Matched unrelated bone marrow transplant for T+ combined immunodeficiency

Cyclosporin treatment improves skin findings in omenn syndrome

Omenn syndrome is a combined immunodeficiency characterized by a generalized erythematous skin rash, enlarged lymph nodes, hepatosplenomegaly, severe susceptibility to infections, eosinophilia, and hyperimmunoglobulinemia E. A 3-month-old girl was admitted to our hospital with a history of recurrent sepsis. Physical examination revealed severe erythroderma, hepatosplenomegaly, lymphadenopathy, and failure to thrive. Laboratory findings revealed leukocytosis, lymphocytosis with high CD3 T-cells, a high CD4:CD8 ratio, absence of CD19 B-cells, high eosinophil count, and low immunoglobulin levels. A heterozygote RAG1 gene mutation was found. She had itchy, scaling, ichthyosiform erythroderma and protracted diarrhea. Cyclosporin treatment up to 10 mg/kg effectively resolved erythroderma and lowered total eosinophil counts, and she gained weight during treatment. Since extensive erythroderma with generalized itching causes patient discomfort in Omenn syndrome, cyclosporin treatment can be considered while waiting for treatment with hematopoietic stem cell transplantation.

Characterizing T cells in SCID patients presenting with reactive or residual T lymphocytes

INTRODUCTION

Patients with severe combined immunodeficiency (SCID) may present with residual circulating T cells. While all cells are functionally deficient, resulting in high susceptibility to infections, only some of these cells are causing autoimmune symptoms.

METHODS

Here we compared T-cell functions including the number of circulating CD3(+) T cells, in vitro responses to mitogens, T-cell receptor (TCR) repertoire, TCR excision circles (TREC) levels, and regulatory T cells (Tregs) enumeration in several immunodeficinecy subtypes, clinically presenting with nonreactive residual cells (MHC-II deficiency) or reactive cells. The latter includes patients with autoreactive clonal expanded T cell and patients with alloreactive transplacentally maternal T cells.

RESULTS

MHC-II deficient patients had slightly reduced T-cell function, normal TRECs, TCR repertoires, and normal Tregs enumeration. In contrast, patients with reactive T cells exhibited poor T-cell differentiation and activity. While the autoreactive cells displayed significantly reduced Tregs numbers, the alloreactive transplacentally acquired maternal lymphocytes had high functional Tregs.

CONCLUSION

SCID patients presenting with circulating T cells show different patterns of T-cell activity and regulatory T cells enumeration that dictates the immunodeficient and autoimmune manifestations. We suggest that a high-tolerance capacity of the alloreactive transplacentally acquired maternal lymphocytes represents a toleration advantage, yet still associated with severe immunodeficiency.

Selective clinical and immune response of the oligoclonal autoreactive T cells in Omenn patients after cyclosporin A treatment

The immunological hallmark of Omenn syndrome (OS) is the expansion and activation of an oligoclonal population of autoreactive T cells. These cells should be controlled rapidly by immunosuppressive agents, such as cyclosporin A (CsA), to avoid tissue infiltration and to improve the general outcome of the patients. Here we studied the clinical and the immune response to CsA in two Omenn patients and also examined the gene expression profile associated with good clinical response to such therapy. T cell receptor diversity was studied in cells obtained from OS patients during CsA therapy. Characterization of gene expression in these cells was carried out by using the TaqMan low-density array. One patient showed complete resolution of his symptoms after CsA therapy. The other patient showed selective response of his oligoclonal T cell population and combination therapy was required to control his symptoms. Transcriptional profile associated with good clinical response to CsA therapy revealed significant changes in 26·6% of the tested genes when compared with the transcriptional profile of the cells before treatment. Different clinical response to CsA in two OS patients is correlated with their immunological response. Varying clonal expansions in OS patients can cause autoimmune features and can respond differently to immunosuppressive therapy; therefore, additional treatment is sometimes indicated. CsA for OS patients causes regulation of genes that are involved closely with self-tolerance and autoimmunity.

The kinetics of early T and B cell immune recovery after bone marrow transplantation in RAG-2-deficient SCID patients

The kinetics of T and B cell immune recovery after bone marrow transplantation (BMT) is affected by many pre- and post-transplant factors. Because of the profoundly depleted baseline T and B cell immunity in recombination activating gene 2 (RAG-2)-deficient severe combined immunodeficiency (SCID) patients, some of these factors are eliminated, and the immune recovery after BMT can then be clearly assessed. This process was followed in ten SCID patients in parallel to their associated transplant-related complications. Early peripheral presence of T and B cells was observed in 8 and 4 patients, respectively. The latter correlated with pre-transplant conditioning therapy. Cells from these patients carried mainly signal joint DNA episomes, indicative of newly derived B and T cells. They were present before the normalization of the T cell receptor (TCR) and the B cell receptor (BCR) repertoire. Early presentation of the ordered TCR gene rearrangements after BMT occurred simultaneously, but this pattern was heterogeneous over time, suggesting different and individual thymic recovery processes. Our findings early after transplant could suggest the long-term patients' clinical outcome. Early peripheral presence of newly produced B and T lymphocytes from their production and maturation sites after BMT suggests donor stem cell origin rather than peripheral expansion, and is indicative of successful outcome. Peripheral detection of TCR excision circles and kappa-deleting recombination excision circles in RAG-2-deficient SCID post-BMT are early markers of T and B cell reconstitution, and can be used to monitor outcome and tailor specific therapy for patients undergoing BMT.

A Markov model to analyze cost-effectiveness of screening for severe combined immunodeficiency (SCID)

OBJECTIVE

To evaluate the cost-effectiveness of universal neonatal screening for T cell lymphocytopenia in enhancing quality of life and life expectancy for children with severe combined immunodeficiency (SCID).

METHODS

Decision trees were created and analyzed to estimate the cost, life years, and quality adjusted life years (QALYs) across a population when universal screening for lack of T cells is used to detect SCID, as implemented in five states, compared to detection based on recognizing symptoms and signs of disease. Terminal values of each tree limb were derived through Markov models simulating the natural history of three cohorts: unaffected subjects; those diagnosed with SCID as neonates (early diagnosis); and those diagnosed after becoming symptomatic and arousing clinical suspicion (late diagnosis). Models considered the costs of screening and of care including hematopoietic cell transplantation for affected individuals. Key decision variables were derived from the literature and from a survey of families with children affected by SCID, which was used to describe the clinical history and healthcare utilization for affected subjects. Sensitivity analyses were conducted to explore the influence of these decision variables.

RESULTS

Over a 70-year time horizon, the average cost per infant was $8.89 without screening and $14.33 with universal screening. The model predicted that universal screening in the U.S. would cost approximately $22.4 million/year with a gain of 880 life years and 802 QALYs. Sensitivity analyses showed that screening test specificity and disease incidence were critical driving forces affecting the incremental cost-effectiveness ratio (ICER). Assuming a SCID incidence of 1/75,000 births and test specificity and sensitivity each at 0.99, screening remained cost-effective up to a maximum cost of $15 per infant screened.

CONCLUSION

At our current estimated screening cost of $4.22/infant, universal screening for SCID would be a cost effective means to improve quality and duration of life for children with SCID.

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.

Combined immunodeficiency, facial dysmorphism, optic nerve atrophy, skeletal anomalies and developmental delay: a new syndrome

Combined immunodeficiency (SCID) can be isolated and involve the immune system only or associated with abnormalities affecting other organs, mainly the skeletal and neurological systems. We report on sisters, born to consanguineous parents, with CID, facial dysmorphism, developmental delay, optic atrophy, myoclonic seizures, and skeletal anomalies. To the best of our knowledge, this is a hitherto new syndrome with most probably autosomal recessive inheritance and unknown etiology.

Molecular assessment of thymus capabilities in the evaluation of T-cell immunodeficiency

T-cell immunodeficiency may pose a diagnostic challenge to clinicians, especially when the basic T-cell immune workup is not sufficiently informative. An intensive assessment of thymus capabilities that involves either measuring the recent thymic emigrant cells or analyzing the T-cell receptor (TCR) repertoire is often required to estimate the severity and nature of the immune disorder. A comprehensive T-cell immune workup, including TCR excision circles (TRECs) and TCR repertoire analyses, was performed in three patients with various degrees of severity of T-cell immunodeficiency. All three patients had normal peripheral CD3+ T lymphocytes. TCR repertoire analysis revealed oligoclonal (patient 1), restricted (patient 2), and near-normal (patient 3) patterns. TREC quantification was significantly reduced in patients 1 and 2 but normal in patient 3. Based on clinical features at presentation and at follow-up, and supported by the results of immunologic studies, patients 1 and 2 were diagnosed as having significant T-cell immunodeficiency and patient 3 as having T-cell immunocompetence. Assessment of thymus capabilities by TRECs and TCR repertoire analyses is helpful in diagnosing patients with T-cell immunodeficiency and should be part of the evaluation of every patient suspected of having that condition.

Improving cellular therapy for primary immune deficiency diseases: recognition, diagnosis, and management

More than 20 North American academic centers account for the majority of hematopoietic stem cell transplantation (HCT) procedures for primary immunodeficiency diseases (PIDs), with smaller numbers performed at additional sites. Given the importance of a timely diagnosis of these rare diseases and the diversity of practice sites, there is a need for guidance as to best practices in management of patients with PIDs before, during, and in follow-up for definitive treatment. In this conference report of immune deficiency experts and HCT physicians who care for patients with PIDs, we present expert guidance for (1) PID diagnoses that are indications for HCT, including severe combined immunodeficiency disease (SCID), combined immunodeficiency disease, and other non-SCID diseases; (2) the critical importance of a high degree of suspicion of the primary care physician and timeliness of diagnosis for PIDs; (3) the need for rapid referral to an immune deficiency expert, center with experience in HCT, or both for patients with PIDs; (4) medical management of a child with suspicion of SCID/combined immunodeficiency disease while confirming the diagnosis, including infectious disease management and workup; (5) the posttransplantation follow-up visit schedule; (6) antimicrobial prophylaxis after transplantation, including gamma globulin administration; and (7) important indications for return to the transplantation center after discharge. Finally, we discuss the role of high-quality databases in treatment of PIDs and HCT as an element of the infrastructure that will be needed for productive multicenter clinical trials in these rare diseases.

Transplantation of human marrow stromal cells and mono-nuclear bone marrow cells into the injured spinal cord: a comparative study

STUDY DESIGN

Two groups of 6 rats received dorsolateral funiculotomies followed by direct injection of bone marrow stromal cells (MSC) or mono-nuclear fraction of bone marrow (mnBM). Animals were killed at 4 or 21 days.

OBJECTIVE

Cellular transplantation is a promising treatment strategy for spinal cord injury (SCI); however, most cells need to be cultured before transplantation introducing burdensome steps for clinical application. Cells immediately available for transplantation, like mnBM, would be preferable.

SUMMARY OF BACKGROUND DATA

Previous studies have shown that MSC transplants promote protection and repair after SCI. MSC are attractive for transplantation because of easy isolation and availability of autologous sources. MSC are derived from whole bone marrow, purified and expanded in culture for a period of at least 2 weeks. Alternatively, mnBM could be used for transplantation. mnBM derived from bone marrow from through simple centrifugation can be reimplantated within hours; however, the presence of immune cells may be problematic.

METHODS

Cultured MSC or mnBM from human donors were acutely transplanted into SCI. After sacrifice, spinal cord sections were histologically analyzed for presence of graft-derived immune cells, host immune response, tissue sparing, glial scar formation, and grafting efficacy.

RESULTS

mnBM did not give rise to mature immune cells after transplantation into SCI, or evoke an increased host immune response or tissue loss compared to MSC-transplanted animals. In contrast, host macrophage/microglia response was increased early after MSC transplantation, perhaps due to exposure of cells to serum-containing media. The glial scar was less prominent after mnBM transplantation at day 4. At 21 days, differences had subsided and MSC and mnBM macrophage responses and effects on glial scarring were comparable. MSC and mnBM engraftment efficiencies were also similar.

CONCLUSION

The use of mnBM is a viable alternative to MSC for transplantation into SCI and may dramatically ease clinical translation.

Reduced central tolerance in Omenn syndrome leads to immature self-reactive oligoclonal T cells

BACKGROUND

Omenn syndrome (OS) is characterized by a peculiar severe T-cell immune deficiency associated with autoimmunelike manifestations. Dysregulations of the central and peripheral immune tolerance, mediated by the protein autoimmune regulator (AIRE) and regulatory T cells, respectively, were proposed as possible mechanisms of this aberrant inflammatory process.

OBJECTIVE

We studied mechanisms of central and peripheral tolerance in patients with OS and also examined the gene expression profile associated with OS features.

METHODS

T-cell receptor diversity, DNA rearrangement, and the expression of AIRE and forkhead box P3 mRNA as well as the expression of regulatory T cells in cells obtained from patients with OS were studied. Characterization of gene expression in these cells was carried out by using the TaqMan Low-Density Array.

RESULTS

Transcript expression of peripheral blood AIRE but not forkhead box P3 was reduced in patients with OS. The expression of natural killer T and regulatory T cells was normal, although the latter showed an abnormal CD4-negative population. Patients with OS have oligoclonal T cells with limited DNA recombination activity, including the presence of early but not late T-cell maturation events, regardless of the genetic defect underlying the syndrome. The transcriptional profile associated with OS features reveals significant changes in 25.5% of the tested genes compared with normal control.

CONCLUSION

Our findings suggest that T-cell oligoclonal expansion in OS emanates from an incomplete block before the maturation stage of negative selection, which may explain escape of autoreactive T cells from the thymus. Dysregulated genes in patients with OS are closely involved with self-tolerance and autoimmunity.

Single-center analysis of long-term outcome after hematopoietic cell transplantation in children with congenital severe T cell immunodeficiency

We review clinical outcome and immune reconstitution in a consecutive series of 74 infants with severe T cell immunodeficiency who received hematopoietic cell transplantation (HCT) from January 1991 to May 2003. Fifty-three patients (71.6%) are alive. Results were significantly better for recipients of HCT from HLA-matched related donors (100% survival) and unrelated donors (86.4%) than from mismatched related donors (51.6%). A detailed analysis of immune reconstitution and clinical status was performed in 49 surviving patients, most of which have attained robust T and B cell reconstitution and are in very good clinical conditions. No cases of late deaths or of chronic graft-versus-host disease (GvHD) have been observed. However, infections and autoimmunity at >1 year after HCT have been observed in a significant number of patients. Persistence of a low number of circulating naive T cells and long-term requirement for intravenous immunoglobulin were associated with a higher incidence of clinical events.

Long-term outcomes of nonconditioned patients with severe combined immunodeficiency transplanted with HLA-identical or haploidentical bone marrow depleted of T cells with anti-CD6 mAb

BACKGROUND

Between 1981 and 1995, 20 children with severe combined immunodeficiency (SCID; median age at transplant, 6.5 [range, 0.5-145] mo, 12 with serious infection) were treated with haploidentical T cell-depleted (anti-CD6 antibody) bone marrow (median number of 5.7 [0.8-18.8] x 10(8) nucleated cells/kg) from mismatched related donors (MMRDs), and 5 children with SCID (median age at transplant, 1.8 [0.5-5.0] mo, 1 with serious infection) were given unmanipulated bone marrow from matched related donors (MRDs). No conditioning or graft-versus-host disease (GvHD) prophylaxis was used.

OBJECTIVE

To assess the outcomes of patients with SCID who received bone marrow from MMRDs or MRDs.

METHODS

We reviewed the medical records of these 25 consecutive patients with SCID (4 with Omenn syndrome).

RESULTS

Of the 20 patients who received bone marrow from MMRDs, 12 engrafted, 10 survived at a median age of 15.2 [10.0-19.1] years, 4 had chronic GvHD (lung, intestine, skin), 5 required intravenous immunoglobulin, and 8 attended school or college. Two of 5 patients who died had chronic GvHD, and 2 developed lymphoproliferative disease. Of the 5 patients who received bone marrow from MRDs, 5 engrafted, 5 survived at a median age of 23.3 [18.5-26] years, 1 had chronic GvHD (lung, skin), 2 required intravenous immunoglobulin, and 4 attended school or college.

CONCLUSIONS

Treatment of critically ill patients with SCID with anti-CD6 antibody T cell-depleted MMRD marrow resulted in an overall 50% long-term survival of patients (83% survival of those engrafted). The principal barriers to long-term survival were delay in diagnosis, life-threatening infection, failure to engraft, and chronic GvHD. Educational goals were achieved in most of the survivors.

Omenn syndrome: inflammation in leaky severe combined immunodeficiency

Omenn syndrome (OS) was reported until recently as a distinct form (phenotype and genotype) of severe combined immunodeficiency (SCID). Similar to other patients with SCID, patients with OS present early in infancy with viral or fungal pneumonitis, chronic diarrhea, and failure to thrive. Unlike typical SCID, patients with OS have enlarged lymphoid tissue, severe erythroderma, increased IgE levels, and eosinophilia. The inflammation observed in these patients is believed to be triggered by clonally expanded T cells, which are predominantly of the T(H)2 type. These abnormal T cells, in the absence of proper regulation by other components of the immune system, secrete a host of cytokines that promote autoimmune as well as allergic inflammation. The emergence of these T-cell clones occurs in patients with hypomorphic mutations in recombination activating gene 1 or 2, but not in patients with deleterious mutations in these enzymes which render them inactive. Recently, OS was also identified in a growing list of other leaky SCIDs with mutations in RNA component of mitochondrial RNA processing endoribonuclease, adenosine deaminase, IL-2 receptor gamma, IL-7 receptor alpha, ARTEMIS, and DNA ligase 4. This new information revealed OS is a distinct inflammatory process that can be associated with genetically diverse leaky SCIDS.

Allogeneic hematopoietic cell transplantation for primary immune deficiency diseases: current status and critical needs

Allogeneic hematopoietic cell transplantation (HCT) has been used for 40 years to ameliorate or cure primary immune deficiency (PID) diseases, including severe combined immunodeficiency (SCID) and non-SCID PID. There is a critical need for evaluation of the North American experience of different HCT approaches for these diseases to identify best practices and plan future investigative clinical trials. Our survey of incidence and prevalence of PID in North American practice sites indicates that such studies are feasible. A conference of experts in HCT treatment of PID has recommended (1) a comprehensive cross-sectional and retrospective analysis of HCT survivors with SCID; (2) a prospective study of patients with SCID receiving HCT, with comparable baseline and follow-up testing across participating centers; (3) a pilot study of newborn screening for SCID to identify affected infants before compromise by infection; and (4) studies of the natural history of disease in patients who do or do not receive HCT for the non-SCID diseases of Wiskott-Aldrich syndrome and chronic granulomatous disease. To accomplish these goals, collaboration by a consortium of institutions in North America is proposed. Participation of immunologists and HCT physicians having interest in PID and experts in laboratory methods, clinical outcomes assessment, databases, and analysis will be required for the success of these studies.