Pulmonary function parameters and use of bronchodilators in patients with cystic fibrosis

Impact of Anaerobic Antibacterial Spectrum on Cystic Fibrosis Airway Microbiome Diversity and Pulmonary Function

BACKGROUND

The role of anaerobic organisms in the cystic fibrosis (CF) lung microbiome is unclear. Our objectives were to investigate the effect of broad (BS) versus narrow (NS) spectrum antianaerobic antibiotic activity on lung microbiome diversity and pulmonary function, hypothesizing that BS antibiotics would cause greater change in microbiome diversity without a significant improvement in lung function.

METHODS

Pulmonary function tests and respiratory samples were collected prospectively in persons with CF before and after treatment for pulmonary exacerbations. Treatment antibiotics were classified as BS or NS. Gene sequencing data from 16S rRNA were used for diversity analysis and bacterial genera classification. We compared the effects of BS versus NS on diversity indices, lung function and anaerobic/aerobic ratios. Statistical significance was determined by multilevel mixed-effects generalized linear models and mixed-effects regression models.

RESULTS

Twenty patients, 6-20 years of age, experienced 30 exacerbations. BS therapy had a greater effect on beta diversity than NS therapy when comparing time points before antibiotics to after and at recovery. After antibiotics, the NS therapy group had a greater return toward baseline forced expiratory volume at 1 second and forced expiratory flow 25%-75% values than the BS group. The ratio of anaerobic/aerobic organisms showed a predominance of anaerobes in the NS group with aerobes dominating in the BS group.

CONCLUSIONS

BS antianaerobic therapy had a greater and possibly longer lasting effect on the lung microbiome of persons with CF, without achieving the recovery of pulmonary function seen with the NS therapy. Specific antibiotic therapies may affect disease progression by changing the airway microbiome.

Variants in the interleukin 8 gene and the response to inhaled bronchodilators in cystic fibrosis

OBJECTIVE

Interleukin 8 protein promotes inflammatory responses, even in airways. The presence of interleukin 8 gene variants causes altered inflammatory responses and possibly varied responses to inhaled bronchodilators. Thus, this study analyzed the interleukin 8 variants (rs4073, rs2227306, and rs2227307) and their association with the response to inhaled bronchodilators in cystic fibrosis patients.

METHODS

Analysis of interleukin 8 gene variants was performed by restriction fragment length polymorphism of polymerase chain reaction. The association between spirometry markers and the response to inhaled bronchodilators was evaluated by Mann-Whitney and Kruskal-Wallis tests. The analysis included all cystic fibrosis patients, and subsequently patients with two mutations in the cystic fibrosis transmembrane conductance regulator gene belonging to classes I to III.

RESULTS

This study included 186 cystic fibrosis patients. There was no association of the rs2227307 variant with the response to inhaled bronchodilators. The rs2227306 variant was associated with FEF_50% in the dominant group and in the group with two identified mutations in the cystic fibrosis transmembrane conductance regulator gene. The rs4073 variant was associated with spirometry markers in four genetic models: co-dominant (FEF_25-75% and FEF_75%), dominant (FEV₁, FEF_50%, FEF_75%, and FEF_25-75%), recessive (FEF_75% and FEF_25-75%), and over-dominant (FEV₁/FVC).

CONCLUSIONS

This study highlighted the importance of the rs4073 variant of the interleukin 8 gene, regarding response to inhaled bronchodilators, and of the assessment of mutations in the cystic fibrosis transmembrane conductance regulator gene.

Difficulties experienced by the mothers of people with cystic fibrosis

This study aimed to understand difficulties experienced by mothers in life with, and caring for, their children with cystic fibrosis. A descriptive-exploratory study with a qualitative character, its population consisted of 14 women. Data collection involved a semi-structured interview. The statements' analysis allowed the identification of two units of meaning: 'The treatment of cystic fibrosis: facing difficulties'; and 'The child's future: the difficult coexistence with the hope for a cure and a normal development'. Difficulties experienced by the mothers relate to disbelief regarding the diagnosis, the mourning for the loss of the dreamt-of child, acceptance of the inevitable and the struggle for the child's life and comfort. It is important for the health team to present another perspective on the health-illness process regarding chronic illnesses in order to support individuals affected and their families in the most efficacious and complete way.