Evaluation of quantitative PCR for early diagnosis of Pseudomonas aeruginosa infection in cystic fibrosis: a prospective cohort study.

OBJECTIVES: Early detection of Pseudomonas aeruginosa lung positivity is a key element in cystic fibrosis (CF) management. PCR has increased the accuracy of detection of many microorganisms. Clinical relevance of P. aeruginosa quantitative PCR (qPCR) in this context is unclear. Our aim was to determine P. aeruginosa qPCR sensitivity and specificity, and to assess the possible time saved by qPCR in comparison with standard practice (culture). METHODS: A multicentre cohort study was conducted over a 3-year period in 96 patients with CF without chronic P. aeruginosa colonization. Sputum samples were collected at each visit. Conventional culture and two-step qPCR (oprL qPCR and gyrB/ecfX qPCR) were performed for 707 samples. The positivity criteria were based on the qPCR results, defined in a previous study as follow: oprL qPCR positivity alone if bacterial density was <730 CFU/mL or oprL qPCR combined with gyrB/ecfX qPCR if bacterial density was ≥730 CFU/mL. RESULTS: During follow up, 36 of the 96 patients with CF were diagnosed on culture as colonized with P. aeruginosa. This two-step qPCR displayed a sensitivity of 94.3% (95% CI 79.7%-98.6%), and a specificity of 86.3% (95% CI 83.4%-88.7%). It enabled P. aeruginosa acquisition to be diagnosed earlier in 20 patients, providing a median detection time gain of 8 months (interquartile range 3.7-17.6) for them. CONCLUSIONS: Implementing oprL and gyrB/ecfX qPCR in the management of patients with CF allowed earlier detection of first P. aeruginosa lung positivity than culture alone.

[National French guidelines for management of infants with cystic fibrosis]. / Recommandations nationales pour la prise en charge du nourrisson dépisté atteint de mucoviscidose. Consensus de la fédération des centres de ressources et de compétences de la mucoviscidose.

These guidelines aim to standardize the care of infants diagnosed with a typical form of cystic fibrosis (CF) at neonatal screening. They have been implemented by the National Working Group for Neonatal Screening of the French Federation for CF and have been validated using the Delphi methodology by a large group of clinicians involved in the care of CF infants. These guidelines encompass management and organization of care at diagnosis and describe nutritional, digestive, and respiratory monitoring and treatment during the first 2 years of life.

Transient elastography and portal hypertension in pediatric patients with cystic fibrosis Transient elastography and cystic fibrosis.

BACKGROUND: Esophageal varices (EV) are a complication of cystic fibrosis-associated liver disease. Esophagogastroduodenoscopy (EGD) is currently used to diagnose varices but is invasive for pediatric patients. The goal of this study was to explore the relationship between transient elastography (FibroScan®) and the presence of EV in patients with liver disease defined by clinical, laboratory, sonographic, and/or endoscopic criteria. METHODS: 18 patients with cystic fibrosis underwent EGD and transient elastography. 12 patients had EV. RESULTS: Patients with EV had higher FibroScan values than those without varices with median values of 22.4 kPa (14.4-30.4 kPa) vs. 7.9 kPa (4.4-13.7 kPa) (p=0.01). Using a threshold of 12 kPa, four of six patients without EV would not have needed EGD. CONCLUSIONS: Elastography should be recommended for all cystic fibrosis patients with liver disease to follow its progression. A prospective study is needed to define an elastography threshold value that predicts the presence of EV.

Frequency of aquagenic palmoplantar keratoderma in cystic fibrosis: a new sign of cystic fibrosis?

BACKGROUND: Aquagenic palmoplantar keratoderma (APPK), also known as aquagenic wrinkling of the palms, is characterized by oedema of palms and/or soles, whitish papules, hyperwrinkling and sometimes pruritus or pain after water immersion. Its frequency in the general population is unknown. About 40 cases have been reported to date, including some among patients with cystic fibrosis (CF) or CF heterozygotes. OBJECTIVES: To determine the frequency of APPK among patients with CF. METHODS: Twenty-seven patients from the Centre of Competence on Cystic Fibrosis of Roscoff were examined by a dermatologist after immersion of the palms in water for 2-3 min. RESULTS: The frequency of APPK was 41% (11 of 27 patients). Some patients had not previously noticed the lesions. The frequency was higher among inpatients than outpatients. We suspect that occlusion (caused by the gloves worn by inpatients) can explain this difference. The number of patients included in this study is not sufficient to draw any conclusions concerning the type of CF mutation and its impact on the frequency of APPK. CONCLUSIONS: APPK is frequent among patients with CF and, thus, should be considered a sign of CF. APPK is underdiagnosed because physicians usually do not look for it. CF screening should be considered for any patient presenting with these symptoms, followed by genetic counselling if necessary.