Quantitative chest computerized tomography and FEV1 equally identify pulmonary exacerbation risk 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.

Culture independent markers of nontuberculous mycobacterial (NTM) lung infection and disease in the cystic fibrosis airway

Nontuberculous mycobacteria (NTM) are opportunistic pathogens that affect a relatively small but significant portion of the people with cystic fibrosis (CF), and may cause increased morbidity and mortality in this population. Cultures from the airway are the only test currently in clinical use for detecting NTM. Culture techniques used in clinical laboratories are insensitive and poorly suited for population screening or to follow progression of disease or treatment response. The lack of sensitive and quantitative markers of NTM in the airway impedes patient care and clinical trial design, and has limited our understanding of patterns of acquisition, latency and pathogenesis of disease. Culture-independent markers of NTM infection have the potential to overcome many of the limitations of standard NTM cultures, especially the very slow growth, inability to quantitate bacterial burden, and low sensitivity due to required decontamination procedures. A range of markers have been identified in sputum, saliva, breath, blood, urine, as well as radiographic studies. Proposed markers to detect presence of NTM or transition to NTM disease include bacterial cell wall products and DNA, as well as markers of host immune response such as immunoglobulins and the gene expression of circulating leukocytes. In all cases the sensitivity of culture-independent markers is greater than standard cultures; however, most do not discriminate between various NTM species. Thus, each marker may be best suited for a specific clinical application, or combined with other markers and traditional cultures to improve diagnosis and monitoring of treatment response.

Neuroendocrine cell hyperplasia of infancy: Feasibility of objective evaluation with quantitative CT

OBJECTIVE

To describe quantitative CT parameters of children with a typical pattern for NEHI and compare them to controls.

MATERIALS AND METHODS

Eleven patients (7 boys) with NEHI and an available chest CT concordant NEHI were identified. Eleven age-, sex-, height-matched, with CT technique-matching were identified for comparison. An open-source software was used to segment the lung parenchyma into lobes using the fissures. Quantitative parameters such as low attenuation areas, mean lung density, kurtosis, skewness, ventilation heterogeneity, lung mass, and volume were calculated for both controls and cases.

RESULTS

Analysis of the lung parenchyma showed that patients with NEHI had a lower mean lung density (-615 HU vs -556 HU, p = 0.03) with higher ventilation heterogeneity (0.23 vs 0.19, p = 0.04), lung mass (232 g vs 146 g, p = 0.01) and volume (595 mL vs 339 mL, p = 0.008) compared to controls. Most lobes followed this trend, except the middle lobe that showed only a higher lung mass (32.9 g vs 19.6 g, p = 0.02) and volume (77.4 vs 46.9, p = 0.005) in patients with NEHI compared to controls.

CONCLUSION

Quantitative CT is a feasible technique in children with a typical pattern for NEHI and is associated with differences in attenuation, ventilation heterogeneity, and lung volume.

Newborn screening alone insufficient to improve pulmonary outcomes for cystic fibrosis

BACKGROUND

The Wisconsin Cystic Fibrosis Neonatal Screening Project was a randomized clinical trial (RCT) revealing that children receiving an early diagnosis of CF via newborn screening (NBS) had improved nutritional outcomes but similar lung disease severity compared to those who presented clinically. Because the evaluations of these subjects by protocol ended in 2012, our objective was to assess long-term pulmonary and mortality outcomes.

METHODS

Retrospective analysis of the RCT cohort utilized longitudinal outcome measures obtained from the Cystic Fibrosis Foundation Patient Registry (CFFPR). Data included screening assignment, clinical characteristics, percent predicted forced expiratory volume in 1 s (ppFEV1) and mortality. A random intercept model was used to compare the ppFEV1 decline of subjects between the two groups up to age 26 years. Mortality was analyzed using the Kaplan-Meier method.

RESULTS

Of the 145 subjects who consented to the original study, 104 subjects met inclusion criteria and had adequate data in the CFFPR. Of 57 subjects in the screened group and 47 in the control group, the rates of ppFEV1 decline were 1.76%/year (95% CI 1.62 to 1.91%) and 1.43%/year (95% CI 1.26 to 1.60%), respectively (p<0.0002). Pseudomonas aeruginosa acquired before 2 years was partially responsible. There was no difference in mortality between the two groups.

CONCLUSIONS

NBS alone does not improve pulmonary outcomes in CF, particularly when other risk factors supervene. In an era prior to strict infection control and current therapies, NBS for CF may be associated with worse pulmonary outcomes.

Predictive value of computed tomography scoring systems evolution in adults with cystic fibrosis

OBJECTIVES

To assess whether the evolution of two consecutive high-resolution computed tomography (HRCT) scores in patients with cystic fibrosis (CF) has prognostic value.

METHODS

A longitudinal retrospective study was performed to research adult patients with CF. Two consecutive HRCT studies were scored using Bhalla and Brody II scoring scales by two senior radiologists. Annual scoring changes for each scale were calculated and correlated with annual FEV1% decline, with pulmonary exacerbations and number of antibiotic treatments.

RESULTS

We selected sixty-four adult patients. The median interval between the two HRCTs was 3.88 ± 1.59 years. The mean spirometric values showed dynamic lung volumes lower than the general population; globally, there was a worsening of respiratory function over time. The change in the annual HRCT scores was positive on both scales, indicating a worse structural situation over time. The Brody II scale annual change showed a significant statistical correlation with a decline in the annual FEV1%, exacerbations and number of oral antibiotic treatments. In contrast, for the Bhalla scale, the relationship was moderately inverse with exacerbations and with the number of oral treatments. No statistically significant relationships were found for the change in the annual FEV1% and exacerbations or number of antibiotic treatments. The interobservational and intraobservational agreements were very strong in both scales.

CONCLUSIONS

The annual evolution of the Brody II HRCT scoring system demonstrated a predictive value and correlated with FEV1% decline, pulmonary exacerbations and oral antibiotic treatments.

KEY POINTS

• HRCT evolution has prognostic value in cystic fibrosis. • Temporal evolution for the Brody II score is useful for clinical follow-up. • Brody II score changes correlate with FEV1% decline, pulmonary exacerbations and number of antibiotic treatments.

Cystic fibrosis year in review 2018, part 2

Cystic fibrosis (CF) research and case reports were robust in the year 2018. This report summarizes publications related the multisystem effects of CF, pulmonary exacerbations, new and expanded therapies other than cystic fibrosis transmembrane conductance regulator modulator studies, and patient-reported priorities and outcomes.