Background Giant cell arteritis (GCA) or Temporal Arteritis is the most common systemic vasculitis in adults. Usually, the diagnosis is based on the American College of Rheumatology (ACR) classification criteria published in 1990, and on the temporal artery biopsy. But according to the literature, the biopsy can be negative in up to 68% of patients with GCA. Today, the validity of Doppler Ultrasound has been shown in at least three metaanalysis.
Objectives Assess the value of Doppler Ultrasonography for the diagnosis of GCA, compared with ACR criteria and biopsy, using the definitive clinical diagnosis of the patient as gold standard.
Methods Two hundred seventy-six patients with clinical suspicion of GCA were evaluated. All of them underwent Doppler Ultrasonography of temporal arteries. Only 92 patients underwent biopsy, and the gold standard was the final diagnosis at least three months after the clinical trial and initiation of treatment. The topographic involvement (number of branches affected by ultrasound) of 267 patients was recorded.
Results Of the 276 patients studied, 189 were women and 87 men (68.5% vs 31.5%), with a mean age of 75.81 ± 9.02. Forty-eight percent had definite diagnosis of GCA while 55.79% met the ACR criteria and 45.28% had ultrasound signs compatible with GCA. Of the 92 biopsies, 24 (26%) were positive. The validity (sensitivity and specificity) and Security (positive predictive value [PPV], negative predictive value [NPV], Likelihood Ratio [LR] + and LR -) of diagnostic tests used were as follows:
According to topographic involvement, 17 patients had a single branch affected with 23.5% false positives. There were only 2% of false positives in the 100 patients with involvement of two or more branches. The only false positive in four branches affected group was a skull base osteomyelitis. ESR showed a variation between patients with ACG and those with othe rdiagnoses not significant (64.05 ± 58.15 vs 29.8 ± 32.3, p = 0.12), while the PCR variation was significant between patients with and without GCA (59.51 ± 63.4 vs. 31.6 ± 53.7, p = 0.016).
Conclusions Doppler Ultrasonography shows great validity and safety as a diagnostic test of GCA, and its use in clinical practice and in the diagnostic criteria of the disease should be valued.
Disclosure of Interest None Declared