Pulmonary arterial hypertension (PAH) is a rare but devastating complication of bone marrow transplantation (BMT). It has been reported after BMT for malignant disease or immune deficiencies.

Over a period of 10 years, all children with PAH after BMT were reviewed for underlying disease, pre-BMT conditioning, associated hepatic veno-occlusive disease, characteristics of PAH, management of PAH and outcome.

14 patients were diagnosed to have PAH after BMT (mean age 8.5 months, mean age at BMT 5.7 months). The underlying disease was an immune deficiency in 11 cases and a malignant disease in 3 cases. Eleven patients received chemoprophylaxis before BMT and conditioning was the same in all cases. Seven patients had a hepatic veno-occlusive disease before the onset of PAH. PAH appeared 40 days after BMT (4–96 days). The presenting symptom was dyspnea in 13 cases and syncope in 1 case. Extensive microbiological investigations were negative in all patients. PAH was diagnosed on echocardiography in all cases and confirmed by right heart catheterization in 7 cases. All patients had normal wedge pressure. Acute vasodilation testing with NO˚ was positive in 4/14. Histology was performed in 1/14 patient and showed arteriolar lesions. Six/14 patients needed mechanical ventilation, 12/14 received specific therapies for PAH. Five patients died. PAH resolved in the remaining 9 patients after a follow-up of 3 months. All the survivors had a favourable haematological issue.

PAH after BMT is a rare complication that occurs mainly in infants less than 2 years of age. It is inconstantly preceded by hepatic veno-occlusive disease. Mortality is high but reversibility is constant in survivors suggesting that an aggressive treatment should be early proposed.