Ataxia-telangiectasia in Iran: clinical and laboratory features of 104 patients

Ataxia-telangiectasia in Latin America: clinical features, immunodeficiency, and mortality in a multicenter study

Ataxia-telangiectasia (AT) is a rare genetic disorder leading to neurological defects, telangiectasias, and immunodeficiency. We aimed to study the clinical and immunological features of Latin American patients with AT and analyze factors associated with mortality. Referral centers from 9 Latin American countries participated in this retrospective cohort study, and 218 patients were included.  Median (IQR) ages at symptom onset and diagnosis were 1.0 (1.0-2.0)  and 5.0 (3.0-8.0) years, respectively. Most patients presented recurrent airway infections, which was significantly associated with IgA deficiency. IgA deficiency was observed in 60.8% of patients and IgG deficiency in 28.6%. T- and B-lymphopenias were also present in most cases. Mean survival was 24.2 years, and Kaplan-Meier 20-year-survival rate was 52.6%, with higher mortality associated with female gender and low IgG levels. These findings suggest that immunologic status should be investigated in all patients with AT.

The clinical spectrum of ataxia telangiectasia in a cohort in Sweden

Ataxia telangiectasia (A-T), caused by biallelic variants in the ATM gene, is a multisystemic and severe syndrome characterized by progressive ataxia, telangiectasia, hyperkinesia, immunodeficiency, increased risk of malignancy, and typically death before the age of 30. In this retrospective study we describe the phenotype of 14 pediatric and adult A-T patients evaluated at the Karolinska University Hospital in Sweden during the last 12 years. Most of the patients in this cohort were severely affected by ataxia and wheelchair use started at a median age of 9 years. One patient died before the age of 30 years, but five patients had survived beyond this age. Four patients received prophylactic immunoglobulin replacement therapy due to hypogammaglobulinemia and respiratory complications ranged from mild to moderate severity. Three patients developed type 2 diabetes in young adulthood and nine patients (64%) had a history of elevated liver function tests. Four patients were diagnosed with cancer at ages 7, 41, 47, and 49 years. All the ATM variants in these patients were previously reported as pathogenic except one, c.6040G > A, which results in a p.Glu2014Lys missense variant. With increased life expectancy, A-T complications such as diabetes type 2 and liver disease may become more common. Despite having severe neurological presentations, the A-T patients in this case series had relatively mild infectious and respiratory complications.

Peripheral neuropathies associated with DNA repair disorders

Repair of genomic DNA is a fundamental housekeeping process that quietly maintains the health of our genomes. The consequences of a genetic defect affecting a component of this delicate mechanism are quite harmful, characterized by a cascade of premature aging that injures a variety of organs, including the nervous system. One part of the nervous system that is impaired in certain DNA repair disorders is the peripheral nerve. Chronic motor, sensory, and sensorimotor polyneuropathies have all been observed in affected individuals, with specific physiologies associated with different categories of DNA repair disorders. Cockayne syndrome has classically been linked to demyelinating polyneuropathies, whereas xeroderma pigmentosum has long been associated with axonal polyneuropathies. Three additional recessive DNA repair disorders are associated with neuropathies, including trichothiodystrophy, Werner syndrome, and ataxia-telangiectasia. Although plausible biological explanations exist for why the peripheral nerves are specifically vulnerable to impairments of DNA repair, specific mechanisms such as oxidative stress remain largely unexplored in this context, and bear further study. It is also unclear why different DNA repair disorders manifest with different types of neuropathy, and why neuropathy is not universally present in those diseases. Longitudinal physiological monitoring of these neuropathies with serial electrodiagnostic studies may provide valuable noninvasive outcome data in the context of future natural history studies, and thus the responses of these neuropathies may become sentinel outcome measures for future clinical trials of treatments currently in development such as adeno-associated virus gene replacement therapies.

The natural history of ataxia-telangiectasia (A-T): A systematic review

BACKGROUND

Ataxia-telangiectasia is an autosomal recessive, multi-system, and life-shortening disease caused by mutations in the ataxia-telangiectasia mutated gene. Although widely reported, there are no studies that give a comprehensive picture of this intriguing condition.

OBJECTIVES

Understand the natural history of ataxia-telangiectasia (A-T), as reported in scientific literature.

SEARCH METHODS

107 search terms were identified and divided into 17 searches. Each search was performed in PubMed, Ovid SP (MEDLINE) 1946-present, OVID EMBASE 1980 -present, Web of Science core collection, Elsevier Scopus, and Cochrane Library.

SELECTION CRITERIA

All human studies that report any aspect of A-T.

DATA COLLECTION AND ANALYSIS

Search results were de-duplicated, data extracted (including author, publication year, country of origin, study design, population, participant characteristics, and clinical features). Quality of case-control and cohort studies was assessed by the Newcastle-Ottawa tool. Findings are reported descriptively and where possible data collated to report median (interquartile range, range) of outcomes of interest.

MAIN RESULTS

1314 cases reported 2134 presenting symptoms. The most common presenting symptom was abnormal gait (1160 cases; 188 studies) followed by recurrent infections in classical ataxia-telangiectasia and movement disorders in variant ataxia-telangiectasia. 687 cases reported 752 causes of death among which malignancy was the most frequently reported cause. Median (IQR, range) age of death (n = 294) was 14 years 0 months (10 years 0 months to 23 years 3 months, 1 year 3 months to 76 years 0 months).

CONCLUSIONS

This review demonstrates the multi-system involvement in A-T, confirms that neurological symptoms are the most frequent presenting features in classical A-T but variants have diverse manifestations. We found that most individuals with A-T have life limited to teenage or early adulthood. Predominance of case reports, and case series demonstrate the lack of robust evidence to determine the natural history of A-T. We recommend population-based studies to fill this evidence gap.

Global systematic review of primary immunodeficiency registries

INTRODUCTION

During the last 4 decades, registration of patients with primary immunodeficiencies (PID) has played an essential role in different aspects of these diseases worldwide including epidemiological indexes, policymaking, quality controls of care/life, facilitation of genetic studies and clinical trials as well as improving our understanding about the natural history of the disease and the immune system function. However, due to the limitation of sustainable resources supporting these registries, inconsistency in diagnostic criteria and lack of molecular diagnosis as well as difficulties in the documentation and designing any universal platform, the global perspective of these diseases remains unclear.

AREAS COVERED

Published and unpublished studies from January 1981 to June 2020 were systematically reviewed on PubMed, Web of Science and Scopus. Additionally, the reference list of all studies was hand-searched for additional studies. This effort identified a total of 104614 registered patients and suggests identification of at least 10590 additional PID patients, mainly from countries located in Asia and Africa. Molecular defects in genes known to cause PID were identified and reported in 13852 (13.2% of all registered) patients.

EXPERT OPINION

Although these data suggest some progress in the identification and documentation of PID patients worldwide, achieving the basic requirement for the global PID burden estimation and registration of undiagnosed patients will require more reinforcement of the progress, involving both improved diagnostic facilities and neonatal screening.

Clinical complications and their management in a child with ataxia-telangiectasia (A-T): A case report study

Ataxia-telangiectasia (A-T) is known as an uncommon autosomal recessive disorder associated with recurrent infections and other clinical complications. The management of its complications can improve life quality of patients.

Variable Abnormalities in T and B Cell Subsets in Ataxia Telangiectasia

BACKGROUND

Ataxia-telangiectasia (AT) is a rare genetic condition, caused by biallelic deleterious variants in the ATM gene, and has variable immunological abnormalities. This study aimed to examine immunologic parameters reflecting cell development, activation, proliferation, and class switch recombination (CSR) and determine their relationship to the clinical phenotype in AT patients.

METHODS

In this study, 40 patients with a confirmed diagnosis of AT from the Iranian immunodeficiency registry center and 28 age-sex matched healthy controls were enrolled. We compared peripheral B and T cell subsets and T cell proliferation response to CD3/CD28 stimulation in AT patients with and without CSR defects using flow cytometry.

RESULTS

A significant decrease in naïve, transitional, switched memory, and IgM only memory B cells, along with a sharp increase in the marginal zone-like and CD21^low B cells was observed in the patients. We also found CD4⁺ and CD8⁺ naïve, central memory, and terminally differentiated effector memory CD4⁺ (T_EMRA) T cells were decreased. CD4⁺ and CD8⁺ effector memory, CD8⁺ T_EMRA, and CD4⁺ regulatory T cells were significantly elevated in our patients. CD4⁺ T cell proliferation was markedly impaired compared to the healthy controls. Moreover, immunological investigations of 15 AT patients with CSR defect revealed a significant reduction in the marginal zone, switched memory, and more intense defects in IgM only memory B cells, CD4⁺ naïve and central memory T cells.

CONCLUSION

The present study revealed that patients with AT have a broad spectrum of cellular and humoral deficiencies. Therefore, a detailed evaluation of T and B cell subsets increases understanding of the disease in patients and the risk of infection.

Update on DNA-Double Strand Break Repair Defects in Combined Primary Immunodeficiency

PURPOSE OF REVIEW

The most serious DNA damage, DNA double strand breaks (DNA-dsb), leads to mutagenesis, carcinogenesis or apoptosis if left unrepaired. Non-homologous end joining (NHEJ) is the principle repair pathway employed by mammalian cells to repair DNA-dsb. Several proteins are involved in this pathway, defects in which can lead to human disease. This review updates on the most recent information available for the specific diseases associated with the pathway.

RECENT FINDINGS

A new member of the NHEJ pathway, PAXX, has been identified, although no human disease has been associated with it. The clinical phenotypes of Artemis, DNA ligase 4, Cernunnos-XLF and DNA-PKcs deficiency have been extended. The role of haematopoietic stem cell transplantation, following reduced intensity conditioning chemotherapy, for many of these diseases is being advanced. In the era of newborn screening, urgent genetic diagnosis is necessary to correctly target appropriate treatment for patients with DNA-dsb repair disorders.

Past and Present of Eye Movement Abnormalities in Ataxia-Telangiectasia

Ataxia-telangiectasia is the second most common autosomal recessive hereditary ataxia, with an estimated incidence of 1 in 100,000 births. Besides ataxia and ocular telangiectasias, eye movement abnormalities have long been associated with this disorder and is frequently present in almost all patients. A handful of studies have described the phenomenology of ocular motor deficits in ataxia-telangiectasia. Contemporary literature linked their physiology to cerebellar dysfunction and secondary abnormalities at the level of brainstem. These studies, while providing a proof of concept of ocular motor physiology in disease, i.e., ataxia-telangiectasia, also advanced our understanding of how the cerebellum works. Here, we will summarize the clinical abnormalities seen with ataxia-telangiectasia in each subtype of eye movements and subsequently describe the underlying pathophysiology. Finally, we will review how these deficits are linked to abnormal cerebellar function and how it allows better understanding of the cerebellar physiology.

Ataxia-telangiectasia: A review of clinical features and molecular pathology

Ataxia-telangiectasia (A-T) is an autosomal recessive primary immunodeficiency (PID) disease that is caused by mutations in ataxia-telangiectasia mutated (ATM) gene encoding a serine/threonine protein kinase. A-T patients represent a broad range of clinical manifestations including progressive cerebellar ataxia, oculocutaneous telangiectasia, variable immunodeficiency, radiosensitivity, susceptibility to malignancies, and increased metabolic diseases. This congenital disorder has phenotypic heterogeneity, and the severity of symptoms varies in different patients based on severity of mutations and disease progression. The principal role of nuclear ATM is the coordination of cellular signaling pathways in response to DNA double-strand breaks, oxidative stress, and cell cycle checkpoint. The pathogenesis of A-T is not limited to the role of ATM in the DNA damage response (DDR) pathway, and it has other functions mainly in the hematopoietic cells and neurons. ATM adjusts the functions of organelles such as mitochondria and peroxisomes and also regulates angiogenesis and glucose metabolisms. However, ATM has other functions in the cells (especially cell viability) that need further investigations. In this review, we described functions of ATM in the nucleus and cytoplasm, and also its association with some disorder formation such as neurologic, immunologic, vascular, pulmonary, metabolic, and dermatologic complications.

The Rare Neurocutaneous Disorders: Update on Clinical, Molecular, and Neuroimaging Features

Phakomatoses, also known as neurocutaneous disorders, comprise a vast number of entities that predominantly affect structures originated from the ectoderm such as the central nervous system and the skin, but also the mesoderm, particularly the vascular system. Extensive literature exists about the most common phakomatoses, namely neurofibromatosis, tuberous sclerosis, von Hippel-Lindau and Sturge-Weber syndrome. However, recent developments in the understanding of the molecular underpinnings of less common phakomatoses have sparked interest in these disorders. In this article, we review the clinical features, current pathogenesis, and modern neuroimaging findings of melanophakomatoses, vascular phakomatoses, and other rare neurocutaneous syndromes that may also include tissue overgrowth or neoplastic predisposition.

Ataxia-telangiectasia with a novel ATM gene mutation and Burkitt leukemia: A case report

Ataxia-telangiectasia (A-T) is an infrequent autosomal recessive disorder that involves multiple systems and is characterized by progressive cerebellar ataxia, oculocutaneous telangiectasias, radiosensitivity, immune deficiency with recurrent respiratory infections, and a tendency to develop lymphoid malignancies. A-T is caused by mutations in the ATM gene, with >1,000 mutations reported to date and gradually increasing in number. Patients with A-T have an increased incidence of cancers. The aim of the present study was to retrospectively review the case of a patient who presented at the age of 5 years with cerebellar ataxia without telangiectasia, and was diagnosed with Burkitt leukemia by bone marrow biopsy and molecular testing at the age of 7 years at the Xiangya Hospital of Central South University (Changsha, China). The patient received chemotherapy with the pediatric CCCG-BNHL-2015 regimen (R4 group) and achieved a complete remission after 2 courses. However, recurrent respiratory infections and thrombosis occurred during chemotherapy. The diagnosis of A-T was confirmed by uncovering two variants of the ATM gene, including c.742C>T (p.R248X; rs730881336) in exon 7 and c.6067-c.6068 ins GAGGGAAGAT in exon 41 by whole-exome sequencing. Unfortunately, the patient's parents refused follow-up treatment and he succumbed to recurrent severe infections 4 months after the diagnosis of Burkitt leukemia. The diagnosis of A-T may be challenging, as its phenotype can be incomplete early in the course of the disease. Detailed medical history, characteristic clinical manifestations and increasingly developed exome sequencing techniques may be helpful in diagnosing this rare disease. Management should be based on multidisciplinary guidance and other treatment options must be investigated in the future.

Inflammation, a significant player of Ataxia-Telangiectasia pathogenesis?

INTRODUCTION

Ataxia-Telangiectasia (A-T) syndrome is an autosomal recessive neurodegenerative disorder characterized by cerebellar ataxia, oculocutaneous telangiectasia, immunodeficiency, chromosome instability, radiosensitivity, and predisposition to malignancy. There is growing evidence that A-T patients suffer from pathologic inflammation that is responsible for many symptoms of this syndrome, including neurodegeneration, autoimmunity, cardiovascular disease, accelerated aging, and insulin resistance. In addition, epidemiological studies have shown A-T heterozygotes, somewhat like deficient patients, are susceptible to ionizing irradiation and have a higher risk of cancers and metabolic disorders.

AREA COVERED

This review summarizes clinical and molecular findings of inflammation in A-T syndrome.

CONCLUSION

Ataxia-Telangiectasia Mutated (ATM), a master regulator of the DNA damage response is the protein known to be associated with A-T and has a complex nuclear and cytoplasmic role. Loss of ATM function may induce immune deregulation and systemic inflammation.

Ataxia-telangiectasia: A review of movement disorders, clinical features, and genotype correlations

Ataxia-telangiectasia is an autosomal recessive neurodegenerative disorder that was initially thought to present exclusively in childhood. With the discovery of the ATM gene, the phenotypic spectrum of the condition has expanded. This review elaborates the expanded phenomenology, including oculomotor apraxia and immunodeficiency, and estimates the presence of each movement disorder feature from previously reported literature. Initial manifestations of Ataxia-telangiectasia include cerebellar symptoms (67%), dystonia (18%), choreoathetosis (10%), and tremor (4%), with parkinsonism and myoclonus not reported as initial features. The prevalence of movement disorders during the course of the disease includes cerebellar symptoms (96%), dystonia (89%), parkinsonism (41%), choreoathetosis (89%), myoclonus (92%), and tremor (74%). Phenomenology and age of onset is modulated by presence of residual ATM kinase activity, with genotypes heavily truncating the ATM protein associated with the most severe phenotypes. Ataxia-telangiectasia commonly results in a spectrum of movement disorders beyond ataxia and telangiectasias. © 2018 International Parkinson and Movement Disorder Society.

Ataxia telangiectasia syndrome: moonlighting ATM

INTRODUCTION

Ataxia-telangiectasia (A-T) a multisystem disorder primarily characterized by cerebellar degeneration, telangiectasia, immunodeficiency, cancer susceptibility and radiation sensitivity. Identification of the gene defective in this syndrome, ataxia-telangiectasia mutated gene (ATM), and further characterization of the disorder together with a greater insight into the function of the ATM protein have expanded our knowledge about the molecular pathogenesis of this disease. Area covered: In this review, we have attempted to summarize the different roles of ATM signaling that have provided new insights into the diverse clinical phenotypes exhibited by A-T patients. Expert commentary: ATM, in addition to DNA repair response, is involved in many cytoplasmic roles that explain diverse phenotypes of A-T patients. It seems accumulation of DNA damage, persistent DNA damage response signaling, and chronic oxidative stress are the main players in the pathogenesis of this disease.

Ataxia telangiectasia in Turkey: multisystem involvement of 91 patients

BACKGROUND

Ataxia telangiectasia (AT) is a genetically based multisystemic disorder. We aimed to make a comprehensive evaluation of multisystem involvement in AT by describing clinical features and outcome of 91 patients.

METHODS

Medical records of the patients who were diagnosed and followed by a multidisciplinary approach during a 27-year period (1988-2015) were reviewed retrospectively.

RESULTS

Forty six female and 45 male patients with a mean follow-up period of 39.13±4.28 months were evaluated. The mean age at the time of symptom onset and diagnosis were 15.4±1.09 months and 73.61±4.11 months, respectively. Neurological abnormalities were progressive truncal ataxia, nystagmus, dysarthria, oculomotor apraxia and choreoathetosis. Thirty one patients (34.1%) became dependent on wheelchair at a mean age of 12.1±2.8 years. Eleven patients (12.1%) became bedridden by a mean age of 14.7±1.8 years. Cranial magnetic resonance imaging revealed pathological findings in 47/66 patients. Abnormal immunological parameters were determined in 51/91 patients: immunoglobulin (Ig)A deficiency (n=38), lymphopenia (n=30), IgG (n=15) and IgG₂ (n=11) deficiency. Occurrence of recurrent sinopulmonary infections (n=45) and bronchiectasis (n=22) were found to be more common in patients with impaired immunological parameters (P=0.029 and P=0.023, respectively). Malignancy developed in 5 patients, being mostly lymphoreticular in origin and resulted in death of 4 patients.

CONCLUSIONS

AT is a long lasting disease with multisystem involvement necessitating multidisciplinary follow up, as described in our cohort. Early diagnosis of malignancy and supportive treatments regarding pulmonary and neurological health may prolong survival and increase the quality of life.

Ataxia-telangiectasia: recommendations for multidisciplinary treatment

Ataxia-telangiectasia is a rare, neurodegenerative, and multisystem disease, characterized by cerebellar ataxia, oculocutaneous telangiectasia, immunodeficiency, progressive respiratory failure, and an increased risk of malignancies. It demands specialized care tailored to the individual patient's needs. Besides the classic ataxia-telangiectasia phenotype, a variant phenotype exists with partly overlapping but some distinctive disease characteristics. This guideline summarizes frequently encountered medical problems in the disease course of patients with classic and variant ataxia-telangiectasia, in the domains of neurology, immunology and infectious diseases, pulmonology, anaesthetic and perioperative risk, oncology, endocrinology, and nutrition. Furthermore, it provides a practical guide with evidence- and expert-based recommendations for the follow-up and treatment of all these different clinical topics.

Ataxia telangiectasia: a review

DEFINITION OF THE DISEASE

Ataxia telangiectasia (A-T) is an autosomal recessive disorder primarily characterized by cerebellar degeneration, telangiectasia, immunodeficiency, cancer susceptibility and radiation sensitivity. A-T is often referred to as a genome instability or DNA damage response syndrome.

EPIDEMIOLOGY

The world-wide prevalence of A-T is estimated to be between 1 in 40,000 and 1 in 100,000 live births.

CLINICAL DESCRIPTION

A-T is a complex disorder with substantial variability in the severity of features between affected individuals, and at different ages. Neurological symptoms most often first appear in early childhood when children begin to sit or walk. They have immunological abnormalities including immunoglobulin and antibody deficiencies and lymphopenia. People with A-T have an increased predisposition for cancers, particularly of lymphoid origin. Pulmonary disease and problems with feeding, swallowing and nutrition are common, and there also may be dermatological and endocrine manifestations.

ETIOLOGY

A-T is caused by mutations in the ATM (Ataxia Telangiectasia, Mutated) gene which encodes a protein of the same name. The primary role of the ATM protein is coordination of cellular signaling pathways in response to DNA double strand breaks, oxidative stress and other genotoxic stress.

DIAGNOSIS

The diagnosis of A-T is usually suspected by the combination of neurologic clinical features (ataxia, abnormal control of eye movement, and postural instability) with one or more of the following which may vary in their appearance: telangiectasia, frequent sinopulmonary infections and specific laboratory abnormalities (e.g. IgA deficiency, lymphopenia especially affecting T lymphocytes and increased alpha-fetoprotein levels). Because certain neurological features may arise later, a diagnosis of A-T should be carefully considered for any ataxic child with an otherwise elusive diagnosis. A diagnosis of A-T can be confirmed by the finding of an absence or deficiency of the ATM protein or its kinase activity in cultured cell lines, and/or identification of the pathological mutations in the ATM gene.

DIFFERENTIAL DIAGNOSIS

There are several other neurologic and rare disorders that physicians must consider when diagnosing A-T and that can be confused with A-T. Differentiation of these various disorders is often possible with clinical features and selected laboratory tests, including gene sequencing.

ANTENATAL DIAGNOSIS

Antenatal diagnosis can be performed if the pathological ATM mutations in that family have been identified in an affected child. In the absence of identifying mutations, antenatal diagnosis can be made by haplotype analysis if an unambiguous diagnosis of the affected child has been made through clinical and laboratory findings and/or ATM protein analysis.

GENETIC COUNSELING

Genetic counseling can help family members of a patient with A-T understand when genetic testing for A-T is feasible, and how the test results should be interpreted.

MANAGEMENT AND PROGNOSIS

Treatment of the neurologic problems associated with A-T is symptomatic and supportive, as there are no treatments known to slow or stop the neurodegeneration. However, other manifestations of A-T, e.g. immunodeficiency, pulmonary disease, failure to thrive and diabetes can be treated effectively.

Loss of the DNA Damage Repair Kinase ATM Impairs Inflammasome-Dependent Anti-Bacterial Innate Immunity

The ATM kinase is a central component of the DNA damage repair machinery and redox balance. ATM dysfunction results in the multisystem disease ataxia-telangiectasia (AT). A major cause of mortality in AT is respiratory bacterial infections. Whether ATM deficiency causes innate immune defects that might contribute to bacterial infections is not known. Here we have shown that loss of ATM impairs inflammasome-dependent anti-bacterial innate immunity. Cells from AT patients or Atm(-/-) mice exhibited diminished interleukin-1β (IL-1β) production in response to bacteria. In vivo, Atm(-/-) mice were more susceptible to pulmonary S. pneumoniae infection in a manner consistent with inflammasome defects. Our data indicate that such defects were due to oxidative inhibition of inflammasome complex assembly. This study reveals an unanticipated function of reactive oxygen species (ROS) in negative regulation of inflammasomes and proposes a theory for the notable susceptibility of AT patients to pulmonary bacterial infection.

Long-term follow-up of ninety eight Iranian patients with primary immune deficiency in a single tertiary centre

PURPOSE

The aim was to describe the clinical manifestations, complications and long-term outcome of a cohort of Iranian patients with primary immune deficiency (PID).

METHOD

We retrospectively studied the demographic, clinical and immunological characteristics of the PID patients in a single tertiary centre, from January 1989 to July 2014. The patients were classified according to the International Union of Immunological Societies Expert Committee on PID.

RESULTS

98 patients were diagnosed with and followed-up for 15 disorders. The mean age at onset and diagnosis and the diagnostic delay were 8±10, 14.2±13.1 and 6.1±7 years, respectively. Parental consanguinity rate was 57%. Predominantly Antibody Deficiency was the most common diagnosis (n=63), followed by congenital defects of phagocytes (n=16), combined immunodeficiencies (n=12), well defined syndromes (n=4) and defects in innate immunity (n=3). Recurrent sinopulmonary infection was the most common presentation. Active infections were treated appropriately, in addition to prophylactic therapy with IVIG and antimicrobials. Not all the patients were compliant with prophylactic regimens due to cost and unavailability. One SCID patient underwent successful bone marrow transplantation. The total mortality rate was 19% during the follow-up period (7.8±7.6 years). The mean age of living patients at the time of study was 23±11.7 years.

CONCLUSIONS

Physicians awareness of PID has been rising dramatically in Iran, ensuring an increasing number of patients being diagnosed and treated. More effective treatment services, including health insurance coverage and drug availability are needed to improve the outcome of PID patients.

ERS statement on the multidisciplinary respiratory management of ataxia telangiectasia

Ataxia telangiectasia (A-T) is a rare, progressive, multisystem disease that has a large number of complex and diverse manifestations which vary with age. Patients with A-T die prematurely with the leading causes of death being respiratory diseases and cancer. Respiratory manifestations include immune dysfunction leading to recurrent upper and lower respiratory infections; aspiration resulting from dysfunctional swallowing due to neurodegenerative deficits; inefficient cough; and interstitial lung disease/pulmonary fibrosis. Malnutrition is a significant comorbidity. The increased radiosensitivity and increased risk of cancer should be borne in mind when requesting radiological investigations. Aggressive proactive monitoring and treatment of these various aspects of lung disease under multidisciplinary expertise in the experience of national multidisciplinary clinics internationally forms the basis of this statement on the management of lung disease in A-T. Neurological management is outwith the scope of this document.

Nutritional status of patients with ataxia-telangiectasia: A case for early and ongoing nutrition support and intervention

AIM

Ataxia-telangiectasia (A-T) is a rare genomic syndrome resulting in severe disability. Chronic childhood disorders can profoundly influence growth and development. Nutrition-related issues in A-T are not well described, and there are no nutritional guidelines. This study investigated the nutrition-related characteristics and behaviours of Australian A-T patients attending a national clinic.

METHODS

A cross-sectional analysis of 13 A-T patients (nine females; aged: 4-23 years): nutritional status was assessed by anthropometric and body cell mass (BCM) calculations. Parents reported their child's diet history and physical and behavioural factors that affect nutrition including fatigue and need for assistance.

RESULTS

Ten (77%) had short stature (height for age z scores <-1), and seven (54%) were underweight for height (weight/height z scores <-1). Significant malnutrition (BCM z scores <-2) was detected in nine (69%) including the one adult who was severely malnourished. Malnutrition increased significantly with age (BCM for height z scores and age, r = -0.937, P < 0.001). Eight (62%) patients ate poorly compared with estimated energy requirement for weight. Poor diet quality was characterised by high fat and sugar choices. Parents reported significant nutritional barriers as chronic tiredness and the need for care giver assistance with meals.

CONCLUSIONS

This study confirms profound malnutrition in Australian A-T patients. Poor intakes and diet quality suggest the need for early nutrition intervention. Ongoing support for families and early discussions on tube feeding are required to address changing needs in childhood and likely nutritional decline into adulthood. A prospective study is required to assess feasibility and effectiveness of nutrition interventions in young people with A-T.

Ataxia-telangiectasia - A historical review and a proposal for a new designation: ATM syndrome

The authors review ataxia telangiectasia, emphasizing historical aspects, genetic discoveries, and the clinical presentations of the classical and atypical forms. In fact, ataxia telangiectasia represents a multisystem entity with pleomorphic neurological and systemic manifestations. ATM syndrome is proposed as a more adequate designation for this entity.

Laboratory diagnosis of primary immunodeficiencies

Primary immune deficiency disorders represent a highly heterogeneous group of disorders with an increased propensity to infections and other immune complications. A careful history to delineate the pattern of infectious organisms and other complications is important to guide the workup of these patients, but a focused laboratory evaluation is essential to the diagnosis of an underlying primary immunodeficiency. Initial workup of suspected immune deficiencies should include complete blood counts and serologic tests of immunoglobulin levels, vaccine titers, and complement levels, but these tests are often insufficient to make a diagnosis. Recent advancements in the understanding of the immune system have led to the development of novel immunologic assays to aid in the diagnosis of these disorders. Classically utilized to enumerate lymphocyte subsets, flow cytometric-based assays are increasingly utilized to test immune cell function (e.g., neutrophil oxidative burst, NK cytotoxicity), intracellular cytokine production (e.g., TH17 production), cellular signaling pathways (e.g., phosphor-STAT analysis), and protein expression (e.g., BTK, Foxp3). Genetic testing has similarly expanded greatly as more primary immune deficiencies are defined, and the use of mass sequencing technologies is leading to the identification of novel disorders. In order to utilize these complex assays in clinical care, one must have a firm understanding of the immunologic assay, how the results are interpreted, pitfalls in the assays, and how the test affects treatment decisions. This article will provide a systematic approach of the evaluation of a suspected primary immunodeficiency, as well as provide a comprehensive list of testing options and their results in the context of various disease processes.

Do elevated serum IgM levels have to be included in probable diagnosis criteria of patients with ataxia-telangiectasia?

Ataxia-telangiectasia (AT) is a rare multisystem, neurodegenerative genetic disorder that is characterised by progressive neurological abnormalities, oculocutaneous telangiectasias and immunodeficiency. Delay in diagnosis or misdiagnosis is probable due to its wide clinical heterogeneity in infancy. Recurrent sinopulmonary infections are often the only presenting symptom and usually patients have decreased immunoglobulins. A total 10% of patients who present with decreased serum immunoglobulin G and A and with normal or elevated immunoglobulin M levels are often misdiagnosed as hyperimmunoglobulin M syndrome. Definitive diagnosis is made if a patient with progressive cerebellar ataxia has a disease causing mutation on the ATM gene. Ataxia-telangiectasia guideline of the European Society for Immunodeficiencies defines the probable diagnosis criteria. We evaluated twenty ataxia-telangiectasia patients (mean age 13.8±4.1 years) retrospectively who were followed-up for a mean of 38.6±27.0 months. Twelve patients had a family history of consanguinity. A total of 80&#x0025; patients suffered from various infections. Neoplasms occurred in three of them. Patients showed immunological abnormalities as low IgG (45%), low IgA (65%) and elevated IgM (60%) levels. CD3+CD4+ T lymphocyte frequency was low in 45% patients. The mean AFP concentration at the diagnosis was 191.9±140.1 ng/mL and the raised IgM values did not show any statistically significant relationship with high AFP concentrations. Frequency of the elevated IgM concentrations in (60%) patients raises the concerns about thinking this finding has to be accepted as a probable diagnosis criterium.

Non invasive assessment of lung disease in ataxia telangiectasia by high-field magnetic resonance imaging

PURPOSE

A sensitive imaging technique that assesses ataxia telangiectasia (AT) lung disease without ionizing radiation is highly desirable. We designed a study to evaluate lung changes using magnetic resonance imaging (MRI), and to investigate the relationships among severity and extent of pulmonary abnormalities and clinical, microbiological and functional data in children and young adults with AT.

METHODS

Fifteen AT patients (age, 11.3 years; range, 6-31) underwent 3.0-T MRI, spirometry, and deep throat or sputum culture. Images were scored using a modified Helbich score.

RESULTS

Although only 8 patients (53 %) had recurrent/chronic respiratory symptoms, MRI identified lung abnormalities in all. Bronchiectasis, peribronchial thickening, mucous plugging, and collapse/consolidation were present in 60 %, 87 %, 67 %, and 13 % of cases, respectively, with no difference between subjects with or without respiratory symptoms. No difference in changes of specific scores was found between the two groups, but the total MRI score was higher in patients with respiratory symptoms (6.5 versus 5, respectively; p = 0.02). Total or specific MRI scores were not associated with patients' age. Of all scores, only mucous plugging subscore appeared significantly related to FEV1 (r = 0.7, p = 0.04) and FEF25-75% (r = 0.9, p = 0.001). MRI scores from patients with positive (n = 5) or negative (n = 10) sputum culture were not significantly different.

CONCLUSIONS

MRI is valuable in the assessment of extent and severity of pulmonary changes in children and adults with AT. It represents an helpful tool for the longitudinal evaluation of patients and may be also used as an outcome surrogate to track the effects of medications.

Clinical predictors of primary immunodeficiency diseases in children

Purpose

To promote awareness of primary immunodeficiency (PID), the "10 warning signs" of PID and an immunodeficiency-related (IDR) score were developed. However, their efficiency in identifying PID cases was not sufficiently evaluated in clinical practice. The objective of this study was to test the validity of the 10 warning signs and IDR score in identifying PID among children with recurrent infections at a tertiary pediatric hospital in Egypt.

Methods

A retrospective analysis of the medical records of 204 patients was performed. Of these patients, 92 had defined PID diseases and 112 were considered non-PID cases because investigations were inconclusive.

Results

Demonstrating two warning signs and an IDR score of 6 led to sensitivities of 94 and 66%, respectively, and specificities of 64 and 75%, respectively, in identifying PID cases. The strongest predictor of PID was family history that, if combined with the need for intravenous antibiotics, recurrent deep-seated infections, and failure to thrive, could identify 81% of PID patients. A family history of PID, sibling death, and/or parental consanguinity would predict 92% of combined immunodeficiencies, 92% of phagocyte defects, 87% of well-identified immunodeficiency syndromes, and 84% of antibody deficiency if the need for intravenous antibiotics is considered in the latter.

Conclusions

The 10 warning signs and IDR score do not aid in an early diagnosis of severe PID. Educational campaigns should target pediatricians aiming to increase PID awareness and to address family history of PID, parental consanguinity, and previous sibling death as key predictors of PID in communities with a high prevalence of consanguineous marriages.

Placental transfer of maternally-derived IgA precludes the use of guthrie card eluates as a screening tool for primary immunodeficiency diseases

There is a need for neonatal screening tools to improve the long-term clinical outcome of patients with primary immunodeficiency diseases (PID). Recently, a PCR-based screening method for both TRECs and KRECs using Guthrie card samples has been developed. However, the applicability of these excision circle assays is limited to patients with severe T or B cell lymphopenia (SCID, XLA and A-T), whereas the most common forms of PID are not detected. Absence of serum IgA is seen in a major fraction of patients with immunological defects. As serum IgA in newborns is considered to be of fetal origin, eluates from routinely collected dried blood spot samples might thus be suitable for identification of children with PID. To assess the applicability of such screening assays, stored Guthrie card samples were obtained from 47 patients with various forms of primary immunodeficiency diseases (SCID, XLA, A-T, HIGM and IgAD), 20 individuals with normal serum IgA levels born to IgA-deficient mothers and 51 matched healthy newborns. Surprisingly, normal serum IgA levels were found in all SCID, XLA, A-T and HIGM patients and, additionally, in all those IgAD patients born to IgA-sufficient mothers. Conversely, no serum IgA was found in any of the 16 IgAD patients born by IgA-deficient mothers. Moreover, half of the IgA-sufficient individuals born by IgA-deficient mothers also lacked IgA at birth whereas no IgA-deficient individuals were found among the controls. IgA in neonatal dried blood samples thus appears to be of both maternal and fetal origin and precludes its use as a reliable marker for neonatal screening of primary immunodeficiency diseases.

Ataxia-telangiectasia presenting with a novel immunodeficiency

Ataxia-telangiectasia is a rare autosomal recessive disorder characterized by progressive cerebellar ataxia, oculocutaneous telangiectasias, and variable degrees of immunodeficiency. Immunologic evaluations of affected patients often reveal anomalies of humoral and cell-mediated immunity. We describe a case of ataxia-telangiectasia with an atypical immunodeficiency and a novel mutation in the ATM gene. The patient presented at age 3 years with a perineal cellulitis associated with profound neutropenia and T-cell lymphopenia. Serum immunoglobulin levels and antibody titers were normal. Neurologic evaluation revealed minimal hypotonia and wide-based gait, without other signs of cerebellar dysfunction. The alpha-fetoprotein level was elevated, and molecular genetic testing confirmed the diagnosis of ataxia-telangiectasia, uncovering a novel ATM gene mutation c.3931C>T (p.Gln1311X) in exon 28. This patient presents a unique immunologic pattern with normal immunoglobulin levels, significant lymphopenia, and profound neutropenia. The diagnosis of ataxia-telangiectasia should be considered in children presenting with gait disorder and immunologic defects, regardless of subtype and severity.

Evaluation and management of pulmonary disease in ataxia-telangiectasia

Ataxia-telangiectasia (A-T) is a rare autosomal recessive disorder caused by mutations in the ATM gene, resulting in faulty repair of breakages in double-stranded DNA. The clinical phenotype is complex and is characterized by neurologic abnormalities, immunodeficiencies, susceptibility to malignancies, recurrent sinopulmonary infections, and cutaneous abnormalities. Lung disease is common in patients with A-T and often progresses with age and neurological decline. Diseases of the respiratory system cause significant morbidity and are a frequent cause of death in the A-T population. Lung disease in this population is thought to exhibit features of one or more of the following phenotypes: recurrent sinopulmonary infections with bronchiectasis, interstitial lung disease, and lung disease associated with neurological abnormalities. Here, we review available evidence and present expert opinion on the diagnosis, evaluation, and management of lung disease in A-T, as discussed in a recent multidisciplinary workshop. Although more data are emerging on this unique population, many recommendations are made based on similarities to other more well-studied diseases. Gaps in current knowledge and areas for future research in the field of pulmonary disease in A-T are also outlined.

Recent developments related to the laboratory diagnosis of primary immunodeficiency diseases

PURPOSE OF REVIEW

The rapid increases in newly recognized primary immunodeficiency diseases (PIDs), including their clinical, genetic and laboratory-associated abnormalities, make staying abreast of the latest developments a challenge. This review provides an overview of current information directly and indirectly related to the laboratory diagnosis of PIDs.

RECENT FINDINGS

The latest classification and several prevalence studies provide the framework for understanding the breadth, categories and incidence rates of over 120 recognized disease entities. The latter is followed by reviews of new information related to specific PIDs including new tests, new genetic associations and newly discovered laboratory-based abnormalities. The final section presents new PIDs and a discussion of the future potential of array-based technologies in the diagnosis of PIDs.

SUMMARY

The information provided in this review will allow a new appreciation of previously underestimated PIDs' prevalence rates and the delay in their diagnosis. Understanding the molecular causes of PIDs will lead to earlier diagnoses and new targets for improved therapeutic intervention. The presentation of new diagnostic tests should encourage other laboratories to assess their potential in their own laboratories. Ultimately, this information will lead to an increase in the understanding of novel laboratory parameters associated with specific PID and should improve the time required to attain an accurate diagnosis.