Deregulation of Interleukin-22 Pathway in Giant Cell Arteritis

Stefania Croci¹, Alessandro Zerbini¹, Francesco Muratore², Lucia Belloni³, Francesco Ciccia⁴, Luigi Boiardi², Elena Simonazzi³, Alberto Cavazza⁵, Luca Cimino⁶, Antonio Moramarco⁶, Aroldo Rizzo⁷, Maria Parmeggiani⁸ and Carlo Salvarani^9,10, ¹Clinical Immunology, Allergy and Advanced Biotechnologies Unit,, Arcispedale S Maria Nuova-IRCCS, Reggio Emilia, Italy, ²Rheumatology Service, Arcispedale S Maria Nuova, IRCCS, Reggio Emilia, Italy, ³Clinical Immunology, Allergy and Advanced Biotechnologies Unit, Arcispedale S Maria Nuova-IRCCS, Reggio Emilia, Italy, ⁴Rheumatology Unit, University of Palermo, Palermo, Italy, ⁵Pathology Unit, Arcispedale S Maria Nuova-IRCCS, Reggio Emilia, Italy, ⁶Ophthalmology Unit, Arcispedale S Maria Nuova-IRCCS, Reggio Emilia, Italy, ⁷Pathology Unit, Azienda Ospedaliera Ospedali Riuniti Villa Sofia-Cervello, Palermo, Italy, ⁸. Clinical Immunology, Allergy and Advanced Biotechnologies Unit, Arcispedale S Maria Nuova-IRCCS, Reggio Emilia, Italy, ⁹Rheumatology, Arcispedale S.Maria Nuova, Reggio Emilia, Italy, ¹⁰Rheumatology, Arcispedale S Maria Nuova-IRCCS, Reggio Emilia, Italy

Meeting: 2015 ACR/ARHP Annual Meeting

Date of first publication: September 29, 2015

Keywords: Giant cell arteritis and interleukins (IL)

Session Information

Date: Monday, November 9, 2015

Title: Vasculitis Poster II

Session Type: ACR Poster Session B

Session Time: 9:00AM-11:00AM

Background/Purpose: Interleukin-22 (IL-22) is produced by immune cells but acts only on non-hematopoietic cells, particularly at the barrier interface. We thus hypothesized that IL-22 pathway might be deregulated in giant cell arteritis (GCA), an inflammatory vasculitis affecting large and medium-sized arteries.

Methods: 22 patients subjected to temporal artery biopsy (TAB) at the Arcispedale Santa Maria Nuova-IRCCS (Reggio Emilia, Italy) for a suspicion of GCA were included in the study. They were divided in two groups after histological analysis: GCA patients with TABs showing a transmural immune infiltrate (n=15) and patients with non-inflamed TABs who received a different diagnosis (n=7). Healthy subjects were also included for the analyzes in peripheral blood (n=10). Expression of IL-22 and IL-22 receptor chain 1 (IL-22R1) were determined in TABs by immunohistochemistry. Levels of IL-22 in peripheral blood mononuclear cells (PBMCs) were investigated by real-time PCR and in plasma by ELISA.

Results: IL-22 and IL-22R1 were more expressed in inflamed TABs compared to normal TABs. IL-22 was mainly expressed by granulomas and cells of the media layer. IL-22R1 was mainly expressed by endothelial cells facing the arterial lumen. Expression of IL-22 mRNA was higher in PBMCs from GCA patients compared to healthy subjects. Similarly, GCA patients had an higher concentration of IL-22 in plasma. Levels of IL-22 in plasma positively correlated with IL-22 gene expression in PBMCs and with serum C-reactive protein. Ongoing studies with flow cytometry will allow to determine if Th22 lymphocytes are also deregulated in GCA patients.

Conclusion: Increased production of IL-22 might be involved in GCA pathogenesis.

Disclosure: S. Croci, None; A. Zerbini, None; F. Muratore, None; L. Belloni, None; F. Ciccia, None; L. Boiardi, None; E. Simonazzi, None; A. Cavazza, None; L. Cimino, None; A. Moramarco, None; A. Rizzo, None; M. Parmeggiani, None; C. Salvarani, None.

To cite this abstract in AMA style:

Croci S, Zerbini A, Muratore F, Belloni L, Ciccia F, Boiardi L, Simonazzi E, Cavazza A, Cimino L, Moramarco A, Rizzo A, Parmeggiani M, Salvarani C. Deregulation of Interleukin-22 Pathway in Giant Cell Arteritis [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/deregulation-of-interleukin-22-pathway-in-giant-cell-arteritis/. Accessed .

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