Large Vessel Vasculitis

Takayasu Arteritis

Pathophysiology

• Granulomatous inflammation of the aorta, its major branches, and the pulmonary arteries, leading to fibrosis and luminal stenosis or aneurysm formation. Triggering mechanism remains unknown ₍₁₎

Presentation ₍₂₎

• Typically, women < 40 years old. Early, nonspecific symptoms include headaches, fever, weight loss, myalgias, and arthralgias (systemic phase)
• Later symptoms include hypertension, discriminatory pulses in limbs or carotid arteries, pain with use of limb, and visual defects (obstructive phase)

Diagnosis ₍₃₎

• ESR and CRP: Elevated
• ANCA: Negative
• MRA/CTA (Magnetic resonance angiography/computed tomography angiography): Vascular narrowings and/or occlusions
• Biopsy: Granulomatous inflammation in large-vessel walls (histopathologically indistinguishable from Giant Cell Arteritis)

Treatment _(4,5)

• Remission induction: Glucocorticoids. Recommended initial treatment prednisone/prednisolone 1 mg/kg/day, tapered over a number of months once symptoms controlled
  • Conventional immunosuppression (Methotrexate, azathioprine, leflunomide, and MMF) can be started during initiation of steroids or while tapering
    • If ineffective: Biologic agents (Anti-TNF-α agents, tocilizumab) may be useful
• Revascularization to address critical, symptomatic stenoses, during inactive disease if possible

Giant Cell Arteritis

Pathophysiology

• Granulomatous inflammation of large- and medium-sized vessels, particularly the carotid, vertebral, and temporal arteries. Initial triggering mechanism has not been well-identified. Likely related to multiple factors, including genetics, environment, and age-related changes ₍₆₎

Presentation ₍₇₎

• Typically, women > 50 years old
• Headache, jaw/tongue claudication, loss of vision in one eye, as well as “B” symptoms (fever, myalgia, weight loss, anorexia, fatigue)
• Polymyalgia rheumatica

Diagnosis ₍₈₎

• American College of Rheumatology (ACR) diagnostic criteria: Patient should meet 3 of the following:
  • New, localized headache
  • Tenderness or decreased pulse in the temporal artery
  • ESR ≥ 50 mm/h
  • Temporal artery biopsy showing mononuclear cell infiltrates or a granulomatous process with multinucleate giant cells

Treatment

• Glucocorticoids should be started immediately (prednisolone 1 mg/kg body weight per day (max. 60 mg) has been suggested by EULAR), tapered over several months after control of disease ₍₉₎
• Tocilizumab, abatacept are currently under investigation as steroid-sparing agents ₍₁₀₎

References

1. Espinoza, J. L., Ai, S., & Matsumura, I. (2018, September 6). New insights on the pathogenesis of takayasu arteritis: Revisiting the microbial theory. Pathogens (Basel, Switzerland). Retrieved December 1, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6160975/. 
2. Takayasu’s arteritis. Johns Hopkins Vasculitis Center. (2012, September 18). Retrieved December 1, 2021, from https://www.hopkinsvasculitis.org/types-vasculitis/takayasus-arteritis/. 
3. Genzen, J. R., & Tebo, A. E. (n.d.). Takayasu arteritis. Takayasu Arteritis | Choose the Right Test. Retrieved December 1, 2021, from https://arupconsult.com/content/takayasu-arteritis. 
4. Keser, G., Direskeneli, H., & Aksu, K. (2013, October 4). Management of takayasu arteritis: A systematic review. OUP Academic. Retrieved December 1, 2021, from https://academic.oup.com/rheumatology/article/53/5/793/1797441. 
5. Hellmich, B., Agueda, A., Monti, S., Buttgereit, F., Boysson, H. de, Brouwer, E., Cassie, R., Cid, M. C., Dasgupta, B., Dejaco, C., Hatemi, G., Hollinger, N., Mahr, A., Mollan, S. P., Mukhtyar, C., Ponte, C., Salvarani, C., Sivakumar, R., Tian, X., … Luqmani, R. A. (2020, January 1). 2018 update of the EULAR recommendations for the management of large vessel vasculitis. Annals of the Rheumatic Diseases. Retrieved December 1, 2021, from https://ard.bmj.com/content/79/1/19. 
6. Terrades-Garcia, N., & Cid, M. C. (2018, February 23). Pathogenesis of giant-cell arteritis: How targeted therapies are influencing our understanding of the mechanisms involved. OUP Academic. Retrieved December 3, 2021, from https://academic.oup.com/rheumatology/article/57/suppl_2/ii51/4898136. 
7. Zwicker, J., Atkins, E. J., Lum, C., & Sharma, M. (2011, March 22). An atypical presentation of giant cell arteritis. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne. Retrieved December 3, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060216/. 
8. Hunder GG;Bloch DA;Michel BA;Stevens MB;Arend WP;Calabrese LH;Edworthy SM;Fauci AS;Leavitt RY;Lie JT; (n.d.). The American College of Rheumatology 1990 criteria for the classification of Giant Cell Arteritis. Arthritis and rheumatism. Retrieved December 3, 2021, from https://pubmed.ncbi.nlm.nih.gov/2202311/. 
9. Ness, T., Bley, T. A., Schmidt, W. A., & Lamprecht, P. (2013, May). The diagnosis and treatment of giant cell arteritis. Deutsches Arzteblatt international. Retrieved December 3, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3679627/. 
10. Ponte, C., Rodrigues, A. F., O’Neill, L., & Luqmani, R. A. (2015, June 16). Giant cell arteritis: Current treatment and management. World journal of clinical cases. Retrieved December 3, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4468893/.