Respiration. 2021 Jul 14:1-7. doi: 10.1159/000517033. Online ahead of print.

ABSTRACT

BACKGROUND: High-flow nasal oxygen (HFNO) improves exercise capacity, oxygen saturation, and symptoms in patients with chronic obstructive pulmonary disease (COPD). Due to the need of electricity supply, HFNO has not been applied during free ambulation.

OBJECTIVE: We evaluated whether HFNO delivered during walking by a battery-supplied portable device was more effective than usual portable oxygen in improving exercise capacity in patients with COPD and severe exercise limitation. The effects on 6-min walking tests (6MWTs) were the primary outcome.

METHODS: After a baseline 6MWT, 20 stable patients requiring an oxygen inspiratory fraction (FiO2) <0.60 during exercise, randomly underwent 2 6MWT carrying a rollator, under either HFNO with a portable device (HFNO test) or oxygen supplementation by a Venturi mask (Control) at isoFiO2. Walked distance, perceived dyspnea, pulse oximetry, and inspiratory capacity at end of the tests as well as patients' comfort were compared between the tests.

RESULTS: As compared to baseline, walked distance improved significantly more in HFNO than in the control test (by 61.1 ± 37.8 and 39.7 ± 43.8 m, respectively, p = 0.01). There were no significant differences between the tests in dyspnea, peripheral oxygen saturation, or inspiratory capacity, but HFNO test was appreciated as more comfortable.

CONCLUSION: In patients with COPD and severe exercise limitation, HFNO delivered by a battery-supplied portable device was more effective in improving walking distance than usual oxygen supplementation.

PMID:34261072 | DOI:10.1159/000517033

Ann Allergy Asthma Immunol. 2021 Jul 11:S1081-1206(21)00493-2. doi: 10.1016/j.anai.2021.07.003. Online ahead of print.

NO ABSTRACT

PMID:34260901 | DOI:10.1016/j.anai.2021.07.003

Pediatr Infect Dis J. 2021 Jul 13. doi: 10.1097/INF.0000000000003256. Online ahead of print.

ABSTRACT

No underlying pathology could be detected in 64% of 208 children presenting with recurrent respiratory tract infections in general pediatric practice. Asthma/preschool wheezing and adenoid hypertrophy were commonly diagnosed. None of the children had a severe primary immunodeficiency or severe pulmonary illness such as cystic fibrosis. Our findings can guide pediatricians in their diagnostic approach of children with respiratory tract infections.

PMID:34260493 | DOI:10.1097/INF.0000000000003256

Pulm Ther. 2021 Jul 14. doi: 10.1007/s41030-021-00165-6. Online ahead of print.

NO ABSTRACT

PMID:34260039 | DOI:10.1007/s41030-021-00165-6

Am J Physiol Gastrointest Liver Physiol. 2021 Jul 14. doi: 10.1152/ajpgi.00024.2021. Online ahead of print.

ABSTRACT

The gallbladder is considered an important organ in maintaining digestive and metabolic homeostasis. Given that therapeutic options for gallbladder diseases are often limited to cholecystectomy, understanding gallbladder pathophysiology is essential in developing novel therapeutic strategies.Since Liver X Receptor β (LXRβ), an oxysterol-activated transcription factor, is strongly expressed in gallbladder cholangiocytes, the aim was to investigate LXRβ physiological function in the gallbladder. Thus, we studied the gallbladders of WT and LXRβ-/- male mice using immunohistochemistry, electron-microscopy, qRT-PCR, bile duct cannulation, bile and blood biochemistry and duodenal pH measurements.LXRβ-/- mice presented a large gallbladder bile volume with high duodenal mRNA levels of the Vasoactive Intestinal Polypeptide (Vip), a strong mediator of gallbladder relaxation. LXRβ-/- gallbladders, showed lower mRNA and protein expression of Aquaporin-1, Aquaporin-8 and Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). A cystic fibrosis-resembling phenotype was evident in the liver showing higher serum cholestatic markers and the presence of reactive cholangiocytes. For LXRβ being a transcription factor, we identified 8 putative binding sites of LXR on the promoter and enhancer of the Cftr gene, suggesting Cftr as a novel LXRβ regulated gene. In conclusion LXRβ was recognized as a regulator of gallbladder bile volume through multiple mechanisms involving CFTR and Aquaporins.

PMID:34259574 | DOI:10.1152/ajpgi.00024.2021

mSphere. 2021 Jul 14:e0039321. doi: 10.1128/mSphere.00393-21. Online ahead of print.

ABSTRACT

Antimicrobial susceptibility in Pseudomonas aeruginosa is dependent on a complex combination of host and pathogen-specific factors. Through the profiling of 971 clinical P. aeruginosa isolates from 590 patients and collection of paired patient metadata, we show that antimicrobial resistance is associated with not only patient-centric factors (e.g., cystic fibrosis and antipseudomonal prescription history) but also microbe-specific phenotypes (e.g., mucoid colony morphology). Additionally, isolates from different sources (e.g., respiratory tract, urinary tract) displayed rates of antimicrobial resistance that were correlated with source-specific antimicrobial prescription strategies. Furthermore, isolates from the same patient often displayed a high degree of heterogeneity, highlighting a key challenge facing personalized treatment of infectious diseases. Our findings support novel relationships between isolate and patient-level data sets, providing a potential guide for future antimicrobial treatment strategies. IMPORTANCE P. aeruginosa is a leading cause of nosocomial infection and infection in patients with cystic fibrosis. While P. aeruginosa infection and treatment can be complicated by a variety of antimicrobial resistance and virulence mechanisms, pathogen virulence is rarely recorded in a clinical setting. In this study, we discovered novel relationships between antimicrobial resistance, virulence-linked morphologies, and isolate source in a large and variable collection of clinical P. aeruginosa isolates. Our work motivates the clinical surveillance of virulence-linked P. aeruginosa morphologies as well as the tracking of source-specific antimicrobial prescription and resistance patterns.

PMID:34259555 | DOI:10.1128/mSphere.00393-21

Microbiol Spectr. 2021 Jul 14:e0034021. doi: 10.1128/Spectrum.00340-21. Online ahead of print.

ABSTRACT

Effector proteins translocated into host cells by the Pseudomonas aeruginosa type III secretion system (T3SS) are critical for phagocytic avoidance and systemic spread of the microorganism. The T3SS genes are present in virtually all P. aeruginosa strains. When examined in environmental isolates and clinical specimens, expression of the T3SS genes is the rule. Isolates from the airways of cystic fibrosis (CF) patients are one exception, and these isolates usually carry mutations that disable T3SS gene expression. In this study, we describe two P. aeruginosa isolates, one pigmented brown and one green, from a keratitis-ichthyosis-deafness (KID) syndrome patient with a chronic cutaneous ankle wound. Similar to most isolates from CF, both of the KID isolates were defective for T3SS gene expression. Providing the primary activator of T3SS transcription (exsA) in trans restored T3SS function. Since the exsA sequences were identical to that of a reference strain with active T3SS gene expression, we examined the cAMP-Vfr system, a critical regulator of T3SS gene expression. Vfr is a cAMP-dependent transcription factor that activates exsA expression. Whereas T3SS activity was corrected in the brown isolate by restoring cAMP synthesis, the same was not observed for the green isolate. These findings suggest that distinct mechanisms resulted in loss of T3SS gene expression in the KID isolates. The mutations responsible for the T3SS defects were not clearly evident by comparison of the whole-genome sequences to a reference strain. Our findings suggest that loss of T3SS gene expression may be a trait common to both CF and non-CF chronic infections. IMPORTANCE A common feature of microorganisms that cause chronic infections is a stealthy lifestyle that promotes immune avoidance and host tolerance. During chronic colonization of cystic fibrosis (CF) patients, Pseudomonas aeruginosa acquires numerous adaptations that include reduced expression of some factors, such as motility, O antigen, and the T3SS, and increased expression of other traits, such as biofilm formation. In this study, we report loss of T3SS gene expression in non-CF chronic isolates. This finding suggests that loss of the T3SS may be a common and important trait that contributes to persistence and may open avenues to explore the significance further using non-CF chronic infection models.

PMID:34259549 | DOI:10.1128/Spectrum.00340-21

Lung India. 2021 Jul-Aug;38(4):326-329. doi: 10.4103/lungindia.lungindia_589_20.

ABSTRACT

BACKGROUND: The function of Vitamin D in preventing inflammation and infection has been studied previously for different pathologies in different populations globally. Relationships between serum Vitamin D levels and its effect on pulmonary exacerbations in the cystic fibrosis (CF) population are not well studied in our part of the world. Therefore, we aimed to ascertain the Vitamin D status in pediatric and adolescent CF patients and its association with pulmonary exacerbations.

MATERIALS AND METHODS: A retrospective study was conducted at The Aga Khan University Hospital from 2015 to 2018. Patients of CF with sweat chloride value >60 mmol/l and who had at least one measurement of 25 hydroxy Vitamin D (25 OHD) were included in the study. Annual serum Vitamin D levels were documented for enrolled patients and their past 1-year data were analyzed for pulmonary exacerbations, average length of stay, and tracheal/airway colonization with organisms.

RESULTS: 69 patients were included in the study. 28 patients (40.57%) were found to be Vitamin D deficient, 22 patients (31.88%) were Vitamin D insufficient and 19 patients (27.53%) were labeled as Vitamin D insufficient. The average number of exacerbations per year was significantly high in Vitamin D deficient group (3.71 ± 0.96) in comparison with insufficient (3.18 ± 1.09) and sufficient groups (2.26 ± 0.93) (P < 0.001).

CONCLUSION: Vitamin D deficiency is related to an increased number of annual pulmonary exacerbations and pseudomonas infections.

PMID:34259170 | DOI:10.4103/lungindia.lungindia_589_20

Curr Med Chem. 2021 Jul 12. doi: 10.2174/0929867328666210713094722. Online ahead of print.

ABSTRACT

The development of safe and efficacious enzyme-based human therapies has increased greatly in the last decades, thanks to remarkable advances in the understanding of the molecular mechanisms responsible for different diseases, and the characterization of the catalytic activity of relevant exogenous enzymes that may play a remedial effect in the treatment of such pathologies. Several enzyme-based biotherapeutics have been approved by FDA (the U.S. Food and Drug Administration) and EMA (the European Medicines Agency) and many are undergoing clinical trials. Apart from enzyme replacement therapy in human genetic diseases, which is not discussed in this review, approved enzymes for human therapy find applications in several fields, from cancer therapy to thrombolysis and the treatment, e.g., of clotting disorders, cystic fibrosis, lactose intolerance and collagen-based disorders. The majority of therapeutic enzymes are of microbial origin, the most convenient source due to fast, simple and cost-effective production and manipulation. The use of microbial recombinant enzymes has broadened prospects for human therapy but some hurdles such as high immunogenicity, protein instability, short half-life and low substrate affinity, still need to be tackled. Alternative sources of enzymes, with reduced side effects and improved activity, as well as genetic modification of the enzymes and novel delivery systems are constantly searched. Chemical modification strategies, targeted- and/or nanocarrier-mediated delivery, directed evolution and site-specific mutagenesis, fusion proteins generated by genetic manipulation are the most explored tools to reduce toxicity and improve bioavailability and cellular targeting. This review provides a description of exogenous enzymes that are presently employed for the therapeutic management of human diseases with their current FDA/EMA-approved status, along with those already experimented at the clinical level and potential promising candidates.

PMID:34259137 | DOI:10.2174/0929867328666210713094722

J Cyst Fibros. 2021 Jul 10:S1569-1993(21)01291-1. doi: 10.1016/j.jcf.2021.06.007. Online ahead of print.

ABSTRACT

BACKGROUND: Chronic pain is common among people living with cystic fibrosis (CF) and associated with worse clinical outcomes. Despite this, little is known about how pain is managed and how opioids are used to treat pain. The purpose of this convergent mixed methods study was to examine self-reported satisfaction and effectiveness of pain management strategies among a sample of adults with CF who are prescribed opioids.

METHODS: We developed an online survey querying 4 domains - demographics, pain characteristics, pain communication, and management strategies. This was distributed nationally to adults with CF (n=48) via various online platforms. We obtained quantitative and qualitative responses regarding satisfaction and effectiveness of pain management. Emerged themes from qualitative data were compared with responses from quantitative survey domains.

RESULTS: Participants reported high levels of satisfaction and effectiveness with their opioid pain management plans. However, qualitative themes emerged regarding fears of addiction, experiences of feeling stigmatized by the healthcare system and ineffectiveness and inefficiency of alternative therapies for adequate pain relief.

CONCLUSIONS: Adults with CF reported opioids as an important component of their current pain management plans despite risks associated with opioid use. CF-specific pain management guideline development is warranted as is further research exploring pain development.

PMID:34257058 | DOI:10.1016/j.jcf.2021.06.007

Tuberk Toraks. 2021 Jun;69(2):167-176. doi: 10.5578/tt.20219806.

ABSTRACT

INTRODUCTION: The diagnosis of asthma is still a difficult problem in cystic fibrosis. There is no consensus on how to define "CF asthma". The aim of this study was to determine the role of bronchodilator response and laboratory evidence of allergy in "CF asthma".

MATERIALS AND METHODS: Patients aged ≥6 years with evaluated bronchodilator response and characteristics of atopy were included in the study. Patients diagnosed with Allergic Bronchopulmonary Aspergillosis or pulmonary exacerbation were excluded.

RESULT: A total of 204 CF patients were evaluated, and 40 who met the criteria were included. Asthma had been diagnosed in ten patients. A positive bronchodilator response was present in 47.3% of the patients tested. Aeroallergen sensitization was present in 52.5% of the patients. While the frequency of recurrent/history of wheezing, family history of atopy and elevated total immunoglobulin E were similar (p> 0.05), the frequencies of inhaled medication use and coexistence of asthma were statistically higher in the group with positive allergen sensitization (p<0.05). The frequencies of positive bronchodilator response (77.7% versus 37.9%) and a family history of asthma/atopy (40% versus. 23%) were found to be similar in CF asthma and CF. There were significant increases in total IgE and allergen-specific IgE and an increase in the frequency of aeroallergen sensitization in CF asthma compared to CF (p<0.05).

CONCLUSIONS: Although not routinely used in the evaluation of patients, allergen specific-IgE and skin prick test for aeroallergen sensitization may be used as an adjunctive test in patients with suspected clinical findings. The recognition of CF asthma may facilitate the development of targeted therapies.

PMID:34256507 | DOI:10.5578/tt.20219806

Adv Drug Deliv Rev. 2021 Jul 10:113862. doi: 10.1016/j.addr.2021.113862. Online ahead of print.

ABSTRACT

Oral inhalation results in pulmonary drug targeting and thereby reduces systemic side effects, making it the preferred means of drug delivery for the treatment of respiratory disorders such as asthma, chronic obstructive pulmonary disease or cystic fibrosis. In addition, the high alveolar surface area, relatively low enzymatic activity and rich blood supply of the distal airspaces offer a promising pathway to the systemic circulation. This is particularly advantageous when a rapid onset of pharmacological action is desired or when the drug is suffering from stability issues or poor biopharmaceutical performance following oral administration. Several cell and tissue-based in vitro and ex vivo models have been developed over the years, with the intention to realistically mimic pulmonary biological barriers. It is the aim of this review to critically discuss the available models regarding their advantages and limitations and to elaborate further which biopharmaceutical questions can and cannot be answered using the existing models.

PMID:34256080 | DOI:10.1016/j.addr.2021.113862

J Med Screen. 2021 Jul 13:9691413211031613. doi: 10.1177/09691413211031613. Online ahead of print.

NO ABSTRACT

PMID:34255582 | DOI:10.1177/09691413211031613

Anal Chem. 2021 Jul 13. doi: 10.1021/acs.analchem.1c01017. Online ahead of print.

ABSTRACT

Herein, SnTe nanobelts (NBs) with efficient oxidase-mimetic activity were synthesized by the simple electrochemical exfoliation method. A specific inhibition effect of Cl- on the enzymatic behavior of the pure SnTe NBs was discovered, which was accordingly used for establishing a highly feasible, sensitive, selective, and stable Cl- colorimetric assay. The detection concentration range was 50 nM to 1 mM, and the lowest detection limit was 20 nM for Cl-. In addition, a signal on-off-on route based on the SnTe NB nanozyme was designed to realize the reliable and specific detection of Hg2+. Therein, the SnTe NBs were grafted with gold nanoparticles to form a hybrid of SnTe/Au, resulting in the depression of the oxidase-like activity, which can then be recovered in the presence of the Hg2+ due to the formation of a gold amalgam. Especially, it was found that the high concentration of Cl- over 3 mM could again exert suppression influence toward the enzymatic activity of the SnTe/Au-Hg system. Based on the to-love-and-to-kill interaction between Cl- and Hg2+, the detection range for Cl- can be extended to 40 to 250 mM. In return, the assays of Cl- could avoid in advance its interference toward the accurate Hg2+ assays. We systematically clarified the oxidase-like catalytic mechanism of the SnTe-derived nanozyme systems. The as-proposed colorimetry can be successfully applied in practical samples including the sweat, human serum, or seawater/tap water, relating to cystic fibrosis, hyper-/hypochloremia, or environmental control, respectively.

PMID:34255490 | DOI:10.1021/acs.analchem.1c01017

Evol Med Public Health. 2020 Jul 11;2020(1):148-157. doi: 10.1093/emph/eoaa026. eCollection 2020.

ABSTRACT

BACKGROUND AND OBJECTIVES: Antimicrobial resistance is a growing global concern and has spurred increasing efforts to find alternative therapeutics. Bacteriophage therapy has seen near constant use in Eastern Europe since its discovery over a century ago. One promising approach is to use phages that not only reduce bacterial pathogen loads but also select for phage resistance mechanisms that trade-off with antibiotic resistance-so called 'phage steering'.

METHODOLOGY: Recent work has shown that the phage OMKO1 can interact with efflux pumps and in so doing select for both phage resistance and antibiotic sensitivity of the pathogenic bacterium Pseudomonas aeruginosa. We tested the robustness of this approach to three different antibiotics in vitro (tetracycline, erythromycin and ciprofloxacin) and one in vivo (erythromycin).

RESULTS: We show that in vitro OMKO1 can reduce antibiotic resistance of P. aeruginosa (Washington PAO1) even in the presence of antibiotics, an effect still detectable after ca.70 bacterial generations in continuous culture with phage. Our in vivo experiment showed that phage both increased the survival times of wax moth larvae (Galleria mellonella) and increased bacterial sensitivity to erythromycin. This increased antibiotic sensitivity occurred both in lines with and without the antibiotic.

CONCLUSIONS AND IMPLICATIONS: Our study supports a trade-off between antibiotic resistance and phage sensitivity. This trade-off was maintained over co-evolutionary time scales even under combined phage and antibiotic pressure. Similarly, OMKO1 maintained this trade-off in vivo, again under dual phage/antibiotic pressure. Our findings have implications for the future clinical use of steering in phage therapies. Lay Summary: Given the rise of antibiotic-resistant bacterial infection, new approaches to treatment are urgently needed. Bacteriophages (phages) are bacterial viruses. The use of such viruses to treat infections has been in near-continuous use in several countries since the early 1900s. Recent developments have shown that these viruses are not only effective against routine infections but can also target antibiotic resistant bacteria in a novel, unexpected way. Similar to other lytic phages, these so-called 'steering phages' kill the majority of bacteria directly. However, steering phages also leave behind bacterial variants that resist the phages, but are now sensitive to antibiotics. Treatment combinations of these phages and antibiotics can now be used to greater effect than either one independently. We evaluated the impact of steering using phage OMKO1 and a panel of three antibiotics on Pseudomonas aeruginosa, an important pathogen in hospital settings and in people with cystic fibrosis. Our findings indicate that OMKO1, either alone or in combination with antibiotics, maintains antibiotic sensitivity both in vitro and in vivo, giving hope that phage steering will be an effective treatment option against antibiotic-resistant bacteria.

PMID:34254028 | PMC:PMC7547624 | DOI:10.1093/emph/eoaa026

J Cyst Fibros. 2021 Jul 10:S1569-1993(21)01294-7. doi: 10.1016/j.jcf.2021.06.010. Online ahead of print.

ABSTRACT

BACKGROUND: Patients with cystic fibrosis (CF) are exposed to overlapping cardiovascular risk factors. We hypothesized that CF is characterized by increased arterial stiffness and greater intima-media thickness (IMT).

METHODS: This cross-sectional study assessed the digital volume pulse arterial stiffness index (SIDVP) using photopletysmography, measured intima-media complex thickness (IMT) at the common carotid artery, and obtained an extended set of clinical and atherosclerosis-related laboratory parameters.

RESULTS: Fifty-five patients with moderate-to-severe CF (mean age 26.3±8.6 years, BMI 20.3±3.1 kg/m2, FEV1 62±26%) and 51 healthy controls (25.1±4.4 years, BMI 21.7±3.0 kg/m2) entered the study. SIDVP was greater in pancreatic insufficient (PI), but not pancreatic sufficient (PS) CF patients compared with control (7.3±1.8 m/s vs 6.0±1.2 m/s; p=7.1 × 10-5). IMT was increased in PS (but not PI) participants relative to control (552±69 µm vs 456±95 µm, p=0.0011). SIDVP was also greater in PI than in PS patients (7.3±1.8 m/s vs 6.3±1.7 m/s, p=0.0232) and IMT was higher in PS compared with PI (552±69 µm vs 453±82 µm, p=0.0002). SIDVP independently associated with age, PI, the lack of liver cirrhosis, and with Pseudomonas aeruginosa colonization. PS was the only independent correlate of IMT in CF.

CONCLUSIONS: PI patients are at risk of developing general arterial stiffness. PS may relate to carotid IMT thickening, which underscores the need for further study that could lead to reconsideration of dietary guidance in PS CF.

PMID:34253491 | DOI:10.1016/j.jcf.2021.06.010

BMC Pulm Med. 2021 Jul 12;21(1):225. doi: 10.1186/s12890-021-01599-z.

ABSTRACT

BACKGROUND: Cystic fibrosis (CF) is a life-threatening multiorgan genetic disease, particularly affecting the lungs, where recurrent infections are the main cause of reduced life expectancy. In CF, mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein impair transepithelial electrolyte and water transport, resulting in airway dehydration, and a thickening of the mucus associated with abnormal viscoelastic properties. Our aim was to develop a rheological method to assess the effects of hypertonic saline (NaCl) and NaHCO3 on CF sputum viscoelasticity in vitro, and to identify the critical steps in sample preparation and in the rheological measurements.

METHODS: Sputum samples were mixed with hypertonic salt solutions in vitro in a ratio of either 10:4 or 10:1. Distilled water was applied as a reference treatment. The rheological properties of sputum from CF patients, and the effects of these in vitro treatments, were studied with a rheometer at constant frequency and strain, followed by frequency sweep tests, where storage modulus (G'), loss modulus (G″) and loss factor were determined.

RESULTS: We identified three distinct categories of sputum: (i) highly elastic (G' > 100,000 Pa), (ii) elastic (100,000 Pa > G' > 1000 Pa), and (iii) viscoelastic (G' < 1000). At the higher additive ratio (10:4), all of the added solutions were found to significantly reduce the gel strength of the sputum, but the most pronounced changes were observed with NaHCO3 (p < 0.001). Samples with high elasticity exhibited the greatest changes while, for less elastic samples, a weakening of the gel structure was observed when they were treated with water or NaHCO3, but not with NaCl. For the viscoelastic samples, the additives did not cause significant changes in the parameters. When the lower additive ratio (10:1) was used, the mean values of the rheological parameters usually decreased, but the changes were not statistically significant.

CONCLUSION: Based on the rheological properties of the initial sputum samples, we can predict with some confidence the treatment efficacy of each of the alternative additives. The marked differences between the three categories suggest that it is advisable to evaluate each sample individually using a rheological approach such as that described here.

PMID:34253193 | DOI:10.1186/s12890-021-01599-z

Expert Rev Respir Med. 2021 Jul 12. doi: 10.1080/17476348.2021.1951707. Online ahead of print.

ABSTRACT

The COVID-19 pandemic has challenged health care across the world, not just by the severity of the disease and the high mortality rate but also by the consequences on the management of the patients with chronic diseases.Areas covered: This review summarizes the most up-to-date published data regarding the impact of COVID-19 on the management and outcomes of patients with chronic non-infectious respiratory illnesses including obstructive sleep apnea, asthma, chronic obstructive pulmonary disease, bronchiectasis, interstitial and pulmonary vascular diseases, and lung cancer.Expert opinion: Most of chronic respiratory diseases (except asthma and cystic fibrosis) are associated with more severe COVID-19 and poor outcomes but the mechanisms involved are not yet identified. The therapeutic management of the patients with chronic respiratory diseases and COVID-19 is similar to the other patients but the post-recovery course could be worse in this population and followed by the developement of pulmonary fibrosis, bronchiectasis, and pulmonary hypertension. The pandemic highly impacted our usual medical activities by limiting the access to several diagnosis procedures, the necessity to develop new methods for the monitoring of the disease and adapt the therapeutic strategies. The long-term consequences of all these changes are still unknown.

PMID:34253132 | DOI:10.1080/17476348.2021.1951707

J Pediatr (Rio J). 2021 Jul 9:S0021-7557(21)00094-2. doi: 10.1016/j.jped.2021.05.010. Online ahead of print.

ABSTRACT

OBJECTIVES: Cystic fibrosis (CF) is a severe autosomal recessive disease that results from mutations in a gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, a chloride channel. This study aims to characterize the clinical and genetic features of a cohort of pediatric people with CF (PwCF) in the center of Portugal and to determine which ones are candidates for the new drugs modulating the CFTR channel.

METHODS: A review of the demographic, genetic and clinical characteristics of PwCF undergoing follow-up at a CF reference center was carried out.

RESULTS: Twenty-three PwCF (12 male), with a median age of 12 years, were followed up. All patients carry the F508del mutation in at least one allele. Fifteen PwCF were F508del-homozygous, median BMI z-score was -0.13, all are pancreatic insufficient and median FEV1 value was 78.1%. These PwCF are eligible for dual therapy (lumacaftor/tezacaftor+ivacaftor) and for triple therapy (tezacaftor+ivacaftor+elexacaftor). PwCF with 711 +1G->T (n = 2), 2184insA (n = 1) mutations and a novel mutation c.3321dup (n = 1) have minimal function mutation which also makes them eligible to triple therapy. Patients with a residual function mutation: R334W (n = 3) and P5L (n = 1) have a less severe phenotype, however, in Europe, they have at present no available therapy.

CONCLUSIONS: Genetic and molecular characterization of PwCF poses an important step not just for CF diagnosis and prognosis which is tightly correlated with the clinical phenotype, but also for the eligibility of CFTR modulator drugs.

PMID:34252371 | DOI:10.1016/j.jped.2021.05.010

Antimicrob Agents Chemother. 2021 Jul 12:AAC0079221. doi: 10.1128/AAC.00792-21. Online ahead of print.

ABSTRACT

Background: The optimal polymyxin B dosage needed to achieve an efficacy target of 50-100 mg·h/L when treating multi-drug-resistant bacterial infections in adult cystic fibrosis (CF) patients is unclear. The pharmacokinetics of intravenous polymyxin B were evaluated to better inform dosing. Methods: This was a prospective, observational pharmacokinetic (PK) study of nine CF adults receiving intravenous polymyxin B as part of usual clinical care. Doses preceding PK sampling ranged from 50-100 mg every 12 hours. Five PK samples were collected following the fourth or fifth dose and concentrations of polymyxin subcomponents, B1 and B2, were quantified using Liquid Chromatography Mass Spectrometry (LC-MS). Population PK (NONMEM® software) analysis was performed using pooled polymyxin B1+B2 concentrations. Results: Participants were Caucasian, predominantly male, with mean age and weight of 31 years (range 21-57 years) and 58.0kg (range 38.3-70.4kg), respectively. A 1-compartment zero-order infusion and linear elimination model adequately described the data with estimated clearance and volume of distribution, 2.09 L/hr and 12.7 L, respectively, corresponding to a 4.1 hour mean half-life (t1/2). Although body weight was observed to influence the volume of distribution, a fixed dose of 75 mg every 12 hours was predicted to achieve the target steady-state exposure. Neurotoxicities were reported in all patients; acute kidney injury events in two patients. These events resolved within 2-4 days after discontinuing polymyxin B. Conclusions: Fixed maintenance dosing of polymyxin B without loading is predicted to achieve the targeted therapeutic exposure in CF adults. Treatment-limiting neurotoxicities are very common in this population.

PMID:34252297 | DOI:10.1128/AAC.00792-21