Which laboratory finding is significant in Takayasu's arteritis?

In Takayasu's arteritis, raised erythrocyte sedimentation rate (ESR) is a significant laboratory finding. This condition is a large vessel vasculitis that primarily affects the aorta and its main branches, leading to inflammation of the blood vessels. The ESR is a nonspecific marker of inflammation, and its elevation indicates an inflammatory process in the body. In patients with active Takayasu's arteritis, this inflammation can be substantial, resulting in markedly elevated ESR levels, which helps clinicians diagnose and monitor the disease's activity.

In contrast, while low hemoglobin might be seen due to chronic disease or anemia of inflammation, it is not specific to Takayasu's arteritis. A high white blood cell count could occur in various infections or other inflammatory processes but is also nonspecific. Increased creatinine levels may indicate renal involvement but, again, are not a hallmark finding in Takayasu's arteritis itself. Therefore, raised ESR serves as a critical indicator of inflammatory activity specifically linked with this condition.