Characterization of serological markers of healed/healing arteritis and giant cell arteritis

Temporal artery biopsy (TAB) is the gold standard for confirming the diagnosis of giant cell arteritis (GCA) when positive. However, the clinical significance of healed/healing (HH) arterial injury on TAB is not well understood. The purpose of this study was to evaluate the clinical significance of this finding on TAB by determining its association with seromarkers typically predictive of GCA. Single-centre, retrospective, investigational cohort study. A total of 385 consecutive TABs for clinical suspicion of GCA between January 2009 and January 2016. Elevations in erythrocyte sedimentation rate, C-reactive protein, and platelet count were compared between patients with negative TAB, GCA-positive TAB, and HH arterial injury using statistical trend testing. Odds ratios of seromarker elevations for HH arterial injury versus GCA were calculated. Seventy-six GCA-positive, 69 HH, and 240 negative TABs were identified. Mantel-Haenszel tests of trend indicated that platelets >400 000/µL (p < 0.01), erythrocyte sedimentation rate ≥50 mm/hr (p < 0.01), and C-reactive protein ≥24.5 mg/L (p < 0.01) occurred with intermediate frequency in the HH TAB group. The odds of HH TAB were 3.6 times greater (95% CI 1.5–8.5) with platelets >400 000/µL. HH arterial injury is a heterogenous group that requires treatment in the appropriate clinical setting. From our study, we found that the HH group is intermediate between GCA-positive and GCA-negative biopsy with respect to serology markers only. Thrombocytosis is an independent predictor of HH TAB. With further studies, this marker may be considered when making treatment decisions. Further studies are required to better understand this entity. La biopsie de l’artère temporale (BAT) est le test de référence pour confirmer le diagnostic d’artérite à cellules géantes (ACG) lorsqu’elle est positive. Cela dit, on comprend moins bien la signification clinique d’une lésion artérielle cicatrisée/en voie de cicatrisation (C/VC) observée lors de la BAT. La présente étude visait à évaluer la signification clinique de cette observation lors de la BAT en examinant son association avec des marqueurs sériques typiques de l’ACG. Étude de cohorte, expérimentale et rétrospective réalisée dans un seul centre. Un total de 385 BAT consécutives réalisées en raison d’une suspicion clinique d’ACG de janvier 2009 à janvier 2016. On a comparé, au moyen de tests de tendance statistique, l’élévation de la vitesse de sédimentation des érythrocytes, du taux d