Which laboratory finding is typically elevated in patients with Giant Cell Arteritis?

In patients with Giant Cell Arteritis (GCA), a very high erythrocyte sedimentation rate (ESR) is a typical laboratory finding. GCA is a type of vasculitis that primarily affects the large and medium-sized blood vessels, particularly those supplying the head and neck. The inflammatory process associated with GCA leads to an increased production of acute phase reactants, including fibrinogen and immunoglobulins, which contribute to the high ESR.

The ESR is a non-specific marker of inflammation; therefore, while it may not be diagnostic on its own, a very high level indicates significant inflammation, which is consistent with the pathology of GCA. In clinical practice, an elevated ESR is often used alongside clinical findings to help support the diagnosis of GCA.

The other options do not exhibit the same typical association with GCA. While abnormalities in the white blood cell (WBC) count may be seen, they are not as consistently elevated as the ESR in GCA. A low platelet count is not characteristic of GCA; in fact, thrombocytosis (high platelet count) can occur due to inflammation. Increased glucose levels are unrelated to the diagnosis of GCA and would not typically be elevated as a marker of the