Genetic Decoding Pulmonary Alveolar Proteinosis in Children: A Case Report

Background: Nonspecific symptoms and variable clinical course are the hurdles in diagnosing pulmonary alveolar proteinosis (PAP), a rare lung disease. We report a pediatric case of hereditary PAP caused by mutations in the gene encoding granulocyte Macrophage colony-stimulating factor (GMCSF) receptor. Case Presentation: A 3 years 10-month-old female child, born to 3rd-degree consanguineous parents presented with fever, intermittent cough, and breathing difficulty ten days before hospitalization. Chest X-ray revealed bilateral diffuse alveolar infiltrates; Computed tomography (CT) showed diffuse interstitial thickening along with a crazy pavement pattern. Bronchoscopy and broncho-alveolar lavage (BAL) was performed. PAP was confirmed with BAL and genetic testing. Serum GM-CSF autoantibody test was normal but serum GM-CSF concentration was high (115.7 pg/mL). There was a continuous heterozygous deletion encompassing exon region 13 of the SLC34A2 gene, suggestive of pulmonary alveolar microlithiasis. : The patient received steroids (x2 weeks), inhalers (bronchodilators & steroids), and intermittent home oxygen therapy (x2 weeks) with a good response. Discussion: Discussion: Due to nonspecific symptomatology, and variation in disease severity, diagnosis of PAP is delayed or missed. Crazy paving on CT, milky fluid on BAL with similar histological features of foamy macrophages, and PAS-positive amorphous material within the alveolus are diagnostic clues. : Asymptomatic patients or those with mild symptoms are managed with supportive care, monitoring, and chest imaging; moderate to severe symptoms require whole lung lavage (WLL); GMCSF Replacement therapy, an alternative to WLL Immunomodulation therapy is also considered. Conclusion: PAP can be managed conservatively with supportive therapy with good clinical outcomes and not all patients require WLL. However, patient selection is crucial.