M. Proesmans

Pseudomonas aeruginosa in the home environment of newly infected cystic fibrosis patients

The source of acquisition of Pseudomonas aeruginosa in cystic fibrosis (CF) patients remains unknown. Patient-to-patient transmission has been well documented but the role of the environment as a source of initial infection is as yet unclear. In the present study, the origin of the first P. aeruginosa isolate in CF patients was investigated by comparing the P. aeruginosa genotype(s) from newly infected patients with genotypes of P. aeruginosa isolates from the home environment and from other patients from the same CF centre. A total of 50 newly infected patients were studied. P. aeruginosa could be cultured from 5.9% of the environmental samples, corresponding to 18 patients. For nine of these, the genotype of the environmental P. aeruginosa isolate was identical to the patients isolate. In total, 72% of the environmental P. aeruginosa isolates were encountered in the bathroom. Patient-to-patient transmission within the CF centre could not be ruled out for three patients. In summary, a low prevalence of Pseudomonas aeruginosa was found in the home environment of the newly infected cystic fibrosis patients. The bathroom should be targeted in any preventive cleaning procedures. An environmental source of the new infection could not be ruled out in nine patients.

Mucociliary transport using 99mTc-albumin colloid: a reliable screening test for primary ciliary dyskinesia

Background: A study was undertaken to assess the reliability of the nasal mucociliary transport test using 99mTc-albumin colloid as a screening test for primary ciliary dyskinesia (PCD) and to compare it with the gold standard nasal biopsy for study of ciliary motility and ultrastructure. Methods: During a 4 year period both tests were performed in 55 children referred with persistent or recurrent respiratory tract infections. Their median age was 4 years (range 1 month to 15 years). Results: The nasal biopsy results were as follows: PCD, n = 8; secondary ciliary dyskinesia (SCD), n = 19; normal, n = 28. The mucociliary transport test was abnormal in 29 patients (all 8 with PCD, 7/19 with SCD, and 14/28 with a normal biopsy). The sensitivity of the mucociliary transport test to diagnose PCD was therefore 100% (8/8) (95% exact confidence limits 63.06 to 100.00); the specificity was only 55% (26/47) (40.95 to 69.89). The negative predictive value was 100% (26/26) (86.77 to 100.00) and the positive predictive value was 28% (8/29) (12.37 to 47.24). Conclusion: Mucociliary transport is a non-invasive screening test that can be performed even in infants. The sensitivity of the test is high but its specificity is low. A normal test result excludes PCD.

Evaluation of dietary fiber intake in Belgian children with cystic fibrosis: is there a link with gastrointestinal complaints?

Background Pancreatic enzyme replacement is the cornerstone of treating pancreatic insufficiency in patients with cystic fibrosis. Additionally, a high-calorie/high-fat diet is required to compensate for the increased energy requirement and the incomplete fat digestion. Even with adequate enzyme treatment, gastrointestinal problems, varying from simple constipation to inspissated stools, and distal intestinal obstruction syndrome (DIOS) may occur. Apart from residual fat malabsorption, a low fiber intake is suspected to be an underlying factor in gastrointestinal complaints. Methods We evaluated fiber intake in 40 patients with cystic fibrosis based on the dietary history method. Patients were classified according to gastrointestinal problems: group 1, no gastrointestinal complaints; group 2, nonspecific and mild gastrointestinal complaints; and group 3, documented DIOS. Results Overall fiber intake was adequate when compared with current recommendations. We could not show a relation between fiber intake and gastrointestinal complaints or DIOS. On the contrary, in patients with DIOS, fiber intake was higher, possibly as a therapeutic response to their gastrointestinal complaints. Conclusion Overall fiber intake is adequate in our cystic fibrosis population. We could show no relation between low fiber intake and gastrointestinal problems in our patients with cystic fibrosis.

Nasal potential measurements on the nasal floor and under the inferior turbinate: Does it matter?

Measurement of nasal potential difference (NPD) is increasingly used as diagnostic test for cystic fibrosis (CF) and for in vivo evaluation of treatments aimed at correcting the defective function of the cystic fibrosis transmembrane regulator (CFTR) protein. Several methods are used to measure NPD. This study explores the influence of the site of measurement and compares NPD results obtained on the nasal floor and under the inferior turbinate.

WS7.4 Does lung clearance index predict time to pulmonary exacerbation

WS7.1 LCI measured with nitrogen multiple breath washout is higher than mass spectrometer SF6 washout in children with cystic fibrosis A. Lindblad1, B. Houltz2, M. Rosberg3, L. Bergh2, P. Gustafsson4. 1Sahlgrenska University Hospital, Pediatrics, Gothenburg, Sweden; 2Sahlgrenska University Hospital, Clinical Physiology, East Hospital, Gothenburg, Sweden; 3Queen Silvia Childrens Hospital, Paediatric Clinical Physiology, Gothenburg, Sweden; 4Central Hospital, Pediatrics, Skovde, Sweden

361 Cleaning a Positive Expiratory Pressure (PEP) mask: an investigation of patient routines

Aim: Cleaning a Positive Expiratory Pressure masks (PEP) requires time and effort. Patients are advised to clean as follows; rinse daily with hot water, dry after each use and store in a dry space. This study evaluates actual routines used by patients. Method: 108/210 patient at a Belgian CF centre use a PEP mask as a therapy device. The Astra Tech PEP ® mask was investigated, other systems were excluded. 82 completed a self-administered questionnaire regarding cleaning routines; frequency and mode of cleaning/drying and method of storage. Results: Fifty-three of 82 patients report to use their PEP mask at least once daily. Twenty-six % (n 21) cleaned the mask at least once daily; 45% (n 33) cleaned 1 5 times a week and 19% (n 15) cleaned their mask less than once a week. 6% (n 5) of patients report to never clean their mask. Usual cleaning routines reported are: rinsing with hot water (72%, n 58), cleaning in a vinegar solution (16%, n 13), bleach water (9%, n 7), steam or electric sterilisation (2.5%, n 2) and dishwasher (9%, n 7). 84% take their mask apart before cleaning. 88% of patients dry the mask after cleaning. The following methods for drying were reported: paper towel (51%, n 36), kitchen towel (45%, n 32), shaking (27%, n 19), on the central heating (10%, n 7) and hairdryer (9%, n 6). Patients stored the mask as follows: in the accompanying bag (63%, n 49), in a cupboard (18%, n 14), in a kitchen towel (12%, n 9), on the sink (4%, n 3), on the central heating (n 1). 72% of patients started PEP therapy more than 3 years before the study Conclusions: Seventy-five percent of patients clean at least daily. Most patients clean their mask with hot water and dry it afterwards, in line with the hospitals advice. However, the frequency of cleaning the mask is not as often as recommended. 9. Physiotherapy

WS13.1 Lung clearance index predicts time to pulmonary exacerbation in children with CF

Lung Clearance Index (LCI) is a promising endpoint for use in CF clinical trials. Since correlation with validated clinical endpoints has not yet been established, we investigated the association between baseline LCI and risk of respiratory tract exacerbations (RTE) in children with CF. Methods: During a prospective observational study, baseline LCI (N2 washout), FEV1 and CFQR respiratory domain (CFQRres) were measured. RTE, defined as an increase in respiratory symptoms treated with IV antibiotics, were recorded during one year. Whether basline LCI predicted RTE was assessed with a Poisson regression model and Kaplan–Meier plots. LCI z-scores were calculated from values in 57 healthy children. Results: In 63 children with CF (median age 12.4 years, range 5−19), mean LCI z-score was 5.3 (SD 4.6) and mean FEV1 z-score −0.9 (SD 1.3). CFQRres correlated with LCI (R = −0.43, p< 0.001), but not with FEV1 (R=0.24, p = 0.051). In the 53 patients with a normal FEV1, CFQRres and LCI were still correlated (R = −0.44, p = 0.002). During the 12 months follow up, 25 patients (40%) experienced 47 RTE. LCI and FEV1 were predictors of RTE. Time to first RTE decreased with worsening LCI quartiles (Log Rank test, p< 0.001). Similarly, compared to the quartile with the lowest LCI, yearly RTE rate ratio in increasing LCI quartiles was 2.8 (95%CI 0.6–13.9, p = 0.205), 4.7 (95%CI 1.0–21.4, p = 0.046) and 13.6 (95%CI 3.2–57.0, p< 0.001). In the group with normal FEV1, LCI but not FEV1 z-score was still a predictor of RTE. Conclusion: Baseline LCI predicts the risk of RTE in children with CF, even in the subgroup with normal FEV1. These data further support the use of LCI as surrogate outcome in CF clinical trials.

WS7.2 Lung clearance index: comparison of helium and nitrogen washout

WS7.1 LCI measured with nitrogen multiple breath washout is higher than mass spectrometer SF6 washout in children with cystic fibrosis A. Lindblad1, B. Houltz2, M. Rosberg3, L. Bergh2, P. Gustafsson4. 1Sahlgrenska University Hospital, Pediatrics, Gothenburg, Sweden; 2Sahlgrenska University Hospital, Clinical Physiology, East Hospital, Gothenburg, Sweden; 3Queen Silvia Childrens Hospital, Paediatric Clinical Physiology, Gothenburg, Sweden; 4Central Hospital, Pediatrics, Skovde, Sweden

104 Antibiotic use in years preceding chronic lung infection with multiresistant Pseudomonas aeruginosa

Intensive treatment of lung infection is standard CF care. We explored whether antibiotic (AB) use in Pseudomonas aeruginosa (Pa) colonized patients drives infection with multiresistant Pa (MRPa). In 241 patients born after 1980 bacteriologic data plus AB use between 1995 and 2010 were analysed retrospectively. Chronic Pa infection was defined according to the Leeds criteria. Pa isolates resistant to all the AB of at least 2 classes were considered MR. Days on AB per year were counted in patients with chronic Pa infection who did and did not become infected with MRPa. 163 patients never acquired chronic Pa infection. 11 had chronic MRPa infection from onset, 35 had chronic Pa throughout, 32 had MRPa after chronic Pa. Yearly AB use during chronic Pa infection was analyzed in 25 subjects with chronic Pa and in 24 before onset of MRPa. Median days on IV AB per year was higher pre MRPa (43.2 days, IQR 30.0–62.4) than in patients never becoming MRPa (29.8 days, IQR 10.1–45.4), (p = 0.05). No difference was noted in use of oral AB (median 45.6 days IQR 24.4–68.7 vs 30.5 days IQR 20.5–124.9, p = 0.54) and inhaled AB (median 248.3 days IQR 168.5–365.0 vs 320.7 days IQR 208.5–353.7, p = 0.45). The proportion of patients who ever used azithromycin was not different (11/24 vs 7/25, p = 0.15). More patients with MRPa had siblings with CF (14/24 vs 3/25, p = 0.02). Median number of years of AB use, age and FEV1 at last year of analysis were not significantly different. A quarter of patients have MRPa from onset of chronic Pa infection. In the other MRPa subjects the yearly burden of AB use and having a sibling with CF were related to the development of MRPa infection.

Bronchoalveolar lavage (BAL) findings in symptomatic preschool children with and without CF

Neutrophilic lung infection and inflammation are typical for CF but have also been reported in preschool children with recurrent wheeze. We therefore compared BAL results in 143 symptomatic preschool (<5 y) children: CF and persistent lung infection (n = 19), recurrent lung infection without wheeze (LI) (n = 77), recurrent lung infection with persistent wheeze (WH) (n = 47). Medians and IQR are reported; for group comparison Kruskal–Wallis was used. Results: Total cell count (×103/ml) was higher (P< 0.001) in CF 1323 (430–2200) than LI 176 (100–311) and WH 207 (120–437); % neutrophils was also higher (p< 0.001) in CF 87% (72−92) than in RI 16% (4−38) and WH 23% (8−56). % eosinophils was <1 in all groups and did not differ between LI and WH. % macrophages was lower in CF 9 (5−20) than in RI 64 (42−84) and WH 56 (29−78) but lipid laden macrophage index was higher (p = 0.007) in CF 132 (100– 175) than RI 68 (44–105) and WH 68 (50−98). BAL cultures were +ve for S. aureus in 42% of CF (p< 0.01) compared to 4% of RI and 8% of WH. H. influenzae was present in 16% of CF, 21% of RI, and 11% of WH. S. pneumoniae was present in 0% of CF, 13% of LI, 4% of WH. P. aeruginosa was not isolated. Conclusion: Symptomatic preschool children with CF have higher BAL total cell counts due to marked increase in neutrophils compared to children with LI and WH. In CF cultures are more often positive with S. aureus prevailing. Eosinophilia is not detected in BAL, not even in group WH. Absolute macrofage count is similar in all groups but lipid laden macrophage index in higher in CF children suggesting that recurrent aspiration may be associated with their persistent symptoms.