Pegfilgrastim (Neulasta)-induced acute aortitis: a case report.

Background: Granulocyte colony-stimulating factor (G-CSF) and especially pegfilgrastim for its long-lasting effects are commonly used to lower the chances of neutropenia during chemotherapy. However, extremely rarely, it may result in large-vessel vasculitis such as aortitis which is hard to detect and manage. Case summary: A 59-year-old woman with pancreatic adenocarcinoma on pegfilgrastim developed fever and upper back pain 2 days after administration. Laboratory investigations showed elevated inflammatory markers, but microbiology and autoimmune tests were negative, including tests for tuberculosis, syphilis, and Q fever. Computed tomography (CT) imaging showing periaortic fat stranding and grade II/III FDG uptake in the ascending aorta and arch on the positron emission tomography (PET) scan aided in the diagnosis of acute aortitis. Absence of other possible aetiologies and the close temporal association to pegfilgrastim administration, a diagnosis of G-CSF-induced acute aortitis was made. A multidisciplinary team managed and monitored her conservatively without glucocorticoids, due to her comorbidities. Clinical improvement with normalization of inflammatory markers and repeat PET imaging was seen over several weeks. Discussion: Granulocyte colony-stimulating factor-induced acute aortitis is a new entity emerging, with possible fatal consequences. This case shows the importance of a thorough diagnostic workup, adept interpretation of PET/CT scans with vasculitis imaging standards, and a multidisciplinary individualized management strategy guided by ESC recommendations. Clinicians should maintain a high index of suspicion for aortitis in patients receiving G-CSF, and early use of CT and PET imaging is essential to guide management and prevent complications.