B63-08 PJP and Air Leak Syndrome in an Infant: A Rare Presentation

Abstract Introduction Pneumothorax and pneumomediastinum are examples of air leak syndromes, where air enters extra-pulmonary spaces due to alveolar and airway rupture. These complications are uncommon in a healthy infant. This study describes a three-month-old male who presented with respiratory distress, found to have pneumomediastinum and tension pneumothorax. Thorough evaluation revealed a diagnosis of X-linked agammaglobulinemia (XLA) with concurrent Pneumocystis jirovecii pneumonia (PJP) as the etiology for his respiratory failure and air leak. Case A three-month-old male born at 37 weeks gestation presented to an emergency department for new onset respiratory distress. He had normal newborn screening and no trauma history. Chest x-ray and confirmatory chest high-resolution CT (HRCT) demonstrated spontaneous pneumomediastinum (Figure 1A/B). Viral and bacterial testing were unremarkable. A sweat test and echocardiogram were normal. A video fluoroscopic swallow study showed trace aspiration and reflux without a clear etiology of his dysphagia. He initially weaned from high flow to low flow nasal cannula as his respiratory status improved with antibiotics and corticosteroids. However, he again developed respiratory distress three weeks later. A repeat HRCT supported worsening air leak (Figure 1C/D). His acute decompensation required endotracheal intubation, needle decompression for tension pneumothorax, and high frequency jet ventilation (HFJV). Genetic testing revealed a pathogenic variant for XLA. After hospital transfer for continued management, he transitioned back to conventional mechanical ventilation. Endotracheal tube sputum was obtained and resulted positive for PJP by PCR. Bactrim was initiated for treatment with rapid clinical improvement. Flexible bronchoscopy with bronchoalveolar lavage was performed to obtain PJP PCR sampling after better clinical stability; this resulted positive. He later extubated and weaned to room air after chest tube removal. The patient discharged home with feeding rehabilitation and monthly IVIG treatments for XLA. Conclusion Here, we describe a rare presentation of PJP in an infant with newly diagnosed immunodeficiency presenting with air leak. P. jiroveci is an opportunistic fungal infection often seen in patients with HIV or in non-HIV patients with immunodeficiency or transplant history. Typical PJP imaging demonstrates ground glass attenuation. Although XLA is a primary humoral immunodeficiency characterized by recurrent bacterial infections, as maternal placental antibodies wean, these patients can develop PJP despite normal T-cell number and function. Pneumomediastinum or pneumothorax are rare complications of severe PJP seen in 2-4% of non-HIV patients, and the etiology remains unclear. Timely diagnosis of PJP is crucial to prevent significant morbidity and mortality. Bactrim remains the gold standard treatment. This abstract is funded by: None