Endocrine Abstracts

Background: Serum C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are useful indicators of inflammation in patients with sub-acute thyroiditis. Despite the widespread use of several diagnostic tests, the purpose of this study was to compare the usefulness serum CRP and ESR in deciding which patient requires of glucocorticoid therapy.

Methods: A total of 28 patients with sub-acute thyroiditis, included in this study. Serum CRP and ESR measured in all the patients. The characteristics of these tests were assessed with use of two different techniques: first, receiver-operating-characteristic curve analysis was performed to determine the optimal positivity criterion for the diagnostic test, and, second, previously accepted criteria for establishing positivity of the tests were used.

Results: Fifteen out of 28 patients were found to have features of significant thyroid inflammation eventually requiring glucocorticoid based on current recommendations. The receiver-operating-characteristic curves indicated that the optimal positivity criterion was 19.3 mg/l for the C-reactive protein level and 46 mm at 1st h for the erythrocyte sedimentation rate. C-reactive protein level with sensitivity of 0.67, specificity of 0.92, positive likelihood ratio of 8.67, and accuracy of 0.64 appeared better than erythrocyte sedimentation rate which showed sensitivity of 0.93, specificity of 0.53, positive likelihood ratio of 2.02, and accuracy of 0.60.

Conclusions: Serum CRP level provided clear advantage over ESR as a diagnostic test with respect to the assessment of inflammation prior to initiation of glucocorticoid therapy in sub-acute thyroiditis. However a well powered study is needed to examine the clinical relevance of such a role for CRP in thyroidology.