DOI: 10.12890/2025_005633
A case of pneumococcal periaortitis: periaortitis is not always autoimmune
Authors
george.hasbany@lau.edu
Keywords
Periaortitis, infections, Karius Spectrum test, PET scanAbstract
Introduction: Periaortitis is a rare inflammatory condition with both infectious and non-infectious aetiologies, often presenting a diagnostic challenge. A comprehensive evaluation—including history, physical examination, imaging, and a broad infectious work-up—is essential, as negative blood cultures do not rule out infection, and premature use of glucocorticoids may be harmful in cases of infectious periaortitis.
Case description: We report the case of a 70-year-old man presenting with flank pain and periaortitis, in whom positron emission tomography/computed tomography (PET/CT) scan revealed moderate-to-severe 18F-fluorodeoxyglucose (FDG) uptake. Despite negative cultures, a Karius test and urine antigen confirmed Streptococcus pneumoniae as the causative agent. The patient underwent successful open surgical repair of a mycotic pararenal abdominal aortic aneurysm, followed by targeted antibiotic therapy.
Discussion: Pneumococcal periaortitis is a rare condition with few reported cases, though S. pneumoniae has been implicated in various vascular infections including mycotic aneurysms, and diagnostic challenges persist, especially when blood cultures are negative. The Karius SpectrumTM, despite its cost and limited guidance for use, and FDG-PET/CT imaging have emerged as helpful tools in identifying infectious aetiologies, with high maximum standardized uptake value values favouring infection over autoimmune causes, as seen in this case.
Conclusion: Infectious periaortitis should be suspected when there is a high uptake of FDG on PET/CT prompting an infectious disease work-up which may include a Karius test.
References
- Stone JR, Bruneval P, Angelini A, Bartoloni G, Basso C, Batoroeva L, et al. Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology: I. Inflammatory diseases. Cardiovasc Pathol 2015;24:267-278. doi: 10.1016/j.carpath.2015.05.001
- Marvisi C, Accorsi Buttini E, Vaglio A. Aortitis and periaortitis: The puzzling spectrum of inflammatory aortic diseases. Presse Med 2020;49:104018. doi: 10.1016/j.lpm.2020.104018
- Ducasse E, Calisti A, Speziale F, Rizzo L, Misuraca M, Fiorani P. Aortoiliac stent graft infection: current problems and management. Ann Vasc Surg 2004;18:521-526. doi: 10.1007/s10016-004-0075-9
- Cartery C, Astudillo L, Deelchand A, Moskovitch G, Sailler L, Bossavy JP, et al. Abdominal infectious aortitis caused by Streptococcus pneumoniae: a case report and literature review. Ann Vasc Surg 2011;25:266.e9 - 16. doi: 10.1016/j.avsg.2010.07.014
- Babady NE. Clinical Metagenomics for Bloodstream Infections: Is the Juice Worth the Squeeze? Clin Infect Dis 2021;72:246-248. doi: 10.1093/cid/ciaa041
- van Der Flier M, Coenjaerts F, Kimpen JL, Hoepelman AM, Geelen SP. Streptococcus pneumoniae induces secretion of vascular endothelial growth factor by human neutrophils. Infect Immun 2000;68:4792-4794. doi: 10.1128/IAI.68.8.4792-4794.2000
- Blockmans D. The use of (18F)fluoro-deoxyglucose positron emission tomography in the assessment of large vessel vasculitis. Clin Exp Rheumatol 2003;21:S15-22.
- Salvarani C, Pipitone N, Versari A, Vaglio A, Serafini D, Bajocchi G, et al. Positron emission tomography (PET): evaluation of chronic periaortitis. Arthritis Rheum 2005;53:298-303. doi: 10.1002/art.21074
- Pijl JP, Nienhuis PH, Kwee TC, Glaudemans AWJM, Slart RHJA, Gormsen LC. Limitations and Pitfalls of FDG-PET/CT in Infection and Inflammation. Semin Nucl Med 2021;51:633-645. doi: 10.1053/j.semnuclmed.2021.06.008
- Yabusaki S, Oyama-Manabe N, Manabe O, Hirata K, Kato F, Miyamoto N, et al. Characteristics of immunoglobulin G4-related aortitis/periaortitis and periarteritis on fluorodeoxyglucose positron emission tomography/computed tomography co-registered with contrast-enhanced computed tomography. EJNMMI Res 2017;7:20. doi: 10.1186/s13550-017-0268-1