Clinical Features and Outcomes in a Case Series of Pediatric Patients with Pneumocystis Pneumonia

Background

Pneumocystis jirovecii pneumonia (PJP) is a frequent infectious complication in immunocompromised pediatric patients in the absence of trimethoprim/sulfamethoxazole prophylaxis. The aim of this case series was to describe the clinical, radiologic features as well as outcomes of pediatric patients with PJP.

Methods

Cases diagnosed as PJP with a positive real-time PCR for P. jirovecii DNA in bronchoalveolar lavage (BAL) between January 2023 and November 2024 in a third level hospital (Instituto Nacional de Pediatría) in Mexico City were included in this study. Clinical and radiological information was obtained from electronic records.

Results

Sixteen patients were identified with a median age of 12.9 years. The most frequent underlying disease was Acute Lymphoblastic Leukemia (ALL) (31.3%), followed by solid tumors (ST) and inborn immune errors (IIE) (18.8% each). Steroid therapy was present before diagnosis in 68.8%, and 62.5% were lymphopenic (<1000 cells/mm3) with a median duration of 11 days. None of the patients in the case-series had received trimethoprim/sulfamethoxazole prophylaxis before diagnosis.

For the clinical presentation patients presented 4.5 days (1 - 14) after symptoms started. The most frequent signs at admission were respiratory distress (68.8%) and hypoxemia (56.3%). Half of patients had fever, cough and dyspnea. 50% developed a severe disease and 56.3% required mechanical ventilation. 93.8% patients had a chest X-ray at diagnosis and 37.5% had a chest CT scan. Radiographic features included bilateral interstitial (43.8%) and alveolar infiltrates (31.3%). Tomographic findings were ground glass opacities (37.5%) and bronchoalveolar infiltrates. In 37.5% of cases rhinovirus/enterovirus was also detected in the respiratory PCR filmarray panel. Treatment was started with trimethoprim/sulfamethoxazole in 87.5% with a median duration of 21 days. Because of severe disease 56.3% required steroid therapy and 68.8% were admitted to the intensive care unit. Thirty-day mortality occurred in 18.8%.

Conclusions

This study shows the importance of considering PJP in immunocompromised pediatric patients and respiratory diseases. With the introduction of molecular techniques for diagnosis of fungal infections we can improve detection and treatment for our immunocompromised population. This data opens the path for more comparative studies to highlight the importance of pneumocystis prophylaxis for high risk patients not only for high-risk leukemia but also for those with prolonged steroid therapy and lymphopenia.