[Concordance of PD-L1 expression detected by two immunohistochemical platforms and antibodies]

Objective: To evaluate the concordance of PD-L1 expression in various tissues using antibodies 28-8 and SP263 on their respective detection platforms. Methods: Three hundred seventy four specimens of surgical resection of pulmonary diseases in the First Affiliated Hospital of Nanjing Medical University from January 1, 2012 to January 31, 2017 were collected. Totally 374 cases were tested for PD-L1 expression using the two antibodies, 28-8 and SP263, by respective detection platforms (Dako and Ventana). Finally, 336 cases were used for further evaluation, and the results were statistically analyzed for concordance. Results: For non-small cell lung carcinoma (NSCLC), the positive rate of PD-L1 was 57.5% (177/308) using SP263, and 57.5% (177/308) using 28-8 antibody. The correlation coefficient was 0.97 (P<0.01). The positive rate of both benign lung diseases and paracancerous tissues was about 10.7% (3/28), and the positive concordance rate was 100.0%. The distribution of both antibodies was also relatively consistent. Conclusions: The expression levels of 28-8 and SP263 antibodies in NSCLC and other tissues are relatively consistent, suggesting both antibodies may be complementary and substitute for each other, which may be useful in guiding clinical management.