Progression of Polysomnographic Abnormalities in Mucolipidosis II (I-Cell Disease)

Mucolipidosis II (Inclusion cell or I-cell disease) is an autosomal recessive lysosomal storage disorder clinically comparable to the mucopolysaccharidoses (MPS), characterized by progressive respiratory and neurologic deterioration. Sleep problems, especially obstructive sleep apnea (OSA) and disrupted sleep architecture, are observed in other lysosomal storage diseases but have not been described in mucolipidosis II. We report the progression of polysomnographic abnormalities in a child with mucolipidosis II, demonstrated by worsening sleep-related hypoventilation, OSA, and sleep state fragmentation despite advancing PAP therapy. Background slowing and reduction in spindle activity on limited EEG may reflect progressive CNS disease affecting thalamic neurons

Population Pharmacokinetics and Safety of Ceftolozane-Tazobactam in Adult Cystic Fibrosis Patients Admitted with Acute Pulmonary Exacerbation

ABSTRACT Ceftolozane-tazobactam has potent activity against Pseudomonas aeruginosa , a pathogen associated with cystic fibrosis (CF) acute pulmonary exacerbations (APE). Due to the rapid elimination of many antibiotics, CF patients frequently have altered pharmacokinetics. In this multicenter, open-label study, we described the population pharmacokinetics and safety of ceftolozane-tazobactam at 3 g every 8 h (q8h) in 20 adult CF patients admitted with APE. Population pharmacokinetics were determined using the nonparametric adaptive grid program in Pmetrics for R. A 5,000-patient Monte Carlo simulation was performed to determine the probability of target attainment (PTA) for the ceftolozane component at 1.5 g and 3 g of ceftolozane-tazobactam q8h across a range of MICs using a primary threshold exposure of 60% free time above the MIC ( fT >MIC). In these 20 adult CF patients, ceftolozane and tazobactam concentration data were best described by 2-compartment models, and ceftolozane clearance (CL) was significantly correlated with creatinine clearance ( r = 0.71, P MIC, ceftolozane-tazobactam regimens of 1.5 g and 3 g q8h should achieve PTAs of ≥90% at MICs up to 4 and 8 μg/ml, respectively. Ceftolozane-tazobactam at 3 g q8h was well tolerated. These observations support additional studies of ceftolozane-tazobactam for Pseudomonas aeruginosa APE in CF patients. (This study has been registered at ClinicalTrials.gov under identifier NCT02421120.

Metabolomic biomarkers predictive of early structural lung disease in cystic fibrosis

Neutrophilic airway inflammation plays a role in early structural lung disease in cystic fibrosis (CF), but the mechanisms underlying this pathway are incompletely understood

Relationship of Sleep to Pulmonary Function in Mucopolysaccharidosis II

To study the sleep characteristics, pulmonary function, and their relationships in an enzyme naive population of patients with mucopolysaccharidosis (MPS) II (Hunter syndrome)

Biomarkers for cystic fibrosis drug development

To provide a review of the status of biomarkers in cystic fibrosis drug development, including regulatory definitions and considerations, a summary of biomarkers in current use with supportive data, current gaps, and future needs

Attenuation of host defense function of lung phagocytes in young cystic fibrosis patients

Recent reports suggest that endotoxin exposure can blunt phagocyte functions. The aim of this study was to examine whether lung phagocytic cells have altered host defense function in young cystic fibrosis (CF) patients, and to explore the contribution of neutrophil elastase (NE) and surfactant proteins to these effects

Population pharmacokinetics of meropenem administered as a prolonged infusion in children with cystic fibrosis

OBJECTIVES: Meropenem is frequently used to treat pulmonary exacerbations in children with cystic fibrosis (CF) in the USA. Prolonged-infusion meropenem improves the time that free drug concentrations remain above the MIC (fT> MIC) in adults, but data in CF children are sparse. We describe the population pharmacokinetics, tolerability and treatment burden of prolonged-infusion meropenem in CF children. METHODS: Thirty children aged 6-17 years with a pulmonary exacerbation received 40 mg/kg meropenem every 8 h; each dose was administered as a 3 h infusion. Pharmacokinetics were determined using population methods in Pmetrics. Monte Carlo simulation was employed to compare 0.5 with 3 h infusions to estimate the probability of pharmacodynamic target attainment (PTA) at 40% fT> MIC. NCT#01429259. RESULTS: A two-compartment model fitted the data best with clearance and volume predicted by body weight. Clearance and volume of the central compartment were 0.41 ± 0.23 L/h/kg and 0.30 ± 0.17 L/kg, respectively. Half-life was 1.11 ± 0.38 h. At MICs of 1, 2 and 4 mg/L, PTAs for the 0.5 h infusion were 87.6%, 70.1% and 35.4%, respectively. The prolonged infusion increased PTAs to >99% for these MICs and achieved 82.8% at 8 mg/L. Of the 30 children, 18 (60%) completed treatment with prolonged infusion; 5 did so at home without any reported burden. Nine patients were changed to a 0.5 h infusion when discharged home. CONCLUSIONS: In these CF children, meropenem clearance was greater compared with published values from non-CF children. Prolonged infusion provided an exposure benefit against pathogens with MICs ≥1 mg/L, was well tolerated and was feasible to administer in the hospital and home settings, the latter depending on perception and family schedule

Multicenter observational study on factors and outcomes associated with various methicillin-resistant Staphylococcus aureus types in children with cystic fibrosis

Rationale: Methicillin-resistant Staphylococcus aureus (MRSA) prevalence continues to increase in patients with cystic fibrosis (CF) in the United States, reaching 26.5% in 2012. Approximately 30% of strains are SCCmec (staphylococcal cassette chromosome mec) IV type, frequently USA300, which in the general population have different genotypic and phenotypic features than SCCmec II type. Objectives: We hypothesized that risk factors for acquisition and outcomes in patients with CF differed for "health care-associated" (SCCmec II) versus "community-associated" (SCCmec IV)MRSAstrains. Methods: To determine the role of SCCmec type and Panton-Valentine leukocidin (PVL), MRSA isolates from patients not more than 18 years old at seven CF centers were typed and the association of potential risk factors and subsequent clinical course was assessed, using data provided by the CF Patient Registry. Measurements and Main Results: Participants with chronic MRSA (295) had typeable isolates and clinical data; 205 (69.5%) had SCCmec II PVL(-), 39 (13.2%) had SCCmec IV PVL(-), and 51 (17.3%) had SCCmec IVPVL(1) strains.SCCmec IV, comparedwith SCCmec II, increased during the study period, 1996-2010 (P = 0.03). SCCmec II was associated with Pseudomonas aeruginosa-positive cultures and three or more clinic visits in the 6 months preceding the first positive MRSA culture (adjusted odds ratio, 2.05; 95% confidence interval, 1.13-3.74; P = 0.019). Lung function and anthropometrics remained unchanged in the 6 months after initial MRSA detection compared with the 6 months prior. Although CF care increased for participants in both groups in the 6 months after MRSA detection, inhaled antibiotics were prescribed more frequently in those with SCCmec II strains and increased hospitalizations occurred in those with SCCmec IV PVL(-) strains compared with those with PVL(1) strains (adjusted difference, 34.10%; 95% confidence interval, 7.58-60.61; P = 0.012). Participants in both groups had an increase in CF care in the 2 years after MRSA detection compared with the 2 years prior. Conclusions: Increased exposure to CF clinics and P. aeruginosa may constitute risk factors for acquisition of SCCmec II MRSA strains. Clinical interventions increased 6 months and 2 years after initial MRSA detection regardless of SCCmec type

Production of extended-spectrum β -lactamases and the potential indirect pathogenic role of Prevotella isolates from the cystic fibrosis respiratory microbiota

Extended-spectrum β-lactamase (ESBL) production and the prevalence of the β-lactamase-encoding gene blaTEM were determined in Prevotella isolates (n = 50) cultured from the respiratory tract of adults and young people with cystic fibrosis (CF). Time–kill studies were used to investigate the concept of passive antibiotic resistance and to ascertain whether a β-lactamase-positive Prevotella isolate can protect a recognised CF pathogen from the action of ceftazidime in vitro. The results indicated that approximately three-quarters (38/50; 76%) of Prevotella isolates produced ESBLs. Isolates positive for ESBL production had higher minimum inhibitory concentrations (MICs) of β-lactam antibiotics compared with isolates negative for production of ESBLs (P < 0.001). The blaTEM gene was detected more frequently in CF Prevotella isolates from paediatric patients compared with isolates from adults (P = 0.002), with sequence analysis demonstrating that 21/22 (95%) partial blaTEM genes detected were identical to blaTEM-116. Furthermore, a β-lactamase-positive Prevotella isolate protected Pseudomonas aeruginosa from the antimicrobial effects of ceftazidime (P = 0.03). Prevotella isolated from the CF respiratory microbiota produce ESBLs and may influence the pathogenesis of chronic lung infection via indirect methods, including shielding recognised pathogens from the action of ceftazidime

Relation of exaggerated cytokine responses of CF airway epithelial cells to PAO1 adherence

In many model systems, cystic fibrosis (CF) phenotype airway epithelial cells in culture respond to P. aeruginosa with greater interleukin (IL)-8 and IL-6 secretion than matched controls. In order to test whether this excess inflammatory response results from the reported increased adherence of P. aeruginosa to the CF cells, we compared the inflammatory response of matched pairs of CF and non CF airway epithelial cell lines to the binding of GFP-PAO1, a strain of pseudomonas labeled with green fluorescent protein. There was no clear relation between GFP-PAO1 binding and cytokine production in response to PAO1. Treatment with exogenous aGM1 resulted in greater GFP-PAO1 binding to the normal phenotype compared to CF phenotype cells, but cytokine production remained greater from the CF cell lines. When cells were treated with neuraminidase, PAO1 adherence was equalized between CF and nonCF phenotype cell lines, but IL-8 production in response to inflammatory stimuli was still greater in CF phenotype cells. The polarized cell lines 16HBEo-Sense (normal phenotype) and Antisense (CF phenotype) cells were used to test the effect of disrupting tight junctions, which allows access of PAO1 to basolateral binding sites in both cell lines. IL-8 production increased from CF, but not normal, cells. These data indicate that increased bacterial binding to CF phenotype cells cannot by itself account for excess cytokine production in CF airway epithelial cells, encourage investigation of alternative hypotheses, and signal caution for therapeutic strategies proposed for CF that include disruption of tight junctions in the face of pseudomonas infection