Helmut Ellemunter

Lung clearance index: Normal values, repeatability, and reproducibility in healthy children and adolescents†

There is increasing interest in using the Multiple Breath Washout technique and the lung clearance index (LCI) for detecting early pulmonary changes, for example, in cystic fibrosis lung disease. However, there are still limited data regarding equipment specific reference ranges, repeatability and reproducibility. The aim of this prospective study was to assess within‐test repeatability, short term reproducibility and long term reproducibility, and to establish normal values for the LCI in healthy children and adolescents using the sidestream ultrasonic flow sensor (EasyOne Pro, MBW Module, ndd Medical Technologies, Switzerland). Fourty‐four volunteers (5.3–20.3 years) were recruited for the 1st test. Twenty‐two out of 44 were measured on a 2nd test occasion after an interval of 1 hr (2nd test). Thirty‐four out of 44 agreed to come back for a follow up test 6–15 months later (3rd test). Mean LCI (SD) was 6.2 (0.4), 6.3 (0.4), and 6.0 (0.4) at the 1st, 2nd, and 3rd test. The upper limit of normal was 7.0 for all subjects. Within‐test repeatability was 5.1%. Short‐term reproducibility (1st test vs. 2nd test) was 4.2% with a mean difference of −0.13 (95% CI −0.350; 0.087). Long‐term reproducibility (1st test vs. 3rd test) was 5.1%, with a mean difference of 0.017 (95% CI −0.016; 0.348). With this low variability of the LCI for both, within and between tests, our study demonstrates reliability and robustness of equipment, protocol and analysis and the reliability of the MBW technique in general. The present data will help to interpret the effect of therapeutic interventions and interpretation of longitudinal data in patients with pulmonary diseases. Pediatr Pulmonol. 2009; 44:1180–1185.

IL-1 receptor antagonist ameliorates inflammasome-dependent inflammation in murine and human cystic fibrosis

Dysregulated inflammasome activation contributes to respiratory infections and pathologic airway inflammation. Through basic and translational approaches involving murine models and human genetic epidemiology, we show here the importance of the different inflammasomes in regulating inflammatory responses in mice and humans with cystic fibrosis (CF), a life-threatening disorder of the lungs and digestive system. While both contributing to pathogen clearance, NLRP3 more than NLRC4 contributes to deleterious inflammatory responses in CF and correlates with defective NLRC4-dependent IL-1Ra production. Disease susceptibility in mice and microbial colonization in humans occurrs in conditions of genetic deficiency of NLRC4 or IL-1Ra and can be rescued by administration of the recombinant IL-1Ra, anakinra. These results indicate that pathogenic NLRP3 activity in CF could be negatively regulated by IL-1Ra and provide a proof-of-concept evidence that inflammasomes are potential targets to limit the pathological consequences of microbial colonization in CF.

A mast cell-ILC2-Th9 pathway promotes lung inflammation in cystic fibrosis

T helper 9 (Th9) cells contribute to lung inflammation and allergy as sources of interleukin-9 (IL-9). However, the mechanisms by which IL-9/Th9 mediate immunopathology in the lung are unknown. Here we report an IL-9-driven positive feedback loop that reinforces allergic inflammation. We show that IL-9 increases IL-2 production by mast cells, which leads to expansion of CD25+ type 2 innate lymphoid cells (ILC2) and subsequent activation of Th9 cells. Blocking IL-9 or inhibiting CD117 (c-Kit) signalling counteracts the pathogenic effect of the described IL-9-mast cell-IL-2 signalling axis. Overproduction of IL-9 is observed in expectorates from cystic fibrosis (CF) patients, and a sex-specific variant of IL-9 is predictive of allergic reactions in female patients. Our results suggest that blocking IL-9 may be a therapeutic strategy to ameliorate inflammation associated with microbial colonization in the lung, and offers a plausible explanation for gender differences in clinical outcomes of patients with CF.

Feasibility and Variability of Measuring the Lung Clearance Index in a Multi-Center Setting

The Lung Clearance Index (LCI) is superior to spirometry in detecting early lung disease in cystic fibrosis (CF) and correlates with structural lung changes seen on CT scans. The LCI has the potential to become a novel outcome parameter for clinical and research purposes. However longitudinal studies are required to further prove its prognostic value. Multi‐center design is likely to facilitate realization of such studies.

Severe cold agglutinin disease caused by recurrent monomorphic Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorder (PTLD), clonally related to an EBV-negative plasmacytic hyperplasia in a pediatric multivisceral organ transplant recipient.

Abstract:  PTLD represent major post‐transplant complications. The major etiologic factor is EBV. Association with cold agglutinin disease has not been described so far. We report a three‐yr‐old girl who developed oligoclonal EBV‐negative plasmacytic hyperplasia as well as Coombs test‐positive anemia one yr after multivisceral organ transplantation, performed after subtotal bowel resection for colointestinal aganglionosis and liver cirrhosis resulting from long‐term parenteral nutrition. The patient was treated for plasmacytic hyperplasia with cyclophosphamide and prednisolone and achieved clinical remission. One yr later PTLD progressed possibly driven by EBV to DLBCL. The migration patterns of the amplified Ig heavy chain genes demonstrated a probable clonal relationship of the DLBCL to a clone almost present in the plasmacytic hyperplasia. This progression was accompanied by a rapid rise of cold agglutinin titers with symptoms of severe cold agglutinin disease, leading to right femoral and extern iliac vein thromboses requiring partial leg amputation. After four cycles of rituximab, cyclophosphamide, and prednisolone, the patient achieved complete PTLD remission and the cold agglutinins disappeared. Summarizing, PTLD may be accompanied by cold agglutinin disease, and both may be successfully treated by immuno‐chemotherapy. The appearance of cold agglutinins in transplant patients may indicate PTLD development.

Long-term glomerular filtration rate following pediatric liver transplantion

Abstract:  In adult patients a significant proportion of chronic renal failure after liver transplantation (LTX) has been described. This was attributed mainly to nephrotoxicity caused by Calcineurin inhibitors (CNI). If these results are transferable to pediatric patients was the aim of this study.

Factors Associated with Worse Lung Function in Cystic Fibrosis Patients with Persistent Staphylococcus aureus.

Background Staphylococcus aureus is an important pathogen in cystic fibrosis (CF). However, it is not clear which factors are associated with worse lung function in patients with persistent S. aureus airway cultures. Our main hypothesis was that patients with high S. aureus density in their respiratory specimens would more likely experience worsening of their lung disease than patients with low bacterial loads. Methods Therefore, we conducted an observational prospective longitudinal multi-center study and assessed the association between lung function and S. aureus bacterial density in respiratory samples, co-infection with other CF-pathogens, nasal S. aureus carriage, clinical status, antibiotic therapy, IL-6- and IgG-levels against S. aureus virulence factors. Results 195 patients from 17 centers were followed; each patient had an average of 7 visits. Data were analyzed using descriptive statistics and generalized linear mixed models. Our main hypothesis was only supported for patients providing throat specimens indicating that patients with higher density experienced a steeper lung function decline (p<0.001). Patients with exacerbations (n = 60), S. aureus small-colony variants (SCVs, n = 84) and co-infection with Stenotrophomonas maltophilia (n = 44) had worse lung function (p = 0.0068; p = 0.0011; p = 0.0103). Patients with SCVs were older (p = 0.0066) and more often treated with trimethoprim/sulfamethoxazole (p = 0.0078). IL-6 levels positively correlated with decreased lung function (p<0.001), S. aureus density in sputa (p = 0.0016), SCVs (p = 0.0209), exacerbations (p = 0.0041) and co-infections with S. maltophilia (p = 0.0195) or A. fumigatus (p = 0.0496). Conclusions In CF-patients with chronic S. aureus cultures, independent risk factors for worse lung function are high bacterial density in throat cultures, exacerbations, elevated IL-6 levels, presence of S. aureus SCVs and co-infection with S. maltophilia. Trial Registration ClinicalTrials.gov NCT00669760

Long-term improvement of lung clearance index in patients with mild cystic fibrosis lung disease: Does hypertonic saline play a role?

To assess whether long-term inhalation with hypertonic saline is able to halt the progression of mild CF lung disease, we analysed longitudinal data of lung clearance index (LCI) and spirometry. A total of 34 patients with mild lung disease (FEV1 ≥ 70% of predicted) had at least one LCI result before and ≥2 LCI measurements after start of hypertonic saline (HS) therapy. After a mean follow-up of 39.7 (SD 7.4) months after starting HS, LCI improved significantly from 7.89 (SD 1.35) at baseline to 6.96 (SD 1.03), and 19/34 patients had a normal LCI value at the last measurement. No decrease in mean FEV1 was observed. Thus, ventilation inhomogeneity can improve in patients with mild lung disease.

Psychological resilience and intolerance of uncertainty in coping with cystic fibrosis.

BACKGROUND Anxiety and depression are lower than to be expected in a considerable portion of cystic fibrosis (CF) patients. This outcome might be a result of substantial resilience and/or tolerance of uncertainty in coping with adversity. Research into resilience in cystic fibrosis is in its infancy. METHODS 57 adult CF patients participated in the study during their routine medical checkup. In addition to regular psychological assessment, the Intolerance of Uncertainty Scale (IUS) and the Resilience Scale (RS) were administered. The relative importance of IUS and RS in predicting quality of life in CF was explored. Bivariate correlations and predictive value of variables in multiple regressions on subscales of the Cystic Fibrosis Questionnaire-Revised (CFQ-R) were calculated. RESULTS Remarkably, resilience (personal competence and acceptance) was clearly elevated, whereas intolerance of uncertainty was comparable to healthy reference groups. In multiple regressions, personal competence emerged as strongest resilience variable in the prediction of quality of life. CONCLUSIONS CF patients in our study seem to be particularly resilient rather than cognitively avoidant. At this stage of research, fostering personal competence in CF patients is most promising in improving quality of life.

Amikacin-containing self-emulsifying delivery systems via pulmonary administration for treatment of bacterial infections of cystic fibrosis patients

AIM The aim of the study was to develop self-emulsifying delivery systems (SEDDS) exhibiting improved permeation rate for pulmonary delivery of amikacin for treatment of cystic fibrosis (CF) patients. MATERIALS & METHODS Solubility of amikacin in lipids was improved by hydrophobic ion pairing with sodium myristyl sulfate. The complex was loaded into SEDDS. Drug-release studies were performed and the permeation properties of SEDDS through human CF mucus were examined. RESULTS A total of 10% complex could be loaded into SEDDS. SEDDS exhibited sustained release. Up to twofold more amounts of amikacin permeated through the CF mucus compared with reference. CONCLUSION The developed SEDDS with amikacin may be a promising tool for the treatment of certain bacterial infections of CF patients.