Single-Center Analysis of Pegfilgrastim-induced Aortitis Using a Drug Prescription Database and CT Findings

[Aortitis]

Aortitis is a rare disease entity of unknown prevalence. Primary aortitis mainly affects the thoracic aorta. They are most often diagnosed on imaging by grade III 18-FDG uptake of the aortic wall on PET, or by circumferential thickening>2.2mm on CT or MRI with late-stage contrast. More rarely, aortitis is histologically proven, as in some cases of clinically isolated aortitis discovered after planned aortic aneurysm surgery or during aortic dissection surgery. The most common histological types are granulomatous/giant cell or lymphoplasmacytic. Clinical signs associated with aortitis are often non-specific: asthenia, fever, dry cough, chest, back, lumbar or abdominal pain. Aortitis can be divided into different etiological categories: primary aortitis, which includes vasculitis with a preferential or exclusive tropism for the aortic wall, aortitis secondary to systemic or iatrogenic diseases, and infectious aortitis. The main etiologies of primary aortitis are giant cell arteritis (GCA), Takayasu arteritis (TA) or clinically isolated aortitis. Aortitis secondary to systemic diseases is seen in atrophying polychondritis, systemic lupus and inflammatory rheumatic diseases such as spondyloarthropathy and rheumatoid arthritis. In both ACG and AT, aortitis is a negative factor, characterized by a higher risk of relapse, cardiovascular complications and increased mortality. The management of aortitis is insufficiently codified, and relies on the control of cardiovascular risk factors, with particular monitoring of blood pressure and LDL cholesterol, and on corticosteroid therapy and immunosuppressive drugs, the use of which will depend on the disease associated with the aortitis, the initial severity and comorbidities.

Large-vessel vasculitis induced by pegfilgrastim and immune checkpoint inhibitor in a patient with small-cell lung cancer

A 75-year-old woman with stage IVB (cT3N3M1c) extensive disease small-cell lung cancer was treated with carboplatin, etoposide, and atezolizumab. Ten days after pegfilgrastim initiation, during the second chemotherapy cycle, she experienced back pain. Contrast-enhanced computed tomography revealed soft tissue thickening around the descending aorta and brachiocephalic artery. She was diagnosed with atezolizumab and pegfilgrastim-induced large-vessel vasculitis (LVV) and was treated with prednisolone, which was tapered and discontinued after 14 weeks, with no symptom recurrence. LVV should be included in the differential diagnosis of patients with nonspecific body pain when pegfilgrastim and immune checkpoint inhibitors are used in combination.

Comparison of 18 F-FDG PET Findings of Pegfilgrastim-Induced Aortitis With Other Types of Large-Vessel Vasculitis : A Retrospective Observational Study

PURPOSE OF THE REPORT

To elucidate the PET/CT findings of pegfilgrastim-induced aortitis (PFIA) and compare them with those of other large-vessel vasculitis.

METHODS

We enrolled 45 patients diagnosed with the following: PFIA, n = 8; Takayasu arteritis (TA), n = 12; giant cell arteritis (GCA), n = 6; and immunoglobulin G4-related aortitis (IgG4-A), n = 19. Records of PET/CT performed before treatment initiation were collected. The aorta and its branches were divided into 16 anatomic regions. Presence of abnormal 18 F-FDG uptake in each region was determined and measured.

RESULTS

The 18 F-FDG-positive areas of PFIA were distributed in the regions of the ascending aorta to the suprarenal abdominal aorta, cervical branches of the aorta, and external iliac arteries, similar to those of TA. However, TA had a higher proportion of 18 F-FDG-positive areas than PFIA in almost all anatomic regions. These areas of GCA were widespread throughout the entire aorta and the upper and lower limbs, whereas those of IgG4-A were observed from the abdominal aorta to iliac arteries. SUV max , SUV peak , metabolic volume, and total lesion glycolysis were higher in GCA than in PFIA, TA, and IgG4-A.

CONCLUSIONS

Pegfilgrastim-induced aortitis distribution on PET/CT was frequently observed in the aorta, cervical branches, and extra iliac arteries. The low proportion of 18 F-FDG-positive areas in PFIA was different from that of TA, GCA, and IgG4-A. These findings may help identify and differentiate various aortitis types in clinical practice.