Cystic Fibrosis Transmembrane Conductance Regulator Research Articles

Comparison of refugee patients with cystic fibrosis and their counterpart children from Turkey during the war

Since the outbreak of the Syrian civil war in 2011, the population of Arab refugees in Turkey has rapidly increased. While cystic fibrosis (CF) is believed to be rare among Arabs, recent studies suggest it is underdiagnosed. This study aims to present the demographic, clinical, and genetic characteristics of CF patients among Arab refugees in Turkey. Additionally, a comparison is made between the findings in the National CF Registry 2021 in Turkey (NCFRT) and the refugee CF patient group. The study included refugee patients between the ages of 0 and 18 years who were diagnosed with CF and received ongoing care at pediatric pulmonology centers from March 2011 to March 2021. The study examined demographic information, age at diagnosis, age of diagnosis of patients through CF newborn screening (NBS), presenting symptoms, CF transmembrane conductance regulator (CFTR) mutation test results, sputum culture results, weight, height, and body mass index (BMI) z score. Their results were compared with the NCFRT results. The study included 14 pediatric pulmonology centers and 87 patients, consisting of 46 (52.9%) boys and 41 (47.1%) girls. All of the patients were Arab refugees, with 80 (92%) being Syrian. All the patients were diagnosed in Turkey. The median age at diagnosis of patients was 22.33 (interquartile range, 1–258) months. The median age of diagnosis of patients through NBS was 4.2 (interquartile range, 1–12) months. The median age of older patients, who were unable to be included in the NBS program, was 32.3 (interquartile range, 3–258) months. Parental consanguinity was observed in 52 (59.7%) patients. The mutation that was most frequently found was F508del, which accounted for 22.2% of the cases. It was present in 20 patients, constituting 32 out of the total 144 alleles. There was a large number of genetic variations. CFTR genotyping could not be conducted for 12 patients. These patients had high sweat tests, and their genetic mutations could not be determined due to a lack of data. Compared to NCFRT, refugee patients were diagnosed later, and long-term follow-up of refugee CF patients had significantly worse nutritional status and pseudomonas colonization. Conclusion: Although refugee CF patients have equal access to NBS programs and CF medications as well as Turkish patients, the median age at diagnosis of patients, the median age of diagnosis of patients through NBS, their nutritional status, and Pseudomonas colonization were significantly worse than Turkish patients, which may be related to the difficulties of living in another country and poor living conditions. The high genetic heterogeneity and rare mutations detected in the refugee patient group compared to Turkish patients. Well-programmed NBS programs, thorough genetic studies, and the enhancement of living conditions for refugee patients in the countries they relocate to can have several advantages such as early detection and improved prognosis.What is Known:• Children who have chronic diseases are the group that is most affected by wars.• The outcome gets better with early diagnosis and treatment in patients with Cystic Fibrosis (CF).What is New:• Through the implementation of a newborn screening program, which has never been done in Syria previously, refugee patients, the majority of whom are Syrians were diagnosed with cystic fibrosis within a duration of 4 months.• Despite equal access to the newborn screening program and CF medications for both Turkish patients and refugee patients, the challenges of living in a foreign country have an impact on refugees.

Pharmacological Improvement of Cystic Fibrosis Transmembrane Conductance Regulator Function Rescues Airway Epithelial Homeostasis and Host Defense in Children with Cystic Fibrosis.

Rationale: Pharmacological improvement of cystic fibrosis transmembrane conductance regulator (CFTR) function with elexacaftor/tezacaftor/ivacaftor (ETI) provides unprecedented improvements in lung function and other clinical outcomes in patients with cystic fibrosis (CF). However, ETI effects on impaired mucosal homeostasis and host defense at the molecular and cellular levels in the airways of patients with CF remain unknown. Objectives: To investigate effects of ETI on the transcriptome of nasal epithelial and immune cells from children with CF at the single-cell level. Methods: Nasal swabs from 13 children with CF and at least one F508del allele aged 6 to 11 years were collected at baseline and 3 months after initiation of ETI, subjected to single-cell RNA sequencing, and compared with swabs from 12 age-matched healthy children. Measurements and Main Results: Proportions of CFTR-positive cells were decreased in epithelial basal, club, and goblet cells, but not in ionocytes, from children with CF at baseline and were restored by ETI therapy to nearly healthy levels. Single-cell transcriptomics revealed an impaired IFN signaling and reduced expression of major histocompatibility complex classes I and II encoding genes in epithelial cells of children with CF at baseline, which was partially restored by ETI. In addition, ETI therapy markedly reduced the inflammatory phenotype of immune cells, particularly of neutrophils and macrophages. Conclusions: Pharmacological improvement of CFTR function improves innate mucosal immunity and reduces immune cell inflammatory responses in the upper airways of children with CF at the single-cell level, highlighting the potential to restore epithelial homeostasis and host defense in CF airways by early initiation of ETI therapy.

The combination of propylene glycol and vegetable glycerin e-cigarette aerosols induces airway inflammation and mucus hyperconcentration

Despite concerns over their safety, e-cigarettes (e-cigs) remain a popular tobacco product. Although nicotine and flavors found in e-cig liquids (e-liquids) can cause harm in the airways, whether the delivery vehicles propylene glycol (PG) and vegetable glycerin (VG) are innocuous when inhaled remains unclear. Here, we investigated the effects of e-cig aerosols generated from e-liquid containing only PG/VG on airway inflammation and mucociliary function in primary human bronchial epithelial cells (HBEC) and sheep. Primary HBEC were cultured at the air–liquid interface (ALI) and exposed to e-cig aerosols of 50%/50% v/v PG/VG. Ion channel conductance, ciliary beat frequency, and the expression of inflammatory markers, cell type-specific markers, and the major mucins MUC5AC and MUC5B were evaluated after seven days of exposure. Sheep were exposed to e-cig aerosols of PG/VG for five days and mucus concentration and matrix metalloproteinase-9 (MMP-9) activity were measured from airway secretions. Seven-day exposure of HBEC to e-cig aerosols of PG/VG caused a significant reduction in the activities of apical ion channels important for mucus hydration, including the cystic fibrosis transmembrane conductance regulator (CFTR) and large conductance, Ca2+-activated, and voltage-dependent K+ (BK) channels. PG/VG aerosols significantly increased the mRNA expression of the inflammatory markers interleukin-6 (IL6), IL8, and MMP9, as well as MUC5AC. The increase in MUC5AC mRNA expression correlated with increased immunostaining of MUC5AC protein in PG/VG-exposed HBEC. On the other hand, PG/VG aerosols reduced MUC5B expression leading overall to higher MUC5AC/MUC5B ratios in exposed HBEC. Other cell type-specific markers, including forkhead box protein J1 (FOXJ1), keratin 5 (KRT5), and secretoglobin family 1A member 1 (SCGB1A1) mRNAs, as well as overall ciliation, were significantly reduced by PG/VG exposure. Finally, PG/VG aerosols increased MMP-9 activity and caused mucus hyperconcentration in sheep in vivo. E-cig aerosols of PG/VG induce airway inflammation, increase MUC5AC expression, and cause dysfunction of ion channels important for mucus hydration in HBEC in vitro. Furthermore, PG/VG aerosols increase MMP-9 activity and mucus concentration in sheep in vivo. Collectively, these data show that e-cig aerosols containing PG/VG are likely to be harmful in the airways.

Advances in the Study of Common and Rare CFTR Complex Alleles Using Intestinal Organoids.

Complex alleles (CAs) arise when two or more nucleotide variants are present on a single allele. CAs of the CFTR gene complicate the cystic fibrosis diagnosis process, classification of pathogenic variants, and determination of the clinical picture of the disease and increase the need for additional studies to determine their pathogenicity and modulatory effect in response to targeted therapy. For several different populations around the world, characteristic CAs of the CFTR gene have been discovered, although in general the prevalence and pathogenicity of CAs have not been sufficiently studied. This review presents examples of using intestinal organoid models for assessments of the two most common and two rare CFTR CAs in individuals with cystic fibrosis in Russia.

Diagnosis and Management of Gastrointestinal Manifestations in Children with Cystic Fibrosis.

Cystic fibrosis (CF) is primarily known for its pulmonary consequences, which are extensively explored in the existing literature. However, it is noteworthy that individuals with CF commonly display gastrointestinal (G-I) manifestations due to the substantial presence of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in the intestinal tract. Recognized as pivotal nonpulmonary aspects of CF, G-I manifestations exhibit a diverse spectrum. Identifying and effectively managing these manifestations are crucial for sustaining health and influencing the overall quality of life for CF patients. This review aims to synthesize existing knowledge, providing a comprehensive overview of the G-I manifestations associated with CF. Each specific G-I manifestation, along with the diagnostic methodologies and therapeutic approaches, is delineated, encompassing the impact of innovative treatments targeting the fundamental effects of CF on the G-I tract. The findings underscore the imperative for prompt diagnosis and meticulous management of G-I manifestations, necessitating a multidisciplinary team approach for optimal care and enhancement of the quality of life for affected individuals. In conclusion, the authors emphasize the urgency for further clinical studies to establish a more robust evidence base for managing G-I symptoms within the context of this chronic disease. Such endeavors are deemed essential for advancing understanding and refining the clinical care of CF patients with G-I manifestations.

Prevalence of cancer and alcohol use in patients with exocrine pancreatic insufficiency compared to patients with cystic fibrosis.

680 Background: Cystic fibrosis (CF), the most prevalent genetic disorder among persons of European decent, is an autosomal recessive disorder due to CFTR gene mutations which lead to abnormally viscid exocrine secretions of the pancreas and other exocrine glands of the body. Exocrine pancreatic insufficiency (EPI) is a condition seen in ~85% of CF patients, in which the pancreas is unable to secrete adequate amounts of digestive enzymes. Although most patients with CF develop EPI, not all cases of EPI are caused by CF. Other risk factors for EPI include acute or chronic pancreatitis which may be triggered by alcohol, among other etiologies. Some studies suggest alcohol use as a possible independent risk factor for development of various cancers. Given these associations, we sought to characterize the prevalence of both alcohol use and cancer in patients with EPI vs patients with CF. Methods: A retrospective observational study was performed using electronic health records in Ochsner System, Louisiana, over a 3 year period: January 2017 to January 2020. Two cohorts were reviewed: patients with EPI excluding CF (n=596) and patients with CF (n=81). Results: While there was no significant difference in the prevalence of cancer at start vs end of the 3 year observation period in the CF cohort (4.1% at start, 7.2% at end), the prevalence of cancer was significantly greater among patients in the EPI cohort, both at start and end of the 3 year period: 15.95% at start, 43.9% at end (p <0.05). Also, while there was no significant change in alcohol use over the 3 year period for the CF cohort, the prevalence of alcohol use was significantly lower in CF cohort (0.45% at start, 2.2% at end) compared to EPI cohort which showed significant increase in alcohol use over the observation period: 7.7% at start vs 16% at end (p <0.05). Conclusions: There was a significantly higher prevalence of cancer in the EPI cohort compared to the CF cohort; while this may be due to higher prevalence of pancreatic cancer associated with EPI compared to CF, it does not explain the entirety of this observation. Not only was there a significantly higher prevalence of alcohol use in EPI cohort compared to CF cohort, but over the 3 year observation there was a 2-fold increase in prevalence of alcohol use within patients who already had a diagnosis of EPI. Within the EPI cohort, the observed increase in cancer prevalence and the increase in alcohol warrant further investigation into which factors unique to EPI patients without CF may modulate these social and health risk indices.

Cystic Fibrosis Transmembrane Regulator Modulator Therapy Perspective: Findings in Clinical Outcomes in a Series of Pediatric Patients

Cystic Fibrosis (CF) is the most frequent autosomal recessive disorder in Caucasians and has reduced life expectancy. It is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene which results in impairment of production, expression, and trafficking of the CFTR protein. CF has a multifaceted clinical representation with respiratory involvement as a main cause of morbidity and mortality. The multidisciplinary approach, care in specialized centers, early diagnosis through neonatal screening, and development of symptomatic treatments improved survival in the last decades. CFTR modulators were developed based on the discovery of the CF gene in 1989 and the improvement of genetic testing and have changed the perspective of a debilitating disease. These therapies, acting more upstream in the pathogenic cascade, overcome the underlying dysfunctions caused by CFTR mutations, having the ability to enhance or restore the resulting functional effects. CFTR modulator therapies are highly effective treatments for cystic fibrosis patients as shown in many clinical trials and real-life analyses so far. Improvement of quality of life, lung function, and pulmonary exacerbation rates are indisputable targets when evaluating the efficacy and efficiency of medical interventions in such a disease as CF, and they have been substantially changed in the era of modulators. We analyzed a small group of patients who were initiated on Kaftrio as per the indicated protocol. All significant clinical and functional aspects were improved, demonstrating the disease-changing potential of this therapy. We did not observe threatening side effects, no patients were stopped from the medication. CFTR modulators are the beginning of a new era in CF, a perspective for the improvement and effectiveness of precision medicine in CF patients.

Genetic analysis and functional study of novel CFTR variants in Chinese children with cystic fibrosis

ObjectivesTo describe the clinical characteristics of Chinese cystic fibrosis (CF) patients and to investigate the variants of CFTR and their potential pathogenicity. Study designChinese patients with potential CF diagnosis were studied. Clinical data were reviewed retrospectively from medical records. Whole exome sequencing and genetic evaluation were conducted to explore potential gene variants. The disruption of the variants to protein structure and function was explored and validated using in vitro experiments and in silico analysis. ResultsFour patients were recruited to the study, three of them were diagnosed as CF, and one was diagnosed as CFTR-related disorder. The age at symptom onset for the patients in this study ranged from newborn to 6 years, while the age at diagnosis varied from 3 to 11 years. All four patients exhibited bilateral diffuse bronchiectasis with Pseudomonas aeruginosa infections, and three of them had malnutrition. Finger clubbing was observed in three patients, two of whom displayed mixed ventilatory dysfunction. The CFTR variants spectrum of Chinese children with CF differs from that of Caucasian. A total of six variants were identified, two of which were first reported (c.1219G > T [p.Glu407*] and c.1367delT [p.Ala457Leufs*12]). The nonsense variants c.1219G > T, c.1657C > T and c.2551C > T and the frameshift variant c.1367delT were predicted to introduce premature stop codon and produce shorten CFTR protein, which was also first validated by in vitro truncation assay in this study. The missense variant c.1810A > C was predicted to disrupt the function of the nucleotide-binding domain 1 (NBD1) in the CFTR protein. The splicing variant c.1766 + 5G > T caused skipping of exon 13 and damaged the integrity of CFTR protein. ConclusionsOur study expands the spectrum of phenotypes and genotypes for CF of Chinese origin, which differs significantly from that of Caucasian. Genetic analysis and counseling are crucial and deserve extensive popularization for the diagnosis ofCF in patients of Chinese origin.

The Inhibition of the Membrane-Bound Transcription Factor Site-1 Protease (MBTP1) Alleviates the p.Phe508del-Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Defects in Cystic Fibrosis Cells.

Cystic Fibrosis (CF) is present due to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, the most frequent variant being p.phe508del. The CFTR protein is a chloride (Cl-) channel which is defective and almost absent of cell membranes when the p.Phe508del mutation is present. The p.Phe508del-CFTR protein is retained in the endoplasmic reticulum (ER) and together with inflammation and infection triggers the Unfolded Protein Response (UPR). During the UPR, the Activating Transcription Factor 6 (ATF6) is activated with cleavage and then decreases the expression of p.Phe508del-CFTR. We have previously shown that the inhibition of the activation of ATF6 alleviates the p.Phe508del-CFTR defects in cells overexpressing the mutated protein. In the present paper, our aim was to inhibit the cleavage of ATF6, and thus its activation in a human bronchial cell line with endogenous p.Phe508del-CFTR expression and in bronchial cells from patients, to be more relevant to CF. This was achieved by inhibiting the protease MBTP1 which is responsible for the cleavage of ATF6. We show here that this inhibition leads to increased mRNA and p.Phe508del-CFTR expression and, consequently, to increased Cl-efflux. We also explain the mechanisms linked to these increases with the modulation of genes when MBTP1 is inhibited. Indeed, RT-qPCR assays show that genes such as HSPA1B, CEBPB, VIMP, PFND2, MAPK8, XBP1, INSIG1, and CALR are modulated. In conclusion, we show that the inhibition of MBTP1 has a beneficial effect in relevant models to CF and that this is due to the modulation of genes involved in the disease.

Molecular-genetic foundations of energy exchange and physical qualities of man. Research perspectives

Human physical qualities represent a complex trait influenced by environmental and genetic factors, with most traits being polygenic in nature. The study of the relationship between molecular genetic data, physical characteristics and metabolic individuality (regulation of biogenesis, energy balance, lipid metabolism, glucose homeostasis, etc.) is a promising vector of research, both in the population as a whole and in various nosologies, primarily for hereditary and metabolic diseases characterized by impaired physical development and metabolic balance, including cystic fibrosis (CF), obesity, diabetes mellitus. The first studies were devoted to the study of these parameters in athletes. The genotype-phenotype study in CF has been actively studied for the past few years. It has been shown that environmental factors can determine clinical polymorphism in CF, which account for nearly 50% of lung function variability in this disease. However, CF patients with similar molecular genetic variants of the CFTR gene and in a single habitat (for example, in siblings) can have highly variable clinical manifestations. Genes whose products provide cell energy exchange (PPARA, PPARG, PPARD, PGC-1, UCP2, UCP3, ACTN, ACE) can also be “modifiers” and have an effect on the phenotype, the difference in clinical manifestations of the disease of patients with CF, the relationship of which in this category of patients has not been studied. The world has seen a steady increase in obesity and its complications. Patients with CF from the category of persons with nutritional deficiency in recent decades began to move into the category of overweight patients, which requires study. This review summarizes the recent achievements of studying genes whose products provide energy exchange of the cell, discusses the development of the relationship both with the physical characteristics of individuals and with pathological changes in the body as a result of the appearance of metabolic products in excess or with altered physicochemical properties and functional activity parameters leading to various diseases.

Raman Spectroscopy and Cystic Fibrosis Disease: An Alternative Potential Tool for Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Modulator Response Differentiation-A Pilot Study Based on Serum Samples.

Cystic fibrosis (CF) is a genetic disorder that alters chloride transport in mucous membranes. Recent studies have demonstrated that treatment with modulators of the chloride channel reduces inflammatory markers, restoring, among others, the imbalance of lipids. In this study, we analyzed the serum samples of treated and non-treated patients with modulators with Raman spectroscopy. Nineteen (eight treated an eleven non-treated) patients were considered. The main difference between the two groups appeared in the 3020-2800 cm-1 range. A Voigt deconvolution fit was performed, and nine sub-bands were identified. To distinguish between treated and non-treated patients, the area ratio between the CH3 and CH2 vibration modes was calculated for each patient. The results were validated using statistical analyses. In particular, receiver operating characteristic (ROC) curves and Youden index (Y) were calculated (Area Under Curve (AUC): 0.977; Y: 3.30). An ROC curve represents the performance of the classification, illustrating the diagnostic ability of Raman spectroscopy. It was demonstrated that Raman spectroscopy is able to highlight peculiar differences between elexacaftor/tezacaftor/ivacaftor (ETI)-treated and non-treated patients, in relation with lipids biomarkers.

Cyclic diacyl thioureas enhance activity of corrector Lumacaftor on F508del-CFTR.

Cystic fibrosis is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. In the search of novel series of CFTR modulators, a library of mono and diacyl thioureas were prepared by sequential synthesis. When tested alone, the obtained compounds 5 and 6 poorly affected F508del-CFTR conductance but, in combination with Lumacaftor, selected derivatives showed the ability to increase the activity of the approved modulator. Analogue 6 i displayed the most marked enhancing effect and acylthioureas 6 d and 6 f were also able to improve efficacy of Lumacaftor. All compounds proved to be non-cytotoxic against different cancer cell lines. Good pharmacokinetic properties were predicted for derivatives 5 and 6, thus supporting the value of these compounds for the development of novel modulators potentially useful for cystic fibrosis.

The bioinformatic analysis of CFTR in essential hypertension

The CFTR gene is associated with cystic fibrosis, a genetic disease primarily affecting the respiratory and digestive systems. Essential hypertension is a common cardiovascular disorder characterized by high blood pressure. In this bioinformatic analysis, various databases and tools were used to investigate the potential mechanisms underlying this association. Gene expression data and epigenetic analyses were used to identify the biological processes between CFTR and hypertension. Additionally, genetic variants within CFTR were analysed for potential effects on hypertension susceptibility. The results of this analysis suggest that CFTR may not play a role in hypertension. Moreover, hypertension has no special epigenetic feather. Further studies are needed to confirm the mechanisms of such a phenomenon.

Evaluation of the efficiency of nanomicellar formulation of fat-soluble vitamins in patients with cystic fibrosis: the study protocol for a randomized controlled trial

BackgroundCystic fibrosis is an inherited disease, which is caused by the CFTR protein defects due to mutations in the CFTR gene. Along with CFTR dysfunction, exocrine pancreatic insufficiency plays a key role in persistent fat malabsorption in CF patients; therefore, deficiency of fat-soluble vitamins (A, D, E, and K) is still a therapeutic challenge. Even with efficient pancreatic enzyme medication and CF-specific vitamins, many patients with CF have fat-soluble vitamins deficiency. The present study aims to evaluate the efficiency of nanomicelle formulation of fat-soluble vitamins in children with CF in order to achieve the appropriate serum levels of these vitamins.MethodsThis prospective, single-blind control trial will be conducted at the Akbar Children’s Hospital in Mashhad, Iran. Patients with CF will be enrolled based on the eligibility criteria. The control group will receive the standard formulation of fat-soluble vitamins similar to the routine CF treatment, and for the intervention group, the nanomicelle formulation of fat-soluble vitamins will be administered for 3 months. The primary outcome of this study is the measurement of serum levels of fat-soluble vitamins. The secondary outcomes are clinical assessment by the Shwachman-Kulczycki score, anthropometrics, and quality of life. Outcomes will be assessed before and after 3 months.DiscussionDue to persistent fat-soluble vitamin deficiency in CF disease, the nanomicelle formulation could be proposed as a new delivery method of fat-soluble vitamins in the treatment of cystic fibrosis.Trial registrationIranian Registry of Clinical Trials IRCT20220415054541N1. Registered on July 23, 2022.

Specifics of cystic fibrosis genetic spectrum in Georgia

Cystic fibrosis (CF) is a life-threatening autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). F508del is the most common mutation in the world. Other mutations are rare and population specific. The study aimed to comprehensively analyze the distribution of CFTR mutations in Georgian CF patients. Knowing the prevalence and characteristics of specific mutations can be reflected in genetic counseling and management strategies. We reviewed the data of 129 CF patients, aged < 18 years, from all parts of Georgia. 91 patients with a clinically confirmed CF diagnosis were tested for CF-causing mutations (constituting 70.5% of all currently registered CF patients in the country). These patients have been analyzed for rare CFTR variants by massively parallel sequencing of the entire CFTR coding region and adjacent introns combined with the analysis of intra-CFTR rearrangements. CFTR gene analysis revealed 29 mutations in Georgian CF patients. The most common mutation was c.1545_1546delTA (1677delTA) with a frequency of 42.7%, while the second most common mutation, W1282X, was detected in 11.2% of all CF alleles. Another 27 CFTR mutations have low frequency, including F508del (6.7% of alleles). 3 novel mutations were found (c.708dupT; CFTRdele16_17; c.3170C>G) and reported to CFTR2 database.According to the data, the distribution of CFTR mutations in the Georgian CF population differs regarding the high frequency of mutation c.1545_1546delTA (1677delTA) and the low frequency of the predominant F508del mutation. Compared to patients with F508 del and W1282X mutations, patients with 1677delTA have typical manifestations and complications; however, the frequency of growth retardation and liver damage is 3 times, and the frequency of chronic respiratory manifestations and chronic malnutrition is 2 times lower, though pancreatic insufficiency is more severe in patients with 1677delTa. CF-associated diabetes, distal intestinal obstruction syndrome, and hemoptysis were only observed in patients with the 1677delTA mutation. The mortality rate is lower compared to patients with F508del and W1282X mutations.

Laboratory Tools to Predict CFTR Modulator Therapy Effectiveness and to Monitor Disease Severity in Cystic Fibrosis.

The implementation of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulator drugs into clinical practice has been attaining remarkable therapeutic outcomes for CF, a life-threatening autosomal recessive genetic disease. However, there is elevated CFTR allelic heterogeneity, and various individuals carrying (ultra)rare CF genotypes remain without any approved modulator therapy. Novel translational model systems based on individuals' own cells/tissue are now available and can be used to interrogate in vitro CFTR modulator responses and establish correlations of these assessments with clinical features, aiming to provide prediction of therapeutic effectiveness. Furthermore, because CF is a progressive disease, assessment of biomarkers in routine care is fundamental in monitoring treatment effectiveness and disease severity. In the first part of this review, we aimed to focus on the utility of individual-derived in vitro models (such as bronchial/nasal epithelial cells and airway/intestinal organoids) to identify potential responders and expand personalized CF care. Thereafter, we discussed the usage of CF inflammatory biomarkers derived from blood, bronchoalveolar lavage fluid, and sputum to routinely monitor treatment effectiveness and disease progression. Finally, we summarized the progress in investigating extracellular vesicles as a robust and reliable source of biomarkers and the identification of microRNAs related to CFTR regulation and CF inflammation as novel biomarkers, which may provide valuable information for disease prognosis.

Magnetic Resonance Imaging of Pulmonary and Paranasal Sinus Abnormalities in Children with Primary Ciliary Dyskinesia Compared to Children with Cystic Fibrosis.

Rationale: Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are characterized by inherited impaired mucociliary clearance leading to chronic progressive lung disease as well as chronic rhinosinusitis (CRS). The diseases share morphological and functional commonalities on magnetic resonance imaging (MRI) of the lungs and paranasal sinuses, but comparative MRI studies are lacking. Objectives: To determine whether PCD shows different associations of pulmonary and paranasal sinus abnormalities on MRI and lung function test results in children (infants to adolescents) compared with children with CF. Methods: Eighteen children with PCD (median age, 9.5 [IQR, 3.4-12.7] yr; range, 0-18 yr) and 36 age-matched CF transmembrane conductance regulator modulator-naive children with CF (median age, 9.4 [3.4-13.2] yr; range, 0-18 yr) underwent same-session chest and paranasal sinus MRI as well as spirometry (to determine forced expiratory volume in 1 s percent predicted) and multiple-breath washout (to determine lung clearance index z-score). Pulmonary and paranasal sinus abnormalities were assessed using previously validated chest MRI and CRS-MRI scoring systems. Results: Mean chest MRI global score was similar in children with PCD and CF (15.0 [13.5-20.8] vs. 15.0 [9.0-15.0]; P = 0.601). Consolidations were more prevalent and severe in children with PCD (56% vs. 25% and 1.0 [0.0-2.8] vs. 0.0 [0.0-0.3], respectively; P < 0.05). The chest MRI global score correlated moderately with forced expiratory volume in 1 second percent predicted in children with PCD and children with CF (r = -0.523 and -0.687; P < 0.01) and with lung clearance index in children with CF (r = 0.650; P < 0.001) but not in PCD (r = 0.353; P = 0.196). CRS-MRI sum score and mucopyocele subscore were lower in children with PCD than in children with CF (27.5 [26.3-32.0] vs. 37.0 [37.8-40.0] and 2.0 [0.0-2.0] vs. 7.5 [4.8-9.0], respectively; P < 0.01). CRS-MRI sum score did not correlate with chest MRI score in PCD (r = 0.075-0.157; P = 0.557-0.788) but correlated moderately with MRI morphology score in CF (r = 0.437; P < 0.01). Conclusions: MRI detects differences in lung and paranasal sinus abnormalities between children with PCD and those with CF. Lung disease does not correlate with CRS in PCD but correlates in CF.

The burden of cystic fibrosis in North Africa.

Background: Over 200 pathogenic variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are associated with cystic fibrosis (CF)-the most prevalent autosomal recessive disease globally, the p.Phe508del variant being the most commonly observed. Main text: Recent epidemiological studies suggest a higher global prevalence of CF than previously thought. Nevertheless, comprehensive CF data remains extremely scarce among African populations, contributing to a significant information gap within the African healthcare system. Consequently, the underestimation of CF among children from African populations is likely. The goal of this article is to review the pathogenesis of CF and its prevalence in the countries of North Africa. Conclusion: The prevalence of CF in North African countries is likely underestimated due to the complexity of the disease and the lack of a timely, proper clinical and genetic investigation that allows the early identification of CF patients and thus facilitates therapeutic recommendations. Therefore, specific genetic and epidemiological studies on African individuals showing CF symptoms should be conducted to enhance the diagnostic yield of CF in Africa.

One year of treatment with elexacaftor/tezacaftor/ivacaftor in patients with cystic fibrosis homozygous for the F508del mutation causes a significant increase in liver biochemical indexes.

Introduction: Modulators of cystic fibrosis transmembrane conductance regulator mutated protein significantly improved the outcome of patients with cystic fibrosis (CF). We describe 63 patients who were independently followed up in two CF regional centers (i.e., Campania and Tuscany regions). Methods: All patients were homozygous for the F508del mutation and were treated with lumacaftor/ivacaftor (LI) for 3years, followed by 1year of treatment with elexacaftor/tezacaftor/ivacaftor (ETI). We studied the biochemical parameters of liver damage and cholesterol metabolism. Results: Beyond the improvement of BMI and lung function with LI treatment and even more with ETI, we found that the 3years of LI treatment significantly improved liver function parameters (total and conjugated bilirubin, ALT, AP, and GGT), while the subsequent ETI treatment caused a significant increase of such parameters. Discussion: We confirm that treatment with LI does not correct hypocholesterolemia, whereas treatment with ETI significantly increases serum cholesterol. Such an increase is likely due to enhanced de novo biosynthesis, as indicated by the significant increase in serum lathosterol, and it is likely that the subsequent liver cholesterol accumulation may contribute to triggering inflammation and worsening liver biochemical indexes. The increase in serum bilirubin and ALT that we observed in approximately 94% and 84% of patients treated with ETI, respectively, suggests further investigation of the impact of ETI therapy on liver function indexes.

What the future holds: cystic fibrosis and aging.

Cystic fibrosis (CF) is one of the most common genetic diseases with around 70,000 affected patients worldwide. CF is a multisystem disease caused by a mutation in the CF transmembrane conductance regulator gene, which has led to a significant decrease in life expectancy and a marked impairment in the quality of life for people with CF (pwCF). In recent years, the use of highly effective CFTR modulator therapy (HEMT) has led to improved pulmonary function, fewer CF exacerbations, lower symptom burden, and increased weight. This has coincided with an increased life expectancy for pwCF, with mean age of survival being now in the 50s. This being a major breakthrough, which the CF population has hoped for, pwCF are now facing new challenges by growing old with a chronic respiratory disease. In this mini review, we are attempting to summarize the current knowledge of the aging process and its effect on CF disease and its manifestations including new developments, the current research gaps and potential future developments in the field to allow healthy aging for the CF community.