Pulmonary interstitial glycogenosis – A systematic analysis of new cases

Background: Pulmonary interstitial glycogenosis (PIG) is a rare paediatric interstitial lung disease of unknown cause. The diagnosis can only be made by lung biopsy. Less than 100 cases have been reported. Clinical features, treatment and outcomes have rarely been assessed systematically in decent cohorts of patients. Methods: In this retrospective multicentre study, the clinical presentation, radiologic findings, pattern of lung biopsy, extrapulmonary comorbidities, treatment and outcome of eleven children with PIG were collected systematically. Results: 10/11 children presented with respiratory distress immediatly after birth and 8/11 needed invasive ventilation. In 8/11 children extrapulmonary comorbidities were present, congenital heart defects being the most common. 7/11 children received systemic glucocorticoids and of these four showed a clear favorable response. During a median follow-up of 3.0 years (range 0.42–12.0) one child died, while 10 patients improved. Chest CT-scans showed ground-glass opacities (7/10), consolidations (6/10), linear opacities (5/10) and mosaic attenuation (4/10) without uniform pattern. Besides interstitial thickening related to undifferentiated glycogen positive mesenchymal cells all tissue samples showed growth abnormalities with reduced alveolarization. Conclusions: PIG is associated with alveolar growth abnormalities and has to be considered in all newborns with unexplained respiratory distress. Apparent treatment benefit of glucocorticosteroids needs to be evaluated systematically.