Which biomarker is typically elevated in suspected giant cell arteritis?

Which biomarker is typically elevated in suspected giant cell arteritis?

• A. ESR
• B. Platelet count
• C. Hemoglobin
• D. Sodium

Answer: (A)

Giant cell arteritis triggers systemic inflammation, so the erythrocyte sedimentation rate rises as part of the acute-phase response. When inflammation causes increased acute-phase proteins like fibrinogen, red blood cells tend to stack together (rouleaux), which makes them settle more quickly in a tube. That faster sedimentation translates into an elevated ESR. This marker is commonly elevated in suspected GCA and helps with screening, though it’s not specific to this condition. Other options don’t fit as well. Platelet counts can rise with inflammation but aren’t a reliable diagnostic biomarker for GCA. Hemoglobin may be reduced in chronic disease, but that’s not a characteristic or sensitive indicator of GCA. Sodium levels aren’t a typical feature of this vasculitis.

Giant cell arteritis triggers systemic inflammation, so the erythrocyte sedimentation rate rises as part of the acute-phase response. When inflammation causes increased acute-phase proteins like fibrinogen, red blood cells tend to stack together (rouleaux), which makes them settle more quickly in a tube. That faster sedimentation translates into an elevated ESR. This marker is commonly elevated in suspected GCA and helps with screening, though it’s not specific to this condition.

Other options don’t fit as well. Platelet counts can rise with inflammation but aren’t a reliable diagnostic biomarker for GCA. Hemoglobin may be reduced in chronic disease, but that’s not a characteristic or sensitive indicator of GCA. Sodium levels aren’t a typical feature of this vasculitis.