Efficacy of Methylprednisolone Pulses in Neuroendocrine Celles Hyperplasia of Infancy : An Early Phase Study

Childhood interstitial lung diseases (chILD) are a heterogeneous group of rare and severe disorders with an estimated prevalence of 1/100,000. Among them, neuroendocrine cells hyperplasia of infancy (NEHI), also called persistent tachypnoea of infancy (PTI), is one of the most common aetiology (up to 16% of the cases). NEHI involves young infants (median age at onset 3 to 6 months) with tachypnoea, hypoxemia, crackles, retractions, failure to thrive and specific localizations of ground glass opacities (GGO) on chest CT-scan (paramediastinal areas and anterior lobes (right middle lobe and lingula). At diagnosis, most patients (50 to 100%) require oxygen supplementation that usually lasts for months to years, sometimes associated with nutritional support with eventual enteral nutrition. NEHI is believed to be related to an increased number of neuroendocrine cells in airway epithelial area. These cells are abundant in foetal life, when they play a role in regulating the lung development and decrease before birth. There is no specific treatment for NEHI. The main treatment of chILD is corticosteroids. However, in NEHI, their efficacy is matter of debate. There is only a few NEHI cases series or cohorts all over the world, accounting for a maximum of 500 reported cases within only retrospective studies. Among them, United States and Argentina teams report supportive care only (oxygen therapy and nutritional support) whereas other teams, like the French ones largely uses IV corticosteroid pulses. Unlike the majority of chILD, NEHI prognosis is usually good. However, at school-age, 26% of the patients remain symptomatic or have an abnormal lung function. Moreover, oxygen therapy significantly affects quality of life (QoL) of the children with ILD (-10.43/100 points, p=0.02) but also QoL and mood of their parents (unpublished data). The present study hypothesis that corticosteroids are associated with a reduction of the length of oxygen support in infants with NEHI.