Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. Currently, CFTR modulators are the most effective treatment for CF; however, they may not be suitable for all patients. A representative and convenient in vitro model is needed to screen therapeutic agents under development. This study, on the most common mutation, F508del, investigates the efficacy of human induced pluripotent stem cell-derived lung organoids (hiLOs) from NKX2.1+ lung progenitors and airway basal cells (hiBCs) as a 3D model for CFTR modulator response assessment by a forskolin-induced swelling assay. Weak swelling was observed for hiLOs from NKX2.1+ lung progenitors and hiBCs in response to modulators VX-770/VX-809 and VX-770/VX-661, whereas the VX-770/VX-661/VX-445 combination resulted in the highest swelling response, indicating superior CFTR function restoration. The ROC analysis of the FIS assay results revealed an optimal cutoff of 1.21, with 65.9% sensitivity and 71.8% specificity, and the predictive accuracy of the model was 76.4%. In addition, this study compared the response of hiLOs with the clinical response of patients to therapy and showed similar drug response dynamics. Thus, hiLOs can effectively model the CF pathology and predict patients’ specific response to modulators.

Cystic fibrosis (CF) is a genetically inherited disorder characterized by a wide range of clinical manifestations and genetic variations. This study focuses on the genetic and molecular epidemiology of CF in the Russian population, utilizing data from the national CF registry. The birth prevalence of CF in Russia has been analyzed over a span of years, revealing variations in frequency. The study delves into the genetic landscape of CFTR gene variants in Russian patients, showcasing a diverse spectrum with a predominance of severe variants, some of which are rare and distinct from global populations. A total of 233 variants have been documented, exhibiting frequencies ranging from 0.01% to 51.5%, with 47 of these variants remaining uncharted within international genetic databases. As of 2021, CFTR modulator therapy has been introduced for patients under 19 years, heightening the importance of genetic diagnosis. In 2023, more than 1,850 patients under 19 received CFTR modulator therapy. Notably, the impact of complex alleles on disease progression and response to targeted therapies is gaining recognition. Comparisons with European registries highlight distinctive features of the Russian population, such as differences in age distribution among patients. Additionally, the study emphasizes the need to ascertain clinical significance and pathogenicity of newly identified genetic variants, along with exploring their suitability for targeted therapies. The integration of genetic insights into the management of CF offers potential for enhanced personalized therapeutic interventions. In conclusion, this thorough analysis provides a comprehensive understanding of the genetic nuances within the Russian CF population. By illuminating the intricate relationship between genetic variations and disease manifestation, the study underscores the essential role of genetics in shaping therapeutic strategies and improving patient outcomes. Further research and ongoing genetic exploration are crucial for optimizing the care of individuals with CF in the era of evolving therapeutic options.

The article discusses results of a prospective observational study of long-term use of the biosimilar dornase alfa (Tigerase) (Generium, Russia) as part of complex therapy in patients with cystic fibrosis in real clinical practice.The aim was to analyze the outcomes of long-term use of the dornase alfa dornase alfa as part of complex therapy in patients with CF (protocol #DRN-CFR-N01).Methods. The study included patients (n = 165) aged 5 years and older from 11 centers for treatment of cystic fibrosis in the Russian Federation with a confirmed diagnosis of cystic fibrosis who were prescribed dornase alfa by their attending physician.Results. The analysis revealed that exacerbations of chronic pulmonary disease during the treatment with dornase alfa were observed in 29 (17.58%) patients included in the study. At the same time, there were no statistically significant changes in FEV1 and FVC (%) against baseline during the treatment in the study population. Adverse events related to the study drug were recorded in 9 (5.45%) patients.Conclusion. Biosimilar dornase alfa demonstrated a favorable efficacy and safety profile in routine clinical practice, which confirms the results of previously published studies.

Cystic fibrosis-associated chronic rhinosinusitis (CRS) is a separate form of CRS that progresses gradually over the course of patient’s life and worsens with age. The reasons for this are the mechanical congestion of mucus in the paranasal sinuses and the persistence of colonies of pathogenic antibiotic-resistant microorganisms. Therapy with CFTR modulators has resulted in a significant reduction in the severity of CRS. The nature of these changes and the dynamics in the microbial landscape of the upper respiratory tract are not sufficiently explored.Aim of the article is to highlight various aspects of the impact of CFTR modulators on the course of CRS in adult patients with cystic fibrosis (CF) based on literature data and a number of our own clinical observations. The article presents a series of clinical cases of CRS in adult CF patients treated with CFTR modulators for different periods of time.Conclusion. During targeted therapy with CFTR modulators, the symptoms of CRS are reversed due to the restoration of normal rheological properties of nasal secretions, the clinical picture improves, and the severity of CRS decreases. However, this type of treatment has no direct effect on the microbial landscape of the respiratory tract and requires additional interventions in the form of local and systemic antibacterial therapy. Therapy with CFTR modulators alters the course of CF in the nasal cavity, as well as in the pharynx and larynx.

Human-induced airway basal cells (hiBCs) derived from human-induced pluripotent stem cells (hiPSCs) offer a promising cell model for studying lung diseases, regenerative medicine, and developing new gene therapy methods. We analyzed existing differentiation protocols and proposed our own protocol for obtaining hiBCs, which involves step-by-step differentiation of hiPSCs into definitive endoderm, anterior foregut endoderm, NKX2.1+ lung progenitors, and cultivation on basal cell medium with subsequent cell sorting using the surface marker CD271 (NGFR). We derived hiBCs from two healthy cell lines and three cell lines with cystic fibrosis (CF). The obtained hiBCs, expressing basal cell markers (NGFR, KRT5, and TP63), could differentiate into lung organoids (LOs). We demonstrated that LOs derived from hiBCs can assess cystic fibrosis transmembrane conductance regulator (CFTR) channel function using the forskolin-induced swelling (FIS) assay. We also carried out non-viral (electroporation) and viral (recombinant adeno-associated virus (rAAV)) serotypes 6 and 9 and recombinant adenovirus (rAdV) serotype 5 transgene delivery to hiBCs and showed that rAAV serotype 6 is most effective against hiBCs, potentially applicable for gene therapy research.

Cystic fibrosis (CF) is characterized by the development of a severe nutritional deficiency. A low BMI directly correlates with low lung function and requires active nutritional support. Pathogenetic (targeted) therapy aimed at restoring the chlorine channel function also leads to weight gain. The effects of CFTR modulators on extrapulmonary pathology in adult CF patients in Russia have been described very little.Aim. To evaluate the sequential impact of two targeted drugs – the potentiator ivacaftor and the triple combination of CF transmembrane regulator modulators elexacaftor/tezacaftor/ivacaftor – on the nutritional status of an adult patient with cystic fibrosis receiving nutritional support.Conclusion. Therapy with CFTR modulator in combination with sipping nutritional support promotes significant weight gain in adult CF patients. The triple combination of elexacaftor/tezacaftor/ivacaftor has a more active effect on nutritional status than ivacaftor alone. The targeted therapy requires supervision by a nutritionist.

Objectives: Russian Cystic Fibrosis Patient Registry (RCFPR) analysis is a tool to assess the status of DNA diagnosis, characterise new pathogenic variants of the CFTR gene, plan DNA screening measures and prescribe targeted therapies. Aim - to analyze the allelic frequency of CFTR gene variants in the Russian Federation and the status of molecular diagnostics over 11 years. Methods: The data of DNA diagnosis of CF patients on the basis of the RCFPR from 2011 to 2021 were analyzed. Results: An increase in the total number of patients from 1026 in 2011 to 3969 in 2021, an increase in coverage by genetic examination from 91.8% to 93.6%, an increase in the number of detected mutations from 80% to 90.5%, a decrease in the number of patients with undetected mutations from 9.5% to 3.2% were revealed. The number of pathogenic variants detected increased from 73 in 2011 to 240 in 2021. Among the 10 most frequent CFTR gene variants: F508del, CFTRdele2,3, E92K, 1677delT>A, 3849+10kbC>T, 2143delT, 2184insA, W1282X, L138ins, N1303K. The pathogenic variants F508del (52.79%/51.55%) and CFTRdele2,3 (6.32%/6.11%) remained in the first two positions (2011/2021). In third place was the "Chuvash mutation" E92K (2.65%/3.46%). The "Caucasian" mutation 1677delT>A (2.25%) ranked fourth in 2021, while in 2011 it was not on the list of 10 frequent pathogenic variants. Fifty-eight undescribed variants of the CFTR gene were identified. In 2021 the allele frequency of p.[F508del;L467F] complex allele was 0.86% (8.12% among F508del homozygous patients in whom the presence of this complex allele in the genotype prevents response to lumacaftor/ivacaftor treatment); the frequency of p.[S466X;R1070Q] complex allele was 0.59%. Conclusion: Thanks to the RCFPR the allelic frequency of CFTR gene variants in Russia has been established. Dynamics of DNA diagnosis showed an improvement in the organization of DNA diagnosis. The impact of complex alleles should be considered when planning targeted therapy.

BACKGROUND : In recent decades, the life expectancy of patients with CF has increased, which leads to an increase in the frequency of conditions associated with impaired carbohydrate metabolism. AIM : to analyze the impact of cystic fibrosis-associated diabetes mellitus (CFDM) in children and adolescents on the course of cystic fibrosis according to the 2021 register of patients with cystic fibrosis of the Russian Federation (RF). MATERIALS AND METHODS : the data of the register of patients with cystic fibrosis of the Russian Federation for 2021 were analyzed. The study included 122 patients with diabetes mellitus requiring the use of insulin — 33 children (27%) and 89 adults (73%), the average age of children was 13.5±4.1, the average age of adult. patients aged 18 years and older was 27.4±6.6. To compare the course of cystic fibrosis in patients with and without diabetes mellitus, groups were formed that were comparable in age, gender, genotype — the group of patients without diabetes included 827 patients, 33 patients made up the group of patients with CFRD using insulin. Diagnostic criteria, indicators of respiratory function, microbiological status, nature of complications, volume of therapy were compared. RESULTS : Patients with CFRD have a lower FEV1 compared to children without diabetes mellitus — M±SD FEV1 (%) 85.2±27.5 in the group of patients without diabetes mellitus and M±SD FEV1 (%) 72.4±26.0 in patients with diabetes mellitus (p < 0.016), compared in the microbiological seeding groups — a trend towards more frequent chronic growth of Pseudomonas aeruginosa 54.50% versus 39.4% in the group without CFRD. An increase in MRSA was also more often detected — 9.1% compared with the group of children without diabetes — 3.1%. Antibacterial therapy is more commonly used — inhaled in 54.6% of patients without diabetes mellitus while children with CFRD received inhaled antibiotic therapy in 75.8% (p=0.017). There was a significant difference in the used antibacterial tablet therapy (p=0.013). A significant difference in the number of patients on oxygen therapy in the group with CFRD — 12.1%, versus 3.4% without CFRD (p=0.01) confirms a more severe course of cystic fibrosis in patients with CFRD. CONCLUSION : The prevalence of CFDM with the need for insulin therapy among children in the Russian Federation is 1.3%. Cystic fibrosis-associated diabetes mellitus significantly worsens the course of cystic fibrosis in terms of lung function, the growth of gram-negative and resistant flora, the presence of severe complications and the frequent use of antibiotic therapy, which is obviously associated with frequent exacerbations of the bronchopulmonary process in cystic fibrosis in patients with developed cystic fibrosis-associated diabetes mellitus.

A registry of patients with cystic fibrosis (CF) of the Russian Federation has been compiled annually since 2011. Analysis of the national registry with large amounts of clinical and laboratory data helps understand changes in demographic indicators, plan measures to improve the quality of medical care and evaluate their effectiveness. Aim. To analyze health status of patients with cystic fibrosis in the Russian Federation and the dynamics of key clinical and laboratory parameters from 2011 to 2021. Methods. The health status of CF patients was assessed using the registry data from 2011 to 2021. Results. The analysis revealed an increase in the total number of patients from 1,026% in 2011 to 3,969 in 2021, in the number of patients identified by neonatal screening from 28.8% to 53.5%, and in coverage by genetic testing from 91.8 to 93.6%. At the same time, the number of mutations detected dropped from 80 to 90.5% and the number of patients with unidentified mutations decreased from 9.5 to 3.2%. The mean age at diagnosis of cystic fibrosis did not change (3.3 ± 5.5 in 2011 and 3.1 ± 6.2 in 2021) despite an increase in the number of patients diagnosed through neonatal screening. There was a difference in M ± SD age from 2011 to 2021 (11.5 ± 8.9 in 2011 and 14 ± 9.8 in 2021). The proportion of adult patients was 24.95% in 2011 and 27.4% in 2021. The therapy changed over 11 years - the number of courses of intravenous therapy decreased from 70.9 to 36.4%, the number of patients using inhaled antipseudomonal therapy expanded to 45%, the number of patients using hypertonic sodium chloride solution expanded from 8.7 to 70.7%, the use of glucocorticoids decreased. The targeted therapy was introduced in 2018, and the number of patients receiving pathogenetic drugs is growing. Conclusion. The observed changes are indicative of the health status of Russian patients with cystic fibrosis. Analysis of registries helps improve the organization of medical care, predict and implement sanitary and epidemic measures, plan therapy, and assist the regions in organizing outpatient monitoring and microbiological control. The registry is analyzed to organize health care for adult patients.

The pathogenic variant E92K (c.274G > A) of the CFTR gene is rare in America and Europe, but it is common for people with cystic fibrosis from Russia and Turkey. We studied the effect of the E92K genetic variant on the CFTR function. The function of the CFTR channel was studied using the intestinal current measurements (ICM) method. The effects of CFTR modulators on the restoration of the CFTR function were studied in the model of intestinal organoids. To assess the effect of E92K on pre-mRNA splicing, the RT-PCR products obtained from patients’ intestinal organoid cultures were analyzed. Patients with the genetic variant E92K are characterized by an older age of diagnosis compared to homozygotes F508del and a high frequency of pancreatic sufficiency. The results of the sweat test and the ICM method showed partial preservation of the function of the CFTR channel. Functional analysis of CFTR gene expression revealed a weak effect of the E92K variant on mRNA-CFTR splicing. Lumacaftor (VX-809) has been shown to restore CFTR function in an intestinal organoid model, which allows us to consider the E92K variant as a promising target for therapy with CFTR correctors.

Chronic lung infections are a consequence of the disturbance of mucociliary clearance process in cystic fibrosis. For most patients with cystic fibrosis, chronic lung infection is associated with a poor prognosis. The impact of chronic Pseudomonas aeruginosa infection on progressive deterioration of lung function and nutritional status has been established. Timely and effective antibiotic therapy aimed at eradication or control of gram-negative flora affects the duration and quality of life. The purpose of the study . To investigate the safety and efficacy of inhaled administration of sodium colistimethate (Colimistin®). Methods . The study enrolled 42 patients (27 patients aged 5 to 17 years and 15 patients over 18 years) with an established diagnosis of cystic fibrosis, 38 with monoculture of P. aeruginosa or various associations, 4 with Achromobacter spp . culture. Microbial status, external respiratory function, nutritional status, assessment of well-being, adverse reactions, exacerbations, and use of antibiotic therapy during colimistin inhalations were recorded in all patients at baseline and at 3 months. Results . A significant improvement in nutritional status in terms of weight ( p < 0.007) and height ( p < 0.001) was shown in the general patient group and the children’s group. In the group of children, there was a significant increase in weight ( p < 0.034) and height ( p < 0.0001). In the group of patients older than 18 years, there was a significant increase in weight ( p < 0.045) and BMI three months after therapy ( p < 0.013). There were no significant improvements in FVC and FEV1. The treatment efficacy was shown by the assessment of well-being in the general patient group ( p < 0.001) and in the children’s group ( p < 0.002). No significant difference was found in the adult patient group ( p < 0.067). Two patients dropped out of the study due to ADR at the start of therapy. Conclusion . Sodium colistimethate showed efficacy and safety in bronchopulmonary infections caused by P. aeruginosa in monoculture and in association with Achromobacter spp . and may be recommended for use in children and adults with cystic fibrosis.

Assessment of the health status of adults with cystic fibrosis in the Russian Federation (RF)