Acute Pulmonary Exacerbation Phenotypes in Patients with Cystic Fibrosis.

Rationale: The etiology of cystic fibrosis (CF) pulmonary exacerbations (PEx) is likely multifactorial with viral, bacterial, and non-infectious pathways contributing. Objectives: To determine whether viral infection status and CRP (C-reactive protein) can classify subphenotypes of PEx that differ in outcomes and biomarker profiles. Methods: Patients were recruited at time of admission for a PEx. Nasal swabs and sputum samples were collected and processed using the respiratory panel of the FilmArray multiplex polymerase chain reaction (PCR). Serum and plasma biomarkers were measured. PEx were classified using serum CRP and viral PCR: "pauci-inflammatory" if CRP < 5 mg/L, "non-viral with systemic inflammation" if CRP ⩾ 5 mg/L and no viral infection detected by PCR and "viral with systemic inflammation" if CRP ⩾ 5 mg/L and viral infection detected by PCR. Results: Discovery cohort (n = 59) subphenotype frequencies were 1) pauci-inflammatory (37%); 2) non-viral with systemic inflammation (41%); and 3) viral with systemic inflammation (22%). Immunoglobulin G, immunoglobulin M, interleukin-10, interleukin-13, serum calprotectin, and CRP levels differed across phenotypes. Reduction from baseline in forced expiratory volume in 1 second as percent predicted (FEV1pp) at onset of exacerbation differed between non-viral with systemic inflammation and viral with systemic inflammation (-6.73 ± 1.78 vs. -13.5 ± 2.32%; P = 0.025). Non-viral with systemic inflammation PEx had a trend toward longer duration of intravenous antibiotics versus pauci-inflammation (18.1 ± 1.17 vs. 14.8 ± 1.19 days, P = 0.057). There were no differences in percent with lung function recovery to <10% of baseline FEV1pp. Similar results were seen in local and external validation cohorts comparing a pauci-inflammatory to viral/non-viral inflammatory exacerbation phenotypes. Conclusions: Subphenotypes of CF PEx exist with differences in biomarker profile, clinical presentation, and outcomes.

Psychometric properties of outcome measures for children and adolescents with brachial plexus birth palsy: a systematic review.

AIM: The aim of this review was to evaluate the psychometric properties of outcome measures used to quantify upper limb function in children and adolescents with brachial plexus birth palsy (BPBP). METHOD: Eleven electronic databases were searched to identify studies on the effects of conservative management to improve upper limb function in young people with BPBP. Outcome measures used in these studies were extracted and used in a subsequent search to identify studies that evaluated the psychometric properties of these measures. The methodological quality of these studies was rated using a standardized critical appraisal tool. RESULTS: Thirty-three outcome measures and 12 psychometric studies were identified. Nine outcome measures had some psychometric evidence, which was variable in quality. The outcome measures which seem to have the most robust psychometric properties include the Active Movement Scale, Assisting Hand Assessment, Pediatric Evaluation of Disability Index, and the Pediatric Outcomes Data Collection Instrument. INTERPRETATION: Further research is required to determine the psychometric properties of outcome measures used for children and adolescents with BPBP. Caution is required when interpreting the results of commonly used outcome measures in this population owing to their relatively unknown psychometric properties.