The long-term effect of elexacaftor/tezacaftor/ivacaftor on cardiorespiratory fitness in adolescent patients with cystic fibrosis: a pilot observational study.

BACKGROUND: Physical activity is a crucial demand on cystic fibrosis treatment management. The highest value of oxygen uptake (VO2peak) is an appropriate tool to evaluate the physical activity in these patients. However, there are several other valuable CPET parameters describing exercise tolerance (Wpeak, VO2VT1, VO2VT2, VO2/HRpeak, etc.), and helping to better understand the effect of specific treatment (VE, VT, VD/VT etc.). Limited data showed ambiguous results of this improvement after CFTR modulator treatment. Elexacaftor/tezacaftor/ivacaftor medication improves pulmonary function and quality of life, whereas its effect on CPET has yet to be sufficiently demonstrated. METHODS: We performed a single group prospective observational study of 10 adolescent patients with cystic fibrosis who completed two CPET measurements between January 2019 and February 2023. During this period, elexacaftor/tezacaftor/ivacaftor treatment was initiated in all of them. The first CPET at the baseline was followed by controlled CPET at least one year after medication commencement. We focused on interpreting the data on their influence by the novel therapy. We hypothesized improvements in cardiorespiratory fitness following treatment. We applied the Wilcoxon signed-rank test. The data were adjusted for age at the time of CPET to eliminate bias of aging in adolescent patients. RESULTS: We observed significant improvement in peak workload, VO2 peak, VO2VT1, VO2VT2, VE/VCO2 slope, VE, VT, RQ, VO2/HR peak and RR peak. The mean change in VO2 peak was 5.7 mL/kg/min, or 15.9% of the reference value (SD ± 16.6; p= 0.014). VO2VT1 improved by 15% of the reference value (SD ± 0.1; p= 0.014), VO2VT2 improved by 0.5 (SD ± 0.4; p= 0.01). There were no differences in other parameters. CONCLUSION: Exercise tolerance improved after elexacaftor/tezacaftor/ivacaftor treatment initiation. We suggest that the CFTR modulator alone is not enough for recovering physical decondition, but should be supplemented with physical activity and respiratory physiotherapy. Further studies are needed to examine the effect of CFTR modulators and physical therapy on cardiopulmonary exercise tolerance.

Significance of plasma fibrinogen and malondialdehyde in the post-inflammatory period in patients with cystic fibrosis.

OBJECTIVES: Evaluation of selected inflammatory parameters and serum malondialdehyde (MDA) significance in the post-inflammatory period in adult patients with cystic fibrosis. BACKGROUND: Laboratory biomarkers can be integrated into clinical practice as part of monitoring the effectiveness of treatment. METHODS: After recovery from an acute exacerbation of lung infection, selected inflammatory parameters (fibrinogen, IL-1, IL-6, SAA, hs-CRP) and serum MDA were examined in 30 adult patients with cystic fibrosis. Their correlation with FEV1, frequency and duration of subsequent hospitalizations and 6-year prognosis in terms of mortality or need for lung transplantation was evaluated. RESULTS: FEV1 negatively correlated with fibrinogen, but positively with MDA. No significant correlation with hs-CRP, IL-1, IL-6 and SAA was recorded. Plasma fibrinogen predicted the frequency and duration of subsequent hospitalizations. The 6-year prognosis was negatively associated with plasma fibrinogen whereas its association with MDA was positive. However, the prognosis of patients in the multivariate analysis was significantly associated only with FEV1. CONCLUSION: Plasma fibrinogen examined in the post-inflammatory period is a marker of lung damage in patients with cystic fibrosis and can be used to predict the prognosis. The positive correlation of serum MDA with FEV1 in the post-inflammatory period may be important to the interpretation of treatment interventions (Tab. 3, Fig. 2, Ref. 17).

What matters in chronic Burkholderia cenocepacia infection in cystic fibrosis: Insights from comparative genomics.

Burkholderia cenocepacia causes severe pulmonary infections in cystic fibrosis (CF) patients. Since the bacterium is virtually untreatable by antibiotics, chronic infections persist for years and might develop into fatal septic pneumonia (cepacia syndrome, CS). To devise new strategies to combat chronic B. cenocepacia infections, it is essential to obtain comprehensive knowledge about their pathogenesis. We conducted a comparative genomic analysis of 32 Czech isolates of epidemic clone B. cenocepacia ST32 isolated from various stages of chronic infection in 8 CF patients. High numbers of large-scale deletions were found to occur during chronic infection, affecting preferentially genomic islands and nonessential replicons. Recombination between insertion sequences (IS) was inferred as the mechanism behind deletion formation; the most numerous IS group was specific for the ST32 clone and has undergone transposition burst since its divergence. Genes functionally related to transition metal metabolism were identified as hotspots for deletions and IS insertions. This functional category was also represented among genes where nonsynonymous point mutations and indels occurred parallelly among patients. Another category exhibiting parallel mutations was oxidative stress protection; mutations in catalase KatG resulted in impaired detoxification of hydrogen peroxide. Deep sequencing revealed substantial polymorphism in genes of both categories within the sputum B. cenocepacia ST32 populations, indicating extensive adaptive evolution. Neither oxidative stress response nor transition metal metabolism genes were previously reported to undergo parallel evolution during chronic CF infection. Mutations in katG and copper metabolism genes were overrepresented in patients where chronic infection developed into CS. Among professional phagocytes, macrophages use both hydrogen peroxide and copper for their bactericidal activity; our results thus tentatively point to macrophages as suspects in pathogenesis towards the fatal CS.

[Cystic fibrosis in adults]. / Cystická fibróza dospelých.

Cystic fibrosis (CF) is an inherited disease caused by mutations in the transmembrane conductance regulator (CFTR) gene. The disease leads to dysfunction of the exocrine glands with high concentration of chloride in the sweat and formation of abnormally viscous mucus in the respiratory, digestive and reproductive tract. Chronic sinopulmonary disease, exocrine pancreatic insufficiency, liver disease, intestinal obstruction, impaired nutritional status, salt loss syndrome and male infertility dominates in the clinical presentation. The examination of sweat chloride concentration and mutations in the CFTR gene is used in CF diagnostics for detection of CFTR protein dysfunction. The treatment comprises especially respiratory physiotherapy with mucolytics inhalations, aggressive antibiotic therapy and high-calorie diet together with adequate pancreatic enzymes substitution. The prevention of airway infection with resistant bacterial pathogens, particularly Pseudomonas aeruginosa, is a fundamental measure. Significant recent progress include the use of newborn screening of CF and drugs targeted to individual CFTR gene mutations in the clinical practise. The prognosis of patients has improved due to using of modern therapeutic methods in CF treatment centres. Children born at present time have survival probability 40-50 years.Key words: adults - cystic fibrosis - diagnostics - therapy.

[Non-CF bronchiectasis of adults: short review for clinical practice Position paper of Board of disease with bronchial obstruction Czech Pulmonological and Phthiseological Society Czech Medical Association of J. E. Purkyne]. / Non-CF bronchiektázie dospelých: strucný prehled pro praxi Dokument Sekce chorob s bronchiální obstrukcí Ceské pneumologické a ftizeologické spolecnosti Ceské lékarské spolecnosti J. E. Purkyne.

Bronchiectasis is a clinically important, but poorly understood, pulmonary condition characterized by dilated and thick-walled bronchi. Bronchiectasis remains a significant cause of morbidity and mortality around the world. Targeted effort to early high-resolution computed tomography diagnosis and detailed confirmation of causation are in the spotlight of respiratory physicians in the developed countries. The risk population consists of subjects with persistent and/or productive cough, where another clear diagnosis has not been performed. Specific treatment tailored on underlying diseases and non-specific airway clearance techniques are able to improve symptoms, and reduce lung impairment. Evidence-based treatment algorithms for anti-inflammatory, and antibiotic treatment of stable non-CF BE will have to await large-scale, long-term controlled studies. Surgery should be reserved for individuals with highly symptomatic, localized bronchiectasis who have failed medical management. Unfortunately, there have been few well designed longitudinal or cross-sectional studies in the field of bronchiectasis. To give truly meaningful and generalizable results, a longitudinal observational study of bronchiectasis would require to enrol several thousand patients, more than any one center can enrol. The European Bronchiectasis Registry will create an open, pan-European registry of patients with non-CF bronchiectasis. The authors emphatically recommend that all respiratory specialist managed non-CF BE subjects should be actively involved in the European Bronchiectasis Registry.Key words: bronchiectasis - diagnosis - registry - treatment.

Immunonutrition in patients with cyctic fibrosis leads to drop of serum amyloid A and increase of oxidative stress.

The aim of the present study is to evaluate of the impact of immunonutrition on parameters of oxidative stress and inflammation in patients with cystic fibrosis and malnutrition. In the 30 patients with cystic fibrosis and long-term enteral nutrition support for malnutrition the effect of standard and immunonutrion sipping on oxidative stress and inflammatory activity parameters was compared. Malonyldialdehyde (MDA) as parameter of oxidative stress and serum amyloid A (SAA), interleukin 1 and 6, hsCRP, IgM, IgA, IgG as parameters of inflammatory activity were examined. Immunonutrition decreased SAA to 17.6 mg/L comparing to 25.6 mg/L when standard nutrition was given (p = 0.014). MDA was 0.66 µM on standard and 0.96 µM on immunonutrition support (p<0.01). The significant negative correlation was recorded between MDA and SAA, hs-CRP, interleukin 6, IgA and IgG. In conclusion, the application of immunonutrition in patients with cystic fibrosis and malnutrition is associated with drop of SAA but with the rise of MDA.

[The differential diagnosis of pleural effusions]. / Diferenciální diagnostika pleurálních výpotku.

UNLABELLED: The problems of pleural effusions are connected with many areas of medicine. The problem affects approx. 0.5 % of the population every year. The paper summarizes pathophysiological data relating to the emergence of effusions, their epidemiology, description of particular types of effusions and possibilities of treatment. More attention is paid to the differential diagnosis and therapy for malign pleural effusions. KEY WORDS: diagnostics - exudate - treatment - pleura - transudate.

[Diagnostics of cystic fibrosis in adults]. / Diagnostika cystické fibrózy u dospelých.

INTRODUCTION: There is an increasing number of cystic fibrosis (CF) patients with the diagnosis established in adulthood worldwide. AIM: To give an overview of our experience with the diagnostics of CF in adulthood in the Czech Republic. METHODS: CF patients with the diagnosis determined at the age 18 years during 2000-2014 period were selected from the Czech Registry of CF (www.cfregistr.cz). Demographic and clinical data were reported from medi-cal records at the time of diagnosis and as of 31st December 2014. Only those with two CF causing mutation or with one CF causing mutation together with sweat chloride concentration > 60 mmol/l were included in the study. The clinical presentation was compared with a control group consisting of homozygous F508del patients with the diagnosis established in childhood. RESULTS: 23 patients (16 men and 7 women) with the diagnosis determined at a mean age of 32.9 ± 8.5 years were included in the study. Presenting symptoms included bronchiectasis and/or haemoptysis in 12 cases, obstructive azoospermia in 7 cases and recurrent pancreatitis in 4 cases. When compared with the control group, the patients had higher age (38.6 ± 8.3 vs. 28.3 ± 4.7 years; p < 0.001), a lower concentration of sweat chloride (62 ± 23 vs. 90 ± 12 mmol/l; p < 0.001), less frequent airway infections with Pseudomonas aeruginosa and/or Burkholderia cepacia complex (4 vs. 12; p = 0.029), bronchiectasis (14 vs. 23; p = 0.001), exocrine pancreatic insufficiency (1 vs. 23; p < 0.001) and therapy with insulin (1 vs. 9; p = 0.01); on the contrary, pancreatitis was more frequent (6 vs. 0; p = 0.022). CONCLUSION: Diagnosis of CF in adults should be considered in those with corresponding symptoms in respiratory, digestive and reproductive tract. Clinical presentation differs from classical CF in many parameters. KEY WORDS: adults - cystic fibrosis - diagnostics.

Gene expression profiling of Burkholderia cenocepacia at the time of cepacia syndrome: loss of motility as a marker of poor prognosis?

Cepacia syndrome (CS) is a fatal septic condition that develops in approximately 20% of cystic fibrosis (CF) patients chronically infected with the Burkholderia cepacia complex (Bcc). The most common causative agent is Burkholderia cenocepacia, a clinically dominant Bcc species that contains the globally distributed epidemic strain sequence type 32 (ST32). Using microarrays, we compared the transcriptomes of ST32 isolates from the bloodstream at the time of CS with their sputum counterparts recovered 1 to 2 months prior to the development of CS. Global gene expression profiles of blood isolates revealed greater activities of the virulence genes involved in the type III secretion system, the bacterial exopolysaccharide cepacian, and quorum sensing, while reduced expression was demonstrated for flagellar genes. Furthermore, a nonmotile phenotype (as evaluated by a swimming motility assay) was identified in blood isolates from 6 out of 8 patients with CS; this phenotype was traceable to 24 months prior to the onset of CS. Loss of motility was not observed in any of the 89 ST32 isolates recovered over the course of chronic infection from 17 patients without CS. In conclusion, the gene expression of Bcc bacteria disseminated during CS has been elucidated for the first time. This study demonstrated marked differences at the transcriptome level between isogenic ST32 isolates that are attributable to the stage and site of infection. The finding of a nonmotile B. cenocepacia isolate may serve as a warning sign for the development of CS in the near future.

Comparison of the efficacy of cisplatin and carboplatin in combination with etoposide in firstline treatment of extensive-stage small cell lung cancer in real-world practice in the Czech Republic - a retrospective analysis of patients from the LUCAS project.

BACKGROUND: Patients with extensive-stage small-cell lung cancer (ES-SCLC) have a poor prognosis. The standard palliative treatment for four decades has been chemotherapy as a combination of etoposide with carboplatin or cisplatin, and in recent years, immunotherapy in addition. AIMS: To determine whether there is a difference in the efficacy of palliative chemotherapy as cisplatin or carboplatin in combination with etoposide in patients with ES-SCLC in real-world practice in the Czech Republic. METHODS: This was a retrospective analysis of a cohort of 348 patients from the LUCAS project with ES-SCLC. 79 were treated with etoposide plus cisplatin and 265 were treated with etoposide plus carboplatin. Kaplan-Meier curves and the Cox regression model were used for analysis. RESULTS: No statistically significant difference in median overall survival (mOS) or median progression free survival (mPFS) was found between groups or between patients grouped according to age and performance status (PS) in mOS. The Cox regression result was similar. CONCLUSION: This study shows that cisplatin and carboplatin do not differ in efficacy in a given indication, thus when choosing a treatment, the physician should consider the expected toxicity in a particular patient, assessing the patient's general condition and comorbidities.

Elexacaftor-tezacaftor-ivacaftor in patients with cystic fibrosis ineligible for clinical trials: a 24-week observational study.

Introduction: Seminal clinical trials with the triple combination of elexacaftor-tezacaftor-ivacaftor (ETI) demonstrated clinical efficacy in people with cystic fibrosis (pwCF) who carry at least one F508del mutation. However, due to exclusion criteria of these clinical trials, the effect of ETI was not studied in a substantial number of pwCF. Thus, we ran a single center trial to evaluate a clinical efficacy of ETI treatment in adult pwCF who were ineligible for enrollment in registration studies. Methods: PwCF on ETI with prior lumacaftor-ivacaftor therapy, severe airway obstruction, well-preserved lung function, or with airway infection with pathogens at risk of more rapid decline in lung function formed the study group, while all the others on ETI formed the control group. Lung function, nutritional status and sweat chloride concentration were assessed before and after initialization of ETI therapy over a 6-month period. Results: Approximately a half of the ETI-treated pwCF at the adult Prague CF center (49 of 96) were assigned to the study group. Their mean changes in body mass index ( + 1.04 kg/m2) and in sweat chloride concentration (-48.4 mmol/L) were similar to the control group ( + 1.02 kg/m2; -49.7 mmol/L), while the mean change in percent predicted forced expiratory volume in 1 s (ppFEV1; + 10.3 points) was significantly lower than in the control group ( + 15.8 points) (p = 0.0015). In the subgroup analysis, pwCF with severe airway obstruction (ppFEV1 <40) and pwCF with well-preserved lung function (ppFEV1 >90) showed a less potential for improvement in lung function during the ETI treatment than controls (median change in ppFEV1 + 4.9 points and + 9.5 points, respectively). Conclusion: PwCF not eligible for inclusion in clinical trials demonstrated improvement in lung function and nutritional status following the initiation of treatment with the ETI combination. Moderate increase in ppFEV1 was observed in those with severe airway obstruction or well-preserved lung function.

Effect of SARS-CoV-2 infection on anti-HLA antibodies and de novo donor specific antibodies incidence in lung transplant recipients.

PURPOSE: There are no clear guidelines on how to handle immunosuppression in lung transplant recipients (LTRs) infected by SARS-CoV-2. Antimetabolite reduction with corticosteroid escalation is the most frequent strategy. The aim of this study was to determine the effect of this therapeutic approach on the incidence of de novo donor specific-antibodies (dnDSA). METHODS: We retrospectively analysed a cohort of 27 LTRs diagnosed with SARS-CoV-2 infection between September 2020 and April 2021 with available anti-HLA antibodies screening before and after infection. Managed as per the centre's SARS-CoV-2 protocol, the treatment modalities included specific virostatic treatment, convalescent plasma administration, reduction or discontinuation of mycophenolate and transient corticosteroid escalation initiated in the second week post-infection. RESULTS: All 27 patients received virostatics: 15 (55.6%) remdesivir and 12 (44.4%) favipiravir. In addition, 18 patients (66.7%) underwent convalescent plasma therapy. Of the 27 patients, 25 (92.6%) received mycophenolate as a part of their maintenance immunosuppressive regimen, which was temporarily reduced in 10 (37%) and discontinued in 15 LTRs (55.6%), the median resumption times for mycophenolate daily doses of at least 1000 mg being 13 days (IQR 11.0-63.5) and 59 days (IQR 26.0-130.0), respectively. Corticosteroids were escalated in 25 patients (92.6%), of whom 9 (33.3%) received IV methylprednisolone (median 80 mg/day; IQR 80-187.5) and 16 (59.3%) had oral prednisone adjusted (median 20 mg/day; IQR 16.3-38.8). The median time to revert to the corticosteroid dosage of ≤20 mg/day was 42 days (IQR 36.0-87.0). Notably, no dnDSA were detected in any LTR between 1 and 9 months from the onset of the SARS-CoV-2 infection. CONCLUSION: Our findings suggest that antimetabolite cessation with a transient corticosteroid escalation is a safe therapeutic strategy regarding anti-HLA dynamics in SARS-CoV-2 infected LTRs.

Monitoring of ECFS quality standards for the clinical management of adults with cystic fibrosis.

BACKGROUND: Although cystic fibrosis (CF) standards of care have been produced and regularly updated, they are not specifically targeting at the adult population. The ECFS Standards of Care Project established an international task force of experts to identify quality standards for adults with CF and assess their adherence. METHODS: This study was composed of two phases. In the first one, a task force of international experts derived from published guidelines and graded ten quality standards for adult CF care using a modified Delphi methodology. In the second phase, an international audit was conducted among adult CF centers to retrospectively validate the quality statements and monitor adherence. RESULTS: The task force identified 10 quality standards specific to the care of adults with CF, mainly based on the 2018 ECFS standards of care. 14 adult CF centers participated in the audit, which showed that most quality standards for the management of CF in adults are met across Europe. Heterogeneity in adherence to standards was found across centers according to geographical setting and centers' characteristics. CONCLUSIONS: The identification of quality standards is a valuable resource for the standardization and monitoring of care delivery across centers taking care of adults with CF.

Response to elexacaftor/tezacaftor/ivacaftor in intestinal organoids derived from people with cystic fibrosis.

Superior efficacy of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) over tezacaftor/ivacaftor (TEZ/IVA) in people with cystic fibrosis (CF) and Phe508del/Phe508del genotype was shown in clinical trials. We utilized intestinal organoid approach to compare in vitro responses to these 2 CFTR modulator drug combinations and to check potential inter-individual variability in therapeutic response to the triple combination. Organoids from 17 subjects with Phe508del/Phe508del were screened with forskolin induced swelling assay. Significantly larger swelling, when exposed to ELX/TEZ/IVA as compared to TEZ/IVA, was observed in 16 of them. However, 1 sample showed no additional effect of ELX. The finding of unique CFTR variants in this sample indicates that genetic traits other than CF-causing CFTR mutation are worth exploring as they may have an impact on the definitive modulator drug response.

Biopsy of lung lesions under CT control.

OBJECTIVES: With the increasing number of detected lung nodules and the need for morphological verification, the number of CT- controlled biopsies is increasing. The aim of this study was to assess the risks and benefits of these biopsies. METHODS: This is a prospective and observational study. We evaluated 101 punctures performed on a group of 90 consecutive patients in the Department of Radiology. RESULTS: In patients with a mean age of 66 years, with mostly accidentally detected lung nodules, we observed complications 38 times. The most common were minor pneumothoraxes or insignificant bleedings. In 6 patients, the complications were more serious, 5 times the pneumothoraxes required chest drainage, once massive hemoptysis was recorded. The lesions were successfully biopsied 78 times, the target was missed 23 times. The diagnosis of lung cancer (LC) was confirmed in 60 patients, 49 LCs were verified by puncture under CT control. 42% (25/60) of patients with LC were diagnosed in TNM stages I and II. 23% (14/60) of patients with LC were treated surgically. The remaining 30 patients most often suffered from lung metastazes (13/30), in 8 of them an inflammatory lung disease was diagnosed. 69 patients underwent bronchoscopy, in only 19% (13/69) it contributed to the diagnosis. In a model "screening like" group of 49 patients with only randomly detected lung deposits, we diagnosed LC in 76% (37/49). 49% (18/37) were in TNM stage I and II, 11 were treated surgically. CONCLUSIONS: CT-controlled biopsy of lung lesions is an effective and safe diagnostic method.

[Examination of exhaled breath condensate in cystic fibrosis]. / Vysetrení kondenzátu vydechovaného vzduchu u cystické fibrózy.

Examination of exhaled breath condensate belongs to experimental methods that are used in many pulmonary diseases and it can take part in the study of their pathophysiology. Its contribution to diagnostics and to monitoring of response to treatment is also evaluated. Many biomarkers of inflammation and oxidative stress were studied in exhaled breath condensate in cystic fibrosis. Examination of pH of exhaled breath condensate is considered to be useful in evaluation of inflammatory acidification of airways, together with evaluation of response to antibiotic treatment of pulmonary exacerbation, due to immediately accessible result. Other important biomarkers include 8-isoprostane and 3-nitrotyrosine as markers of oxidative stress (both with negative correlation with pulmonary function) and leukotriene B4 as marker of neutrophilic inflammation. Opposite to other pulmonary diseases, hydrogen peroxide does not belong to useful markers of oxidative stress in cystic fibrosis, due to abundant reduced thiols and glutathione peroxidase in sputum of these patients. Attempts to detect bacterial DNA in exhaled breath condensate in cystic fibrosis also failed. In spite of mentioned progress, examination of exhaled breath condensate remains a research method and it has not been introduced into clinical practice.

Evaluation of TD test for analysis of persistence or tolerance in clinical isolates of Staphylococcus aureus.

Besides natural and acquired mechanisms of resistance, bacteria can cope with presence of antibiotics by using complex mechanisms such as persistence or tolerance. The main purpose of this study was to evaluate the suitability of newly developed Tolerance Disk Test (TDtest) (Gefen et al., 2017) to detect persistent or tolerant bacterial cells in clinical isolates of Staphylococcus aureus. The principle of the test is to resuscitate the subpopulation of persistent or tolerant bacterial cells following a disk diffusion test by glucose. Results of the TDtest were evaluated using time killing experiments for three pairs of consecutive S. aureus isolates from lower respiratory airway samples of three cystic fibrosis patients with chronic staphylococcal infections. TDtest enabled semi-quantitative detection of persistent or tolerant bacterial populations in all analyzed isolates for oxacillin, vancomycin, and ciprofloxacin to which isolates studied were susceptible. Therefore, TDtest is a promising method for rapidly determining persistence/tolerance in clinical isolates of S. aureus.

Detection of two Alu insertions in the CFTR gene.

BACKGROUND: LINE-1 (long interspersed element-1) or L1-mediated retrotransposition is a potent force in human genome evolution and an occasional cause of human genetic disease. Since the first report of two de novo L1 insertions in the F8 gene causing hemophilia A, more than 50 L1-mediated retrotranspositional events have been identified as causing human genetic disease. However, a significant bias has generally militated against the detection of these pathological events at autosomal loci. Based upon this and other observations, we surmised that some previously unresolved cystic fibrosis chromosomes might carry hitherto undetected L1-mediated retrotranspositional insertions at the CFTR locus. This study represents an attempt to identify such mutational events. METHODS: 100 previously unresolved cystic fibrosis chromosomes were carefully reanalyzed using quantitative high-performance liquid chromatography (QHPLC). RESULTS: Two simple Alu insertions were identified in the CFTR gene, within exons 16 and 17b respectively. CONCLUSIONS: Our findings have not only revealed a previously unknown mutational mechanism responsible for cystic fibrosis but also represent an important addition to the already diverse spectrum of known CFTR gene mutations. Experience with the CFTR gene suggests that pathological L1-mediated retrotranspositional events may also have been overlooked at other gene loci and should always be considered in cases that appear to be refractory to analysis.

Burkholderia cepacia complex in cystic fibrosis in the post-epidemic period: multilocus sequence typing-based approach.

Cystic fibrosis (CF) patients in the Czech Republic suffered in the late 1990s from an epidemic with ST32 strain of Burkholderia cepacia complex (Bcc). Cohort segregation of Bcc and of ST32 positive patients was introduced in 1999 and 2002, respectively. We performed a study to evaluate the molecular epidemiology of Bcc infection after implementation of these infection control measures. Patients attending the Prague CF adult Centre from 2000 to 2015 were included in the present study. Demographic data and microbial statuses were collected from patient records. All Bcc isolates were analyzed using multilocus sequence typing (MLST). The prevalences of epidemic strain ST32 and of other Bcc strains were calculated. Ninety out of 227 CF patients were infected with Bcc during the study period. The prevalence of ST32 cases significantly decreased from 46.5% in 2000-2001 to 10.4% in 2014-2015 (P < 0.001) due to occurrence of only one new case in 2003, as well as to the death of 72% of ST32-infected patients. Conversely, there was a significant increase in prevalence of other Bcc strains, which rose from 0 to 14.9% (P = 0.015) and of transient infections. A micro-epidemic of infection with ST630 strain was observed in 2014 in lung transplant patients hospitalized in intensive care unit. The prevalence of epidemic strain ST32 decreased, whereas that of non-clonal strains of Bcc increased. Routine use of MLST allowed early detection of new and potentially epidemic strains.

Cost-of-illness analysis and regression modeling in cystic fibrosis: a retrospective prevalence-based study.

BACKGROUND: Economic data pertaining to cystic fibrosis (CF), is limited in Europe generally, and completely lacking in Central and Eastern Europe. We performed an analysis of all direct costs associated with CF relative to key disease features and laboratory examinations. METHODS: A retrospective prevalence-based cost-of-illness (COI) study was performed in a representative cohort of 242 CF patients in the Czech Republic, which represents about 65 % of all Czech CF patients. Medical records and invoices to health insurance companies for reference year 2010 were analyzed. RESULTS: The mean total health care costs were €14,486 per patient, with the majority of the costs going towards medicinal products and devices (€10,321). Medical procedures (€2676) and inpatient care (€1829) represented a much smaller percentage of costs. A generalized linear model showed that the strongest cost drivers, for all cost categories, were associated with patient age and lung disease severity (assessed using the FEV1 spirometric parameter), when compounded by chronic Pseudomonas aeruginosa airway infections. Specifically, maximum total costs are around the age 16 years; a FEV1 increase of 1 % point represented a cost decrease of: 0.9 % (medicinal products), 1.7 % (total costs), 2.8 % (procedures) and 7.0 % (inpatient care). CONCLUSIONS: COI analysis and regression modeling using the most recent data available can provide a better understanding of the overall economic CF burden. A comparison of our results with other methodologically similar studies demonstrates that although overall costs may differ, FEV1 can nonetheless be utilized as a generally transferrable indicator of the relative economic impact of CF.