Background Chronic tachypnoe of infancy (CTI) is an infrequently diagnosed entity in infants and young children with only limited information on its clinical, biochemical and histological features. Objectives & Methods The kids-lung-register data base was searched for cases categorized as CTI from 2000-2013. 74 children (31 with lung biopsies) were retrieved and characterized clinically. Histological diagnosis for NEHI (neuroendocrine cell hyperplasia of infancy) was done using bombesin, synaptophysin, chromogranin and CD56 staining. As controls for histologic analysis age-matched biopsies of 9 children with tumour-free, healthy lung tissue were used.Concentrations of surfactant protein (SP)-B and SP-C in bronchoalveolar lavage (BAL), and bombesin in urine were measured. As controls we used for measurements in urine 13 age-matched healthy children, and for BAL analysis 69 infants assessed for chronic bronchitis. Results This prospective cohort study identified 56 cases with CTI, 13 cases with NEHI based on histological analysis and 5 cases with pulmonary interstitial glycogenosis. Clinically, all patients presented with chronic tachypnoe since early infancy and show characteristic ground-glass opacities in high resolution CT with typical distribution. A differential diagnosis using bombesin levels in urine (CTI vs NEHI/CTI vs controls) was not possible. Concentrations of SP-B/-C in BAL compared to age-matched control group allowed exclusion of hydrophobic surfactant protein deficiency as possible causes of the tachypnoe. Conclusion Lung biopsy can differentiate and diagnose precisely, however the benefit for the individual patient is limited. Investigation of additional non-invasive markers is warranted.
Rauch et al. (Mon,) studied this question.