Peripheral polyneuropathy in children and young adults with ataxia-telangiectasia

BACKGROUND AND PURPOSE

Ataxia-telangiectasia (A-T) is a rare, autosomal recessive, multisystem disorder that leads to progressive neurodegeneration with cerebellar ataxia and peripheral polyneuropathy. Cerebellar neurodegeneration is well described in A-T. However, peripheral nervous system involvement is an underdiagnosed but important additional target for supportive and systemic therapies. The aim of this study was to conduct neurophysiological measurements to assess peripheral neurodegeneration and the development of age-dependent neuropathy in A-T.

METHODS

In this prospective study, 42 classical A-T patients were assessed. The motor and sensory nerve conduction of the median and tibial nerves was evaluated. Data were compared to published standard values and a healthy age- and gender-matched control group of 23 participants. Ataxia scores (Klockgether, Scale for the Assessment and Rating of Ataxia) were also assessed.

RESULTS

In A-T, neurophysiological assessment revealed neuropathic changes as early as the first year of life. Subjective symptomatology of neuropathy is rarely described. In the upper extremities, motor neuropathy was predominantly that of a demyelinating type and sensory neuropathy was predominantly that of a mixed type. In the lower extremities, motor and sensory neuropathy was predominantly that of a mixed type. We found significant correlations between age and the development of motor and sensory polyneuropathy in A-T compared with healthy controls (p < 0.001).

CONCLUSIONS

In A-T, polyneuropathy occurs mostly subclinically as early as the first year of life. The current study of a large national A-T cohort demonstrates that development of neuropathy in A-T differs in the upper and lower extremities.

Methacholine and FeNO Measurement in Patients with Habit Cough

BACKGROUND

Chronic cough is one of the most common symptoms in childhood. Making a definite diagnosis is a challenge for all pediatricians especially in patients when cough is without an organic cause like in habit cough.

PATIENTS AND METHODS

In this retrospective analysis, all electronic outpatient charts of the Division of Allergology and Pneumology, between January 1, 2010 and December 31, 2019 were reviewed in order to study all children with potential habit cough. All children underwent the following diagnostic algorithms, skin prick test (SPT), measurement of fractional exhaled nitric oxide (FeNO), spirometry and methacholine challenge test (MCT). The value of a normal MCT and FeNO measurement for diagnosing habit cough was investigated.

RESULTS

The chart review revealed 482 patients with chronic cough>4 weeks. Of these, 99 (20.5%) with suspected habit cough were collected. 13 patients had to be excluded for other diagnosis and a complete data set was available in 55 patients. 33 (60.0%) of 55 patients were SPT negative and 22 (40.0%) had sensitization to common allergens. Five patients had elevated FeNO≥20 ppb and three showed severe bronchial hyperresponsiveness<0.1 mg methacholine, challenging the diagnosis of habit cough.

CONCLUSION

A normal FeNO and MCT can help confirm the clinical diagnosis of habit cough. However, in patients with positive MCT and/or elevated FeNO habit cough can be present. Especially in patients with elevated FeNO and severe BHR cough variant asthma and eosinophilic bronchitis have to be ruled out.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978)

The incidence and type of cancer in patients with ataxia-telangiectasia via a retrospective single-centre study

Ataxia-telangiectasia (A-T) is a hereditary immune system disorder with neurodegeneration. Its first neurologic symptoms include ataxic gait in early childhood, with slowly progressive cerebellar ataxia, oculomotor apraxia, oculocutaneous telangiectasia, and progressive muscle weakness. Neonatal screening for severe T-cell deficiency was recently found to diagnose A-T patients with a significantly reduced naïve T-cell pool. Our study includes 69 A-T patients between 8 January 2002 and 1 December 2019. Nineteen cases of cancer were diagnosed in 17 patients (25%), with a median overall survival [OS; 95% cumulative indcidence (CI)] of 26·9 years for the entire cohort. The 15-year OS of 82·5% (72-95%) was significantly decreased among A-T patients with malignancies, who had a median OS of 2·11 years, with a two-year-estimated OS of 50·7% (31-82%). Haematological malignancies were the major causes of death within the initial years of life with a 15 times increased risk for death [HR (95% CI): 6·9 (3·1-15.2), P < 0·001] upon malignancy diagnosis. Male patients with A-T are at a higher cancer risk than their female counterparts. This manuscript highlights the need for cancer surveillance and prevention, as well as optimal treatment in this cohort.

Neurofilament Light Chain Is a Biomarker of Neurodegeneration in Ataxia Telangiectasia

Ataxia telangiectasia (A-T) is a progressive and life-limiting disease associated with cerebellar ataxia due to progressive cerebellar degeneration. In addition to ataxia, which is described in detail, the presence of chorea, dystonia, oculomotor apraxia, athetosis, parkinsonism, and myoclonia are typical manifestations of the disease. The study aimed to evaluate the specificity and sensitivity of neurofilament light chain (NfL) as a biomarker of neurodegeneration in relation to SARA score. In this prospective trial, one visit of 42 A-T patients aged 1.3–25.6 years (mean 11.6 ± 7.3 years) was performed, in which NfL was determined from serum by ELISA. Additionally, a neurological examination of the patients was performed. Blood was collected from 19 healthy volunteers ≥ 12 years of age. We found significantly increased levels of NfL in patients with A-T compared to healthy controls (21.5 ± 3.6 pg/mL vs. 9.3 ± 0.49 pg/mL, p ≤ 0.01). There was a significant correlation of NfL with age, AFP, and SARA. NfL is a new potential progression biomarker in blood for neurodegeneration in A-T which increases with age.

Diabetes in Patients With Ataxia Telangiectasia: A National Cohort Study

Background: Ataxia telangiectasia (A-T) is a rare autosomal-recessive multisystem disorder characterized by pronounced cerebellar ataxia, telangiectasia, cancer predisposition and altered body composition. In addition, evidence is rising for endocrine dysfunction. Objectives: To determine the evolution of diabetes and its prevalence in a larger A-T cohort. Methods: A retrospective analysis of the patient charts of 39 subjects from the Frankfurt A-T cohort was performed between August 2002 and 2018 concerning HbA1c and oral glucose tolerance (OGTT). The median follow-up period was 4 years (1-16 years). In addition, in 31 A-T patients aged 1 to 38 years HbA1c and fasting glucose were studied prospectively from 2018 to 2019. Results: In the retrospective analysis, we could demonstrate a longitudinal increase of HbA1c. The prospective analysis showed a significant increase of HbA1c and fasting glucose with age (r = 0.79, p ≤ 0.0001). OGTT has a good sensitivity for insulin resistance screening, whereas HbA1c can be used to evaluate individual courses and therapy response. Seven out of 39 (17.9%) patients suffered from diabetes. Metformin did not always lead to sufficient diabetes control; one patient was treated successfully with repaglinide. Conclusion: Diabetes is a common finding in older A-T patients and often starts in puberty. Our data clearly demonstrate the need for an annual diabetes screening in patients > 12 years.

Progressive Liver Disease in Patients With Ataxia Telangiectasia

Ataxia telangiectasia (A-T) is a devastating multi-system disorder characterized by progressive cerebellar ataxia, immunodeficiency, genetic instability, premature aging and growth retardation. Due to better care the patients get older than in the past and new disease entities like disturbed glucose tolerance and liver disease emerge. The objective of the present investigation is to determine the evolution of liver disease and its relation to age and neurological deterioration. The study included 67 patients aged 1 to 38 years with classical A-T. At least two measurements of liver enzymes were performed within a minimum interval of 6 months in 56 patients. The median follow-up period was 4 years (1-16 years). A total of 316 liver enzyme measurements were performed. For analysis, patients were divided into two age groups (Group 1: <12 years; group 2: ≥12 years). In addition, ultrasound of the liver and Klockgether Ataxia Score (KAS) were analyzed. We found significantly higher levels of alpha-fetoprotein (AFP) (226,8 ± 20.87 ng/ml vs. 565,1 ± 24.3 ng/ml, p < 0.0001), and liver enzymes like ALT (23.52 ± 0.77 IU/L vs. 87.83 ± 5.31 IU/L, p < 0.0001) in patients in group 2. In addition, we could show a significant correlation between age and AFP, GGT, and KAS. Ultrasound revealed hepatic steatosis in 11/19 (57.9%) patients in group 2. One female patient aged 37 years died due to a hepato-cellular carcinoma (HCC). Liver disease is present in the majority of older A-T patients. Structural changes, non-alcoholic fatty liver disease and fibrosis are frequent findings. Progress of liver disease is concomitant to neurological deterioration.

Pre-emptive Allogeneic Hematopoietic Stem Cell Transplantation in Ataxia Telangiectasia

Ataxia telangiectasia (A-T) is a primary immunodeficiency with mutations in the gene encoding the A-T mutated (ATM) protein that interacts with immune, hematopoietic, and endocrine targets resulting in broad multi-systemic clinical manifestations with a devastating outcome. Apart from a progressive neurodegenerative disorder, A-T leads to significantly increased susceptibility to malignancies. It is a matter of discussion whether pre-emptive allogeneic hematopoietic stem cell transplantation (alloHSCT) using a reduced intensity conditioning regimen would be an option to restore immune-competence and prevent malignancy, as shown in animal models, because conventional treatment protocols of malignant diseases using radio- and/or chemotherapy have a high rate of therapy-related morbidity and mortality in these patients. We present the course of the disease, including immune reconstitution and neurological outcome following pre-emptive alloHSCT in a 4-year-old boy with A-T on a 6 year follow-up. Our manuscript provides a proof-of-concept of alloHSCT as an individual pre-emptive treatment strategy from which some A-T patients might benefit.

Treatment of Granulomas in Patients With Ataxia Telangiectasia

Background: Ataxia telangiectasia (A-T) is a devastating multi-system disorder characterized by progressive cerebellar ataxia, growth retardation, immunodeficiency, chronic pulmonary disease and chromosomal instability. Cutaneous granulomas are a known phenomenon in A-T but extra-dermal manifestation of granulomas at bone and synovia has not been reported so far. The clinical presentation, immunological findings, the long-term course and treatment options of eight patients with severe granulomas will be reported.

Methods: From our cohort of 44 classical A-T patients, eight patients aged 2–11 years (18.2%) presented with granulomas. Immunological features of patients with and without granulomas were compared. Five patients suffered from cutaneous manifestation, in two patients we detected a bone and in one a joint involvement. Patients with significant extra-dermal involvement as well as one patient with massive skin manifestation were treated with TNF inhibitors. The patient with granulomas at his finger joint and elbow was treated with hematopoietic stem cell transplantation (HSCT).

Results: Interestingly, seven of eight patients with granulomas were total IgA deficient, but there were no differences in IgG and IgM levels. All lymphocytes subsets were equally distributed except patients with granuloma had significantly lower naïve CD8 cells. In patients without treatment, four of eight showed a slow but significant enlargement of the granuloma. Treatment success with TNF inhibitors was variable. In one patient, treatment with TNF inhibitors led to a total remission for 3 years up to now. In two patients, treatment with TNF inhibitors led to a partial regression of granulomas. Treatment interruptions caused deterioration again.

Conclusions: Granulomas in A-T progress slowly over years and can lead to significant morbidity.Treatment with TNF inhibitors was safe and in part successful in our patients. Interestingly HSCT leads to complete remission, and indicates that aberrant immune function is responsible for granulomas in A-T patients. What This Study Adds to the Field: Granulomas in A-T progress slowly over years and can lead to significant morbidity. Treatment with TNF inhibitors was safe and in part successful in our patients.

AT A GLANCE COMMENTARY:

Scientific knowledge on the subject: Little is known about the clinical presentation, course and treatment of granulomas in ataxia telangiectasia (A-T). In addition, this is the first report of extra-dermal manifestation of granulomas at bone and synovia in patients with A-T.

What This Study Adds to the Field: Granulomas in A-T progress slowly over years and can lead to significant morbidity. Treatment with TNF inhibitors was safe and in part successful in our patients.

Growth hormone treatment in patients with ataxia telangiectasia

INTRODUCTION

Ataxia telangiectasia (A-T) is a devastating autosomal recessive disorder with chromosomal instability and growth failure. Low levels of growth hormone (GH) and growth factors may be related to advanced neurological deterioration, wasting syndrome and more pronounced immunodeficiency.

OBJECTIVE

The objective of this study is to study safety and effectiveness of GH therapy in patients with A-T and evaluate the effect of GH on ataxia and lymphocyte subsets.

METHODS

Three patients with classical A-T were treated with GH (0.3 mg/kg/d) for 1 year. Growth rate, ataxia score and lymphocyte subsets were monitored.

RESULTS

GH treatment was well tolerated. All patients showed a significant increase of height SDS of +1.3 (mean height SDS -1.994), a mean increase of 8 (6-11) cm/12 months. Lymphocytes subsets and ataxia were not altered before and after GH treatment.

CONCLUSIONS

Treatment with GH is feasible and effective in A-T patients with severe growth arrest, but no effect on ataxia and lymphocytes could be recorded.