patient received stem cells from a matched related donor and survived after a second transplant, needing substantial conditioning in order to engraft. Only 2 of 7 other patients who received a mismatched related donor transplant survived; 2 of them had no conditioning, whereas the others received various combinations of conditioning regimens. Engraftment of T cells in the survivors appears incomplete. Three other patients who received stem cells from a matched unrelated donor survived and enjoyed full immune reconstitution. Two patients received unrelated cord blood without conditioning. One of them has had a partial but stable engraftment, whereas the other engrafted well but is only 12 months after HSCT. We also report here for the first time that patients with CD3δ deficiency can present with typical features of Omenn syndrome.

CONCLUSIONS

HSCT is a successful treatment for patients with CD3δ deficiency. The small number of patients in this report prevents definitive statements on the importance of survival factors, but several are suggested: (1) HLA-matched donor transplants are associated with superior reconstitution and survival than are mismatched donor transplants; (2) substantial conditioning appears necessary; and (3) early diagnosis and absence of opportunistic infections may affect outcome.

Bone marrow transplantation using HLA-matched unrelated donors for patients suffering from severe combined immunodeficiency

Severe combined immunodeficiency (SCID) is fatal in infancy unless corrected with allogeneic bone marrow transplants (BMT), preferably from a family-related genotypically HLA-identical donor (RID) or phenotypically HLA-matched family donor (PMD). For the majority of SCID patients, such donors are not available; Therefore, parents who are HLA-haploidentical donors (HID) or HLA-matched unrelated donors (MUD) have been used. MUD BMT are associated with increased frequency of acute graft versus host disease, which can be controlled by high doses of steroids. HID BMT are associated with increased frequency of short- and long-term graft failure, need for repeated transplants, fatal pneumonitis, impaired immune reconstitution, and long-term complications, contributing to lower survival. In conclusion, the excellent long-term survival, immune reconstitution, and normal quality of life after MUD BMT suggests that in the absence of RID or PMD, MUD BMT should be offered for patients suffering from SCID.

Hematopoietic stem cell transplantation for profound T-cell deficiency (combined immunodeficiency)

Typical cases of severe combined immunodeficiency present at infancy (most frequently at 6 months of age) with repeated opportunistic infections; failure to thrive; and scarcity of lymphoid tissues, including undetectable lymph nodes and a small dysplastic thymus. Patients with profound T-cell dysfunction (PTD)/combined immunodeficiency (CID) have moderate to large numbers of circulating autologous lymphocytes with variable residual function. These cells may interfere with proper engraftment and may complicate the procedure of HSCT, hence the need for conditioning. There is no immediate explanation for the excellent outcome of hematopoietic stem cell transplantation (HSCT) for PTD/CID. Historically, protocols for mismatched related donor HSCT did not include conditioning regimens, which could jeopardize engraftment. Careful studies on the role of conditioning, especially myeloablative conditioning, should be conducted in the future. It is possible that in some genotypes, related identical donor can be accepted by the recipient with little or no conditioning. Until such studies become instructive, the protocols in current use seem to provide excellent, although not perfect, outcome in patients with PTD/CID.

Thymus microenvironment in human primary immunodeficiency diseases

PURPOSE OF REVIEW

Severe combined immunodeficiencies represent a heterogeneous group of genetic disorders affecting genes of both early and late steps in lymphocytes development, a process tightly controlled by thymic epithelial cells. Detailed analysis of thymic morphology aids to the assessment of the severity of the immune disorder and may be critical to the understanding of the role of the genetic defects in the pathophysiology of these diseases. In this review, we highlight recent advancements in the characterization of the thymic microenvironment in primary immunodeficiencies.

RECENT FINDINGS

Crosstalk between thymocytes and thymic epithelial cells is essential to preserve thymic architecture and function, and therefore to promote T-cell maturation and development of self-tolerance. Early severe defects in T-cell development result in profound abnormalities of thymic epithelial cells differentiation with loss of AIRE expression and severe reduction of thymic dendritic and T-regulatory cells. Differently, later defects in T-cell development that are permissive for normal thymocytes development allow cortico-medullary differentiation with partially preserved AIRE expression and dendritic/T-regulatory cells distribution. Hypomorphic mutations in the same genes partially permissive to T-cell development may result in a more complex phenotype with immunodysreactivity and peculiar thymic alterations.

SUMMARY

Although the molecular and genetic bases of primary immunodeficiencies directly aid to both diagnosis and management of the patients, the detailed analysis of thymic morphology critically contributes to unveil the pathophysiology of these diseases.

Systematic evidence review of newborn screening and treatment of severe combined immunodeficiency

CONTEXT

Severe combined immunodeficiency (SCID) is a group of disorders that leads to early childhood death as a result of severe infections. Recent research has addressed potential newborn screening for SCID.

OBJECTIVE

To conduct a systematic review of the evidence for newborn screening for SCID, including test characteristics, treatment efficacy, and cost-effectiveness.

METHODS

We searched Medline and the OVID In-Process & Other Non-Indexed Citations databases. We excluded articles if they were reviews, editorials or other opinion pieces, or case series of fewer than 4 patients or if they contained only adult subjects or nonhuman data. The remaining articles were systematically evaluated, and data were abstracted by 2 independent reviewers using standardized tools. For topics that lacked published evidence, we interviewed experts in the field.

RESULTS

The initial search resulted in 719 articles. Twenty-six met inclusion criteria. The results of several small studies suggested that screening for SCID is possible. Interviews revealed that 2 states have begun pilot screening programs. Evidence from large case series indicates that children receiving early stem-cell transplant for SCID have improved outcomes compared with children who were treated later. There is some inconclusive evidence regarding the need for donor-recipient matching and use of pretransplant chemotherapy. Few data on the cost-effectiveness of a SCID-screening program.

CONCLUSIONS

Evidence indicates the benefits of early treatment of SCID and the possibility of population-based newborn screening. Better information on optimal treatment and the costs of treatment and screening would benefit policy makers deciding among competing health care priorities.

Transplant outcomes for primary immunodeficiency disease

Primary immune deficiencies (PIDs) are rare diseases, and most are lethal without appropriate intervention. Hematopoietic cell transplantation (HCT) can cure the majority of patients, but most lack a suitable matched related donor. Alternative donor stem cells (mismatched related donor bone marrow, unrelated donor bone marrow, and unrelated donor umbilical cord blood [UCB]) are therefore frequently required. Published data comparing outcomes after alternative donor transplant for PID are scarce. The outcomes and potential advantage and disadvantages of each alternative stem cell source are discussed in this chapter. Although there are insufficient prospective data to make meaningful comparisons between the alternative stem cell sources, the results presented here demonstrate clearly that the use of UCB transplantation for PID is a viable option and may be advantageous in many situations.

Rapid full engraftment and successful immune reconstitution after allogeneic hematopoietic stem cell transplantation with reduced intensity conditioning in Omenn syndrome

OS is a variant of SCID characterized by generalized erythroderma, alopecia, eosinophilia, and elevated IgE levels. It is fatal unless treated with allogeneic HSCT, which is the only curative approach. However, treatment related complications and graft rejection are major obstacles to the success of treatment. In this report, we describe a patient with OS, complicated by prolonged cytomegalovirus infection, successfully treated by reduced intensity conditioning allogeneic HSCT from sibling donor.

Allogeneic haemopoietic stem cell transplantation in children: what alternative donor should we choose when no matched sibling is available?

Allogeneic haemopoietic stem cell transplantation has provided curative therapy for life-threatening malignant and non-malignant diseases in children for over 40 years. Only 25% of children in whom an allograft is indicated have the ideal option of a human leucocyte antigen-identical sibling donor. Substantial advances in the use of alternative donors (unrelated volunteer donors, haploidentical family donors and unrelated umbilical cord blood donors) now make it possible for almost all children to benefit from this life-saving treatment. Each donor choice is associated with distinct advantages and disadvantages, which have greater or lesser importance in different diseases. We review the current status of alternative donor transplantation for haematological malignancies, primary immunodeficiencies, inherited metabolic disorders and bone marrow failure syndromes and outline the current UK consensus donor selection algorithms for these disease groups.

Disseminated Bacillus Calmette-Guerin infection after BCG vaccination

The BCG is administered to all the newborns at birth in Iran. Systemic adverse reactions to BCG vaccine such as osteomyelitis and disseminated BCG infection are rare. This is a retrospective study of 15 cases <72 months who were admitted with systemic syndrome compatible with disseminated mycobacterial disease during 2004-07. Disseminated BCG disease occurred in eight children younger than 6-months old and 12 patient younger than 12-months old. Twelve patients were male. Nine of 15 patients had well known primary immune deficiency disorders including severe combined immunodeficiency, chronic granulomatous disease; cell mediated immune defect and HIV infection. Nine (60%) cases had good response to four anti-mycobacterial drug therapy and interferon gamma. Disseminated BCG disease is a rare but devastating complication of BCG vaccination that should be considered in the appropriate clinical setting. Severe immune-compromised infants are at greatest risk and they respond poorly to standard therapies.

Megadose CD34(+) cell grafts improve recovery of T cell engraftment but not B cell immunity in patients with severe combined immunodeficiency disease undergoing haplocompatible nonmyeloablative transplantation

To determine whether T cell engraftment and recovery of B cell immunity could be improved, we prospectively treated 15 children with severe combined immunodeficiency disease (SCID) with megadoses of haplocompatible CD34(+) cells and a fixed number of CD3(+) cells without previous myeloablative chemotherapy. Evidence of T cell engraftment was seen in 73% of patients (95% confidence interval [CI] = 48%-90%). Engraftment was more likely in patients with X-linked SCID and in those with evidence of maternal engraftment at the time of diagnosis. In patients with T cell engraftment, the median time to development of a CD4 count > 200 cells/mm(3) and a phytohemagglutinin response > 50% of control was 1.2 and 4.9 months, respectively. Clearance of preexisting infections occurred after a median of 2.8 months. B cell function developed in 33% of engrafted patients (95% CI = 14%-61%). The 1-year event-free survival (EFS) rate was 60% (95% CI = 36%-80%), and the overall survival (OS) rate was 87% (95% CI = 61%-98%), with a median follow-up of 39 months. The use of megadoses of CD34(+) cells with a fixed number of CD3(+) cells in nonmyeloablative hematopoietic stem cell transplantation (HSCT) in patients with SCID is associated with excellent engraftment, T cell recovery, and OS; however, B cell function does not recover in most patients.

Advances in hematopoietic stem cell transplantation for primary immunodeficiency

The molecular bases of most primary immunodeficiencies (PID) have been discovered. Long-term follow-up of patient cohorts treated with antimicrobial prophylaxis has demonstrated good short-term prognosis but with increasing morbidity and mortality over time. The results of hematopoietic stem cell transplantation (HSCT) for PID have improved incrementally over time, with survival and cure of 90% for some defined diseases. This article examines the advances in HSCT for PID and argues that HSCT should be considered earlier for most patients.

Unrelated cord blood transplantation for severe combined immunodeficiency and other primary immunodeficiencies

HCT is currently the treatment of choice for children with severe primary immunodeficiencies (PIDs). Frequently, these patients lack an HLA-identical sibling donor, and umbilical cord blood (UCB) transplantation may be an option; however, experience in this field remains scant. Fifteen children with PID (SCID 11, X-linked lymphoproliferative syndrome 2, Omenn's syndrome 1, Wiskott-Aldrich syndrome 1) received a UCB transplant. The donor was unrelated in 14 cases and related in 1. Median age at transplant was 11.6 months (range, 2.9-68.0) and median weight 7 kg (range, 4-21). Thirteen patients were conditioned with busulphan and cyclophosphamide and 2 with fludarabine and melphalan. Nine patients received antithymocyte globulin. Median NC x 10(7)/kg infused was 7.9 (range, 2.9-25.0) and median CD34 x 10(5)/kg 2.9 (range, 1.0-7.9). All patients engrafted. Median days to >0.5 x 10(9)/l neutrophils was 31. Eight patients developed acute graft-versus-host disease (GvHD) grades II-IV and one chronic GvHD. Viral and fungal infections were frequent. Four patients died: three from GvHD grade IV complicated by infection and one from progressive interstitial lung disease. Five-year survival was 0.73+/-0.12. All surviving patients presented complete immunologic reconstitution. No patient is intravenous immunoglobulin (IVIg) replacement therapy-dependent. UCB transplantation is a valid option for children with PID who lack an HLA-identical sibling donor.

Hematopoietic stem cell transplantation for primary immunodeficiency disease

Hematopoietic stem cell transplantation is the definitive therapy for a variety of rare primary cellular immunodeficiency syndromes diagnosed in children. All primary immunodeficiencies benefit from early diagnosis and transplantation before the development of serious infections, which contribute to a significant increased risk of mortality following transplant. In the absence of a matched sibling, parental haplocompatible, matched unrelated donor and cord blood stem cells have all been utilized with varying degrees of success and immune reconstitution. The role of pretransplant conditioning in patients with SCID disease in terms of its effects upon T- and B-cell immune reconstitution and late effects is still under debate and will require further study.

Human T cell immunodeficiency: when signal transduction goes wrong

Severe combined immunodeficiency (SCID) is a heterogeneous group of diseases that are invariably fatal in infancy unless treated by hematopoietic stem cell replacement. For many years we have worked to better manage patients affected by SCID through rapid and accurate diagnosis followed by treatment aimed at achieving long-lasting immune reconstitution. By extensive immunological, biochemical, and genetic studies of patient samples, and with the realization of differences between human and murine T cell development, we have successfully been able to identify some of the molecular defects causing SCID. Among these discoveries, we described the first mutated signal transduction protein in T cells (ZAP-70); the first genetic defect leading to SCID and autoimmune phenomena (IL2R alpha); and, recently, the critical importance of CD3delta in the development of T cells. Our efforts have significantly advanced the understanding of the role of some of the signal-transducing proteins in T cell maturation and function. This review summarizes several of these discoveries and some of their impact on our understanding of T cells development, function, and homeostasis in humans.

Bone marrow transplantation for cartilage-hair-hypoplasia

The association of cartilage hair hypoplasia (CHH) with severe combined immunodeficiency (SCID) has been known for more than three decades. Bone marrow transplantation (BMT) remains the only effective treatment that might cure SCID. Surprisingly little has been reported on the experience with BMT in CHH. We report here survival and long-term reconstitution of immunity after BMT in three patients with CHH. Regardless of whether a related human leukocyte antigen-matched or unrelated matched donors were used as the source of BMT, all patients are alive and well 5-20 years after BMT. Engraftment appears robust with most cells of donors origin. Repeated evaluation of the immune system showed normal cellular and humoral immunity. Our results should encourage the use of BMT in patients with CHH who have profound immunodeficiency.

The benefits and risks of bacille Calmette-Guérin vaccination among infants at high risk for both tuberculosis and severe combined immunodeficiency: assessment by Markov model

BACKGROUND

Bacille Calmette-Guérin (BCG) vaccine is given to Canadian Aboriginal neonates in selected communities. Severe reactions and deaths associated with BCG have been reported among infants born with immunodeficiency syndromes. The main objective of this study was to estimate threshold values for severe combined immunodeficiency (SCID) incidence, above which BCG is associated with greater risk than benefit.

METHODS

A Markov model was developed to simulate the natural histories of tuberculosis (TB) and SCID in children from birth to 14 years. The annual risk of tuberculous infection (ARI) and SCID incidence were varied in analyses. The model compared a scenario of no vaccination to intervention with BCG. Appropriate variability and uncertainty analyses were conducted. Outcomes included TB incidence and quality-adjusted life years (QALYs).

RESULTS

In sensitivity analyses, QALYs were lower among vaccinated infants if the ARI was 0.1% and the rate of SCID was higher than 4.2 per 100,000. Assuming an ARI of 1%, this threshold increased to 41 per 100,000. In uncertainty analyses (Monte Carlo simulations) which assumed an ARI of 0.1%, QALYs were not significantly increased by BCG unless SCID incidence is 0. With this ARI, QALYs were significantly decreased among vaccinated children if SCID incidence exceeds 23 per 100,000. BCG is associated with a significant increase in QALYs if the ARI is 1%, and SCID incidence is below 5 per 100,000.

CONCLUSION

The possibility that Canadian Aboriginal children are at increased risk for SCID has serious implications for continued BCG use in this population. In this context, enhanced TB Control--including early detection and treatment of infection--may be a safer, more effective alternative.

Single centre experience of umbilical cord stem cell transplantation for primary immunodeficiency

Primary immunodeficiencies (PID) are an important cause of childhood mortality. Haematopoietic stem cell transplantation (HSCT) is the best treatment for many PID. Umbilical cord stem cells are an alternative source of HSC. There is little data regarding outcome of umbilical cord stem cell transplantation (UCSCT) for PID. Our single centre experience is reported. A retrospective study of 14 of 148 patients transplanted for PID, who have received 15 UCSCT was performed, with specific regard to graft-versus-host disease (GvHD) and immune reconstitution. Eight patients with severe combined immunodeficiency (SCID), and six with other combined immunodeficiencies were treated. Of the patients, 12 received unrelated cords, and two had sibling transplants. Median age at transplant was 3.5 months, median nucleated cell dose was 0.8 x 10(8)/kg. All engrafted. Median time to neutrophil engraftment was 22 days, median time to platelet engraftment was 51 days. One developed significant grade III GvHD post transplantation. In total, 11 patients had full donor T and six full donor B-cell chimerism, six of nine patients >1 year post-BMT had normal IgG levels and specific antibody responses to tetanus and Hib vaccines; two are being assessed. Two patients died of multi-organ failure related to pre-existing infection and inflammatory complications respectively. UCSCT should be considered for patients requiring stem cell therapy for PID.

Serious adverse events associated with bacille Calmette-Guérin vaccine in Canada

BACKGROUND

Targeted Bacille Calmette-Guérin (BCG) vaccination is offered to neonates in some First Nations and Inuit (FNI) communities in Canada. Serious adverse events associated with BCG vaccine prompted a review to assess causality.

METHODS

The Immunization Monitoring Program Active (IMPACT), a pediatric hospital-based active surveillance network, reported admissions for BCG-related adverse events between 1993 and April 2002. The Canadian Advisory Committee on Causality Assessment (ACCA) reviewed the reports to assess causality. Data between 1987 and September 2002 from the Vaccine-Associated Adverse Event Surveillance (VAAES) Program, a passive national reporting system, were also reviewed.

RESULTS

IMPACT identified 21 pediatric cases; 19 were Canadian-born, and 18 were FNI. Six disseminated BCG cases were identified; 5 were FNI infants who subsequently died. All had immunodeficiencies and concurrent infections. Other adverse events included 2 cases of osteomyelitis, BCG abscesses and lymphadenitis. ACCA reviewed the 21 cases and determined that 14 were very likely associated with the vaccine, including the 6 disseminated BCGs; 5 were probably associated and 1 was possibly associated with the vaccine; 1 was unclassifiable. The VAAES program identified 157 adverse events. No additional serious systemic adverse events (disseminated BCG or osteomyelitis) were identified.

CONCLUSIONS

Serious BCG vaccine-associated complications continue to occur in Canada. The numbers of FNI children with disseminated disease was greater than expected from reported rates in the literature.

Unrelated donor marrow transplantation for congenital immunodeficiency and metabolic disease: an update of the experience of the Japan Marrow Donor Program

We retrospectively analyzed the clinical results of 81 patients with congenital genetic diseases who were treated with bone marrow transplantation (BMT) from unrelated donors identified through the Japan Marrow Donor Program. The patients were aged between 1 and 38 years (median, 4 years). Thirty-five patients underwent transplantation for metabolic disease (MD), ie, mucopolysaccharidosis (n = 25), adrenoleukodystrophy (n = 7), and others (n = 3). The remaining 46 patients had Wiskott-Aldrich syndrome (n = 16), hemophagocytic syndrome including the inherited type (n = 9), severe combined immunodeficiency (n = 6), hyper-IgM syndrome (n = 4), Chédiak-Higashi syndrome (n = 3), Kostmann syndrome (n = 3), and others (n = 5). Fifty-two donor-patient pairs were fully matched at HLA-A, HLA-B, and HLA-DRB1 alleles. The remaining 24 patients received allele-mismatched grafts (20 matched at 5 of 6 loci and 4 matched at 4 of 6 loci). Engraftment occurred in 82.4% of the MD group and 90.7% of the other genetic disease (OGD) group; however, 14 patients (18.2%) experienced either early or late graft failure. The cumulative incidence of grade II to IV acute graft-versus-host disease (GVHD) was 35.5% - 9.8% in the MD group and 47.3% - 9.5% in the OGD group, and the rate of chronic GVHD was 20% in both groups. Forty-nine patients have survived for 3 to 96 months (median, 20 months). The probabilities of 5-year overall survival and event-free survival were 72.6% - 11.5% and 65.3% - 8.6%, respectively, for MD (n = 35) and 72.5% - 7.3% and 63.6% - 7.3% for OGD (n = 46). Although patient status before BMT and the occurrence of grade III to IV acute GVHD significantly affected outcome, unrelated BMT is a curative therapeutic option for children with congenital genetic diseases who have no HLA-matched family donors.

CAMPATH-1M T-cell depleted BMT for SCID: long-term follow-up of 19 children treated 1987-98 in a single center

BACKGROUND

SCID can be cured by BMT. Depletion of mature T cells from BM has enabled HLA non-identical stem-cell transplantation. We report the outcome of 30 patients treated with 37 T-cell depleted BMT procedures using CAMPATH-1M in vitro between 1987-98 in a single center.

METHODS

Immune reconstitution and quality-of-life were assessed in 19 longterm survivors. All but two received pre-transplant conditioning. T- and B-cell chimerism, numbers and function were analyzed during a median follow-up of 5.3 years (range 1.33-12).

RESULTS

The overall engraftment rate was 59%, six children required repeated BMT and the survival rate was 63%. All have donor T cells, 58% normal T-cell numbers and 74% normal T-cell function. Of 17 evaluated, 16 patients (94%) have normal IgM and IgG levels, and production of specific Abs to protein Ags, but only 5/16 (31%) have a good response to pneumococcal polysaccharide. Early and late post-BMT complications were rare and there were no delayed deaths. Only one child continues on long-term i.v. Ig 4-years post-BMT. Eleven children died (37%).

DISCUSSION

CAMPATH-1M T-cell depleted BMT for SCID resulted in 63% survival. Deaths of 11 children were mainly due to pre-existing infections. Seventeen of 19 long-term survivors have normal immune function and good quality-of-life.

Managing space and marking time: mothering severely ill infants in hospital isolation

In this study, mothers retrospectively describe their experiences of prolonged protective isolation with infants hospitalized for severe combined immune deficiency. Mothers (N = 5) spent approximately 10 hours every day for 10.5 months in an 11-foot-square isolation room. Dressed in masks and surgical garb, they cared for their infants but were prohibited from engaging in skin contact. Although the rooms' characteristics and regulations remained fixed, mothers' sociospatial experiences varied dramatically over the course of the infants' treatment trajectories. The findings illustrate how place, space, and time affect women's well-being and their social and mothering relations in health care settings.

Hematopoietic stem cell transplantation for severe combined immune deficiency

Hematopoietic stem cell transplantation (HSCT) has been the definitive therapy for severe combined immune deficiency (SCID) since the first successful transplant for SCID in 1968. Improvements in the use of HSCT to treat patients with SCID are continuing. For example, during the last 5 years, the first successful in-utero HSCT, and the first success with gene therapy have occurred in patients with SCID. Debate still continues about the role of pretransplantation therapy for SCID patients, and the biology of post-HSCT immune reconstitution is under investigation.

[Substitution therapy with hematopoietic progenitors in the primary immunodeficiencies]

Hematopoietic stem-cell transplantation is currently the most appropriate substitution therapy in the most severe forms of primary immunodeficiency diseases (all the variants of SCID, WA, CID etc.). It can achieve total and permanent immunological reconstitution in 60% of patients, depending on histocompatibility, source of the hematopoietic stem cells and the underlying disease. Stem-cell sources may be bone marrow, umbilical cord blood and the peripheral blood of donors previously treated with colony stimulating factors for the mobilization CD34. We discuss the differences in the results obtained in patients treated at the Hospital Materno-Infantil Vall d'Hebron. Gene therapy opens a new era in the treatment of primary immunodeficiency diseases. The first patient to undergo this treatment in the United States of America had adenosine-deaminase deficiency, even though sustained remodeling has not been achieved. The favorable results obtained in patients with SCID by deficit in the gamma chain of the IL-2 receptor in Paris, with more than a year of follow up, suggest that the near future is promising. We also discuss the differences observed according to the vectors used and the underlying disease.