Pulmonary hypertension associated with busulfan

Area of Science:

• Oncology
• Pulmonology
• Pharmacology

Background:

• Busulfan is a key chemotherapeutic agent used in stem cell transplantation for malignant diseases.
• Pulmonary hypertension (PH) and bronchiolitis obliterans are rare but documented side effects of busulfan.
• Limited data exists on subacute pulmonary hypertension following busulfan treatment.

Purpose of the Study:

• To report and analyze cases of subacute pulmonary hypertension after busulfan administration.
• To investigate the clinical presentation, treatment response, and pathological findings in patients developing PH post-busulfan.
• To highlight the association between busulfan and severe pulmonary vascular and interstitial lung disease.

Main Methods:

• Case series analysis of four patients from the French Pulmonary Hypertension Registry.
• Review of clinical data, treatment regimens, and outcomes.
• Pathological examination of explanted lungs for histological evidence of lung injury.

Main Results:

• Four patients developed severe pulmonary arterial hypertension (PAH) 2-4.5 months after busulfan treatment for various malignancies.
• PH improved with standard PAH therapies and/or corticosteroids.
• Two patients progressed to chronic respiratory insufficiency requiring lung transplantation due to interstitial lung disease and bronchiolar lesions.
• Histopathology revealed diffuse pulmonary vascular damage and interstitial lung injury.

Conclusions:

• Pulmonary arterial hypertension is a rare but significant complication of adult busulfan chemotherapy.
• Busulfan-induced lung injury involves both pulmonary vasculature and interstitial lung tissue.
• Prompt recognition and treatment of PAH are crucial, though long-term respiratory sequelae can occur.