Pneumocystis jirovecii in Neuroendocrine Hyperplasia of Infancy: accomplice or bystander?

Abstract

Abstract Background: Neuroendocrine hyperplasia of infancy (NEHI) is a rare childhood disease of the airways. Existing literature regarding the aetiology of NEHI is limited and predominately centred on genetic mutations. However, there does not appear to be a common genetic mutation among all children with NEHI, suggesting that other causative factors likely contribute to disease pathogenesis. While no infectious disease has been attributed to the aetiology of NEHI, infectious agents are certainly known to precipitate or exacerbate other Childhood Interstitial Lung Diseases (ChILDs). Case presentation: We report the presence of Pneumocystis jirovecii in the lungs of five infants with NEHI. Conclusions: The significance of this association is unclear but is suspicious for an immunological or other pulmonary aberrancy among children with NEHI that predisposes to P. jirovecii infection. Alternatively, P jirovecii may be an important co-factor in the pathogenesis of NEHI, or simply be an innocent bystander within the lung. This finding may help to explain the pathogenesis of this poorly understood disease. Future studies comparing the clinical course of children with NEHI infected with P. jirovecii against those without infection may further clarify the pathogenesis of this condition.