Assessment of serology and spirometry and the combination of both to complement microbiological isolation for earlier detection of Pseudomonas aeruginosa infection in children with cystic fibrosis

What diagnostic tests are available for respiratory infections or pulmonary exacerbations in cystic fibrosis: A scoping literature review

A scoping review methodological framework formed the basis of this review. A search of two electronic databases captured relevant literature published from 2013. 1184 articles were screened, 200 of which met inclusion criteria. Included studies were categorised as tests for either respiratory infections OR pulmonary exacerbations. Data were extracted to ascertain test type, sample type, and indication of use for each test type. For infection, culture is the most common testing method, particularly for bacterial infections, whereas PCR is utilised more for the diagnosis of viral infections. Spirometry tests, indicating lung function, facilitate respiratory infection diagnoses. There is no clear definition of what an exacerbation is in persons with CF. A clinical checklist with risk criteria can determine if a patient is experiencing an exacerbation event, however the diagnosis is clinician-led and will vary between individuals. Fuchs criteria are one of the most frequently used tests to assess signs and symptoms of exacerbation in persons with CF. This scoping review highlights the development of home monitoring tests to facilitate earlier and easier diagnoses, and the identification of novel biomarkers for indication of infections/exacerbations as areas of current research and development. Research is particularly prevalent regarding exhaled breath condensate and volatile organic compounds as an alternative sampling/biomarker respectively for infection diagnosis. Whilst there are a wide range of tests available for diagnosing respiratory infections and/or exacerbations, these are typically used clinically in combination to ensure a rapid, accurate diagnosis which will ultimately benefit both the patient and clinician.

[CF Lung Disease - a German S3 Guideline: Pseudomonas aeruginosa]

Cystic Fibrosis (CF) is the most common autosomal recessive genetic multisystemic disease. In Germany, it affects at least 8000 people. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the airway epithelial lining fluid which leads to reduction of the mucociliary clearance.Even if highly effective, CFTR modulator therapy has been available for some years and people with CF are getting much older than before, recurrent and chronic infections of the airways as well as pulmonary exacerbations still occur. In adult CF life, Pseudomonas aeruginosa (PA) is the most relevant pathogen in colonisation and chronic infection of the lung, leading to further loss of lung function. There are many possibilities to treat PA-infection.This is a S3-clinical guideline which implements a definition for chronic PA-infection and demonstrates evidence-based diagnostic methods and medical treatment in order to give guidance for individual treatment options.

Combination of Serologic Tests and Sputum Culture Results as the Best Diagnostic Method of Pseudomonas aeruginosa Infection in Cystic Fibrosis Patients

Background

One of the most common reasons for mortality in patients with cystic fibrosis (CF) is lung infections, among which Pseudomonas aeruginosa (Pa) infection has the largest share. Diagnosis of Pa can be assessed by various methods such as sputum culture results and IgG antibody level via measuring the specific anti-Pa antibodies. This study aimed to select the best predictive technique in the diagnosis of Pa in CF patients through spirometry, sputum culture, and serum IgG antibody levels.

Materials and Methods

In this cross-sectional study, blood and sputum or pharyngeal samples were taken from 68 patients with cystic fibrosis. Because spirometry was not possible in all patients, 34 patients could do the spirometry. The samples were studied concerning Pa infection. The data including variables such as age, sex, and spirometry results were obtained. Then, in the serologic method, 3 serum-specific antibody levels were determined by enzyme-linked immune sorbent assay (ELISA).

Results

The average age of children was 7.4 ± 5.6 (ranging from 0.5 to 23) years. Generally, the percentage of Pa infection increased in CF patients with higher ages. A statistically direct significant relationship was observed between the concentration of serum IgG antibodies in patients with CF and Pa-positive sputum culture results (p<0.05).

Conclusion

Serum IgG antibodies against specific Pa antigens could be a diagnostic method against Pa infection, especially in patients who cannot expectorate. However, because of the positive and negative predictive value of both serum IgG antibody levels and the results of the sputum culture, we suggested that utilizing the combination of these methods could be beneficial in earlier diagnosis of Pa.

Recent advances in the early treatment of cystic fibrosis: Bridging the gap to highly effective modulator therapy

Highly effective modulator therapy (HEMT) for cystic fibrosis (CF) has been touted as one of the greatest advances to date in CF care. As these therapies are now available for many older children and adults with CF, marked improvement of their nutritional status, pulmonary and gastrointestinal symptoms has been observed. However, most infants and younger children are not current candidates for HEMT due to age and/or cystic fibrosis transmembrane conductance regulator (CFTR) mutation. For these young children, it is essential to provide rigorous monitoring and care to avoid potential disease sequelae while awaiting HEMT availability. The following article highlights recent advances in the care of infants and young children with CF with regard to surveillance and treatment of nutritional, pulmonary, and gastrointestinal disorders. Recent clinical trials in this population are also reviewed.