Immunohistochemical detection of dipeptidyl peptidase IV (CD 26) in thyroid neoplasia using biotinylated tyramine amplification
Abstract
The aim of the study was to evaluate dipeptidyl peptidase IV (DPP IV/CD 26) in differential diagnostics of thyroid lesions. DPP IV/CD 26 was evaluated in thyroid glands of 309 patients (261 females and 48 males, age range of patients 15-80 years).
DPP IV/CD 26 was assessed in paraffin-embedded thyroid specimens immunohistochemically using commercially available antibody (Serotec) and biotinylated tyramine amplification kit (DAKO). Well-differentiated carcinoma revealed DPP IV/CD 26 positivity in 33 out of 42 cases (79%).
Neither medullary nor insular carcinoma was DPP IV/CD 26 positive (only one case of each tested). DPP IV/CD 26 expression in isolated cells was seen in 18/261 (7%) benign disorders.
The sensitivity of the method was 68%, the specificity was 94%, and the diagnostic accuracy was 91%, respectively, using 5% threshold of positive follicular cells. DPP IV/CD 26 can be assessed immunohistochemically using biotinylated tyramine amplification kit.