Mediastinal Nontuberculous Mycobacterial Infection in Children: A Multidisciplinary Approach

BACKGROUND

Mediastinal infections due to nontuberculous mycobacteria remain an exceedingly rare entity. Most cases in the published literature do not include pediatric patients. Due to their clinical infrequency, poor response to antimicrobial therapy and often precarious anatomical location, the optimal management of these lesions can be challenging.

METHODS

Retrospective medical record review of 4 pediatric cases of mediastinal nontuberculous mycobacteria infection was undertaken. Each child presented with nonspecific respiratory symptoms, including significant acute airway obstruction and required a range of investigations to confirm the diagnosis. Nonresponsiveness to conservative measures and antimycobacterial therapy ultimately resulted in surgical intervention to obtain clinical improvement.

RESULTS

All 4 children had extensive evaluation and multidisciplinary involvement in otolaryngology, respiratory medicine, pediatric surgery, infectious diseases and cardiothoracic surgery. They all eventually had their disease debulked via thoracotomy in addition to prolonged antimycobacterial therapy, with successful clinical outcomes.

CONCLUSIONS

Mediastinal nontuberculous mycobacteria infections in the pediatric population are rare and diagnostically challenging. A high clinical suspicion should be maintained, and multidisciplinary input sought. Targeted surgery with adjuvant medical therapy can reduce disease burden with minimal long-term morbidity.

Comparing Cytology Brushes for Optimal Human Nasal Epithelial Cell Collection: Implications for Airway Disease Diagnosis and Research

Primary nasal epithelial cells and culture models are used as important diagnostic, research and drug development tools for several airway diseases. Various instruments have been used for the collection of human nasal epithelial (HNE) cells but no global consensus yet exists regarding the optimal tool. This study compares the efficiency of two cytology brushes (Olympus (2 mm diameter) and Endoscan (8 mm diameter)) in collecting HNE cells. The study involved two phases, with phase one comparing the yield, morphology and cilia beat frequency (CBF) of cells collected from paediatric participants using each of the two brushes. Phase two compared nasal brushing under general anaesthetic and in the awake state, across a wide age range, via the retrospective audit of the use of the Endoscan brush in 145 participants. Results indicated no significant difference in CBF measurements between the two brushes, suggesting that the choice of brush does not compromise diagnostic accuracy. However, the Endoscan brush collected significantly more total and live cells than the Olympus brush, making it a more efficient option. Importantly, the Endoscan brush is more cost-effective, with a notable price difference between the two brushes.

Phage Therapy of Mycobacterium Infections: Compassionate Use of Phages in 20 Patients With Drug-Resistant Mycobacterial Disease

BACKGROUND

Nontuberculous Mycobacterium infections, particularly Mycobacterium abscessus, are increasingly common among patients with cystic fibrosis and chronic bronchiectatic lung diseases. Treatment is challenging due to intrinsic antibiotic resistance. Bacteriophage therapy represents a potentially novel approach. Relatively few active lytic phages are available and there is great variation in phage susceptibilities among M. abscessus isolates, requiring personalized phage identification.

METHODS

Mycobacterium isolates from 200 culture-positive patients with symptomatic disease were screened for phage susceptibilities. One or more lytic phages were identified for 55 isolates. Phages were administered intravenously, by aerosolization, or both to 20 patients on a compassionate use basis and patients were monitored for adverse reactions, clinical and microbiologic responses, the emergence of phage resistance, and phage neutralization in serum, sputum, or bronchoalveolar lavage fluid.

RESULTS

No adverse reactions attributed to therapy were seen in any patient regardless of the pathogen, phages administered, or the route of delivery. Favorable clinical or microbiological responses were observed in 11 patients. Neutralizing antibodies were identified in serum after initiation of phage delivery intravenously in 8 patients, potentially contributing to lack of treatment response in 4 cases, but were not consistently associated with unfavorable responses in others. Eleven patients were treated with only a single phage, and no phage resistance was observed in any of these.

CONCLUSIONS

Phage treatment of Mycobacterium infections is challenging due to the limited repertoire of therapeutically useful phages, but favorable clinical outcomes in patients lacking any other treatment options support continued development of adjunctive phage therapy for some mycobacterial infections.

Diet and the gut-lung axis in cystic fibrosis - direct & indirect links

Cystic fibrosis (CF) is a multisystem, autosomal, recessive disease primarily affecting the lungs, pancreas, gastrointestinal tract, and liver. Whilst there is increasing evidence of a microbial 'gut-lung axis' in chronic respiratory conditions, there has been limited analysis of such a concept in CF. We performed a comprehensive dietary and microbiota analysis to explore the interactions between diet, gastrointestinal microbiota, respiratory microbiota, and clinical outcomes in children with CF. Our results demonstrate significant alterations in intestinal inflammation and respiratory and gastrointestinal microbiota when compared to age and gender matched children without CF. We identified correlations between the gastrointestinal and respiratory microbiota, lung function, CF pulmonary exacerbations and anthropometrics, supporting the concept of an altered gut-lung axis in children with CF. We also identified significant differences in dietary quality with CF children consuming greater relative proportions of total, saturated and trans fats, and less relative proportions of carbohydrates, wholegrains, fiber, insoluble fiber, starch, and resistant starch. Our findings position the CF diet as a potential modulator in gastrointestinal inflammation and the proposed gut-lung axial relationship in CF. The dietary intake of wholegrains, fiber and resistant starch may be protective against intestinal inflammation and should be explored as potential therapeutic adjuvants for children with CF.

Care recommendations for the respiratory complications of esophageal atresia-tracheoesophageal fistula

Tracheoesophageal fistula (TEF) with esophageal atresia (EA) is a common congenital anomaly that is associated with significant respiratory morbidity throughout life. The objective of this document is to provide a framework for the diagnosis and management of the respiratory complications that are associated with the condition. As there are no randomized controlled studies on the subject, a group of experts used a modification of the Rand Appropriateness Method to describe the various aspects of the condition in terms of their relative importance, and to rate the available diagnostic methods and therapeutic interventions on the basis of their appropriateness and necessity. Specific recommendations were formulated and reported as Level A, B, and C based on whether they were based on "strong", "moderate" or "weak" agreement. The tracheomalacia that exists in the site of the fistula was considered the main abnormality that predisposes to all other respiratory complications due to airway collapse and impaired clearance of secretions. Aspiration due to impaired airway protection reflexes is the main underlying contributing mechanism. Flexible bronchoscopy is the main diagnostic modality, aided by imaging modalities, especially CT scans of the chest. Noninvasive positive airway pressure support, surgical techniques such as tracheopexy and rarely tracheostomy are required for the management of severe tracheomalacia. Regular long-term follow-up by a multidisciplinary team was considered imperative. Specific templates outlining the elements of the clinical respiratory evaluation according to the patients' age were also developed.

Pepsin as a Marker of Reflux Aspiration in Children With Esophageal Atresia: A Pilot Study

Background: Reflux aspiration secondary to gastroesophageal reflux disease (GERD) is one of the causes of chronic gastrointestinal and respiratory morbidity in children with esophageal atresia (EA). Currently there are no simple, validated non-invasive tests for the diagnosis of reflux aspiration in children. Objectives: The aim of this pilot study was to investigate pepsin detected in exhaled breath condensate (EBC) and saliva as a potential non-invasive marker of reflux aspiration in children with EA. Methods: EBC and saliva samples were prospectively collected from children with EA aged between 5 and 18 years attending a multidisciplinary EA Clinic. Pepsin in the samples was assayed by two methods, a commercial lateral flow device, the Peptest™ and an enzyme-linked immunosorbent assay (ELISA) and correlated with validated gastrointestinal and respiratory symptom questionnaires and objective measures of GERD and respiratory function. Results: EBC were collected from 18 children with EA, 15/18 also provided salivary samples. Pepsin was not detected in any of the EBC samples using the Peptest™ and only 1/14 (7.1%) samples by the ELISA. However, pepsin was detected in 33 and 83% of saliva samples when analyzed with Peptest™ and the ELISA respectively. Salivary pepsin levels were significantly higher in children with reflux symptoms or wheeze. Pepsin was detected by the Peptest™ in the saliva of 5/5 (100%) children with histological evidence of reflux esophagitis compared with 0/2 (0%) in children with normal histology (p = 0.048). Conclusions: Salivary pepsin was detected in a large proportion of children with EA and was significantly associated with GERD symptoms or wheeze. The role of salivary pepsin as a potential non-invasive marker of reflux aspiration in children with EA needs further validation in future studies with larger cohorts.

Distress during airway sampling in children with cystic fibrosis

BACKGROUND

Oropharyngeal suction and oropharyngeal swab are two methods of obtaining airway samples with similar diagnostic accuracy in children with cystic fibrosis (CF). The primary aim was comparing distress between suctioning and swabbing. A secondary aim was establishing the reliability of the Groningen Distress Rating Scale (GDRS).

METHODS

Randomised oropharyngeal suction or swab occurred over two visits. Two physiotherapists and the child's parent rated distress using the GDRS. Heart rate (HR) was also measured.

RESULTS

24 children with CF, mean age of 3 years, participated. Both physiotherapist and parent rating showed significantly higher distress levels during suction than swab. Inter-rater reliability for the GDRS was very good between physiotherapists, and good between physiotherapist and parents.

CONCLUSION

The study found that oropharyngeal swab is less distressing in obtaining samples than oropharyngeal suction and that the GDRS was reliable and valid.

Age-related levels of fecal M2-pyruvate kinase in children with cystic fibrosis and healthy children 0 to 10years old

BACKGROUND

The pathogenesis of gut inflammation, bacterial dysbiosis and increased rates of malignancy in CF is unclear. Fecal M2-pyruvate kinase (M2-PK) is a biomarker indicative of cellular proliferation that may be raised in intestinal malignancy and inflammation. Biomarkers, including M2-PK, may be useful in assessing effects of novel therapies on the gastrointestinal tract.

METHODS

M2-PK was measured in stools collected from patients with CF and HC (0-10years). Linear mixed model analysis was used.

RESULTS

M2-PK levels did not significantly change in children with CF (36 patients, 77 samples) (P=0.998) or HC (45 patients, 45 samples) (P=0.21), over the age range 0-10years. Patients with CF had elevated M2-PK compared to HC (median [IQR; range]: 10.7 [5.7-28.6; 1.0-239.1] (n=77) vs. 1.0 [1.0-1.0; 1.0-50.0] (n=45) U/mL, respectively; P=0.001).

CONCLUSIONS

Fecal M2-PK was elevated in children with CF compared with HC during infancy and throughout childhood suggesting abnormalities in the CF gut exist in early life.

Association of rhinovirus with exacerbations in young children affected by cystic fibrosis: Preliminary data

Rhinovirus (RV) is a common respiratory viral infection linked to worsening of chronic respiratory diseases including cystic fibrosis (CF) and asthma. RV was tested by RT-PCR in samples (n = 465) collected from the upper (nasal swab, oropharyngeal suction, and sputum) and lower (bronchoalveolar washings) respiratory tract of 110 children with CF. Air samples (n = 52) collected from the operating theatres and outpatient clinics were tested for RV. RV was found in 43% of children <5 years suffering an exacerbation, and 12% of older children (5-17 years). RV particles were detected in the air of clinic rooms. Detection of RV is important in better understanding viral infections in patients with CF.

Absence of back to school peaks in human rhinovirus detections and respiratory symptoms in a cohort of children with asthma

Much of what is known about the seasonality of human rhinovirus (hRV) infections has been learned from the study of acute asthma exacerbations presenting to emergency care, including those among children at the start of the school term. Much less is known about the patterns of hRVs in the community. In this study, viruses and day-to-day symptoms of asthma and colds were monitored twice weekly in 67 children with asthma aged 5-12 years, over a 15 month period in Sydney, Australia. Overall hRV was detected in 314/1232 (25.5%) of nasal wash samples and 142/1231 (11.5%) of exhaled breath samples; of these, 231 and 24 respectively were genotyped. HRVs were detected with similar prevalence rate throughout the year, including no peak in hRV prevalence following return to school. No peaks were seen in asthma and cold symptoms using twice-weekly diary records. However, over the same period in the community, there were peaks in asthma emergency visits both at a large local hospital and in state-wide hospitalizations, following both return to school (February) and in late autumn (May) in children of the same age. This study suggests that hRV infections are common throughout the year among children, and differences in virus prevalence alone may not account for peaks in asthma symptoms.

Rhinoviruses significantly affect day-to-day respiratory symptoms of children with asthma

BACKGROUND

Viruses are frequently associated with acute exacerbations of asthma, but the extent to which they contribute to the level of day-to-day symptom control is less clear.

OBJECTIVE

We sought to explore the relationship between viral infections, host and environmental factors, and respiratory symptoms in children.

METHODS

Sixty-seven asthmatic children collected samples twice weekly for an average of 10 weeks. These included nasal wash fluid and exhaled breath for PCR-based detection of viral RNA, lung function measurements, and records of medication use and asthma and respiratory symptoms in the previous 3 days. Atopy, mite allergen exposure, and vitamin D levels were also measured. Mixed-model regression analyses were performed.

RESULTS

Human rhinoviruses (hRVs) were detected in 25.5% of 1232 nasal samples and 11.5% of breath samples. Non-hRV viruses were detected in less than 3% of samples. hRV in nasal samples was associated with asthma symptoms (cough and phlegm: odds ratio = 2.0; 95% CI = 1.4-2.86, P = .0001; wheeze and chest tightness: odds ratio = 2.34, 95% CI = 1.55-3.52, P < .0001) and with cold symptoms, as reported concurrently with sampling and 3 to 4 days later. No differences were found between the 3 hRV genotypes (hRV-A, hRV-B, and hRV-C) in symptom risk. A history of inhaled corticosteroid use, but not atopic status, mite allergen exposure, or vitamin D levels, modified the association between viruses and asthma symptoms.

CONCLUSION

The detection of nasal hRV was associated with a significantly increased risk of day-to-day asthma symptoms in children. Host, virus genotype, and environmental factors each had only a small or no effect on the relationship of viral infections to asthma symptoms.

Refractory otitis media: an unusual presentation of childhood granulomatosis with polyangiitis

Childhood granulomatosis with polyangiitis (cGPA), previously known as Wegener's granulomatosis, is a rare, potentially fatal necrotizing vasculitis, the symptoms of which overlap with infection. We present a 16-year-old girl who, following 6 months of treatment for persistent middle ear effusion with progressive sensorineural hearing loss, developed rapidly progressing pneumonia, with pleural effusion, and multiple cavitatory lung lesions. Investigations demonstrated high titer c-ANCA and nasal septal biopsy confirmed the diagnosis of cGPA. This case highlights the difficulty in diagnosing cGPA and the potentially life-threatening consequences of failing to do so.

Once daily insulin detemir in cystic fibrosis with insulin deficiency

The aim of this study was to determine if once daily insulin detemir reverses decline in weight and lung function in patients with cystic fibrosis (CF). 12 patients with early insulin deficiency and six with CF related diabetes (aged 7.2-18.1 years) were treated for a median of 0.8 years. Changes in weight and lung function following treatment were compared to pretreatment changes. Before treatment, the change in weight SD score (ΔWtSDS), percentage of predicted forced expiratory volume in 1 s (Δ%FEV(1)) and percentage of predicted forced vital capacity (Δ%FVC) declined in the whole study population (-0.45±0.38, -7.9±12.8%, -5.8±14.3%) and in the subgroup with early insulin deficiency (-0.41±0.43, -9.8±9.3%, -6.8±10.3%). Following treatment with insulin ΔWtSDS, Δ%FEV(1) and Δ%FVC significantly improved in the whole study population (+0.18±0.29 SDS, p=0.0001; +3.7±10.6%, p=0.007; +5.2±12.7%, p=0.013) and in patients with early insulin deficiency (+0.22±0.31 SDS, p=0.003; +5.3±11.5%, p=0.004; +5.8±13.4%, p=0.024). Randomised controlled trials are now needed.

Acid and non-acid reflux during physiotherapy in young children with cystic fibrosis

BACKGROUND

Gastro-esophageal reflux (GOR) may contribute to lung disease in children with cystic fibrosis (CF). There is conflicting evidence regarding the effect of chest physiotherapy (CPT) in the head-down position on GOR. Furthermore, there is currently no evidence on the impact of physiotherapy on GOR as assessed by pH-multichannel intraluminal impedance (pH-MII).

AIMS

(1) To characterize GOR in young children with CF. (2) To determine whether the head-down position during physiotherapy exacerbates GOR.

METHODS

Children were studied using pH-MII monitoring over 24-hr, during which they received two 20-min sessions of CPT. One session was performed in "modified" drainage positions with no head-down tilt and the alternate session in "gravity-assisted" drainage positions, which included 20° head-down tilt.

RESULTS

Twenty children with CF (8 males), median age 12 months (range 8-34) were recruited. A total of 1,374 reflux episodes were detected in all children, of which 869 (63%) were acid and 505 (37%) were non-acid. Seventy-two percent of the episodes migrated proximally. During CPT, there was no significant difference between total number of reflux episodes in the modified or gravity-assisted positions, median [inter-quartile range (IQR)] 1 (0-2.5) compared to 1 (0.75-3) episode, respectively, P = 0.63. There was also no significant difference between the number of reflux episodes which migrated proximally, median (IQR) 1 (0-2) compared to 0 (0-2) episodes, respectively, P = 0.75.

CONCLUSION

In young children with CF, GOR is primarily acidic and proximal migration is common. Physiotherapy in the head-down position does not appear to exacerbate GOR. The impact of GOR on lung disease remains to be elucidated.

Early glucose abnormalities in cystic fibrosis are preceded by poor weight gain

OBJECTIVE

Progressive beta-cell loss causes catabolism in cystic fibrosis. Existing diagnostic criteria for diabetes were based on microvascular complications rather than on cystic fibrosis-specific outcomes. We aimed to relate glycemic status in cystic fibrosis to weight and lung function changes.

RESEARCH DESIGN AND METHODS

We determined peak blood glucose (BG(max)) during oral glucose tolerance tests (OGTTs) with samples every 30 min for 33 consecutive children (aged 10.2-18 years). Twenty-five also agreed to undergo continuous glucose monitoring (CGM) (Medtronic). Outcome measures were change in weight standard deviation score (wtSDS), percent forced expiratory volume in 1 s (%FEV1), and percent forced vital capacity (%FVC) in the year preceding the OGTT.

RESULTS

Declining wtSDS and %FVC were associated with higher BG(max) (both P = 0.02) and with CGM time >7.8 mmol/l (P = 0.006 and P = 0.02, respectively) but not with BG(120 min). A decline in %FEV1 was related to CGM time >7.8 mmol/l (P = 0.02). Using receiver operating characteristic (ROC) analysis to determine optimal glycemic cutoffs, CGM time above 7.8 mmol/l > or =4.5% detected declining wtSDS with 89% sensitivity and 86% specificity (area under the ROC curve 0.89, P = 0.003). BG(max) > or =8.2 mmol/l gave 87% sensitivity and 70% specificity (0.76, P = 0.02). BG(120 min) did not detect declining wtSDS (0.59, P = 0.41). After exclusion of two patients with BG(120 min) > or =11.1 mmol/l, the decline in wtSDS was worse if BG(max) was > or =8.2 mmol/l (-0.3 +/- 0.4 vs. 0.0 +/- 0.4 for BG(max) <8.2 mmol/l, P = 0.04) or if CGM time above 7.8 mmol/l was > or =4.5% (-0.3 +/- 0.4 vs. 0.1 +/- 0.2 for time <4.5%, P = 0.01).

CONCLUSIONS

BG(max) > or =8.2 mmol/l on an OGTT and CGM time above 7.8 mmol/l > or =4.5% are associated with declining wtSDS and lung function in the preceding 12 months.

Risk factors for an intensive care unit admission in children with asthma

An admission to an intensive care unit (ICU) with asthma is a marker of asthma severity and may be a precursor of asthma death. The aim of this study was to investigate risk factors for acute severe asthma needing an ICU admission. We hypothesized that children admitted to the ICU represent a severe phenotype with identifiable premorbid clinical features. The study was case-control in design. One hundred and forty-one children were studied. Seventy children admitted to the ICU and 71 children admitted to the general medical ward served as cases and controls, respectively. Children were aged between 1-16 years. They underwent skin prick allergy testing, and had a nasopharyngeal aspirate and serology performed to screen for respiratory pathogens. Their parents completed an asthma and allergy symptom questionnaire and the Newcastle Asthma Knowledge Questionnaire (NAKQ). On univariate analysis, an admission to the ICU was more likely in children with 1) "frequent episodic" or "persistent" background asthma; 2) three or more previous admissions for asthma; 3) one or more asthma admissions in the previous 12 months; 4) three or more presentations to the Emergency Department (ED) in the preceding 12 months; 5) three or more positive responses on skin prick allergy testing; 6) an elevated IgE level; 7) oxygen saturation on presentation < or =91%; 8) longer duration of asthma; 9) lower level of maternal education; 10) an admission during autumn; 11) three or more siblings; and 12) being prescribed antibiotics. Risk factors that remained significant on multivariate analysis were three or more presentations to the ED in the preceding 12 months (P=0.003), an elevated IgE level (P=0.01), oxygen saturation on presentation < or =91% (P=0.003), and longer asthma duration (P=0.02). ICU patients took longer to see a doctor and to commence oral steroids. No differences were found between cases and controls in the proportion taking preventer therapy (58% vs. 52%), provided with a written asthma action plan (32% vs. 25%), or in whom spirometry or peak flow was measured (28% vs. 42%). However, rates were low in both groups. Parental asthma knowledge was generally poor. This study identified risk factors for an ICU admission in children with asthma. A potentially preventable risk factor is a history of multiple ED presentations in the past year. Specialist referral of children with multiple ED presentations may improve asthma control and reduce the risk of an ICU admission. Background asthma management remains suboptimal in children needing hospitalization.