Case Report: A pediatric case of chronic active Epstein-Barr virus infection complicated by pulmonary arterial hypertension.

Objective: To enhance clinicians' awareness of pulmonary arterial hypertension (PAH) complicating chronic active Epstein-Barr virus infection (CAEBV) in pediatric patients. Method: Clinical data of a pediatric patient diagnosed with CAEBV complicated by PAH, admitted to Shanghai Children's Medical Centre affiliated with Shanghai Jiao Tong University School of Medicine, were analyzed. Results: The patient, a 11-year-old girl, was admitted with "dyspnea on exertion accompanied by left lower abdominal pain for 1 month." The primary clinical manifestations constituted progressive decline in exercise tolerance and abdominal pain. Physical examination revealed hepatosplenomegaly and scattered eczematous rashes on the left lower limb. Cardiac ultrasound demonstrated moderate tricuspid regurgitation with a velocity of 3.56 m/s and estimated pulmonary artery pressure of 50 mm Hg. The outpatient department considered PAH and referred her to cardiology. Right heart catheterization upon admission revealed pulmonary artery pressure of 81/56/67 mm Hg, synchronous aortic pressure of 121/76/92 mm Hg, and pulmonary vascular resistance index (PVRI) of 24 Wood, confirming PAH. During comprehensive screening for PAH etiology, markedly abnormal EBV antibody levels were identified, and levels of EBV-DNA in the peripheral were significantly increased, raising the suspicion of chronic active Epstein-Barr virus infection (CAEBV). Subsequent skin biopsy of the left-lower-limb lesion demonstrated EBER positivity, confirming diagnosis of CAEBV with PAH. Allogeneic hematopoietic stem-cell transplantation was recommended after diagnosis but declined by the family. Eight months later, EBV had disseminated to multiple systemic organs. Cerebrospinal fluid tested positive for EBV nucleic acid; bone marrow biopsy showed partial EBER positivity; hepatosplenomegaly was present; and concomitant conditions included abdominal wall varicosities, multiple serosal effusions, hypoxemia, and PAH. Upon readmission, the patient's baseline condition deteriorated to the point where allogeneic hematopoietic stem-cell transplantation was no longer feasible. Conservative chemotherapy was initiated; however, the patient succumbed to septic shock complicated by gastrointestinal hemorrhage one month into treatment. Conclusion: The etiology of PAH is complex and diverse, with CAEBV representing a rare causative factor. Comprehensive EBV-related pathogen testing should be performed in children with PAH, particularly those presenting with hepatosplenomegaly. Routine imaging investigations, including cardiac echocardiography, are essential in the assessment and management of CAEBV patients to promptly identify potential cardiovascular complications.