Peripheral neuropathy in cystic fibrosis: a prevalence study

Glycemic Variability and the Thickness of Retinal Layers in Cystic Fibrosis Patients with and without Cystic Fibrosis Related Diabetes

PURPOSE

Patients with cystic fibrosis (CF) are at risk to develop CF related diabetes (CFRD) and subsequently even diabetic neuro- and/or vasculopathy. We sought to determine if there are typical signs of diabetes-related retinal alterations present in CF patients with preserved and impaired glycemic control.

METHODS

During routine annual examination CF patients were offered an additional 7-day period of real time continuous glucose monitoring (rtCGM) and an ophthalmological examination including retinal optical coherence tomography (OCT). Patients were categorized according to the glycemic control, i.e. the results of an oral glucose tolerance test (OGTT) and rtCGM were taken into consideration. OCT data was analyzed by our previously published visual analysis software generating dedicated and spatially resolved deviation maps for visualization and quantification of differences in total retinal thickness and thickness of retinal nerve fiber layer (RNFL) as well as ganglion cell layer (GCL) in comparison to age-matched healthy controls and patients with either type 1 or type 2 diabetes mellitus.

RESULTS

Results of the rtCGM and/or OGTT enabled discrimination between patients with normal glycemic control (CFNG; n = 6), with abnormal glycemic control (CFAG; n = 6) and overt CFRD (n = 4). OCT data indicates gradually increasing retinal thinning in all 3 groups, depending on the degree of glucose metabolism disorder compared to healthy controls. At the foveal region total retinal thickness and GCL thickness were significantly thinner in CFRD patients compared to CFNG patients (total retinal thickness: 260.4 µm (239.3-270.8) vs. 275.4 µm (254.3-289.5); GCL: 11.82 µm (11.16-15.25) vs. 17.30 µm (13.95-19.82); each p < 0.05).

CONCLUSION

Although we investigated a rather small number of patients, we obtained evidence that intraretinal neurodegenerative changes occur in each of our subgroups (CFNG, CFAG, CFRD). Beyond this, our results favor the detrimental role of additional diabetes, as the deviations from healthy controls were most pronounced in the CFRD group and are similar to those seen in patients suffering from type 1 or type 2 diabetes.

Importance of Vitamin D Status and Nerve Conduction in Pediatric Cystic Fibrosis Patients

Cystic fibrosis is one of the most common inherited diseases. It presents with recurrent respiratory infections, pancreatic insufficiency, and growth retardation. Neurological involvement becomes more common as life expectancy increases. Chronic hypoxia, impaired glucose intolerance, autoimmune mechanisms, vasculitis changes, and micronutrient deficiencies seem to cause neuropathy in cystic fibrosis. This study was aimed to investigate peripheral neuropathy in pediatric cystic fibrosis patients. Twenty-one cystic fibrosis patients and 19 healthy control subjects between the ages of 7 and 17 years were included. Their nerve conduction study results and laboratory investigations were analyzed. Participants were classified into four groups; 1. Cystic fibrosis with vitamin D deficiency, 2. Cystic fibrosis with normal vitamin D levels, 3. Healthy subjects with vitamin D deficiency, 4. Healthy subjects with normal vitamin D levels. We found statistically significantly lower sensory median nerve sensorial nerve action potential, sensorial sural nerve conduction velocity, and motor peroneal nerve compound motor action potential in cystic fibrosis patients with vitamin D deficiency than in other cases. We also found that the main difference between cystic fibrosis and control groups was especially in patients with low vitamin D levels. Nerve damage starts at an early age, especially in cystic fibrosis patients especially those with vitamin D deficiency. Electrophysiological evaluation to assess neuropathy is important even in asymptomatic patients. Prevention of hypovitaminosis D is important to prevent neuropathy in cystic fibrosis patients.

Differential adaptability between reference strains and clinical isolates of Pseudomonas aeruginosa into the lung epithelium intracellular lifestyle

Intracellular invasion is an advantageous mechanism used by pathogens to evade host defense and antimicrobial therapy. In patients, the intracellular microbial lifestyle can lead to infection persistence and recurrence, thus worsening outcomes. Lung infections caused by Pseudomonas aeruginosa, especially in cystic fibrosis (CF) patients, are often aggravated by intracellular invasion and persistence of the pathogen. Proliferation of the infectious species relies on a continuous deoxyribonucleotide (dNTP) supply, for which the ribonucleotide reductase enzyme (RNR) is the unique provider. The large genome plasticity of P. aeruginosa and its ability to rapidly adapt to different environments are challenges for studying the pathophysiology associated with this type of infection. Using different reference strains and clinical isolates of P. aeruginosa independently combined with alveolar (A549) and bronchial (16HBE14o- and CF-CFBE41o-) epithelial cells, we analyzed host-pathogen interactions and intracellular bacterial persistence with the aim of determining a cell type-directed infection promoted by the P. aeruginosa strains. The oscillations in cellular toxicity and oxygen consumption promoted by the intracellular persistence of the strains were also analyzed among the different infectious lung models. Significantly, we identified class II RNR as the enzyme that supplies dNTPs to intracellular P. aeruginosa. This discovery could contribute to the development of RNR-targeted strategies against the chronicity occurring in this type of lung infection. Overall our study demonstrates that the choice of bacterial strain is critical to properly study the type of infectious process with relevant translational outcomes.

Copper and Copper/Zinc Ratio in a Series of Cystic Fibrosis Patients

Cystic fibrosis (CF) patients require a stable and sufficient supply of micronutrients. Since copper is an essential micronutrient for human development, a cross-sectional study was carried out to investigate the serum copper levels, serum copper/zinc (Cu/Zn) ratios, and their relationship with nutritional indicators in a group of CF patients. Anthropometric, biochemical, and dietary measurements, an abdominal ultrasound, and respiratory and pancreatic tests were conducted. Seventeen CF patients were studied (10 females, 59%), 76.5% of whom were ∆F580. Their mean serum copper (113 ± 23 μg/dL) was normal, and there was only one teenager with hypocupremia (6%) and two children with hypercupremia (18%). A significant association between serum copper and zinc levels was discovered. The Cu/Zn ratio was higher than 1.00 for 94% of patients, which is an indicator of an inflammation status. There was no significant correlation between the serum copper concentrations and respiratory and pancreatic function, respiratory colonization, and the results of the abdominal ultrasound. Linear regression analysis showed that serum copper had a positive association with both the Z-score body mass index (BMI) and mean bone conduction speed (BCS). Therefore, since 94% of CF patients had a Cu/Zn ratio > 1.00, this factor must alert us to consider the risk of zinc deficiency and high inflammatory response. The measurement of serum zinc alone does not show one’s zinc status. However, the Cu/Zn ratio may be an indicator of zinc deficiency and the inflammatory status of CF patients.

Nutrition in cystic fibrosis: From the past to the present and into the future

Nutritional management is an integral part of multidisciplinary care for persons with cystic fibrosis. This review will look at how nutrition care has evolved over time. In addition, we will look at how some newer therapies impact nutrition care.

Polyneuropathy in Critically Ill Mechanically Ventilated Children: Experience From a Tertiary Care Hospital in North India

OBJECTIVES

To determine the prevalence of critical illness polyneuropathy and its risk factors in critically ill children mechanically ventilated for 7 days or more.

DESIGN

Observational cohort study.

SETTING

PICU of a tertiary care hospital from North India.

PATIENTS

Children 1-15 years old admitted in PICU from June 2016 to September 2017, mechanically ventilated for 7 days or more, excluding those with diagnosed neuromuscular disease, stroke, or spinal pathology.

INTERVENTION

Demographic details, diagnosis, treatment details, and anthropometry at admission and enrolment were recorded. Nerve conduction studies were performed after enrolment and repeated a week later, if the child was still in PICU. Medical Research Council scoring for muscle strength was performed in survivors. Risk factors including Pediatric Index of Mortality-2 score, sepsis, multiple organ dysfunction, hypoalbuminemia, use of steroids, neuromuscular-blocking agents, and vasopressors were recorded. Samples for the level of micronutrients (copper, zinc, folate, and vitamin B12) were collected at the time of enrolling the child and at the time of discharge.

MEASUREMENTS AND MAIN RESULTS

Thirty-two children were enrolled, of whom 29 had features of critical illness polyneuropathy on evaluation at day 8 of mechanical ventilation (prevalence, 90.6% [95% CI, 80.5-100%]). The polyneuropathy was axonal in 26 (81.2%), mixed in one patient (3.1%), and uncharacterized in two (6.2%). Sepsis and multiple organ dysfunction were present in 31 subjects (96.9%). No risk factors for critical illness polyneuropathy could be identified although the study was not sufficiently powered to do so. The difference between serum micronutrient levels (copper, zinc, folate, and vitamin B12) between patients who developed polyneuropathy, and those who did not, was statistically insignificant.

CONCLUSIONS

We observed a high prevalence of critical illness polyneuropathy in children in PICU, mechanically ventilated for 7 days or more; almost all of whom had underlying sepsis.

Peripheral nerve disease secondary to systemic conditions in children

This review is an overview of systemic conditions that can be associated with peripheral nervous system dysfunction. Children may present with neuropathic symptoms for which, unless considered, a causative systemic condition may not be recognized. Similarly, some systemic conditions may be complicated by comorbid peripheral neuropathies, surveillance for which is indicated. The systemic conditions addressed in this review are critical illness polyneuropathy, chronic renal failure, endocrine disorders such as insulin-dependent diabetes mellitus and multiple endocrine neoplasia type 2b, vitamin deficiency states, malignancies and reticuloses, sickle cell disease, neurofibromatosis, connective tissue disorders, bowel dysmotility and enteropathy, and sarcoidosis. In some disorders presymptomatic screening should be undertaken, while in others there is no benefit from early detection of neuropathy. In children with idiopathic peripheral neuropathies, systemic disorders such as celiac disease should be actively excluded. While management is predominantly focused on symptomatic care through pain control and rehabilitation, some neuropathies improve with effective control of the underlying etiology and in a small proportion a more targeted approach is possible. In conclusion, peripheral neuropathies can be associated with a diverse range of medical conditions and unless actively considered may not be recognized and inadequately managed.

Vitamin E: Mechanism of transport and regulation in the CNS

Although vitamin E has been recognized as a critical micronutrient to neuronal health for more than half a century, vitamin E transport and regulation in the brain remain a mystery. Currently, the majority of what is known about vitamin E transport has been delineated in the liver. However, clues from the pathogenesis of neurological-related vitamin E deficient diseases point to compromised neuronal integrity and function, underlining the critical need to understand vitamin E regulation in the CNS. Additionally, most of the same molecular players involved in vitamin E transport in the liver are also found in CNS, including sterol SRB1, TTP, and ABCA/ABCG, suggesting similar intracellular pathways between these organ systems. Finally, based on chemical similarities, intracellular CNS shuttling of vitamin E likely resembles cholesterol's use of ApoE particles. Utilizing this information, this review will address what is currently known about trafficking vitamin E across the blood brain barrier in order to ensure an adequate supply of the essential nutrient to the brain. Although debatable, the health of the brain in relation to vitamin E levels has been demonstrated, most notably in oxidative stress-related conditions such as ataxias, Alzheimer's disease, and Parkinson's disease. Future vitamin E research is vital in understanding how the regulation of the vitamin can aid in the prevention, treatment, and curing of neurological diseases. © 2018 IUBMB Life, 71(4):424-429, 2019.

Infantile Tremor Syndrome and Subdural Hemorrhage in an Infant with Cystic Fibrosis

Cystic fibrosis (CF), an autosomal recessive disease with multi-system involvement, may present with bleeding in infancy owing to vitamin K malabsorption. Infantile tremor syndrome (ITS) is an obscure condition associated with vitamin B12 and other micronutrient deficiencies, described predominantly in Indian subcontinent. We describe an infant presenting with ITS and chronic subdural hemorrhage. He was subsequently diagnosed to have CF. The ITS and subdural hemorrhage is rarely reported in children with CF. In the background of increasing recognition of CF in Indian children, this case demonstrates a new association of this disease.

Neurological Complications of Respiratory Disease

The respiratory and central nervous systems are intimately connected. Ventilatory control is strictly regulated by central mechanisms in a complex process that involves central and peripheral chemoreceptors, baroreceptors, the cardiovascular system, and specific areas of the brain responsible for autonomic control. Disorders of the lung and respiratory system can interfere with these mechanisms and temporarily or permanently disrupt this complex network resulting in mild to severe neurological sequelae. This article explores the wide variety of neurological problems resulting from respiratory dysfunction, with emphasis on its pathophysiology, clinical features, prognosis, and long-term outcome.

Epidemiology and genetics of cystic fibrosis in Asia: In preparation for the next-generation treatments

Cystic fibrosis (CF) in the Asian population is less frequently reported due to under-diagnosis and lack of centralized CF patient registries. Clinical studies on CF cases from Asia have documented a severe course of the disease. The spectrum of the cystic fibrosis transmembrane conductance regulator (CFTR) variants in this population is quite heterogeneous. In total, 166 variants have been reported on approximately 3700 Asian CF chromosomes. The frequency of F508del among Asians is low compared with Caucasians. Recent in vitro studies have shown promise of small molecule correction and potentiation of 45 different CFTR variants. Of these variants, 16 (including G551D and F508del) have also been observed among Asian CF individuals. We suggest undertaking molecular studies extensively to annotate CFTR variants that will help Asian CF individuals to benefit from the precision medicine gaining momentum in the Western countries.

The Cystic Fibrosis Symptom Progression Survey (CF-SPS) in Arabic: A Tool for Monitoring Patient's Symptoms

OBJECTIVE

Our study aimed to develop a survey that could be used by nurses during regular cystic fibrosis (CF) clinic visits, providing clinicians with a standardized means of longitudinally assessing and monitoring symptom progression in their patients. In addition, the use of this survey would provide an opportunity for patient engagement and relationship building, thereby enhancing patient education and improving adherence to treatment. This is the first such survey designed specifically for use in Arab populations. .

METHODS

The Cystic Fibrosis Symptom Progression Survey (CF-SPS) was developed using previously published patient reported outcomes relating to pulmonary exacerbations in CF. It contains 10 items that provide a patient-focused account of symptoms. The survey was translated into Arabic and was completed by 12 patients on 139 occasions over 22 months. The psychometric properties of the survey were evaluated, as was the relationship between the survey findings and other known clinical measures of health status in CF. .

RESULTS

The CF-SPS performs well as a psychometrically valid clinical tool, with good internal consistency as determined by Cronbach's alpha analysis. Our results suggest that the CF-SPS is able to identify significant declines in health status in line with routine clinical patient assessment (chest sounds, body mass index and admissions). As such it is a useful tool that can support clinical decision making in the care of Arabic speaking CF patients. .

CONCLUSION

We recommend the CF-SPSa (Arabic version) as a valid tool for the longitudinal monitoring of symptom progression in CF in Arabic speaking populations.