Background/Purpose: GCA is the most frequent systemic vasculitis in Europe and North America. In spite of the initial response to glucocorticoid treatment more than 60% of patients relapse when glucocorticoids are tapered indicating the need for more effective therapies. Search for therapeutic targets in GCA is hampered by the lack of an animal model to assess the consequences of therapeutic intervention. Subcutaneous engraftment of temporal artery fragments into the SCID mice is the only existing functional system (Brack et al, J Clin Invest 1997) to assess the effects of intervention. However it is costly, complex and only a limited number of conditions can be evaluated. We previously described a temporal artery culture model (Arthritis Rheum 2008 (suppl) 58:9; S929-S929), and the effects of the some cytokine blockade on cultured GCA arteries. Our purpose is to explore changes induced by corticosteroids on the expression of inflammatory mediators between control arteries, treatment naïve GCA arteries and GCA arteries treated with dexamethasone
Methods: Fresh temporal artery sections surgically removed for diagnoses purposes from 20 GCA patients and 18 controls were embedded in the reconstituted basement membrane MatrigelTM and cultured for 10 days as described (Arthritis Rheum 2008 (suppl) 58:9; S929-S929). Cultured sections were treated with medium alone or with medium supplemented with 0.5mg/ml of dexamethasone. IFNg, TNFα, IL-1β, IL-6, CD3, CD20 and CD68 mRNA were measured in recovered sections by quantitative real-time PCR (Applied Biosystems). Proinflammatory cytokine secretion was also measured in the supernatant fluid by immunoassay (R&D Systems)
Results: As expected, cultured inflamed arteries produced remarkable amounts of proinflammatory cytokine mRNAs (IFNg, TNFα, IL-1β, and IL-6) compared with control biopsies. Moreover, mRNA expression of CD3, CD20 and CD68 cell markers was significantly increased in biopsies from patients compared with controls. Glucocorticoid treatment of the GCA biopsies for 10 days markedly reduced mRNA expression of all cytokines and cell markers. At the protein level we found a significant decrease in IL-1β, TNFα and IL-6 which was less marked for IFNg. Our model reproduces previous results obtained in other functional systems or in cross-sectional or serial comparison of biopsies obtained from patient naïve versus treated patiens (Visvanathan S, Rheumatology 2011)
Conclusion: Our temporal artery culture system in tridimenional matrix is viable and is a suitable model to evaluate functional changes in biomarker expression and secretion after intervention. This model has several advantages compared with the SCID mice engraftment: it is simpler and cheaper, it allows continuous assessment of viability, the analysis of more conditions per specimen and the assessment of proteins in the supernatant fluid. Unfortunately, as in the SCID mice, disease outcomes cannot be assessed in our model.
Supported by SAF 08/04328 and SAF 11/30073
Disclosure:
M. Corbera Bellalta,
None;
E. Planas Rigol,
None;
E. Lozano,
None;
M. A. Alba,
None;
I. Tavera-Bahillo,
None;
S. Prieto-González,
None;
G. Espígol Frigolé,
None;
M. Butjosa,
None;
J. Hernández-Rodríguez,
None;
A. García-Martínez,
None;
M. C. Cid,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/temporal-artery-biopsy-culture-in-tridimensional-matrix-an-in-vitro-model-for-functional-studies-in-giant-cell-arteritis/