M. Gilljam

High Rate of Exophiala dermatitidis Recovery in the Airways of Patients with Cystic Fibrosis Is Associated with Pancreatic Insufficiency

ABSTRACT The black-pigmented fungus Exophiala dermatitidis is considered to be a harmless colonizer of the airways of cystic fibrosis (CF) patients. The aim of this study was to establish the recovery rate of E. dermatitidis in respiratory specimens from CF patients, transplant recipients, and subjects with other respiratory disorders in Sweden. Second, we wished to determine if particular clinical traits were associated with E. dermatitidis colonization of the airways and the antifungal susceptibility profiles of Exophiala strains. Sputum and bronchoalveolar lavage samples (n = 492) derived from 275 patients were investigated. E. dermatitidis was isolated in respiratory specimens from 19% (18/97) of the CF patients but in none of the other patient categories. All isolates were recovered after 6 to 25 days of incubation on erythritol-chloramphenicol agar (ECA) medium. Morphological and genetic analyses confirmed species identity. Pancreatic insufficiency was positively associated with the presence of E. dermatitidis in sputum samples (P = 0.0198). Antifungal susceptibility tests demonstrated that voriconazole and posaconazole had the lowest MICs against E. dermatitidis. In conclusion, E. dermatitidis is a frequent colonizer of the respiratory tract in CF patients in Sweden and appears to be associated with more advanced disease. Whether E. dermatitidis is pathogenic remains to be elucidated.

Development of IgG antibodies to Exophiala dermatitidis is associated with inflammatory responses in patients with cystic fibrosis.

BACKGROUNDnThe clinical importance of airway colonisation by the fungus Exophiala dermatitidis in patients with cystic fibrosis (CF) is unclear. We have previously shown that E. dermatitidis frequently colonises the airways of patients with CF. The aims of the present study were to determine whether patients who are colonised by E. dermatitidis have detectable fungal antigens in the circulation, develop anti-fungal antibodies, and show signs of inflammation and impaired respiratory function.nnnMETHODSnWe collected sputum and serum samples consecutively from 98 sputum-producing patients with CF aged more than 12 years. The serum samples were subjected to bacterial and fungal culturing and analyses for fungal antigens and inflammatory factors.nnnRESULTSnE. dermatitidis was recovered from 17 (17%) patients, the same isolation rate as for Aspergillus fumigatus. There were no difference regarding the levels of β-glucan in the sera from E. dermatitidis culture-positive and culture-negative patients with CF. Serological analysis revealed significantly higher levels of IgG antibodies to E. dermatitidis cell wall fragments in the E. dermatitidis culture-positive patients. Patients with higher level of E. dermatitidis IgG antibodies were more often colonised with non-tuberculous Mycobacteria, and less often with Staphylococcus aureus. The increased levels of IgG antibodies directed against E. dermatitidis were positively associated with higher white blood cell counts, increased erythrocyte sedimentation rate, pancreatic insufficiency, intravenous antibiotic treatment, and they were negatively associated with respiratory function (FEV1 % predicted). Overall, 4/17 Exophiala-positive patients were diagnosed as having symptomatic infection with E. dermatitidis and were treated with broad-spectrum azoles.nnnCONCLUSIONnE. dermatitidis triggers antibody production and may cause significant airway infection in patients with cystic fibrosis.

Slow and fast lung compartments in cystic fibrosis measured by nitrogen multiple-breath washout

Imaging studies describe significant ventilation defects across a wide range of cystic fibrosis (CF) related lung disease severity. These are unfortunately poorly reflected by phase III slope analysis-derived Scond and Sacin from multiple-breath washout (MBW). Methodology extending previous two-lung compartment model-based analysis is presented describing size and function of fast- and slow-ventilating lung compartments from nitrogen (N2) MBW and correlation to obstructive lung disease severity. In 37 CF subjects (forced expiratory volume in 1 s [FEV1] mean [SD] 84.8 [19.9] % predicted; abnormal lung clearance index [LCI] in 36/37, range 7.28-18.9) and 74 matched healthy controls, volume and specific ventilation of both fast and slowly ventilated lung compartments were derived from N2-based MBW with commercial equipment. In healthy controls lung emptying was characterized by a large compartment constituting 75.6 (8.4)% of functional residual capacity (FRC) with a specific ventilation (regional alveolar tidal volume/regional lung volume) of 13.9 (3.7)% and a small compartment with high specific ventilation (48.4 [15.7]%). In CF the slowly ventilated lung compartment constituted 51.9(9.1)% of FRC, with low specific ventilation of 5.3 (2.4)%. Specific ventilation of the slowly ventilated lung compartment showed stronger correlation with LCI (r2 = 0.70, P < 0.001) vs. Sacin (r2 = 0.44, P < 0.001) or Scond (no significant correlation). Overventilation of the fast lung compartment was no longer seen in severe CF lung disease. Magnitude and function of under- and overventilated lung volumes can be derived from routine N2 MBW in CF. Reported values agree with previous modelling-derived estimates of impaired ventilation and offer improved correlation to disease severity, compared with SnIII analysis.

Genotyping of Pseudomonas aeruginosa isolates from lung transplant recipients and aquatic environment- detected in-hospital transmission

Lung infection with Pseudomonas aeruginosa is common in lung transplant recipients and may lead to severe complications. Bacteriological surveillance aims to detect transmission of microbes between hospital environment and patients. We sought to determine whether genotyping of P. aeruginosa isolates could improve identifications of pathways of infection. From 2004 to 2009, we performed genotyping with multiple‐locus variable number of tandem repeats analysis (MLVA) and pulsed‐field gel electrophoresis (PFGE) of P. aeruginosa isolates cultured from lung transplant recipients at Sahlgrenska University Hospital, Gothenburg. During a small outbreak in 2008, cultivation and genotyping of isolates from sink and drains samples from the hospital ward were performed. Pseudomona aeruginosa from 11/18 patients were genotyped to unique strains. The remaining seven patients were carriers of a P. aeruginosa strain of cluster A genotype. Pseudomona aeruginosa was isolated in 4/8 water samples, typed by MLVA also as cluster A genotype and confirmed by PFGE to be similar or identical to the isolates from four transplanted patients. In conclusion, genotyping of isolates revealed a clonal relationship between patient and water isolates, indicating in‐hospital transmission of P. aeruginosa. We suggest genotyping with MLVA for rapid routine surveillance, with the PFGE method used for extended, confirmatory analyses.

VISIBILITY OF STRUCTURES OF RELEVANCE FOR PATIENTS WITH CYSTIC FIBROSIS IN CHEST TOMOSYNTHESIS: INFLUENCE OF ANATOMICAL LOCATION AND OBSERVER EXPERIENCE

The aims of this study were to assess the visibility of pulmonary structures in patients with cystic fibrosis (CF) in digital tomosynthesis (DTS) using computed tomography (CT) as reference and to investigate the dependency on anatomical location and observer experience. Anatomical structures in predefined regions of CT images from 21 patients were identified. Three observers with different levels of experience rated the visibility of the structures in DTS by performing a head-to-head comparison with visibility in CT. Visibility of the structures in DTS was reported as equal to CT in 34 %, inferior in 52 % and superior in 14 % of the ratings. Central and peripheral lateral structures received higher visibility ratings compared with peripheral structures anteriorly, posteriorly and surrounding the diaphragm (p ≤ 0.001). Reported visibility was significantly higher for the most experienced observer (p ≤ 0.01). The results indicate that minor pathology can be difficult to visualise with DTS depending on location and observer experience. Central and peripheral lateral structures are generally well depicted.

Genotyping of Pseudomonas aeruginosa reveals high diversity, stability over time and good outcome of eradication ☆

BACKGROUNDnGenotyping of Pseudomonas aeruginosa (P.a) is used for surveillance at our CF clinic.nnnMETHODSnP.a from 1999 to 2012 were analysed, using pulsed-field gel electrophoresis (PFGE) and multiple-locus variable number of tandem repeats analysis (MLVA).nnnRESULTSnAmong 232 isolates from 104 patients, we identified 78 unique strains, of which 56 were isolated from individual patients. The B-clone was isolated from 13 patients and the camp transmission clone J-strains from 8 patients at the start of the study. There was no indication of transmission within the clinic. PFGE and MLVA clone identification was in 91% agreement. For patients who provided more than 2 P.a isolates, similar strains were identified over time for 45/49 chronically- and for 6/16 intermittently-colonized patients despite, periods of no detectable P.a after eradication therapy.nnnCONCLUSIONSnAnalyses revealed high genotypic diversity, acceptable outcome of eradication therapy and no indication of cross-infection at the CF centre.

138 Depiction of anatomic structures of relevance for scoring of cystic fibrosis changes by chest tomosynthesis and computed tomography

Sleep disorders are common in CF patients. Pediatric studies are contradictory. Being aware of the incidence of respiratory sleep disturbance (RSD) and clinical and respiratory function predictive factors is essential. We aimed to identify sleep disturbances in CF children and determine associated spirometric indices as severity predictors. In-lab polysomnography (PSG) followed by spirometry was carried out in CF children, 6 to 18 y. Baseline SpO2 was assessed. A questionnaire was applied. Descriptive statistics and comparative tests were performed. Significance level was set at 5%. Thirty-three subjects were included [16 males (48.5%); median age 12 y (6−18); average BMI z-score −0.35 (dp 0.78)]. 29 patients (87.9%) had sleep quality and/or RSD complaints. Sleep efficiency was reduced and sleep latency and wake after sleep increased. N1, N2, N3, REM and awakenings were normal. The A/HI was 0.6/h (dp 0.9); mean RDI: 6.6 (dp 5.2). Mean wake SpO2 [97% (dp 1.1)] and sleep SpO2 [95% (dp 2.7)] were normal; mean ODI was 2.36; minSpO2 was 89% (dp 4.1). TcCO2 was normal. 51.5% of patients had nocturnal cough. There was a statistically significant difference between the waking and sleep SpO2 (r = 0.326, p = 0.064). FEV1 was associated with sleep SpO2 (r = 0.528, p = 0.002). PSG data significantly correlate with the questionnaire for night awakenings and wake after sleep (p = 0.985) and difficulty breathing during sleep and RDI (p = 0.722). Most children had sleep complaints. The subjective assessment of sleep correlates with PSG findings. These mild respiratory disease children had scarce nocturnal SpO2 events, associated with disease severity assessed by spirometry. The association between SpO2 awake and mean sleep SpO2 indicates a possible risk predictor for nocturnal desaturation.

133 Slow and fast lung compartments in cystic fibrosis measured by nitrogen multiple-breath washout (N2 MBW)

133 Slow and fast lung compartments in cystic fibrosis measured by nitrogen multiple-breath washout (N2 MBW) B. Houltz1, M. Gilljam2, A. Lindblad3, P.D. Robinson4, P. Gustafsson5. 1Sahlgrenska University Hospital/East, Clinical Physiology, Gothenburg, Sweden; 2Sahlgrenska University Hospital, Dept of Pulmonology and Allergology, Gothenburg, Sweden; 3Queen Silvia Childrens Hospital, Dept of Pediatrics, Gothenburg, Sweden; 4The Children’s Hospital at Westmead, Dept of Respiratory Medicine, Sydney, Australia; 5Skaraborg Hospital, Dept of Pediatrics, Skovde, Sweden