Nicolo Pipitone1, Francesco Muratore2, Ione Tamagnini3, Alberto Cavazza3, Luca Cimino4, Luigi Boiardi5, Giovanna Restuccia5, Stefania Croci6, Martina Bonacini6, Carlo Salvarani2. 1. Rheumatology Unit, Department of Internal Medicine, Azienda Unità Sanitaria Locale-IRCCS, Reggio Emilia, Italy. pipitone.nicolo@ausl.re.it. 2. Rheumatology Unit, Department of Internal Medicine; University of Modena and Reggio Emilia, Azienda Unità Sanitaria Locale-IRCCS, Reggio Emilia, Italy. 3. Pathology Unit, Department of Oncology, Azienda Unità Sanitaria Locale-IRCCS, Reggio Emilia, Italy. 4. Ophthalmology Unit, Department of Surgery, Azienda Unità Sanitaria Locale-IRCCS, Reggio Emilia, Italy. 5. Rheumatology Unit, Department of Internal Medicine, Azienda Unità Sanitaria Locale-IRCCS, Reggio Emilia, Italy. 6. Clinical Immunology, Allergy and Advanced Biotechnologies, Department of Laboratory Medicine, Azienda Unità Sanitaria Locale-IRCCS, Reggio Emilia, Italy.
Abstract
OBJECTIVES: To evaluate whether interleukin-6 expression in the temporal arteries could be a more sensitive marker of active inflammation compared to the presence of an inflammatory infiltrate. METHODS: Sixty-three formalin-fixed, paraffin-embedded temporal artery biopsies performed between 2009 and 2012 from 32 patients with biopsy-proven giant cell arteritis, 8 patients with a negative biopsy but with a final diagnosis of giant cell arteritis, and 23 controls (patients with an initial clinical suspicion of giant cell arteritis in whom an alternative diagnosis subsequently was made) were examined. Biopsy specimens showing a transmural inflammatory infiltrate were considered positive for giant cell arteritis. Immunochemistry was performed to detect interleukin-6 in the temporal artery specimens. Slides of temporal artery biopsies were independently assessed by five readers. Interleukin-6 expression was graded as 0 (absent), 1 (mild), 2 (moderate) and 3 (marked). We considered anti-IL-6 staining positive if staining was of grade 2 or 3. RESULTS: Temporal artery biopsies specimens from patients with biopsy-proven giant cell arteritis, biopsy-negative giant cell arteritis and controls were positive for anti-interleukin-6 staining in 59%, 13% and 48% of cases, respectively. CONCLUSIONS: Interleukin-6 expression does not increase the sensitivity of temporal artery biopsy in patients with giant cell arteritis who have morphologically uninflamed arteries.
OBJECTIVES: To evaluate whether interleukin-6 expression in the temporal arteries could be a more sensitive marker of active inflammation compared to the presence of an inflammatory infiltrate. METHODS: Sixty-three formalin-fixed, paraffin-embedded temporal artery biopsies performed between 2009 and 2012 from 32 patients with biopsy-proven giant cell arteritis, 8 patients with a negative biopsy but with a final diagnosis of giant cell arteritis, and 23 controls (patients with an initial clinical suspicion of giant cell arteritis in whom an alternative diagnosis subsequently was made) were examined. Biopsy specimens showing a transmural inflammatory infiltrate were considered positive for giant cell arteritis. Immunochemistry was performed to detect interleukin-6 in the temporal artery specimens. Slides of temporal artery biopsies were independently assessed by five readers. Interleukin-6 expression was graded as 0 (absent), 1 (mild), 2 (moderate) and 3 (marked). We considered anti-IL-6 staining positive if staining was of grade 2 or 3. RESULTS: Temporal artery biopsies specimens from patients with biopsy-proven giant cell arteritis, biopsy-negative giant cell arteritis and controls were positive for anti-interleukin-6 staining in 59%, 13% and 48% of cases, respectively. CONCLUSIONS:Interleukin-6 expression does not increase the sensitivity of temporal artery biopsy in patients with giant cell arteritis who have morphologically uninflamed arteries.