LMO2-associated clonal T cell proliferation in two patients after gene therapy for SCID-X1

We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.

Insertional oncogenesis in 4 patients after retrovirus-mediated gene therapy of SCID-X1

Previously, several individuals with X-linked SCID (SCID-X1) were treated by gene therapy to restore the missing IL-2 receptor gamma (IL2RG) gene to CD34+ BM precursor cells using gammaretroviral vectors. While 9 of 10 patients were successfully treated, 4 of the 9 developed T cell leukemia 31-68 months after gene therapy. In 2 of these cases, blast cells contained activating vector insertions near the LIM domain-only 2 (LMO2) proto-oncogene. Here, we report data on the 2 most recent adverse events, which occurred in patients 7 and 10. In patient 10, blast cells contained an integrated vector near LMO2 and a second integrated vector near the proto-oncogene BMI1. In patient 7, blast cells contained an integrated vector near a third proto-oncogene,CCND2. Additional genetic abnormalities in the patients' blast cells included chromosomal translocations, gain-of-function mutations activating NOTCH1, and copy number changes, including deletion of tumor suppressor gene CDKN2A, 6q interstitial losses, and SIL-TAL1 rearrangement. These findings functionally specify a genetic network that controls growth in T cell progenitors. Chemotherapy led to sustained remission in 3 of the 4 cases of T cell leukemia, but failed in the fourth. Successful chemotherapy was associated with restoration of polyclonal transduced T cell populations. As a result, the treated patients continued to benefit from therapeutic gene transfer.

Sustained correction of X-linked severe combined immunodeficiency by ex vivo gene therapy

BACKGROUND

X-linked severe combined immunodeficiency due to a mutation in the gene encoding the common gamma (gamma(c)) chain is a lethal condition that can be cured by allogeneic stem-cell transplantation. We investigated whether infusion of autologous hematopoietic stem cells that had been transduced in vitro with the gamma(c) gene can restore the immune system in patients with severe combined immunodeficiency.

METHODS

CD34+ bone marrow cells from five boys with X-linked severe combined immunodeficiency were transduced ex vivo with the use of a defective retroviral vector. Integration and expression of the gamma(c) transgene and development of lymphocyte subgroups and their functions were sequentially analyzed over a period of up to 2.5 years after gene transfer.

RESULTS

No adverse effects resulted from the procedure. Transduced T cells and natural killer cells appeared in the blood of four of the five patients within four months. The numbers and phenotypes of T cells, the repertoire of T-cell receptors, and the in vitro proliferative responses of T cells to several antigens after immunization were nearly normal up to two years after treatment. Thymopoiesis was documented by the presence of naive T cells and T-cell antigen-receptor episomes and the development of a normal-sized thymus gland. The frequency of transduced B cells was low, but serum immunoglobulin levels and antibody production after immunization were sufficient to avoid the need for intravenous immunoglobulin. Correction of the immunodeficiency eradicated established infections and allowed patients to have a normal life.

CONCLUSIONS

Ex vivo gene therapy with gamma(c) can safely correct the immune deficiency of patients with X-linked severe combined immunodeficiency.

Efficacy of gene therapy for X-linked severe combined immunodeficiency

BACKGROUND

The outcomes of gene therapy to correct congenital immunodeficiencies are unknown. We reviewed long-term outcomes after gene therapy in nine patients with X-linked severe combined immunodeficiency (SCID-X1), which is characterized by the absence of the cytokine receptor common gamma chain.

METHODS

The nine patients, who lacked an HLA-identical donor, underwent ex vivo retrovirus-mediated transfer of gamma chain to autologous CD34+ bone marrow cells between 1999 and 2002. We assessed clinical events and immune function on long-term follow-up.

RESULTS

Eight patients were alive after a median follow-up period of 9 years (range, 8 to 11). Gene therapy was initially successful at correcting immune dysfunction in eight of the nine patients. However, acute leukemia developed in four patients, and one died. Transduced T cells were detected for up to 10.7 years after gene therapy. Seven patients, including the three survivors of leukemia, had sustained immune reconstitution; three patients required immunoglobulin-replacement therapy. Sustained thymopoiesis was established by the persistent presence of naive T cells, even after chemotherapy in three patients. The T-cell-receptor repertoire was diverse in all patients. Transduced B cells were not detected. Correction of the immunodeficiency improved the patients' health.

CONCLUSIONS

After nearly 10 years of follow-up, gene therapy was shown to have corrected the immunodeficiency associated with SCID-X1. Gene therapy may be an option for patients who do not have an HLA-identical donor for hematopoietic stem-cell transplantation and for whom the risks are deemed acceptable. This treatment is associated with a risk of acute leukemia. (Funded by INSERM and others.)

Ribosomal protein SA haploinsufficiency in humans with isolated congenital asplenia

Isolated congenital asplenia (ICA) is characterized by the absence of a spleen at birth in individuals with no other developmental defects. The patients are prone to life-threatening bacterial infections. The unbiased analysis of exomes revealed heterozygous mutations in RPSA in 18 patients from eight kindreds, corresponding to more than half the patients and over one-third of the kindreds studied. The clinical penetrance in these kindreds is complete. Expression studies indicated that the mutations carried by the patients-a nonsense mutation, a frameshift duplication, and five different missense mutations-cause autosomal dominant ICA by haploinsufficiency. RPSA encodes ribosomal protein SA, a component of the small subunit of the ribosome. This discovery establishes an essential role for RPSA in human spleen development.

Transurethral microwave thermotherapy for nonbacterial prostatitis: a randomized double-blind sham controlled study using new prostatitis specific assessment questionnaires

PURPOSE

We investigated the effectiveness and durability of transurethral microwave thermotherapy in the treatment of chronic nonbacterial prostatitis using 2 new prostatitis specific assessments in a randomized, double-blind, sham controlled trial.

MATERIALS AND METHODS

Patients with nonbacterial prostatitis were randomly assigned to receive either transurethral microwave thermotherapy or sham therapy. Patients were assessed using a symptom severity index and symptom frequency questionnaire. These 2 new prostatitis symptom assessment tools were validated by applying them to 30 similar patients without prostatitis. All nonresponders received transurethral microwave thermotherapy at 3 months and were reassessed at 6 months. Long-term followup of the responder group averaged 21 months.

RESULTS

The symptom severity index and symptom frequency questionnaire were confirmed to be valid for symptom assessment in prostatitis patients. The transurethral microwave thermotherapy group benefited from therapy compared to the sham group. Of the sham group 50% had a favorable response after subsequent transurethral microwave thermotherapy. The 7 responders in the treatment group continued to improve during the subsequent 21 months.

CONCLUSIONS

Transurethral microwave thermotherapy appears to be an effective, safe and durable treatment for some patients with nonbacterial prostatitis unresponsive to traditional therapy.

Comparison of the efficacy of IGIV-C, 10% (caprylate/chromatography) and IGIV-SD, 10% as replacement therapy in primary immune deficiency. A randomized double-blind trial

A novel method of large-scale chromatography has been developed to improve recovery and purity of immunoglobulin G (IgG) from pooled plasma. The current study compares safety, toxicity and efficacy of two intravenous immunoglobulin products: a novel formulation, IGIV caprylate/chromatography (IGIV-C; Gamunex, 10%) and a licensed solvent/detergent-treated product, Gamimune N, 10% (IGIV-SD). The study, a randomized, double-blind, parallel group, therapeutic equivalence trial, was conducted at 25 treatment centers in Canada and the United States. Patients (n=172) having confirmed chronic primary immunodeficiency (PID), aged 1-75 years, and receiving IGIV therapy were enrolled. For 9 months, patients were treated with IGIV-C or IGIV-SD in accordance with the patient's individualized treatment regimen utilized before study entry. The primary endpoint was the proportion of patients with >or=1 validated acute sinopulmonary infection during the treatment period. Secondary endpoints included the proportion of patients with all infections, time to first infection, annual infection rates, lung function parameters, infusion-related safety and viral safety. The annual validated infection rate in the IGIV-C group was 0.18 compared to 0.43 in the IGIV-SD group (p=0.023). Nine patients receiving IGIV-C experienced validated infections, compared to 17 patients in IGIV-SD group (p=0.06). Acute sinusitis (validated plus clinically defined) was less frequent in the IGIV-C group (p=0.012). Presence of bronchiectasis did not affect efficacy. Adverse reactions were similar in frequency and severity in both groups. No evidence of viral transmission was observed. IGIV-C appears to be superior to IGIV-SD in preventing validated sinopulmonary infections, especially acute sinusitis, in patients with PID.

Cloning of the low-affinity murine granulocyte-macrophage colony-stimulating factor receptor and reconstitution of a high-affinity receptor complex

A cDNA clone (clone 71) that encodes a low-affinity receptor for murine granulocyte-macrophage colony-stimulating factor (GM-CSF) has been isolated by direct expression. This molecule is the homologue of the human GM-CSF receptor alpha subunit, although homology between these molecules is surprisingly low (less than 35% amino acid identity). The cDNA encodes a polypeptide of 387 amino acids, which contains the conserved features of the hematopoietin receptor superfamily. When expressed in COS-7 cells, this clone encodes a protein that binds radiolabeled murine GM-CSF with low affinity. Coexpression of clone 71 with a cDNA corresponding to a low-affinity interleukin 3 (IL-3) receptor (AIC2A) did not alter the affinity of binding of either GM-CSF or IL-3. However, coexpression of clone 71 with the IL-3 receptor-related cDNA AIC2B generated high-affinity binding sites for murine GM-CSF but not murine IL-3. These studies show that clone 71 and AIC2B are capable of forming an alpha beta complex capable of binding murine GM-CSF with high affinity, while AIC2A appears not to be a component of the murine GM-CSF receptor.

First report of the Hyper-IgM syndrome Registry of the Latin American Society for Immunodeficiencies: novel mutations, unique infections, and outcomes

Hyper-IgM (HIGM) syndrome is a heterogeneous group of disorders characterized by normal or elevated serum IgM levels associated with absent or decreased IgG, IgA and IgE. Here we summarize data from the HIGM syndrome Registry of the Latin American Society for Immunodeficiencies (LASID). Of the 58 patients from 51 families reported to the registry with the clinical phenotype of HIGM syndrome, molecular defects were identified in 37 patients thus far. We retrospectively analyzed the clinical, immunological and molecular data from these 37 patients. CD40 ligand (CD40L) deficiency was found in 35 patients from 25 families and activation-induced cytidine deaminase (AID) deficiency in 2 unrelated patients. Five previously unreported mutations were identified in the CD40L gene (CD40LG). Respiratory tract infections, mainly pneumonia, were the most frequent clinical manifestation. Previously undescribed fungal and opportunistic infections were observed in CD40L-deficient patients but not in the two patients with AID deficiency. These include the first cases of pneumonia caused by Mycoplasma pneumoniae, Serratia marcescens or Aspergillus sp. and diarrhea caused by Microsporidium sp. or Isospora belli. Except for four CD40L-deficient patients who died from complications of presumptive central nervous system infections or sepsis, all patients reported in this study are alive. Four CD40L-deficient patients underwent successful bone marrow transplantation. This report characterizes the clinical and genetic spectrum of HIGM syndrome in Latin America and expands the understanding of the genotype and phenotype of this syndrome in tropical areas.

Clinical and Genotypic Spectrum of Chronic Granulomatous Disease in 71 Latin American Patients: First Report from the LASID Registry

AIM

We analyzed data from 71 patients with chronic granulomatous disease (CGD) with a confirmed genetic diagnosis, registered in the online Latin American Society of Primary Immunodeficiencies (LASID) database.

RESULTS

Latin American CGD patients presented with recurrent and severe infections caused by several organisms. The mean age at disease onset was 23.9 months, and the mean age at CGD diagnosis was 52.7 months. Recurrent pneumonia was the most frequent clinical condition (76.8%), followed by lymphadenopathy (59.4%), granulomata (49.3%), skin infections (42%), chronic diarrhea (41.9%), otitis (29%), sepsis (23.2%), abscesses (21.7%), recurrent urinary tract infection (20.3%), and osteomyelitis (15.9%). Adverse reactions to bacillus Calmette-Guérin (BCG) vaccination were identified in 30% of the studied Latin American CGD cases. The genetic diagnoses of the 71 patients revealed 53 patients from 47 families with heterogeneous mutations in the CYBB gene (five novel mutations: p.W361G, p.C282X, p.W483R, p.R226X, and p.Q93X), 16 patients with the common deletion c.75_76 del.GT in exon 2 of NCF1 gene, and two patients with mutations in the CYBA gene.

CONCLUSION

The majority of Latin American CGD patients carry a hemizygous mutation in the CYBB gene. They also presented a wide range of clinical manifestations most frequently bacterial and fungal infections of the respiratory tract, skin, and lymph nodes. Thirty percent of the Latin American CGD patients presented adverse reactions to BCG, indicating that this vaccine should be avoided in these patients.

Blockade by dendrotoxin homologues of voltage-dependent K+ currents in cultured sensory neurones from neonatal rats

1. Homologues of dendrotoxin (Dtx) were isolated from the crude venom of Green and Black Mamba snakes and examined for K+ channel blocking activity in neonatal rat dorsal root ganglion cells (DRGs) by whole-cell patch clamp recording. 2. Outward potassium current activated by depolarization was composed of two major components: a slowly inactivating current (SIC, tau decay approximately 50 ms, 200 ms and 2s), and a non-inactivating current (NIC, tau decay > 2 min). Tail current analysis revealed two time constants of deactivation of total outward current, 3-12 ms and 50-150 ms (at -80 mV) which corresponded to SIC and NIC, respectively. 3. All the homologues (alpha-, beta-, gamma- and delta-Dtx and toxins I and K) blocked outward current activated by depolarization in a dose-dependent manner. The most potent in blocking total outward current was delta-Dtx (EC50 of 0.5 +/- 0.2 nM), although there were no statistically significant differences in potency between any of the homologues. 4. Qualitative differences in the nature of the block were noted between homologues. In particular, the block by delta-Dtx was time-dependent, whereas that by alpha-Dtx was not. 5. alpha-Dtx was a much better blocker of SIC (EC50 = 1.0 +/- 0.4 nM) than was delta-Dtx (EC50 = 17.6 +/- 5.8 nM). Furthermore, delta-Dtx was selective for NIC (EC50 +/- 0.24 +/- 0.03 nM) over SIC and reduced the slow component of tail currents (NIC), preferentially. On the other hand, a-Dtx did not significantly distinguish between SIC and NIC although tail current analysis showed that a-Dtxpreferentially reduced the fast component of tail currents (SIC).6. The results confirm, using direct electrophysiological methods, that homologues of dendrotoxins from Mamba snake venom block K+ channels in rat sensory neurones. Furthermore, a-Dtx and 6-Dtx distinguish between sub-types of K+ channels in these cells and may thus be useful pharmacological tools in other neuronal K+ channel studies.

Advances in primary immunodeficiency diseases in Latin America: epidemiology, research, and perspectives

Primary immunodeficiencies (PIDs) are genetic disorders of the immune system comprising many different phenotypes. Although previously considered rare, recent advances in their clinical, epidemiological, and molecular definitions are revealing how much we still need to learn about them. For example, geographical and ethnic variations as well as the impact of certain practices influence their frequency and presentation, making it necessary to consider their study in terms of regions. The Latin American Society for Immunodeficiencies was established as an organization dedicated to provide scientific support for basic and clinical research and to develop tools and educational resources to promote awareness in the medical community. Initiatives such as these are positively influencing the way PIDs are tackled in these countries, as shown by recent reports and publications. This paper provides a historical compilation and a current view of the many issues faced by scientists studying these diseases in these countries, highlighting the diverse scientific contributions and offering a promising perspective for the further developments in this field in Latin America.

A parent training model for toilet training children with autism

BACKGROUND

Azrin & Foxx pioneered an intensive toilet training protocol for individuals with intellectual disability living in a residential setting. Since the development of the Rapid Toilet Training (RTT) protocol, many have replicated the efficacy, most notably in educational and outpatient treatment settings, but often training over longer periods of time. This study presents data from a parent training model that replicates Azrin and Foxx's results and training time.

METHOD

This multiple baseline across subjects design study employs an ABA design where two boys diagnosed with autism were toilet trained using a modified Azrin & Foxx intensive teaching protocol. The first subject, a 4-year-old boy, did not have a history of attempted toilet training. The second subject, a 6-year-old boy, demonstrated a history of failed toilet training attempts in both the home and school settings. The trainings were conducted in the home setting where a novel parent-training approach was implemented.

RESULTS

Participant 1 was continent at the end of the second day of training, and completely toilet trained (including initiation and communication) by day 10 of the intervention. Participant 2 was continent after day 1 and completely toilet trained by day 5 of the intervention.

CONCLUSIONS

Long-term follow-up demonstrates maintenance of skills 3 years post training. Social validity via parent satisfaction was assessed. Limitations to the current study and recommendations for future research were discussed.

Case report: steroid sparing effect of intravenous gamma globulin in a child with necrotizing vasculitis

This article reports the case of a boy aged 2 years 6 months, who had fever, arthritis, and necrotizing cutaneous vasculitis. Evaluation revealed no evidence of direct infectious causes. However, high anti-streptolysin and streptozyme titers during the acute phase support the possibility that streptococcal infection played an important role in the pathogenesis of this disease. The patient's condition improved significantly with the administration of prednisone. However, several attempts to diminish the prednisone dose resulted in relapses. Subsequently, the prednisone was successfully tapered and discontinued after intravenous gamma globulin administration. It is recommended that intravenous gamma globulin should be considered before immunosuppressive therapy in the treatment of necrotizing vasculitis.

Thromboembolic prophylaxis in total hip replacement: a comparison between the low molecular weight heparinoid Lomoparan and heparin-dihydroergotamine

In a prospective, randomized, assessor-blind multicentre study two antithrombotic subcutaneous regimens were compared in patients undergoing total hip replacement. Group 1 (154 patients) received 750 anti-Xa units of a new low molecular weight heparinoid (Lomoparan) subcutaneously twice a day and group 2 (155 patients) received 5000 units heparin and 0.5 mg dihydroergotamine (heparin-DHE 5000) twice a day. The incidence of deep vein thrombosis, assessed by routine bilateral venography on day 10 (+/- 1), was 17 and 32 per cent in groups 1 and 2 respectively (risk reduction 47 per cent; P = 0.007). One patient in each group developed a symptomatic pulmonary embolism confirmed by lung scanning. Major bleeding complications occurred in one patient in each group and no significant difference was observed between the two groups with respect to minor bleeding complications. Subcutaneous Lomoparan appears to be as safe as heparin-DHE 5000 at the above doses with regard to bleeding complications, and is more efficacious with respect to venous thrombosis.

Quantitation of soluble HLA class I heterodimers and beta 2-microglobulin in patients with active pulmonary tuberculosis

Beta 2m serum levels have been shown to be increased in patients with tuberculosis and HIV infection. We determined the stability of beta 2m and of sHLA-I dimers in serum, and then determined the levels of both molecules in 60 non-HIV-infected patients with active pulmonary tuberculosis and in 55 adult controls. The levels of sHLA-I in samples kept at room temperature declined by 8% at 30 minutes, 16% at 60 minutes, and 36% at 120 minutes. Beta 2m levels remained stable at all times tested. Mean sHLA-I levels were 0.99 +/- 0.16 micrograms/ml in controls and 1.34 +/- 0.11 micrograms/ml in patients with tuberculosis (P < 0.0001). Beta 2m levels were 1.23 +/- 0.26 micrograms/ml in controls and 2.26 +/- 0.64 micrograms/ml in patients with tuberculosis (P < 0.0001). All patients with tuberculosis had elevation of sHLA-I and/or beta 2m above 1 standard deviation of normal values. However, there was no correlation between sHLA-I and beta 2m levels in individual samples. Evaluation of sHLA-I holds the promise of further understanding of the biology and genetic regulation of the immune response to mycobacterial infection.

Is it necessary to identify molecular defects in primary immunodeficiency disease?

The identification of the molecular bases of more than 130 primary immunodeficiency diseases has prompted the use of mutation analysis in the diagnostic approach to these patients. Here we discuss the importance of and the limitations associated with molecular diagnosis of these disorders and emphasize the need that mutation analysis be accompanied by appropriate evidence that the identified genetic defect has pathologic consequences on RNA/protein expression and function.

6th International Immunoglobulin Symposium: poster presentations

The posters presented at the 6th International Immunoglobulin Symposium covered a wide range of fields and included both basic science and clinical research. From the abstracts accepted for poster presentation, 12 abstracts were selected for oral presentations in three parallel sessions on immunodeficiencies, autoimmunity and basic research. The immunodeficiency presentations dealt with novel, rare class-switch recombination (CSR) deficiencies, attenuation of adverse events following IVIg treatment, association of immunoglobulin (Ig)G trough levels and protection against acute infection in patients with X-linked agammaglobulinaemia (XLA) and common variable immunodeficiency (CVID), and the reduction of class-switched memory B cells in patients with specific antibody deficiency (SAD). The impact of intravenous immunoglobulin on fetal alloimmune thrombocytopenia, pregnancy and postpartum-related relapses in multiple sclerosis and refractory myositis, as well as experiences with subcutaneous immunoglobulin in patients with multi-focal motor neuropathy, were the topics presented in the autoimmunity session. The interaction of dendritic cell (DC)-SIGN and alpha2,6-sialylated IgG Fc and its impact on human DCs, the enrichment of sialylated IgG in plasma-derived IgG, as wells as prion surveillance and monitoring of anti-measles titres in immunoglobulin products, were covered in the basic science session. In summary, the presentations illustrated the breadth of immunoglobulin therapy usage and highlighted the progress that is being made in diverse areas of basic and clinical research, extending our understanding of the mechanisms of immunoglobulin action and contributing to improved patient care.

Rheumatologic manifestations of primary immunodeficiency diseases

In the last 5 years, several hundred articles have been published concerning the link between primary immunodeficiency disease (PID) and rheumatologic diseases. Although rheumatologic complications were originally thought to be at the opposite ends of the spectrum of immunopathologic manifestations, they are now all being considered secondary manifestations of a causative primary "immune derangement." For the rheumatologist, it is important to be able to identify patients who may present with typical rheumatologic findings but who have an underlying PID. In a systematic manner, this overview addresses both the systemic and organ-based rheumatologic diseases which have known associations with primary immunodeficiencies, and explores how immunodeficiency may actually cause these clinical manifestations.