2417: Influence of Histological Tempol Artery Biopsy Findings on Outcomes of Biopsy-proven Giant Cell Arteritis in Italian Patients : A Long Single Center Follow-up Study

LUIGI BOIARDI¹, PIERLUIGI MACCHIONI², Francesco Muratore³, Elena Galli⁴, chiara marvisi⁴, caterina Ricordi⁴, federica Macaluso¹, alberto cavazza⁴, Stefania Croci⁴ and Carlo Salvarani⁵, ¹IRCCS REGGIO EMILIA, Reggio Emilia, Italy, ²Azienda USL -IRCCS di Reggio Emilia, Reggio Emilia, Italy, ³IRCCS di Reggio Emilia, Reggio Emilia, Italy, ⁴Azienda Unità Sanitaria Locale-IRCCS Di Reggio Emilia, Reggio Emilia, Italy, ⁵Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy

Background/Purpose: Few studies have evaluted the influence of histological features of temporal artery biopsy (TAB) on disease outcome in giant cell arteritis (GCA) patients. Our aim was to investigate potential associations between TAB histological characterstics and outcomes of GCA in a long term single center retrospective follow-up study.

Methods: Two hundred and four Italian patients with biopsy-proven GCA resident in Reggio Emilia area (Italy) followed up for at least 12 months entered the study (median duration of FU 130 months(range 13-435 months). The following histological findings of TAB were recorded : localisation of inflammatory infiltrate (peri-adventitial and vasa vasorum small vessel vascultis (SVV+VVV), inflammation limited to adventitia (ILA), trans mural inflammation TMI), presence of giant cells (GC), presence of infiltrating neutrophils, plasma cells, histiocytes, eosinophils, presence of laminar necrosis (LN), vessel wall calcifications, luminal trombosis (LT) and intimal hyperplasia (IH). The severity of inflammation (SI) was graded on a semiquantitative scale (mild, moderate and severe), the severity of i IH (was graded as mild < 25% reduction in lumen diameter, moderate from 25% to 75%, and severe >75%).

The following data were recorded during follow up : presence of relapses, long term remission (LTR), cumulative steroid dose at 6, 12 months and at end of FU, duration of treatment and of LTR and mortality. Survival curve were compared with K-M method using log rank test.

Results: Relapses were recorded by 42.5% of the patients during a median FU period of 130 months (13-435). Factors which influenced the time of first relapse were : presence of GC (140 vs 207 months, p=0.025), presence of LT (91 vs 171 months, p=0.036) and histological subtype (80 vs 156 vs 249 months for SVV+VVV, ILA and TMI respectively, p=0.017). Fifty-seven % of patients were able to withdraw steroids for at least 12 month. Histological subtypes influenced the duration of treatment (SVV+VVV 2.7 months, ILA 17.9 months, TMI 32.0 months, p=0.019). Seventy % of patients died during the follow up period. Factors with impact on survival time were : SI severe vs mild infiltrate (107 months vs 155 months, p=0.006), presence of GC (112 vs 154 months, p=0.049), presence of LN (96 months vs 132 months, p=0.029), histological subtypes (TMI 115 months vs ILA 161 months vs SVV+VVV 195 months, p= 0.017).

Conclusion: Histological findings of TAB influenced survival time, first relapse time and duration of steroid treatment in GCA pts.


L. BOIARDI: None; P. MACCHIONI: None; F. Muratore: None; E. Galli: None; c. marvisi: None; c. Ricordi: None; f. Macaluso: None; a. cavazza: None; S. Croci: None; C. Salvarani: CSL Vifor, 1, 2, 6, Eli Lilly, 1, 2, 6.