Pseudo-Bartter syndrome in infant with cystic fibrosis screen positive, inconclusive diagnosis: A case report

The introduction of newborn screening for cystic fibrosis (CF) increased diagnosis of cystic fibrosis screen positive inconclusive diagnosis (CFSPID). We described the case of a 12-month-old boy with CFSPID who, during summer, presented Pseudo-Bartter syndrome with no diagnostic criteria for CF.

The Role of Bronchoscopy in the Management of Children With Cystic Fibrosis

BACKGROUND

Currently, no consensus guidelines recommend routine bronchoscopy procedure in cystic fibrosis (CF), as no evidence is available concerning its use as either a diagnostic or therapeutic tool. Its efficacy is controversial, and no randomized controlled prospective trials are available to check its effectiveness. The aims of the present study were to evaluate the effectiveness of bronchoscopy as a diagnostic/therapeutic tool in CF children and adolescents; and to verify the effect of serial bronchoscopy on lung disease progression in subjects with CF not responding to a single procedure.

METHODS

Data of patients who received bronchoscopy at 2 Italian CF centers were collected. Bronchoalveolar lavage was performed during the procedure including airway clearance with mucolytics, inhaled antibiotics, and/or surfactant instillation.

RESULTS

A total of 16 patients in center 1 and 17 in center 2 underwent, respectively, 28 and 23 bronchoscopic procedure in the study period. Five patients in each center underwent >1 procedure. All procedures were generally well tolerated. No patient required admission to the pediatric intensive therapy unit. In 19.6% of bronchoalveolar lavages, growth of Aspergillus fumigatus was evident, although not detected by sputum analyses. After the procedure, an increase in mean percent predicted forced expiratory volume in the 1 second >10% was observed, and a significant decrease in pulmonary exacerbations yearly was evident.

CONCLUSION

Based on the results, we suggest bronchoscopy is not to be considered an obsolete tool, and it remains useful in CF management, although in selected cases. We encourage to support longitudinal observational studies to standardize the procedure, focusing on the choice of drugs to be instilled, modalities and timing of serial bronchoscopy and subsequent follow-up in selected severe clinical conditions.

The STING/TBK1/IRF3/IFN type I pathway is defective in cystic fibrosis

Cystic fibrosis (CF) is a rare autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The most common mutation is F508del-CFTR (ΔF) which leads the encoded ion channel towards misfolding and premature degradation. The disease is characterized by chronic bronchopulmonary obstruction, inflammation and airways colonization by bacteria, which are the major cause of morbidity and mortality. The STING pathway is the main signaling route activated in the presence of both self and pathogen DNA, leading to Type I Interferon (IFN I) production and the innate immune response. In this study, we show for the first time the relationship existing in CF between resistant and recurrent opportunistic infections by Pseudomonas aeruginosa and the innate immunity impairment. We demonstrate through ex vivo and in vivo experiments that the pathway is inadequately activated in ΔF condition and the use of direct STING agonists, as 2',3'-cyclic GMP-AMP (2', 3' cGAMP), is able to restore the immune response against bacterial colonization. Indeed, upon treatment with the STING pathway agonists, we found a reduction of colony forming units (CFUs) consequent to IFN-β enhanced production in Pseudomonas aeruginosa infected bone marrow derived macrophages and lung tissues from mice affected by Cystic Fibrosis. Importantly, we also verified that the impairment detected in the primary PBMCs obtained from ΔF patients can be corrected by 2', 3' cGAMP. Our work indicates that the cGAS/STING pathway integrity is crucial in the Cystic Fibrosis response against pathogens and that the restoration of the pathway by 2', 3' cGAMP could be exploited as a possible new target for the symptomatic treatment of the disease.

Use of mucoactive agents in cystic fibrosis: A consensus survey of Italian specialists

Background

The goal of mucoactive therapies in cystic fibrosis (CF) is to enhance sputum clearance and to reduce a progressive decline in lung function over the patient's lifetime. We aimed to investigate the level of consensus among specialists from Italian CF Centers on appropriateness of therapeutic use of dornase alfa (rhDNase) for CF patients.

Method

A consensus on appropriate prescribing in CF mucoactive agents was appraised by an online Delphi method, based on a panel of 27 pulmonologists, coordinated by a Scientific Committee of six experts in medical care of patients with CF.

Results

Full or very high consensus was reached on several issues related to therapeutic use of dornase alfa for CF patients in clinical practice.

Conclusions

The consensus reached on a number of topics regarding use of mucoactive agents in patients with CF can help guide clinicians in daily practice based on expert experience and define the most appropriate therapeutic strategy for the individual patient.

Clinical course and risk factors for severe COVID-19 among Italian patients with cystic fibrosis: a study within the Italian Cystic Fibrosis Society

PURPOSE

To describe the clinical course of COVID-19 in patients with cystic fibrosis (CF) and to identify risk factors for severe COVID-19.

METHODS

We conducted a prospective study within the Italian CF Society. CF centers collected baseline and follow-up data of patients with virologically confirmed SARS-CoV-2 infection between March 2020 and June 2021. Odds ratios (ORs) for severe SARS-CoV-2 (as defined by hospital admission) were estimated by logistic regression models.

RESULTS

The study included 236 patients with positive molecular test for SARS-CoV-2. Six patients died, 43 patients were admitted to hospital, 4 admitted to intensive care unit. Pancreatic insufficiency was associated with increased risk of severe COVID-19 (OR 4.04, 95% CI 1.52; 10.8). After adjusting for age and pancreatic insufficiency, forced expiratory volume in one second (FEVp) < 40% (OR 4.54, 95% CI 1.56; 13.2), oxygen therapy (OR 12.3, 95% CI 2.91-51.7), underweight (OR 2.92, 95% CI 1.12; 7.57), organ transplantation (OR 7.31, 95% CI 2.59; 20.7), diabetes (OR 2.67, 95% CI 1.23; 5.80) and liver disease (OR 3.67, 95% CI 1.77; 7.59) were associated with increased risk of severe COVID-19, while use of dornase alfa was associated with a reduced risk (OR 0.34, 95% CI 0.13-0.88). No significant changes were observed in FEVp from baseline to a median follow-up of 2 months (median difference: 0, interquartile range: - 4; 5, P = 0.62).

CONCLUSION

Clinical features indicative of severe form of CF are associated with increased risk of COVID-19 hospitalization. SARS-CoV-2 infected patients do not experience a deterioration of respiratory function.

Non-invasive tools for detection of liver disease in children and adolescents with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multi-organ genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes the CFTR protein. CF-associated liver disease (CFLD) is a common complication; diagnosis is based on clinical, laboratory findings and abdominal imaging. However, non-invasive diagnostic approaches are needed to early detect CFLD, its progression and severity. Recent studies demonstrate a possible role of point shear wave elastography (p-SWE) with liver stiffness measurement (LSM) as a tool for CFLD diagnosis also in children. This non-invasive technique measures liver stiffness to assess liver fibrosis and is suggested to be less operator-dependent compared to ultrasonography. Aim of our prospective observational study is to investigate the role of p-SWE with LSM for CFLD diagnosis in children and adolescents with CF and to compare this finding with aspartate aminotransferase to platelet ratio index (APRI), fibrosis index based on four factors (FIB-4) and gamma-glutamyl-transpeptidase to platelet ratio (GPR) indices.

METHODS

Fifty-nine children with CF, who had routinely undergone abdominal imaging, were consecutively enrolled. Laboratory findings and clinical data were recorded, as abdominal ultrasound and shear wave elastography at baseline. The cases were divided into two groups based on collected data and classified as CFLD and CFnoLD (without liver disease) according to Debray criteria. APRI, FIB-4 and GPR fibrosis indices were also evaluated.

RESULTS

Twenty-four/59 (40.7%) were defined as CFLD. LSM test is superior to the APRI (P<0.001), the FIB-4 test (P=0.001) and the GPR test for early detection of liver fibrosis. LSM had an area under receiver operating characteristic (ROC) curve =0.818 (95% CI: 0.702-0.934) compared with APRI (0.571, 95% CI: 0.421-0.722), FIB-4 (0.656, 95% CI: 0.511-0.801) and GPR (0.632, 95% CI: 0.485-0.779). At a cut-off of ≥6.2 LSM show a sensitivity of 75.0% and a specificity of 88.6%.

CONCLUSIONS

LSM by transient p-SWE is a non-invasive, highly accessible, reliable, and reproducible test that can be used to assess early detection of liver fibrosis and its severity in children and adolescents with CF, limiting the use of liver biopsy. These preliminary observations point to the need of larger study population to confirm our data.

Diabetes outbreak during COVID19 lock-down in a prediabetic patient with cystic fibrosis long treated with glargine

BACKGROUND

Cystic Fibrosis Related Diabetes (CFRD) is a frequent comorbidity of patients with Cystic Fibrosis (CF). A worsening of clinical conditions appears before CFRD. It has been demonstrated a decline in pulmonary function and nutritional status also in patients with prediabetes. Few trials show that insulin may be beneficial in prediabetic CF patients, to date guidelines do not recommend for this condition.

CASE PRESENTATION

We report a case of a patient treated with insulin glargine at 13 years, due to glycemic intolerance, and with Lumacaftor/Ivacaftor at 15 years. A reduction of pulmonary exacerbations was observed after glargine therapy, also confirmed after the starting of Lumacaftor/ Ivacaftor in this patient. Pulmonary function improved only after the first year of glargine therapy, then a deterioration appeared due to the natural history of CF lung damage. During the COVID-19 lockdown, poor adherence to care contributed to diabetes mellitus onset needing high insulin requirements. After two weeks the patient returned to prediabetic condition and his previous dose of glargine.

CONCLUSIONS

our case highlights firstly that insulin glargine has contributed to preserve him from further clinical worsening due to prediabetes in the years before pandemic, secondly the negative impact of COVID-19 lockdown on the clinical course of a chronic disease as CF.

Elevated sweat chloride test: is it always cystic fibrosis?

BACKGROUND

The sweat chloride test (ST) is the gold standard for cystic fibrosis (CF) diagnosis in symptomatic patients, within the newborn screening and in the follow-up of CF patients during molecular therapies. However, false positives have been reported in patients with different diseases. We describe and discuss 4 cases due to different clinical conditions in which we recorded false positive ST, and the test remained altered for a period of varying length.

CASES PRESENTATION

Case 1: Eight months old female child suffering from constipation, recurrent vomiting and failure to thrive, family history of recurrent pancreatitis without mutations in the PRSS1 and SPINK1 genes. Both ST and fecal elastase were altered although no CFTR gene mutations were found. Due to rapid clinical deterioration, celiac disease was suspected and diagnosed by laboratory tests and intestinal biopsy. After 2 weeks of gluten-free diet ST and fecal elastase normalized. Case 2: 14 months old male suffering from bilateral renal dysplasia, episodes of metabolic alkalosis, recurrent respiratory infections and recurrent vomiting. The child had more ST positives, but no CFTR mutations were found. During follow-up, he developed sensorineural hearing loss and an atrial septic defect was found. Finally, a diagnosis of Klinefelter was made, but the ST normalized several years later. Case 3 and 4: Two boys with stubborn constipation and fecal occlusion treated with Poly Ethylene Glycol (PEG) with salts showed pathological ST. The test returned normal a few days after stopping treatment.

CONCLUSIONS

We hypotesized the possible causes of ST alteration in these conditions: in celiac disease it could be due to a transient dysregulation of the aquaporins, rapidly reversed by the diet; in Klinefelter, it may be due to stable pubertal hypoandrogenism; while, the PEG formulation itself contains salts that can temporarily alter ST.

Lumevis ™: a new medical device to prepare patients for esophagogastroduodenoscopy. Experimental clinical study

BACKGROUND

Esophagogastroduodenoscopy (EGDS) is the gold standard exam for upper gastrointestinal diseases. EGDS is very important in Early Gastric Cancer diagnosis and treatment but it is an operator-dependent exam and there are lots of factors that reduce its visibility (mucus, bubbles and foam).

AIM

The aim of our study is to evaluate if the use of Lumevis™ improves mucosa visualization during EGDS without increasing the examination time and complications' rate and comparing the differences in patients prepared with water or no intervention.

MATERIALS AND METHODS

we recruited 50 patients from 01/08/2020 to 31/08/2020 who came to our observation for epigastric pain, dyspepsia and gastroesophageal reflux (GERD). For each patient we evaluate the satisfaction of the procedure, vision quality, EGDS duration and the presence of bubbles following the administration of: nothing (group 1); 50 ml of water alone (W) (group 2); W + simethicone (S) 150 mg+N-acetylcysteine (NAC) 250 mg+10% acetic acid 2.5 ml (group 3); W+S 100 mg + NAC 300 mg + 10% acetic acid 2 ml (group 4); W + S 100 mg + NAC 200 mg + 10% acetic acid 1.5 ml (group 5).

RESULTS

Our results suggest that the lesion detection rate improves with the use of simethicone, acetylcysteine and acetic acid prior to EGDS, although this needs to be studied prospectively.

CONCLUSIONS

Lumevis™ is proposed as a new product in the routine preparation of all patients who have to undergo an EGDS, raising the level in the quality of the exam.

A survey of the prevalence, management and outcome of infants with an inconclusive diagnosis following newborn bloodspot screening for cystic fibrosis (CRMS/CFSPID) in six Italian centres

OBJECTIVE

We evaluated the prevalence, Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene profile, clinical data, management and outcome for infants with a CFTR-related metabolic syndrome/CF Screen Positive, Inconclusive Diagnosis (CRMS/CFSPID) designation from six Italian centres.

METHODS

All newborn bloodspot screening (NBS) positive infants born from January 2011 to August 2018 with a CF diagnosis or a CRMS/CFSPID designation were enrolled. Data on sweat testing, genetics, clinical course and management were collected.

RESULTS

We enrolled 257 CF patientsand 336 infants with a CRMS/CFSPID designation (CF: CRMS/CFSPID ratio of 1:1.30).Blood immuno-reactive trypsinogen (IRT) was significantly lower in CRMS/CFSPID infants and the F508del variant accounted for only 20% of alleles. Children with CRMS/CFSPID showed a milder clinical course, pancreatic sufficiency compared to CF infants. Varied practice across centres was identified regarding sweat testing, chest radiograph (8-100%) and salt supplementation (11-90%). Eighteen (5.3%) CRMS/CFSPID infants converted or were reclassified to diagnosis of CF. Four infants (1.3%) developed a clinical feature consistent with a CFTR-related disorder (1.2%). Twenty-seven were re-classified as healthy carriers (8.0%) and 16 as healthy infants (4.8%).

CONCLUSIONS

We have identified considerable variability in the evaluation and management of infants with an inconclusive diagnosis following NBS across six Italian centres. CRMS/CFSPID is more regularly seen in this population compared to countries with higher prevalence of F508del.Conversion to a CF diagnosis was recorded in 18 (5.3%) of CRMS/CFSPID infants and in 16 was as a result of increasing sweat chloride concentration.

Probiotics Supplements Reduce ER Stress and Gut Inflammation Associated with Gliadin Intake in a Mouse Model of Gluten Sensitivity

Exposure to gluten, a protein present in wheat rye and barley, is the major inducer for human Celiac Disease (CD), a chronic autoimmune enteropathy. CD occurs in about 1% worldwide population, in genetically predisposed individuals bearing human leukocyte antigen (HLA) DQ2/DQ8. Gut epithelial cell stress and the innate immune activation are responsible for the breaking oral tolerance to gliadin, a gluten component. To date, the only treatment available for CD is a long-term gluten-free diet. Several studies have shown that an altered composition of the intestinal microbiota (dysbiosis) could play a key role in the pathogenesis of CD through the modulation of intestinal permeability and the regulation of the immune system. Here, we show that gliadin induces a chronic endoplasmic reticulum (ER) stress condition in the small intestine of a gluten-sensitive mouse model and that the coadministration of probiotics efficiently attenuates both the unfolded protein response (UPR) and gut inflammation. Moreover, the composition of probiotics formulations might differ in their activity at molecular level, especially toward the three axes of the UPR. Therefore, probiotics administration might potentially represent a new valuable strategy to treat gluten-sensitive patients, such as those affected by CD.

Glucose Tolerance Stages in Cystic Fibrosis Are Identified by a Unique Pattern of Defects of Beta-Cell Function

OBJECTIVE

We aimed to assess the order of severity of the defects of 3 direct determinants of glucose regulation-beta-cell function, insulin clearance, and insulin sensitivity-in patients with cystic fibrosis (CF), categorized according their glucose tolerance status, including early elevation of mid-level oral glucose tolerance test (OGTT) glucose values (>140 and <200 mg/dL), referred to as AGT140.

METHODS

A total of 232 CF patients aged 10 to 25 years underwent OGTT. Beta-cell function and insulin clearance were estimated by OGTT mathematical modeling and OGTT-derived biomarkers of insulin secretion and sensitivity were calculated. The association between glucometabolic variables and 5 glucose tolerance stages (normal glucose tolerance [NGT], AGT140, indeterminate glucose tolerance [INDET], impaired glucose tolerance [IGT], cystic fibrosis-related diabetes CFRD]) was assessed with a general linear model.

RESULTS

Beta-cell function and insulin sensitivity progressively worsened across glucose tolerance stages (P < 0.001), with AGT140 patients significantly differing from NGT (all P < 0.01). AGT140 and INDET showed a degree of beta-cell dysfunction similar to IGT and CFRD, respectively (all P < 0.01). Insulin clearance was not significantly associated with glucose tolerance stages (P = 0.162). Each stage of glucose tolerance was uniquely identified by a specific combination of defects of the direct determinants of glucose regulation.

CONCLUSIONS

In CF patients, each of the 5 glucose tolerance stages shows a unique pattern of defects of the direct determinants of glucose regulation, with AGT140 patients significantly differing from NGT and being similar to IGT. These findings suggest that AGT140 should be recognized as a distinct glucose tolerance stage and that reconsideration of the grade of glucometabolic deterioration across glucose tolerance stages in CF is warranted.

Impaired cholesterol metabolism in the mouse model of cystic fibrosis. A preliminary study

This study aims to investigate cholesterol metabolism in a mouse model with cystic fibrosis (CF) by the comparison of affected homozygous versus wild type (WT) mice. In particular, we evaluated the effects of a diet enriched with cholesterol in both mice groups in comparison with the normal diet. To this purpose, beyond serum and liver cholesterol, we analyzed serum phytosterols as indirect markers of intestinal absorption of cholesterol, liver lathosterol as indirect marker of de novo cholesterol synthesis, liver cholestanol (a catabolite of bile salts synthesis) and the liver mRNA levels of LDL receptor (LDLR), 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoAR), acyl CoA:cholesterol acyl transferase 2 (ACAT2), cytochrome P450 7A1 (CYP7A1) and tumor necrosis factor alpha (TNFα). CF mice showed lower intestinal absorption and higher liver synthesis of cholesterol than WT mice. In WT mice, the cholesterol supplementation inhibits the synthesis of liver cholesterol and enhances its catabolism, while in CF mice we did not observe a reduction of LDLR and HMG-CoAR expression (probably due to an altered feed-back), causing an increase of intracellular cholesterol. In addition, we observed a further increase (5-fold) in TNFα mRNA levels. This preliminary study suggests that in CF mice there is a vicious circle in which the altered synthesis/secretion of bile salts may reduce the digestion/absorption of cholesterol. As a result, the liver increases the biosynthesis of cholesterol that accumulates in the cells, triggering inflammation and further compromising the metabolism of bile salts.

The Multifaceted Roles of MicroRNAs in Cystic Fibrosis

Cystic fibrosis (CF) is a lifelong disorder affecting 1 in 3500 live births worldwide. It is a monogenetic autosomal recessive disease caused by loss-of-function mutations in the gene encoding the chloride channel cystic fibrosis transmembrane conductance regulator (CFTR), the impairment of which leads to ionic disequilibria in exocrine organs. This translates into a chronic multisystemic disease characterized by airway obstruction, respiratory infections, and pancreatic insufficiency as well as hepatobiliary and gastrointestinal dysfunction. Molecular characterization of the mutational heterogeneity of CFTR (affected by more than 2000 variants) improved the understanding and management of CF. However, these CFTR variants are linked to different clinical manifestations and phenotypes, and they affect response to treatments. Expanding evidence suggests that multisystemic disease affects CF pathology via impairing either CFTR or proteins regulated by CFTR. Thus, altering the expression of miRNAs in vivo could constitute an appealing strategy for developing new CF therapies. In this review, we will first describe the pathophysiology and clinical management of CF. Then, we will summarize the current knowledge on altered miRNAs in CF patients, with a focus on the miRNAs involved in the deregulation of CFTR and in the modulation of inflammation. We will highlight recent findings on the potential utility of measuring circulating miRNAs in CF as diagnostic, prognostic, and predictive biomarkers. Finally, we will provide an overview on potential miRNA-based therapeutic approaches.

Cystic Fibrosis-Screening Positive Inconclusive Diagnosis: Newborn Screening and Long-Term Follow-Up Permits to Early Identify Patients with CFTR-Related Disorders

Background: Newborn screening (NBS) early-identifies cystic fibrosis (CF), but in CF-screening positive inconclusive diagnosis (CF-SPID) the results of immunoreactive trypsinogen (IRT), molecular analysis and sweat test (ST) are discordant. A percentage of CF-SPID evolves to CF, but data on long-term monitoring are lacking. We describe the follow-up of all CF and CF-SPID identified between 2008 and 2019. Methods: NBS was performed by IRT followed by molecular analysis and ST between 2008 and 2014; double IRT followed by molecular analysis and ST after 2014. Results: NBS revealed 47 CF and 99 CF-SPID newborn, a ratio 1:2.1—the highest reported so far. This depends on the identification by gene sequencing of the second variant with undefined effect in 40 CF-SPID that otherwise would have been defined as carriers. Clinical complications and pulmonary infections occurred more frequently among CF patients than among CF-SPID. Two CF-SPID cases evolved to CF (at two years), while eight evolved to CFTR-related disorders (CFTR-RD), between one and eight years, with bronchiectasis (two), recurrent pneumonia (four, two with sinonasal complications), recurrent pancreatitis (two). No clinical, biochemical or imaging data predicted the evolution. Conclusion: Gene sequencing within the NBS reveals a higher number of CF-SPID and we first describe an approach to early identify CFTR-RD, with relevant impact on their outcome.

The Italian External Quality Assessment Program for Cystic Fibrosis Sweat Chloride Test: Does Active Participation Improve the Quality?

(1) Background: Diagnostic testing for cystic fibrosis (CF) is based on a sweat chloride test (SCT) considering the appropriate signs and symptoms of the disease and results of a gene mutation analysis. In 2014, the Istituto Superiore di Sanità (ISS) established a pilot Italian external quality assessment program for CF SCT (Italian EQA-SCT), which is now a third party service carried out by the ISS. (2) Methods: The ongoing scheme is prospective, enrollment is voluntary, and the payment of a fee is required. Results are shared through a dedicated web-facility. Assessment covers the analysis, interpretation, and reporting of results. (3) Results: Thirteen, fifteen, sixteen, and fifteen different laboratories, respectively, participated from 2015 to 2016 and from 2018 to 2019 in the Italian EQA-SCT scheme. Eleven different laboratories participated each year in all four rounds of the Italian EQA-SCT. (4) Conclusions: The overall results obtained from the laboratories participating constantly clearly show that their qualitative and quantitative performance improved significantly. This is due to the opportunity-after receiving the EQA results-to constantly review their performance and address any inconsistencies. We firmly believe that participation in the EQA program will improve the quality of participating laboratories and that EQA participation should become mandatory as a fundamental requirement for laboratory accreditation.

Salivary Cytokines and Airways Disease Severity in Patients with Cystic Fibrosis

About 50% of patients with cystic fibrosis (CF) have sinonasal complications, which include inferior turbinate hypertrophy (NTH) and/or nasal polyposis (NP), and different degrees of lung disease, which represents the main cause of mortality. Monitoring of sinonasal disease requires complex instrumental procedures, while monitoring of lung inflammation requires invasive collection of bronchoalveolar lavage fluid. The aim of this study was to investigate the associations between salivary cytokines levels and CF-related airway diseases. Salivary biochemical parameters and cytokines, i.e., interleukin-6 (IL-6), IL-8, and tumor necrosis factor alpha (TNF-α), were analyzed in resting saliva from healthy subjects and patients with CF. Patients with CF showed significantly higher levels of salivary chloride, IL-6, IL-8, and TNF-α and lower calcium levels than healthy subjects. Among patients with CF, IL-6 and IL-8 were significantly higher in patients with NTH, while TNF-α was significantly lower in patients with NP. A decreasing trend of TNF-α in patients with severe lung disease was also observed. On the other hand, we did not find significant correlation between cytokine levels and Pseudomonas aeruginosa or Stenotrophomonas maltophilia colonization. These preliminary results suggest that salivary IL-6 and IL-8 levels increase during the acute phase of sinonasal disease (i.e., NTH), while the end stages of pulmonary disease and sinonasal disease (i.e., NP) show decreased TNF-α levels.

An investigation on parenting stress of children with cystic fibrosis

Background

The management of chronic diseases, particularly in children, requires an integrated physical and psychological approach to both sick children and their family. This is the case of Cystic Fibrosis (CF), a complex genetic chronic disease, where, a comprehensive evaluation of the emotional impact and an effective multidimensional approach are indicated.

Aim

This study investigates on parenting stress in children and adolescents with CF and its determinants related to parents, children and the disease severity.

Methods

The study involved 34.04% adult males and 65.96% adult females (range 21-55 years) and 47 children with CF, 54.35% males and 45.65% females (range 1-17 years). The data were obtained through a Parenting Stress Index – Short Form (PSI-SF) questionnaire. According to the PSI-SF scoring system, three types of stress were detected: a typical stress pattern (normal), a high stress pattern (increased) and a defensive response, which may be considered as a high stress feature in children which requires monitoring and clinical evaluation.

Results

This study shows a significant presence of stress in females (60.23%), of subject married (84.62%), unemployed (69.23%) and with education level such as “middle School” (61.54%). Concerning children of parents with high stress, it resulted most frequent children with one sibling (53.85%). Finally, by univariate analysis, it resulted a significant positive correlation between parenting stress and disease degree of children. Instead by multivariate analysis, we found that the variables: Number of siblings and Birth order were a significant positive and negative predictor of parenting stress respectively.

Conclusion

An increased stress level was detected in less than one third of parents of subjects with CF. These data may be related to the psychological support which is part of the routine management of CF care team. However, as children’s features seem to act as a determinant of stress more than parental ones, the parental-child dysfunction should be the target for further integrated interventions.

Does virtual reality reduce pain in pediatric patients? A systematic review

Virtual Reality (VR) as a tool for pain reduction is the research topic of several clinical trial for Randomized Controlled Trials despite its wide use in the daily clinical practice for non- pharmacological reduction of pain in some countries. At present, there are no published reviews of VR-efficacy of pain reduction in pediatric patients. That is why we made a systematic review of the efficacy of VR as a tool for pain reduction in children and adolescents. Electronic databases and gray literature published between 2014 and 2019 were analyzed. A total of 9 studies were eligible according to the established inclusion criteria. Results show that virtual reality is a valid tool for non-pharmacological pain reduction and that this approach is to be preferred to the standard reduction techniques currently in use. However, more studies using standardized experimental methodologies are needed to provide more systematic comparison and quantitative synthesis.

IL-9 and Mast Cells Are Key Players of Candida albicans Commensalism and Pathogenesis in the Gut

Candida albicans is implicated in intestinal diseases. Identifying host signatures that discriminate between the pathogenic versus commensal nature of this human commensal is clinically relevant. In the present study, we identify IL-9 and mast cells (MCs) as key players of Candida commensalism and pathogenicity. By inducing TGF-β in stromal MCs, IL-9 pivotally contributes to mucosal immune tolerance via the indoleamine 2,3-dioxygenase enzyme. However, Candida-driven IL-9 and mucosal MCs also contribute to barrier function loss, dissemination, and inflammation in experimental leaky gut models and are upregulated in patients with celiac disease. Inflammatory dysbiosis occurs with IL-9 and MC deficiency, indicating that the activity of IL-9 and MCs may go beyond host immunity to include regulation of the microbiota. Thus, the output of the IL-9/MC axis is highly contextual during Candida colonization and reveals how host immunity and the microbiota finely tune Candida behavior in the gut.

•

IL-9/IL-9R signaling affects MC function in mucosal candidiasis

•

IL-9 and mucosal MCs contribute to barrier function loss in leaky gut models

•

IL-9 and stromal MCs induce local protective tolerance in infection via IDO1

•

IL-9 and mucosal MCs expand and IDO1 decreases in human celiac disease

GH-IGF-1 Axis in Children with Cystic Fibrosis

OBJECTIVE

To verify whether growth hormone receptor (GHR) gene expression plays a role in growth of children with cystic fibrosis (CF), as a consequence of the chronic inflammatory condition and malnutrition.

DESIGN

We enrolled 49 prepubertal patients (24 males and 25 females) affected by CF in a stable clinical condition, 19 of whom had been diagnosed through newborn screening and 30 following presentation of symptoms. Patients had no significant comorbidity affecting growth or cystic fibrosis transmembrane conductance regulator (CFTR)-related diabetes requiring insulin therapy. Blood was collected during two follow-up visits to measure insulin-like growth factor (IGF-I), growth hormone-binding protein (GHBP), and GHR gene expression. Recruited as a control group were 52 healthy children, sex- and age-matched, were recruited as a control group.

METHODS

We compared body mass index (BMI), height, weight, IGF-I, GHBP, and GHR gene expression values (evaluated by Chemiluminescent Immunometric assay; ELISA and real-time PCR, respectively) in CF patients diagnosed through newborn screening (NBS) or by symptoms (late diagnosis [LD]) and in healthy controls.

RESULTS

BMI increased significantly in patients between the time of diagnosis and check-up (P<0.001), particularly in the LD group; median value was lower at diagnosis and significantly higher (P<0.001) at follow-up visits compared to controls. At initial evaluation, higher levels of IGF-I (not statistically significant) were found in both the NBS group and the LD group compared to the control group. At the second evaluation, significantly higher levels of IGF-I (P=0.003) were found in both the NBS and LD groups compared to controls; GHR mRNA expression had significantly increased (P=0.013) in LD patients compared with the first evaluation and was significantly higher in the NBS and LD groups than in controls. GHBP values had significantly increased (P=0.047) in the NBS group after one year of therapy compared to first visit levels and were significantly higher (P<0,0001) in the NBS and LD groups compared to controls.

CONCLUSION

In our LD patients during childhood, we observed good auxological values and a GH/IGF-I axis function within normal range for the factor evaluated. However, earlier diagnosis through NBS might further minimize and prevent growth retardation, by reducing the duration of symptoms before treatment.

Cystic fibrosis transmembrane conductance regulator (CFTR) and autophagy: hereditary defects in cystic fibrosis versus gluten-mediated inhibition in celiac disease

Cystic Fibrosis (CF) is the most frequent lethal monogenetic disease affecting humans. CF is characterized by mutations in cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel whose malfunction triggers the activation of transglutaminase-2 (TGM2), as well as the inactivation of the Beclin-1 (BECN1) complex resulting in disabled autophagy. CFTR inhibition, TGM2 activation and BECN1 sequestration engage in an ‘infernal trio’ that locks the cell in a pro-inflammatory state through anti-homeostatic feedforward loops. Thus, stimulation of CFTR function, TGM2 inhibition and autophagy stimulation can be used to treat CF patients. Several studies indicate that patients with CF have a higher incidence of celiac disease (CD) and that mice bearing genetically determined CFTR defects are particularly sensitive to the enteropathogenic effects of the orally supplied gliadin (a gluten-derived protein). A gluten/gliadin-derived peptide (P31–43) inhibits CFTR in mouse intestinal epithelial cells, causing a local stress response that contributes to the immunopathology of CD. In particular, P31–43-induced CFTR inhibition elicits an epithelial stress response perturbing proteostasis. This event triggers TGM2 activation, BECN1 sequestration and results in molecular crosslinking of CFTR and P31-43 by TGM2. Importantly, stimulation of CFTR function with a pharmacological potentiator (Ivacaftor), which is approved for the treatment of CF, could attenuate the autophagy-inhibition and pro-inflammatory effects of gliadin in preclinical models of CD. Thus, CD shares with CF a common molecular mechanism involving CFTR inhibition that might respond to drugs that intercept the "infernal trio". Here, we highlight how drugs available for CF treatment could be repurposed for the therapy of CD.

Methicillin-resistant Staphylococcus aureus eradication in cystic fibrosis patients: A randomized multicenter study

BACKGROUND

Few studies, based on a limited number of patients using non-uniform therapeutic protocols, have analyzed Methicillin-resistant Staphylococcus aureus (MRSA) eradication.

METHODS

In a randomized multicenter trial conducted on patients with new-onset MRSA infection we evaluated the efficacy of an early eradication treatment (arm A) compared with an observational group (B). Arm A received oral rifampicin and trimethoprim/sulfamethoxazole (21 days). Patients' microbiological status, FEV1, BMI, pulmonary exacerbations and use of antibiotics were assessed.

RESULTS

Sixty-one patients were randomized. Twenty-nine (47.5%) patients were assigned to active arm A and 32 (52.5%) patients to observational arm B. Twenty-nine (47.5%) patients, 10 patients in arm A and 19 in arm B, dropped out of the study. At 6 months MRSA was eradicated in 12 (63.2%) out of 19 patients in arm A while spontaneous clearance was observed in 5 (38.5%) out of 13 patients in arm B. A per-protocol analysis showed a 24.7% difference in the proportion of MRSA clearance between the two groups (z = 1.37, P(Z>z) = 0.08). Twenty-seven patients, 15 (78.9%) out of 19 in arm A and 12 (92.3%) out of 13 in arm B, were able to perform spirometry. The mean (±SD) FEV1 change from baseline was 7.13% (±14.92) in arm A and -1.16% (±5.25) in arm B (p = 0.08). In the same period the BMI change (mean ±SD) from baseline was 0.54 (±1.33) kg/m2 in arm A and -0.38 (±1.56) kg/m2 in arm B (p = 0.08). At 6 months no statistically significant differences regarding the number of pulmonary exacerbations, days spent in hospital and use of antibiotics were observed between the two arms.

CONCLUSIONS

Although the statistical power of the study is limited, we found a 24.7% higher clearance of MRSA in the active arm than in the observational arm at 6 months. Patients in the active arm A also had favorable FEV1 and BMI tendencies.

The gliadin-CFTR connection: new perspectives for the treatment of celiac disease

Familial loss-of-function mutations of the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) channel protein cause cystic fibrosis (CF), the most frequent inherited life-threatening disease in the Caucasian population. A recent study indicates that the gluten/gliadin-derived peptide (P31–43) can cause CFTR inhibition in intestinal epithelial cells, thus causing a local stress response that contributes to the immunopathology of celiac disease (CD). Accordingly, an increased prevalence of CD has been observed in several cohorts of CF patients. CD is characterized by a permanent intolerance to gluten/gliadin proteins occurring in a proportion of susceptible individuals who bear the human leukocyte antigen (HLA) DQ2/DQ8. In CD, perturbations of the intestinal environment, together with the activation of the innate immune system by P31–43, are essential for rendering other immunodominant gliadin peptide fully antigenic, thus triggering an adaptive immune response with an autoimmune component. P31–43-induced CFTR inhibition elicits the danger signals that ignite the epithelial stress response and perturb epithelial proteostasis. Importantly, potentiators of CFTR channel gating, such as the FDA-approved drug Ivacaftor, prevent P31–43 driven CFTR inhibition and suppress the gliadin-induced stress response in cells from celiac patients, as well as the immunopathology developing in gliadin-sensitive mice. Thus, CFTR potentiators may represent a novel therapeutic option for celiac patients.

Autophagy suppresses the pathogenic immune response to dietary antigens in cystic fibrosis

Under physiological conditions, a finely tuned system of cellular adaptation allows the intestinal mucosa to maintain the gut barrier function while avoiding excessive immune responses to non-self-antigens from dietary origin or from commensal microbes. This homeostatic function is compromised in cystic fibrosis (CF) due to loss-of-function mutations in the CF transmembrane conductance regulator (CFTR). Recently, we reported that mice bearing defective CFTR are abnormally susceptible to a celiac disease-like enteropathy, in thus far that oral challenge with the gluten derivative gliadin elicits an inflammatory response. However, the mechanisms through which CFTR malfunction drives such an exaggerated response to dietary protein remains elusive. Here we demonstrate that the proteostasis regulator/transglutaminase 2 (TGM2) inhibitor cysteamine restores reduced Beclin 1 (BECN1) protein levels in mice bearing cysteamine-rescuable F508del-CFTR mutant, either in homozygosis or in compound heterozygosis with a null allele, but not in knock-out CFTR mice. When cysteamine restored BECN1 expression, autophagy was increased and gliadin-induced inflammation was reduced. The beneficial effects of cysteamine on F508del-CFTR mice were lost when these mice were backcrossed into a Becn1 haploinsufficient/autophagy-deficient background. Conversely, the transfection-enforced expression of BECN1 in human intestinal epithelial Caco-2 cells mitigated the pro-inflammatory cellular stress response elicited by the gliadin-derived P31–43 peptide. In conclusion, our data provide the proof-of-concept that autophagy stimulation may mitigate the intestinal malfunction of CF patients.

Personalization of therapies in rare diseases: a translational approach for the treatment of cystic fibrosis

High variability in the response rates to treatments can make the interpretation of data from clinical trials very difficult, particularly in rare genetic diseases in which the enrolment of thousands of patients is problematic. Personalized medicine largely depends on the establishment of appropriate early detectors of drug efficacy that may guide the administration (or discontinuation) of specific treatments. Such biomarkers should be capable of predicting the therapeutic response of individual patients and of monitoring early benefits of candidate drugs before late clinical benefits become evident. The identification of these biomarkers implies a rigorous stepwise process of translation from preclinical evaluation in cultured cells, suitable animal models or patient-derived freshly isolated cells to clinical application. In this review, we will discuss how a process of research translation can lead to the implementation of functional and mechanistic disease-relevant biomarkers. Moreover, we will address how preclinical data can be translated into the clinic in a personalized medical approach that can provide the right drug to the right patient within the right timeframe.

Inhaled medications in cystic fibrosis beyond antibiotics

Structural lung disease begins very early in children with cystic fibrosis (CF), often in the first three months of life. Inhaled medications represent an attractive therapeutic approach in CF that are routinely used as early intervention strategies. Two aerosolized solutions, hypertonic saline and dornase alfa, have significant potential benefits by improving mucociliary clearance, with minimal associated side-effects. In particular, they favor rehydration of airway surface liquid and cleavage of extracellular DNA in the airways, respectively, consequently reducing rate of pulmonary disease exacerbations. Indirect anti-inflammatory effects have been documented for both drugs, addressing each of the three interrelated elements in the vicious cycle of lung disease in CF: airway obstruction, inflammation and infection. This short review aimed to summarize the main papers that support potential clinical impact of inhaled solutions on pulmonary disease in CF.

Defective proteostasis in celiac disease as a new therapeutic target

Cystic fibrosis (CF) is a disease caused by loss-of-function mutations affecting the CF transmembrane conductance regulator (CFTR), a chloride channel. Recent evidence indicates that CFTR is inhibited by a gluten/gliadin-derived peptide (P31-43), causing an acquired state of CFTR inhibition within the gut that contributes to the pathogenesis of celiac disease (CD). Of note, CFTR inhibition does not only cause intra- and extracellular ion imbalances but also affects proteostasis by activating transglutaminase-2 (TGM2) and by disabling autophagy. These three phenomena (CFTR inhibition, TGM2 activation, and autophagy impairment) engage in multiple self-amplifying circuitries, thus forming an "infernal trio". The trio hinders enterocytes from returning to homeostasis and instead locks them in an irreversible pro-inflammatory state that ultimately facilitates T lymphocyte-mediated immune responses against another gluten/gliadin-derived peptide (P57-68), which,upon deamidation by activated TGM2, becomes fully antigenic. Hence, the pathogenic protein gliadin exemplifies a food constituent the exceptional immunogenicity of which arises from a combination of antigenicity (conferred by deaminated P57-68) and adjuvanticity (conferred by P31-43). CF can be treated by agents targeting the "infernal trio" including CFTR potentiators, TGM2 inhibitors, and autophagy enhancers. We speculate that such agents may also be used for CD therapy and indeed could constitute close-to-etiological treatments of this enteropathy.

Clinical expression of cystic fibrosis in a large cohort of Italian siblings

Background

A clinical heterogeneity was reported in patients with Cystic Fibrosis (CF) with the same CFTR genotype and between siblings with CF.

Methods

We investigated all clinical aspects in a cohort of 101 pairs of siblings with CF (including 6 triplets) followed since diagnosis.

Results

Severe lung disease had a 22.2% concordance in sib-pairs, occurred early and the FEV₁% at 12 years was predictive of the severity of lung disease in the adulthood. Similarly, CF liver disease occurred early (median: 15 years) and showed a concordance of 27.8% in sib-pairs suggesting a scarce contribution of genetic factors; in fact, only 2/15 patients with liver disease in discordant sib-pairs had a deficiency of alpha-1-antitrypsin (a known modifier gene of CF liver phenotype). CF related diabetes was found in 22 pairs (in 6 in both the siblings). It occurred later (median: 32.5 years) and is strongly associated with liver disease. Colonization by P. aeruginosa and nasal polyposis that required surgery had a concordance > 50% in sib-pairs and were poorly correlated to other clinical parameters. The pancreatic status was highly concordant in pairs of siblings (i.e., 95.1%) but a different pancreatic status was observed in patients with the same CFTR mutations. This suggests a close relationship of the pancreatic status with the “whole” CFTR genotype, including mutations in regulatory regions that may modulate the levels of CFTR expression. Finally, a severe course of CF was evident in a number of patients with pancreatic sufficiency.

Conclusions

Physicians involved in care of patients with CF and in genetic counseling must be aware of the clinical heterogeneity of CF even in sib-pairs that, at the state of the art, is difficult to explain.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0766-6) contains supplementary material, which is available to authorized users.

A pathogenic role for cystic fibrosis transmembrane conductance regulator in celiac disease

Intestinal handling of dietary proteins usually prevents local inflammatory and immune responses and promotes oral tolerance. However, in ~ 1% of the world population, gluten proteins from wheat and related cereals trigger an HLA DQ2/8‐restricted T_H1 immune and antibody response leading to celiac disease. Prior epithelial stress and innate immune activation are essential for breaking oral tolerance to the gluten component gliadin. How gliadin subverts host intestinal mucosal defenses remains elusive. Here, we show that the α‐gliadin‐derived LGQQQPFPPQQPY peptide (P31–43) inhibits the function of cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel pivotal for epithelial adaptation to cell‐autonomous or environmental stress. P31–43 binds to, and reduces ATPase activity of, the nucleotide‐binding domain‐1 (NBD1) of CFTR, thus impairing CFTR function. This generates epithelial stress, tissue transglutaminase and inflammasome activation, NF‐κB nuclear translocation and IL‐15 production, that all can be prevented by potentiators of CFTR channel gating. The CFTR potentiator VX‐770 attenuates gliadin‐induced inflammation and promotes a tolerogenic response in gluten‐sensitive mice and cells from celiac patients. Our results unveil a primordial role for CFTR as a central hub orchestrating gliadin activities and identify a novel therapeutic option for celiac disease.

Trans-heterozygosity for mutations enhances the risk of recurrent/chronic pancreatitis in patients with Cystic Fibrosis

BACKGROUND

Recurrent (RP) and chronic pancreatitis (CP) may complicate Cystic Fibrosis (CF). It is still unknown if mutations in genes involved in the intrapancreatic activation of trypsin (IPAT) or in the pancreatic secretion pathway (PSP) may enhance the risk for RP/CP in patients with CF.

METHODS

We enrolled: 48 patients affected by CF complicated by RP/CP and, as controls 35 patients with CF without pancreatitis and 80 unrelated healthy subjects. We tested a panel of 8 genes involved in the IPAT, i.e. PRSS1, PRSS2, SPINK1, CTRC, CASR, CFTR, CTSB and KRT8 and 23 additional genes implicated in the PSP.

RESULTS

We found 14/48 patients (29.2%) with mutations in genes involved in IPAT in the group of CF patients with RP/CP, while mutations in such genes were found in 2/35 (5.7%) patients with CF without pancreatitis and in 3/80 (3.8%) healthy subjects (p < 0.001). Thus, we found mutations in 12 genes of the PSP in 11/48 (22.9%) patients with CF and RP/CP. Overall, 19/48 (39.6%) patients with CF and RP/CP showed one or more mutations in the genes involved in the IPAT and in the PSP while such figure was 4/35 (11.4%) for patients with CF without pancreatitis and 11/80 (13.7%) for healthy controls (p < 0.001).

CONCLUSIONS

The trans-heterozygous association between CFTR mutations in genes involved in the pathways of pancreatic enzyme activation and the pancreatic secretion may be risk factors for the development of recurrent or chronic pancreatitis in patients with CF.

Intra-individual biological variation in sweat chloride concentrations in CF, CFTR dysfunction, and healthy pediatric subjects

BACKGROUND

The sweat test is one of the main diagnostic tools used in newborn screening programs and as a confirmatory test, in case of suspect of Cystic Fibrosis (CF). Since sweat chloride (Cl) concentration is also considered an appropriate parameter to explore the efficacy of CFTR modulators in clinical trials, it is crucial to evaluate the biological variability of this test in healthy and pathological conditions. The aim of this pilot study was to determine the intra-individual biological variability of sweat Cl, both in healthy individuals and CF patients and to assess its correlation with diet, season, and menstrual cycle.

METHODS

Thirty-five out of 36 selected subjects (6-18 years) were enrolled by 2 CF care centers and assigned to 3 cohorts: CF, CFTR-related disorder (CFTR-RD) and healthy volunteers. Each participant was subjected to eight sweat tests in different conditions and time of the year. Data were analyzed using linear mixed effects models for repeated measures, taking also into account intra-individual correlations.

RESULTS

We observed a high intra-individual variability of sweat Cl, with the lowest mean CV% values among CF patients (20.21 in CF, 29.74 in CFTR-RD, and 31.15 in healthy subjects). Gender and diet had no influence on sweat Cl variability, nor had pubertal age and menstrual phase.

CONCLUSION

Results of this pilot study confirmed that sweat Cl variability is high in CF patients, although non-CF individuals displayed even higher mean CV% values. Season significantly influenced sweat test values only in CF patients, likely due to changes in their hydration status.

An "ex vivo model" contributing to the diagnosis and evaluation of new drugs in cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. About 2000 mutations have been described so far. We setup an ex vivo model of human nasal epithelial cells (HNECs) to study CF patients testing the effect of novel mutations and molecular therapies. We performed sampling (by brushing), followed by culture and analysis of HNECs using a series of molecular techniques. We performed 50 brushings from CF patients and controls. Using cultured cells, we: i) demonstrated the widely heterogeneous CFTR expression in patients and in controls; ii) defined the splicing effect of a CFTR mutation; iii) assessed the CFTR gating activity in patients bearing different mutations; iv) demonstrated that butyrate significantly enhances CFTR expression. Based on our data, we can conclude: 1) HNEC brushing is performed without anaesthesia and is well tolerated in all CF patients (children and adults); 2) HNECs can be preserved for up to 48 hours before culture allowings multicentre studies; 3) HNECs culture can be considered a suitable model to study the molecular effects of new CFTR gene mutations and/or uncertain meaning specific mutations of carriers; 4) an ex vivo model of HNECs may be used to evaluate, before human use, the effect of new drugs on patients’ cells bearing specific CFTR mutations; 5) the methodology is adequate for a quantitative measurement, by fluorescence, of the CFTR gating activity of the HNECs from patients with different genotypes identifying: a) CF patients bearing two severe mutations with an activity < 10% (compared to controls – 100%); b) CF patients bearing at least a mild mutation with an activity of 10-20%; c) CF carriers (heterozygous subjects) with an activity between 40-70%.

TG2 regulates the heat-shock response by the post-translational modification of HSF1

Heat-shock factor 1 (HSF1) is the master transcription factor that regulates the response to proteotoxic stress by controlling the transcription of many stress-responsive genes including the heat-shock proteins. Here, we show a novel molecular mechanism controlling the activation of HSF1. We demonstrate that transglutaminase type 2 (TG2), dependent on its protein disulphide isomerase activity, triggers the trimerization and activation of HSF1 regulating adaptation to stress and proteostasis impairment. In particular, we find that TG2 loss of function correlates with a defect in the nuclear translocation of HSF1 and in its DNA-binding ability to the HSP70 promoter. We show that the inhibition of TG2 restores the unbalance in HSF1-HSP70 pathway in cystic fibrosis (CF), a human disorder characterized by deregulation of proteostasis. The absence of TG2 leads to an increase of about 40% in CFTR function in a new experimental CF mouse model lacking TG2. Altogether, these results indicate that TG2 plays a key role in the regulation of cellular proteostasis under stressful cellular conditions through the modulation of the heat-shock response.

S737F is a new CFTR mutation typical of patients originally from the Tuscany region in Italy

Background

An increasing number of patients have been described as having a number of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) variants for which it lacks a clear genotype–phenotype correlation. We assesses the clinical features of patients bearing the S737F (p.Ser737Phe) CFTR missense variant and evaluated the residual function of CFTR protein on nasal epithelial cells (NEC).

Methods

A retrospective database was performed from individuals homozygous or compound heterozygous for the S737F variant followed in the Cystic Fibrosis (CF) Centre of Florence. We performed a nasal brushing in cooperating patients and compared the results with those of patients followed in the pediatric CF Centre of Naples.

Results

9/295 (3%) subjects carrying at least S737F CFTR variant on one allele were identified. Patients were diagnosed in 7/9 cases by newborn screening and in two cases for dehydration with hypochloremic metabolic alkalosis; at diagnosis sweat chloride levels (SCL) were in the pathological range in only one case. After a mean follow up of 8,6 years (range 0,5–15,8), SCL were in the pathological range in 8/9 cases (mean age at CF diagnosis: 1,5 years), all patients were pancreatic sufficiency and respiratory function was normal. The gating activity on NEC was 15.6% and 12.7% in two patients compound heterozygous for W1282X and DelE22_24, while it was ranged between 6,2% and 9,8% in CF patients.

Conclusions

S737F is a CFTR mutation associated to hypochloremic alkalosis in childhood, mild CF phenotype in teenage years and a residual function of CFTR protein.

Long-Term Follow-Up in a Girl with Cystic Fibrosis and Diabetes Since the First Year of Life

Diabetes mellitus is the most common comorbidity in cystic fibrosis (CF). Recently, more attention has been paid to early glucose metabolism derangements (GMDs). The subject of this report is a female patient, affected by CF since 3 months of age. She presented with intermittent diabetes during early childhood. At the age of 10 years, oral glucose tolerance test (OGTT) was performed and showed glucose intolerance (IGT) status; glargine insulin therapy was started. At the age of 13 years, CF-related diabetes with fasting hyperglycemia occurred, so rapid insulin at meals was added. During the following year, clinical and nutritional status improved. Stable clinical conditions were observed in the following 3 years. This is the first case of very long-term follow-up concerning a CF patient with GMDs. Our case confirms the importance of paying attention to early GMDs in very young CF patients and seems to suggest that earlier therapy could ameliorate CF natural history.

Lung structure and function similarities between primary ciliary dyskinesia and mild cystic fibrosis: a pilot study

Background

Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are increasingly compared. There are no chest magnetic resonance imaging (MRI) comparative studies of PCD and CF. We assessed clinical, functional, microbiological and MRI findings in PCD and mild CF patients in order to evaluate different expression of lung disease.

Methods

Twenty PCD (15.1 years) and 20 CF subjects with mild respiratory impairment (16 years, 70% with pancreatic insufficiency) underwent MRI, spirometry, and sputum cultures when clinically stable. MRI was scored using the modified Helbich system.

Results

PCD was diagnosed later than CF (9.9 versus 0.6 years, p = 0.03), despite earlier symptoms (0.1 versus 0.6 years, p = 0.02). In the year preceding the study, patients from both groups underwent two systemic antibiotic courses (p = 0.48). MRI total scores were 11.6 ± 0.7 and 9.1 ± 1 in PCD and CF, respectively. FEV₁ and FVC Z-scores were −1.75 (range, −4.6–0.7) and −0.6 (−3.9–1.8) in PCD, and −0.9 (range, −5.4–2.3) and −0.3 (−3.4–2.5) in CF, respectively. No difference was found between lung function or structure, despite a higher MRI subscore of collapse/consolidation in PCD versus CF (1.6 ± 0.1 and 0.6 ± 0.2, p < 0.001). These findings were confirmed after data-control for diagnostic delay. Pseudomonas aeruginosa and Staphylococcus aureus were more frequent in CF than in PCD (p = 0.05 and p = 0.003, respectively).

Conclusions

MRI is a valuable radiation-free tool for comparative PCD and CF lung disease assessment. Patients with PCD may exhibit similar MRI and lung function changes as CF subjects with mild pulmonary disease. Delay in PCD diagnosis is unlikely the only determinant of similarities.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-017-0351-2) contains supplementary material, which is available to authorized users.