My name is Dr. Alison Clifford.
I'm an Assistant Professor of Rheumatology at
the University of Alberta in Edmonton, Canada.
And today we will review "An Approach to the Diagnosis and
Treatment of Giant Cell Arteristis or GCA".
The objectives for today's lecture are number
one to review the epidemiology and current understanding of disease pathogenesis in GCA.
Number two to discuss the common symptoms and signs that should lead one to
consider this diagnosis as well as the appropriate workup to be undertaken.
And number three to review the approach to
treatment and latest data on disease prognosis.
Beginning first with epidemiology,
Giant cell arteristis is a primary systemic large vessel
vasculitis characterized by granulomatous inflammation at the blood vessel walls.
Classically, it targets the temporal arteries,
thoracic aorta and major branch vessels.
However, it bears keeping in mind that any medium to large vessel may be affected.
By definition, giant cell arteristis is a disease affecting persons over
the age of 50 and it is about three times more common in women than men.
The incidence of disease appears to increase
steadily with increasing age with peak onset in
the eighth decade of life and a mean age at diagnosis of 76.6 years.
The incidence of GCA appears to vary significantly based on geography and ethnicity.
It is most common in patients of Northern European or Scandinavian descent.
Less common in those living in
Mediterranean countries and less common still in patients from Australia and Japan.
Accordingly, incidence rates based on
clinical diagnosis or positive temporal artery biopsy vary from as low
as 3.2 in Australia to 18.8 in Sweden per 100,000 persons greater than the age of 50.
With prevalence rates of 1.5 in Japan
to 204 in Olmsted County Minnesota per 100,000 person.
Although epidemiologic data supports these numbers,
this may in fact, be an underestimate of disease burden.
In one sequential histopathologic review of
temporal arteries taken from consecutive autopsies in Sweden,
the true prevalence of histopathologic temporal arteritis
is appeared to be closer to one percent.