No Longer a Great Gulf Fixed? Introduction to an AJRCCM Special Section on Respiratory Disease across the Developmental Spectrum

Traditionally, for both pediatric and adult patients, pulmonologists have plied their trades in separate silos, with an occasional uneasy meeting over the adolescent in transition. Fortunately, silos are being abandoned and the gulf crossed, and this issue of the Journal recognizes how much we all need to work together. It is impossible to do justice to all the contributions in this issue, and apologies if yours has been missed out, but here goes for some of the many highlights.

Early Detection of Disease: It All Begins in Childhood or Even Earlier!

Early detection offers the chance of intervention, especially when the disease is active, not burned out, a distinction very familiar to rheumatologists (1). Chronic obstructive pulmonary disease (COPD) is a case in point. Adults who received an early diagnosis and care for COPD or asthma fared better than control subjects did, especially if they had a greater burden of disease at presentation (pp. 2053–2059). However, both diseases begin in childhood and have their origins in early deprivation (2)! Surely, that is where early diagnosis and intervention need to be focused? A research letter reports that oscillometry-defined increased airway resistance was often abnormal in smokers with normal spirometry and predicted a more rapid decline in lung function (pp. 2142–2145). This technique is easily applicable to young children and perhaps would define those who have normal spirometry but are at risk for poor lung growth. Failure to attain normal spirometry is a well-known risk factor for COPD (3), and recent work has highlighted exercise (4) and reversal of obesity (5) as allowing catch-up growth in lung function. Detection in childhood may well be worthwhile!

Common Toxicities across the Developmental Spectrum

New hazards do not suddenly appear at 18 years of age. Smoking, vaping, and substance abuse are increasingly common among high school students and even younger children, in part because of the aggressive tactics of suppliers who target especially vulnerable and young children (6). Pediatric addiction services have lagged behind adults, and we all need to study carefully the official American Thoracic Society statement on tobacco and cannabis co-use (pp. 2021–2042). This is far from being solely an adult issue; hopefully, the next iteration will recognize this to a greater extent. Low socioeconomic status, of which addiction is but one manifestation, is an important determinant of lung function. Non-White races are disproportionally affected, and the effects start well before adulthood (pp. 2117–2126).

Pollution affects people of all ages, including the unborn child. What a pity that vaccines and Tylenol use during pregnancy are in the firing line on the most dubious of grounds, whereas pollution continues to be below the political radar, despite the known adverse effects on fetuses and their subsequent lung function (7). Two papers highlight the effect of wildfires on atmospheric pollution (pp. 2060–2071 and pp. 2086–2095). There is also a research letter on the dust effects of a drying saline lake (pp. 2133–2136). None make comfortable reading. It is important to state that something can be done if pollution is tackled (8): This section includes the results of a natural experiment when a coal coking plant was closed (pp. 2072–2085), which led to an immediate reduction in pediatric emergency department visits for asthma and a longer term reduction in COPD admissions. Pollution deniers in high places, please take note.

Modern diagnostic imaging has transformed the care of children, but does it come with a price? Yes, a very small but increased risk of hematological malignancies, as reported in a recent study (9). The risk is exaggerated, according to our Viewpoint article (pp. 1999–2000). Cancer is the main focus, but what about fibrosis? Physicians for adult patients may need to be sensitive to a possible increased risk of idiopathic pulmonary fibrosis, for example, in adults who had multiple imaging studies. In the meantime, pediatricians should only be imaging children to answer an important question that cannot be answered by other means. Serial computed tomography scans for the sake of it, as has been practice in some cystic fibrosis centers, may carry an unexpected cost, especially given that patients with cystic fibrosis have an increased risk of epithelial cancers (10).

Coming Soon to a Chest Clinic Near You: New Diseases

There was a time when preterm babies could not be ventilated and either died or got better. With the advent of neonatal intensive care, even babies that weigh around 300 g now survive, creating a new generation of respiratory and multimorbidity in adult life. Zanetto and colleagues apply the treatable trait approach (11) to these survivors across the life course (pp. 1996–1998). They rightly stress that holistic care has been in short supply and propose a new framework that should be very familiar to adult chest physicians treating the multimorbidity of COPD. Long-term tracheostomy ventilation is increasingly used in children who will live to adult life. The official American Thoracic Society statement on their care will be increasingly relevant to adult physicians and, it is hoped, this too will be addressed in future iterations (pp. 2001–2020).

Old Diseases, New Insights

Primary ciliary dyskinesia (PCD) should be diagnosed in childhood but is often not identified until adult life. Seek and you shall find; a recent study showed that undiagnosed PCD was not uncommon if guideline-recommended tests (nasal nitric oxide, transmission electron microscopy, and high-speed video microscopy) were performed in adult bronchiectasis clinics (12). The genetic landscape of PCD has been extended by the finding of the importance of noncoding variants, mainly affecting splicing (pp. 2043–2052), which should increase detection of this important condition.

Pulmonary hypertension is a feared complication of sickle cell anemia, and in adults older than 18 years of age, a pulmonary vascular resistance of >1.5 Wood units predicts mortality if the mean pulmonary arterial pressure is higher than 20 mm Hg (pp. 2096–2104). This study in adult patients should encourage pediatricians to look for early warnings in younger children with sickle cell anemia, when treatment could be more effective.

Snoring children are often a figure of fun (e.g., the morbidly obese Joe in Charles Dickens’s novel The Pickwick Papers), but there is really nothing funny about the neurocognitive effects of pediatric sleep-disordered breathing. An important magnetic resonance imaging study has related reduced upper airway volume (a surrogate for obstructive sleep apnea) to worse adolescent neurocognition and brain size and gray matter changes (pp. 2105–2116). How will this affect the adult care in adulthood of these young people?

As reported in an article in this special section, a young girl was very sick, yet no diagnosis was made (pp. 2127–2129). She recovered spontaneously and was on no medical treatment. At age 30, she was referred for lung transplantation, and a diagnosis of a surfactant protein C mutation was made. In treating interstitial lung disease in adults, physicians should always remember genetics, which, as pediatricians are finding, often lead to specific diagnoses and, sometimes, specific treatments (13). Surfactant protein C mutations can present at any age, from severe respiratory distress in neonatal patients to usual interstitial pneumonia in late adult life (14); hopefully, better understanding of pathophysiology will lead to specific treatments for this and other surfactant protein–related diseases (15).

And to Wrap Up

We hope that this issue will stretch your minds and stimulate the evacuation of silos. Ask yourself: Is my study relevant to people outside my age silo, and should it be widened? Above all, we want more excellent submissions from across the whole developmental spectrum.