Cystic Fibrosis

Exploring the diversity of <em>CFTR</em> gene mutations in cystic fibrosis individuals of South Asia

Thu, 2023-12-28 06:00

J Asthma. 2023 Dec 28:1-9. doi: 10.1080/02770903.2023.2297365. Online ahead of print.

ABSTRACT

OBJECTIVE: Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. This study aimed to identify the spectrum of CFTR variants reported in individuals with CF from South Asia (ISA).

DATA SOURCES AND STUDY SELECTION: We conducted a PubMed search for CFTR variants reported in ISA. Full text of original articles and case reports was read to compile data on reported variants. To gather additional data, we independently cross-referenced each variant with the CFTR Mutation Database and ClinVar.

RESULTS: Our investigation identified a total of 92 CFTR variants reported across 30 articles. The most frequently tested, and reported variant was ΔF508 with a global frequency of 69.74%. Notably, we found 14 pathogenic CFTR mutations shared among ISA, originating from more than one South Asian country: ΔF508, 1525-1 G > A, G542X, S549N, R117H, S549R, R709X, V456A, Y569D, L1077P, 1161delC, 1898 + 1 G > T, G551D, and 2184insA.

CONCLUSION: In summary, the higher prevalence of consanguinity and the limited availability of CF diagnostic resources in South Asia considerably contribute to the prevalence of genetic disorders like CF. The spectrum of CFTR mutations exhibits noticeable variations within South Asian and other populations. The inclusion of current study-enlisted CFTR gene variants is highly recommended for CF disease genetic testing in South Asia which may aid in achieving a precise diagnosis, enhancing disease management, and discovering drugs for currently untreatable genetic variants. It is also imperative to conduct a comprehensive study in this region, especially in previously unexplored countries such as Nepal, Bhutan, Maldives, and Bangladesh.

PMID:38153325 | DOI:10.1080/02770903.2023.2297365

Categories: Literature Watch

Boolean model of the gene regulatory network of <em>Pseudomonas aeruginosa</em> CCBH4851

Thu, 2023-12-28 06:00

Front Microbiol. 2023 Nov 30;14:1274740. doi: 10.3389/fmicb.2023.1274740. eCollection 2023.

ABSTRACT

INTRODUCTION: Pseudomonas aeruginosa infections are one of the leading causes of death in immunocompromised patients with cystic fibrosis, diabetes, and lung diseases such as pneumonia and bronchiectasis. Furthermore, P. aeruginosa is one of the main multidrug-resistant bacteria responsible for nosocomial infections worldwide, including the multidrug-resistant CCBH4851 strain isolated in Brazil.

METHODS: One way to analyze their dynamic cellular behavior is through computational modeling of the gene regulatory network, which represents interactions between regulatory genes and their targets. For this purpose, Boolean models are important predictive tools to analyze these interactions. They are one of the most commonly used methods for studying complex dynamic behavior in biological systems.

RESULTS AND DISCUSSION: Therefore, this research consists of building a Boolean model of the gene regulatory network of P. aeruginosa CCBH4851 using data from RNA-seq experiments. Next, the basins of attraction are estimated, as these regions and the transitions between them can help identify the attractors, representing long-term behavior in the Boolean model. The essential genes of the basins were associated with the phenotypes of the bacteria for two conditions: biofilm formation and polymyxin B treatment. Overall, the Boolean model and the analysis method proposed in this work can identify promising control actions and indicate potential therapeutic targets, which can help pinpoint new drugs and intervention strategies.

PMID:38152377 | PMC:PMC10752298 | DOI:10.3389/fmicb.2023.1274740

Categories: Literature Watch

Strategies for non-viral vectors targeting organs beyond the liver

Wed, 2023-12-27 06:00

Nat Nanotechnol. 2023 Dec 27. doi: 10.1038/s41565-023-01563-4. Online ahead of print.

ABSTRACT

In recent years, nanoparticles have evolved to a clinical modality to deliver diverse nucleic acids. Rising interest in nanomedicines comes from proven safety and efficacy profiles established by continuous efforts to optimize physicochemical properties and endosomal escape. However, despite their transformative impact on the pharmaceutical industry, the clinical use of non-viral nucleic acid delivery is limited to hepatic diseases and vaccines due to liver accumulation. Overcoming liver tropism of nanoparticles is vital to meet clinical needs in other organs. Understanding the anatomical structure and physiological features of various organs would help to identify potential strategies for fine-tuning nanoparticle characteristics. In this Review, we discuss the source of liver tropism of non-viral vectors, present a brief overview of biological structure, processes and barriers in select organs, highlight approaches available to reach non-liver targets, and discuss techniques to accelerate the discovery of non-hepatic therapies.

PMID:38151642 | DOI:10.1038/s41565-023-01563-4

Categories: Literature Watch

Molecular diagnosis of cystic fibrosis by RNA obtained from nasal epithelial cells

Wed, 2023-12-27 06:00

J Cyst Fibros. 2023 Dec 26:S1569-1993(23)01729-0. doi: 10.1016/j.jcf.2023.12.007. Online ahead of print.

ABSTRACT

BACKGROUND: The diagnosis of cystic fibrosis (CF) is established when characteristic clinical signs are coupled with biallelic CFTR pathogenic variants. No previously reported non-canonical splice site variants have to be considered as variants of uncertain significance unless their effect on splicing has been validated.

METHODS: Two variants identified by next-generation sequencing were evaluated. We assayed their effects on splicing employing RNA analysis and real-time expression quantification from RNA obtained from the nasal epithelial cells of a patient with clinically suspected CF and of two patients with milder phenotypes (CFTR-related disorders).

RESULTS: The variant c.164+2dup causes skipping of exon 2 (p.(Ser18_Glu54del)) and exon 2 plus 3 (p.(Ser18Argfs*16)) in CFTR mRNA. Exon 2 expression in the patient heterozygous for c.164+2dup was decreased to 7 % of the exon 2 expression in the controls. The synonymous variant c.1584G>A causes a partial skipping of exon 11. The exon 11 expression in the two patients heterozygous for this variant was 22 % and 42 % of that of the controls, respectively.

CONCLUSION: We conclude that variant c.164+2dup affects mRNA processing and can be considered a CF-causing variant. The results of the functional assay also showed that the p.(Glu528=) variant, usually categorized as a neutral variant based on epidemiological data, partially affects mRNA processing in our patients. This finding would allow us to reclassify the variant as a CFTR-related variant with incomplete penetrance. RNA obtained from nasal epithelial cells is an easy and accurate tool for CFTR functional studies in patients with unclassified splice variants.

PMID:38151412 | DOI:10.1016/j.jcf.2023.12.007

Categories: Literature Watch

Omitting placebos from early-stage clinical trials of cystic fibrosis therapies

Wed, 2023-12-27 06:00

J Cyst Fibros. 2023 Dec 26:S1569-1993(23)01734-4. doi: 10.1016/j.jcf.2023.12.010. Online ahead of print.

NO ABSTRACT

PMID:38151411 | DOI:10.1016/j.jcf.2023.12.010

Categories: Literature Watch

Case Report: Gastrointestinal Basidiobolomycosis in a Young Girl with Cystic Fibrosis and Celiac Disease

Wed, 2023-12-27 06:00

Am J Trop Med Hyg. 2023 Dec 26:tpmd230404. doi: 10.4269/ajtmh.23-0404. Online ahead of print.

ABSTRACT

Basidiobolomycosis is an uncommon fungal infection that has been reported in the literature mainly as a cause of infection in the skin and subcutaneous tissue. Intraabdominal infections have been reported in tropical and subtropical areas in the Middle East, such as Iran and Saudi Arabia, and in the United States. Our patient was a 6-year-old girl with cystic fibrosis and celiac disease who was referred to our department with a history of chronic abdominal pain. In the imaging studies of the abdomen and pelvis, a large retroperitoneal mass was reported in the right upper part of the abdomen with involvement of the duodenum and the mesentery of the small and large intestines, as well as the superior mesenteric vessels, and was diagnosed as basidiobolomycosis through biopsy. Because of the large unresectable mass, the patient was first treated with antifungal drugs for 2 months and then surgical resection was performed. The main point in the management of these patients is a combination of antifungal therapy and surgical resection. In some patients, complex surgeries such as the Whipple procedure may be performed to appropriately manage intraabdominal infections.

PMID:38150739 | DOI:10.4269/ajtmh.23-0404

Categories: Literature Watch

Viral Airway Injury Promotes Cell Engraftment in an In Vitro Model of Cystic Fibrosis Cell Therapy

Wed, 2023-12-27 06:00

Am J Physiol Lung Cell Mol Physiol. 2023 Dec 27. doi: 10.1152/ajplung.00421.2022. Online ahead of print.

ABSTRACT

Cell therapy is a potential treatment for cystic fibrosis (CF). However, cell engraftment into the airway epithelium is challenging. Here, we model cell engraftment in vitro using the air-liquid interface (ALI) culture system by injuring well-differentiated CF ALI cultures and delivering non-CF cells at the time of peak injury. Engraftment efficiency was quantified by measuring chimerism by droplet digital PCR and functional ion transport in Ussing chambers. Using this model, we found that human bronchial epithelial cells (HBECs) engraft more efficiently when they are cultured by conditionally reprogrammed cell (CRC) culture methods. Cell engraftment into the airway epithelium requires airway injury, but the extent of injury needed is unknown. We compared three injury models and determined that severe injury with partial epithelial denudation facilitates long-term cell engraftment and functional CFTR recovery up to 20% of wildtype function. The airway epithelium promptly regenerates in response to injury, creating competition for space and posing a barrier to effective engraftment. We examined competition dynamics by time-lapse confocal imaging and found that delivered cells accelerate airway regeneration by incorporating into the epithelium. Irradiating the repairing epithelium granted engrafting cells a competitive advantage by diminishing resident stem cell proliferation. Intentionally causing severe injury to the lungs of people with CF would be dangerous. However, naturally occurring events like viral infection can induce similar epithelial damage with patches of denuded epithelium. We found that viral preconditioning promoted effective engraftment of cells primed for viral resistance.

PMID:38150545 | DOI:10.1152/ajplung.00421.2022

Categories: Literature Watch

Secretagogue effect of PDE4 inhibitor apremilast on human salivary gland organoids obtained from primary Sjögren's syndrome patients

Wed, 2023-12-27 06:00

Clin Exp Rheumatol. 2023 Dec;41(12):2493-2501. doi: 10.55563/clinexprheumatol/7f4fzu. Epub 2023 Dec 23.

ABSTRACT

OBJECTIVES: The aim of the study was to culture vital salivary gland organoids obtained through labial or parotid biopsy of primary Sjögren's syndrome (pSS) patients in order to evaluate their morphological and functional features in basal condition and after stimulation with Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) activator forskolin and phosphodiesterase 4 (PDE4) inhibitor apremilast, their in vitro regenerative capacity and the immune-histological resemblance with original tissue.

METHODS: Salivary gland tissues from five pSS patients were processed to obtain vital organoids; swelling assay and cell proliferation tests were performed after forskolin and apremilast application. Immunochemistry evaluation on original salivary gland tissue and corresponding organoids was performed, and secretomics analysis was conducted to assess their functional status.

REULTS: After application of forskolin and apremilast, we observed organoid swelling after 30 minutes, compatible with a positive functional status and enhancement of saliva production. In 3 cases, apremilast induced organoid proliferation. All cases were positive for cytokeratin 14 (CK14) and most for cytokeratin 5 (CK5). All the cases were positive for amylase; its secretion, and thus functional status of organoids, was confirmed by its high concentration in the culture medium. A focal ductal differentiation was found in some cases, highlighted by epithelial membrane antigen (EMA) positivity. The more differentiated EMA positive areas were negative for the staminal marker CK14, showing a sort of "complementary staining".

CONCLUSIONS: Our data highlighted that differentiated cells and vital functional organoids that recapitulate the development of original salivary glands can be obtained from pSS epithelium. For the first time, the direct stimulating effect of PDE4 inhibitor apremilast on pSS human salivary gland organoids is reported, opening new perspectives on targeting oral dryness with drugs that combine secretagogue and immunomodulatory effects.

PMID:38149513 | DOI:10.55563/clinexprheumatol/7f4fzu

Categories: Literature Watch

Factors guiding gastrostomy tube decision-making for caregivers of children with cystic fibrosis: a scoping review protocol

Wed, 2023-12-27 06:00

BMJ Open. 2023 Dec 7;13(12):e076539. doi: 10.1136/bmjopen-2023-076539.

ABSTRACT

INTRODUCTION: While ensuring appropriate growth is essential for all children, optimising nutritional status in children with cystic fibrosis (CF) is critical for improving health outcomes. Nutritional challenges in CF are multifactorial and malnutrition is common. While gastrostomy tubes (G-tubes) can improve weight status in individuals with CF, they also have common and chronic complications resulting in clinical equipoise. To date, factors influencing G-tube decision-making among caregivers of children with CF have not been systematically explored. This review aims to chart existing knowledge about caregivers' decisional needs related to G-tube placement, with a focus on caregivers of children with CF, as well as known medical and psychosocial benefits and risks of G-tube feedings in paediatric care.

METHODS AND ANALYSIS: This scoping review will follow the JBI methodological framework. We will include articles published between 1 January 1985 and 1 November 2023 in English and Spanish from MEDLINE (Ovid), Embase, CINAHL, PsycInfo, Cochrane Database of Systematic Reviews and Web of Science related to G-tube decision-making. Articles published in languages besides English and Spanish will be excluded. Articles will be screened for final eligibility and inclusion according to title and abstract, followed by full texts. Articles will be independently reviewed by two reviewers and any disagreements discussed with a third reviewer for consensus. We will map themes and concepts, and data extracted will be presented in tabular, diagrams and descriptive summaries.

ETHICS AND DISSEMINATION: As a form of secondary analysis, scoping reviews do not require ethics approval. This review will inform future research with caregivers involved in G-tube decision-making for children with CF. The final review will be submitted to a peer-reviewed scientific journal, disseminated at relevant academic conferences and will be shared with patients and clinicians.

TRIAL REGISTRATION NUMBER: Center for Open Science. https://osf.io/g4pdb.

PMID:38149423 | DOI:10.1136/bmjopen-2023-076539

Categories: Literature Watch

Putting bicarbonate on the spot: pharmacological insights for CFTR correction in the airway epithelium

Wed, 2023-12-27 06:00

Front Pharmacol. 2023 Dec 11;14:1293578. doi: 10.3389/fphar.2023.1293578. eCollection 2023.

ABSTRACT

Introduction: Cystic fibrosis (CF) is caused by defective Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) proteins. CFTR controls chloride (Cl-) and bicarbonate (HCO3 -) transport into the Airway Surface Liquid (ASL). We investigated the impact of F508del-CFTR correction on HCO3 - secretion by studying transepithelial HCO3 - fluxes. Methods: HCO3 - secretion was measured by pH-stat technique in primary human respiratory epithelial cells from healthy subjects (WT) and people with CF (pwCF) carrying at least one F508del variant. Its changes after CFTR modulation by the triple combination VX445/661/770 and in the context of TNF-α+IL-17 induced inflammation were correlated to ASL pH and transcriptional levels of CFTR and other HCO3 - transporters of airway epithelia such as SLC26A4 (Pendrin), SLC26A9 and NBCe1. Results: CFTR-mediated HCO3 - secretion was not detected in F508del primary human respiratory epithelial cells. It was rescued up to ∼ 80% of the WT level by VX-445/661/770. In contrast, TNF-α+IL-17 normalized transepithelial HCO3 - transport and increased ASL pH. This was related to an increase in SLC26A4 and CFTR transcript levels. VX-445/661/770 induced an increase in pH only in the context of inflammation. Effects on HCO3 - transport were not different between F508del homozygous and F508del compound heterozygous CF airway epithelia. Conclusion: Our studies show that correction of F508del-CFTR HCO3 - is not sufficient to buffer acidic ASL and inflammation is a key regulator of HCO3 - secretion in CF airways. Prediction of the response to CFTR modulators by theratyping should take into account airway inflammation.

PMID:38149052 | PMC:PMC10750368 | DOI:10.3389/fphar.2023.1293578

Categories: Literature Watch

Acute exposure to realistic simulated urban atmospheres exacerbates pulmonary phenotype in cystic fibrosis-like mice

Tue, 2023-12-26 06:00

J Hazard Mater. 2023 Dec 23;465:133340. doi: 10.1016/j.jhazmat.2023.133340. Online ahead of print.

ABSTRACT

Cystic Fibrosis (CF) is a lethal genetic disorder caused by pathogenic mutations of the CFTR gene. CF patients show a high phenotypic variability of unknown origin. In this context, the present study was therefore dedicated to investigating the effects of acute exposure to air pollution on the pulmonary morbidity of a CF-like mice model. To achieve our aim, we developed a multidisciplinary approach and designed an innovative protocol using a simulation chamber reproducing multiphasic chemical processes at the laboratory. A particular attention was paid to modulate the composition of these simulated atmospheres, in terms of concentrations of gaseous and particulate pollutants. Exposure to simulated urban atmospheres induced mucus secretion and increased inflammatory biomarkers levels, oxidative stress as well as expression of lung remodeling actors in both WT and CF-like mice. The latter were more susceptible to develop such a response. Though we could not establish direct mechanistic link between biological responses and specific components, the type of immune response induced depended on the chemical composition of the atmospheres. Overall, we demonstrated that air pollution is an important determinant of CF-like lung phenotypic variability and emphasized the added value of considering air pollution with a multi-pollutant approach.

PMID:38147748 | DOI:10.1016/j.jhazmat.2023.133340

Categories: Literature Watch

Chronic rhinosinusitis and olfaction after highly effective modulator therapy: The role of individual sinus inflammation

Tue, 2023-12-26 06:00

Int Forum Allergy Rhinol. 2023 Dec 26. doi: 10.1002/alr.23299. Online ahead of print.

ABSTRACT

Individual sinus opacification (ISO) is measurable via a convolutional neural network approach. ISO decreased through 2 years after highly effective modulator therapy was initiated. In adults with cystic fibrosis, ISO did not correlate with quality of life or olfaction.

PMID:38146638 | DOI:10.1002/alr.23299

Categories: Literature Watch

Determining the minimal clinically important difference for the questionnaire of olfactory disorders in people with cystic fibrosis and factors associated with improvement after highly effective modulator therapy

Mon, 2023-12-25 06:00

Int Forum Allergy Rhinol. 2023 Dec 25. doi: 10.1002/alr.23312. Online ahead of print.

ABSTRACT

INTRODUCTION: Olfactory dysfunction (OD) is common among people with cystic fibrosis (PwCF). The Questionnaire of Olfactory Disorders (QOD) is a validated instrument that evaluates olfactory-specific quality-of-life. The QOD minimal clinically important difference (MCID) and factors associated with olfactory improvement after elexacaftor/tezacaftor/ivacaftor have not been determined for PwCF.

METHODS: Prospective observational data were pooled from three studies that enrolled adult PwCF with chronic rhinosinusitis (CRS). QOD scores and disease characteristics were assessed. To evaluate internal consistency and calculate the QOD MCID, Cronbach's alpha and four distribution-based methods were employed. For participants who enrolled prior to elexacaftor/tezacaftor/ivacaftor, QOD scores were obtained at baseline and after elexacaftor/tezacaftor/ivacaftor initiation. Multivariable regression was used to identify factors associated with QOD improvement.

RESULTS: Of 129 PwCF included, 65 had QOD scores before and 3-6 months after starting elexacaftor/tezacaftor/ivacaftor. Mean baseline QOD score was 6.5 ± 7.9. Mean Cronbach's alpha was ≥0.85. The MCID estimates were as follows: Cohen's effect size = 1.6, standard error of measurement = 2.5, ½ baseline standard deviation = 4.0, and minimal detectable change = 6.9. Mean MCID was 3.7. Of those with pre/post elexacaftor/tezacaftor/ivacaftor QOD scores, the mean change in QOD was -1.3 ± 5.4. After elexacaftor/tezacaftor/ivacaftor, QOD improvement surpassed the MCID in 22% of participants (14/65). Worse baseline QOD scores and nasal polyps were associated with improved QOD scores after elexacaftor/tezacaftor/ivacaftor (both p < 0.04).

CONCLUSION: The QOD MCID in PwCF was estimated to be 3.7. Elexacaftor/tezacaftor/ivacaftor led to qualitative but not clinically meaningful improvements in QOD score for most PwCF; PwCF with worse baseline QOD scores and nasal polyps improved in a clinically significant manner.

PMID:38145393 | DOI:10.1002/alr.23312

Categories: Literature Watch

Increased ENaC-mediated liquid absorption across vitamin-D deficient human airway epithelia

Mon, 2023-12-25 06:00

Am J Physiol Cell Physiol. 2023 Dec 25. doi: 10.1152/ajpcell.00369.2023. Online ahead of print.

ABSTRACT

Vitamin D deficiency is a risk factor for exacerbation of obstructive airway disease, a hallmark of which is mucus dehydration and plugging. Calcitriol (the active form of vitamin D) deficiency in cultured human airway epithelia resulted in increased SCNN1G and ATP1B1 mRNAs encoding subunits of ENaC and the Na-K pump compared to supplemented epithelia. These drive absorption of airway surface liquid. Consistently, calcitriol-deficient epithelia absorbed liquid faster than supplemented epithelia. Calcitriol-deficiency also increased amiloride-sensitive Isc and Gt without altering Na-K pump activity, indicating the changes in amiloride-sensitivity arose from ENaC. ENaC activity can be regulated by trafficking, proteases, and channel abundance. We found the effect was likely not induced by changes to endocytosis of ENaC given that calcitriol did not affect the half-lives of amiloride-sensitive Isc and Gt. Further, trypsin nominally increased Isc produced by epithelia ± calcitriol, suggesting calcitriol did not affect proteolytic activation of ENaC. Consistent with mRNA and functional data, calcitriol deficiency resulted in increased γENaC protein. These data indicate that the vitamin D receptor response controls ENaC function and subsequent liquid absorption, providing insight into the relationship between vitamin D deficiency and respiratory disease.

PMID:38145296 | DOI:10.1152/ajpcell.00369.2023

Categories: Literature Watch

Real world study on elexacaftor-tezacaftor-ivacaftor impact on cholesterol levels in adults with cystic fibrosis

Sun, 2023-12-24 06:00

Pharmacotherapy. 2023 Dec 24. doi: 10.1002/phar.2903. Online ahead of print.

ABSTRACT

INTRODUCTION: The introduction of the highly effective modulator therapy elexacaftor-tezacaftor-ivacaftor (ETI) has revolutionized the care of persons with cystic fibrosis (PwCF) with major improvements seen in lung function and body mass index (BMI). Effects of ETI therapy in real-world cohorts on other parameters such as cholesterol levels are largely unknown.

METHODS: A single-center, retrospective chart review study was conducted to assess the change in lipid panels before and after ETI initiation. The study investigated total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels using both a univariate and multivariate mixed-effects model to evaluate the change after initiation of ETI in a cohort of PwCF.

RESULTS: There were 128 adult PwCF included in the analysis. Statistically significant changes were seen in both univariate and multivariate analyses for TC, LDL-C, and HDL-C. On multivariate analysis, TC increased by an average of 15.0 mg/dL after ETI initiation (p<0.0001), LDL-C increased by an average of 9.3 mg/dL (p<0.001), and HDL-C increased by an average of 3.8 mg/dL (p < 0.001) after ETI initiation.

CONCLUSION: In this real-world cohort of PwCF, cholesterol parameters increased after initiation with ETI therapy. Further consideration may need to be given for PwCF in regards to screening for cardiometabolic risk factors as PwCF age as well as the potential need for cholesterol-lowering therapies.

PMID:38143243 | DOI:10.1002/phar.2903

Categories: Literature Watch

Reply to the letter Regarding the article entitled "Standards for the care of people with CF: a timely and accurate diagnosis"

Sun, 2023-12-24 06:00

J Cyst Fibros. 2023 Dec 23:S1569-1993(23)01731-9. doi: 10.1016/j.jcf.2023.12.006. Online ahead of print.

NO ABSTRACT

PMID:38143213 | DOI:10.1016/j.jcf.2023.12.006

Categories: Literature Watch

Short-term outcomes after third-time lung transplantation: A single institution experience

Sat, 2023-12-23 06:00

J Heart Lung Transplant. 2023 Dec 21:S1053-2498(23)02179-4. doi: 10.1016/j.healun.2023.12.010. Online ahead of print.

ABSTRACT

BACKGROUND: Re-operative lung transplantation (LTx) survival has improved over time such that a growing number of patients may present for third-time LTx (L3Tx). To understand the safety of L3Tx, we evaluated perioperative outcomes and three-year survival after L3Tx at a high-volume US LTx center.

METHODS: This retrospective study included all patients who underwent bilateral L3Tx at our institution. Using an optimal matching technique, a primary LTx (L1Tx) cohort was matched 1:2 and a second-time LTx (L2Tx) cohort 1:1. Recipient, operative, and donor characteristics, perioperative outcomes, and three-year survival were compared among L1Tx, L2Tx, and L3Tx groups.

RESULTS: 11 L3Tx, 11 L2Tx, and 22 L1Tx recipients were included. Among L3Tx recipients, median age at transplant was 37 years and most (73%) had cystic fibrosis. L3Tx was performed median 6.0 and 10.6 years after L2Tx and L1Tx, respectively. Compared to L1Tx and L2Tx recipients, L3Tx recipients had greater intraoperative transfusion requirements, a higher incidence of post-operative complications, and a higher rate of unplanned reoperation. Rates of grade 3 primary graft dysfunction at 72 hours (PGD3), ECMO at 72 hours, reintubation, and in-hospital mortality were similar among groups. There were no differences in three-year patient (log-rank p=0.61) or rejection-free survival (log-rank p=0.34) after L1Tx, L2Tx, and L3Tx.

CONCLUSIONS: At our institution, L3Tx was associated with similar perioperative outcomes and three-year patient survival compared to L1Tx and L2Tx. L3Tx represents the only safe treatment option for patients with allograft failure after L2Tx; however, further investigation is needed to understand the long-term survival and durability of L3Tx.

PMID:38141895 | DOI:10.1016/j.healun.2023.12.010

Categories: Literature Watch

Association between Dietary Intake and Faecal Microbiota in Children with Cystic Fibrosis

Sat, 2023-12-23 06:00

Nutrients. 2023 Dec 5;15(24):5013. doi: 10.3390/nu15245013.

ABSTRACT

A "high-fat, high-energy diet" is commonly recommended for children with cystic fibrosis (CF), leading to negative consequences on dietary patterns that could contribute to altered colonic microbiota. The aim of this study was to assess dietary intake and to identify possible associations with the composition of faecal microbiota in a cohort of children with CF. A cross-sectional observational study was conducted, including a 3-day food record simultaneously with the collection of faecal samples. The results showed a high fat intake (43.9% of total energy intake) and a mean dietary fibre intake of 10.6 g/day. The faecal microbiota was characterised at the phylum level as 54.5% Firmicutes and revealed an altered proportion between Proteobacteria (32%) and Bacteroidota (2.2%). Significant associations were found, including a negative association between protein, meat, and fish intake and Bifidobacterium, a positive association between lipids and Escherichia/Shigella and Streptococcus, a negative association between carbohydrates and Veillonella and Klebsiella, and a positive association between total dietary fibre and Bacteroides and Roseburia. The results reveal that a "high-fat, high-energy" diet does not satisfy dietary fibre intake from healthy food sources in children with CF. Further interventional studies are encouraged to explore the potential of shifting to a high-fibre or standard healthy diet to improve colonic microbiota.

PMID:38140272 | DOI:10.3390/nu15245013

Categories: Literature Watch

Photodynamic Eradication of <em>Pseudomonas aeruginosa</em> with Ru-Photosensitizers Encapsulated in Enzyme Degradable Nanocarriers

Sat, 2023-12-23 06:00

Pharmaceutics. 2023 Nov 27;15(12):2683. doi: 10.3390/pharmaceutics15122683.

ABSTRACT

The development of new approaches for the treatment of the increasingly antibiotic-resistant pathogen Pseudomonas aeruginosa was targeted by enhancing the effect of local antimicrobial photodynamic therapy (aPDT) using poly(ethylene glycol)-block-poly(lactic acid) (PEG114-block-PLAx) nanocarriers that were loaded with a ruthenium-based photosensitizer (PS). The action of tris(1,10-phenanthroline) ruthenium (II) bis(hexafluorophosphate) (RuPhen3) encapsulated in PEG114-block-PLAx micelles and vesicles was shown to result in an appreciable aPDT inactivation efficiency against planktonic Pseudomonas aeruginosa. In particular, the encapsulation of the PS, its release, and the efficiency of singlet oxygen (1O2) generation upon irradiation with blue light were studied spectroscopically. The antimicrobial effect was analyzed with two strains of Pseudomonas aeruginosa. Compared with PS-loaded micelles, formulations of the PS-loaded vesicles showed 10 times enhanced activity with a strong photodynamic inactivation effect of at least a 4.7 log reduction against both a Pseudomonas aeruginosa lab strain and a clinical isolate collected from the lung of a cystic fibrosis (CF) patient. This work lays the foundation for the targeted eradication of Pseudomonas aeruginosa using aPDT in various medical application areas.

PMID:38140023 | DOI:10.3390/pharmaceutics15122683

Categories: Literature Watch

In Silico and In Vitro Evaluation of the Mechanism of Action of Three VX809-Based Hybrid Derivatives as Correctors of the F508del CFTR Protein

Sat, 2023-12-23 06:00

Pharmaceuticals (Basel). 2023 Dec 8;16(12):1702. doi: 10.3390/ph16121702.

ABSTRACT

Cystic fibrosis (CF), the most common autosomal recessive fatal genetic disease in the Caucasian population, is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel that regulates salt and water transport across a variety of secretory epithelia. Deletion of phenylalanine at position 508, F508del, the most common CF-causing mutation, destabilises the CFTR protein, causing folding and trafficking defects that lead to a dramatic reduction in its functional expression. Small molecules called correctors have been developed to rescue processing-defective F508del CFTR. We have combined in silico and in vitro approaches to investigate the mechanism of action and potential as CFTR correctors of three hybrid derivatives (2a, 7a, and 7m) obtained by merging the amino-arylthiazole core with the benzodioxole carboxamide moiety characterising the corrector lumacaftor. Molecular modelling analyses suggested that the three hybrids interact with a putative region located at the MSD1/NBD1 interface. Biochemical analyses confirmed these results, showing that the three molecules affect the expression and stability of the F508del NBD1. Finally, the YFP assay was used to evaluate the influence of the three hybrid derivatives on F508del CFTR function, assessing that their effect is additive to that of the correctors VX661 and VX445. Our study shows that the development and testing of optimised compounds targeting different structural and functional defects of mutant CFTR is the best strategy to provide more effective correctors that could be used alone or in combination as a valuable therapeutic option to treat an even larger cohort of people affected by CF.

PMID:38139828 | DOI:10.3390/ph16121702

Categories: Literature Watch

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