[Giant cell arteritis (temporal arteritis). Pathophysiology, immunology]

Spectrum of Aortic Disease in the Giant Cell Arteritis Population

We report the spectrum of aortic involvement in patients with giant cell arteritis (GCA) following review of medical records of 4,006 patients including those with imaging studies. A total of 1,450 patients (36%) had a confirmed diagnosis of GCA. Of these, 974 had aortic imaging. Of the 974 patients with imaging, 435 (45%) had an identified aortopathy. The most common aortopathy was aneurysm/dilation (69%). Overall, an annual aneurysmal growth rate of 1.5 mm/y was calculated. In patients with aneurysm/dilation, aortic dissection occurred in 18 patients (6%), and these patients had a significantly higher aneurysmal growth rate compared with those without dissection (4.5 vs 1.4 mm/y, p = 0.005). The median size of the aorta at the time of dissection was 51 mm, with 7 (39%) occurring with a maximal aortic aneurysm/dilation <50 mm. In conclusion, our findings indicate higher aneurysmal growth rate in GCA compared with that reported for degenerative aortic disease. Moreover, patients who develop dissection had a significantly higher growth rate than those without dissection with over a third of these patients suffering dissection at a caliber <50 mm.

The diagnosis and treatment of giant cell arteritis

BACKGROUND

Giant cell arteritis (GCA) is the most common systemic vasculitis in persons aged 50 and above (incidence, 3.5 per 100,000 per year). It affects cranial arteries, the aorta, and arteries elsewhere in the body, e.g., in the limbs.

METHODS

We selectively review the pertinent literature, including guidelines and recommendations from Germany and abroad.

RESULTS

The typical symptoms of new-onset GCA are bitemporal headaches, jaw claudiacation, scalp tenderness, visual disturbances, systemic symptoms such as fever and weight loss, and polymyalgia. The diagnostic assessment comprises laboratory testing (erythrocyte sedimentation rate, C-reactive protein), imaging studies (duplex sonography, high-resolution magnetic resonance imaging, positron-emission tomography), and temporal artery biopsy. The standard treatment is with corticosteroids (adverse effects: diabetes mellitus, osteoporosis, cataract, arterial hypertension). A meta-analysis of three randomized controlled trials led to a recommendation for treatment with methotrexate to lower the recurrence rate and spare steroids. Patients for whom methotrexate is contraindicated or who cannot tolerate the drug can be treated with azathioprine instead.

CONCLUSION

Giant cell arteritis, if untreated, progresses to involve the aorta and its collateral branches, leading to various complications. Late diagnosis and treatment can have serious consequences, including irreversible loss of visual function.

[Vasculitis: histopathology and differential diagnosis]

A histopathologically confirmed biopsy is the gold standard for the diagnosis of vasculitis. Possible etiologies include primary systemic vasculitis, secondary vasculitis or isolated single organ vasculitis, although on histopathological grounds alone a clear differentiation is frequently not possible. The key criteria of morphological vasculitis work-up include vessel size, type of inflammation (granulomatous, necrotizing and/or leukocytoclastic) as well as the presence or absence of immune complexes and extravascular inflammatory changes. Together with the typical organ involvement and serological data, these criteria constitute the basis of vasculitis classification. Differential diagnostic overlaps and possible discrimination methods are presented. In the same way that the clinical approach of vasculitis patients is an interdisciplinary one, histopathology can only provide a definite diagnosis in combination with clinical and serological data. A conclusive morphological diagnosis depends on the right time of biopsy and the selection of appropriate biopsy material.