Recurrent acute myocardial and renal infarction with aplastic anaemia/paroxysmal nocturnal haemoglobinuria syndrome: a case report.

Background: Aplastic anaemia (AA) is known to progress to paroxysmal nocturnal haemoglobinuria (PNH) during treatment, and thrombosis is a characteristic symptom of PNH. This case report investigates a case of repeated and rapidly progressive multiple arterial thrombosis due to PNH. Case Summary: This case is a 24-year-old woman undergoing treatment for AA. She presented with chest pain and underwent emergency coronary angiography. Thrombus occlusion was found in the distal portion of the right coronary artery, acute myocardial infarction was diagnosed and percutaneous coronary intervention was performed. Thrombus aspiration and balloon dilation were performed. Anticoagulants were administered, but chest pain flared up again on Day 9; coronary angiography was performed, indicating that the proximal portion of the right coronary artery had caused occlusion. On Days 9 and 24, she experienced back pain and was diagnosed with renal infarction. Considering that AA had evolved into PNH and intravascular haemolysis and thrombosis appeared, the diagnosis of PNH was made via flow cytometry. Multiple arterial thrombosis due to PNH was diagnosed, and ravulizumab treatment was started, resulting in the improvement of thrombus progression, chest pain, and back pain. Discussion: Thrombosis due to PNH can recur even after the administration of anticoagulants and antiplatelet agents and has been associated with a high fatality rate. The treatment with ravulizumab, a humanized monoclonal antibody against complement C5, helps with the prevention of thrombosis. Furthermore, anti-complement component C5 therapy is very effective in improving rapidly progressive multiple arterial thrombosis resistant to anticoagulants and antiplatelet agents due to PNH.