A novel automated IHC staining system for quality control application in ALK immunohistochemistry testing

The establishment of positive and negative controls in immunohistochemistry (IHC) screening for anaplastic lymphoma kinase (ALK) rearrangements is essential in the treatment of lung adenocarcinoma. However, positive control of patient tissue is rare and comes with ethical issues. A novel automated solution for ALK IHC quality control management was investigated by comparison with the established D5F3 antibody on the VENTANA system in 87 lung adenocarcinoma specimens with known ALK status re-analyzed by fluorescence in situ hybridization. The BP6165 concentrated antibody on the LYNX480 PLUS platform demonstrated excellent sensitivity and specificity (98.30% and 100%, respectively) in 87 biopsy specimens. The ALK controls in liquid form (CLFs) applied in an automated way showed a more regular circular shape and better cell distribution than those applied manually. In addition, the novel controls can show changes in the same pattern as tissue controls under different antibody concentrations and antigen retrieval conditions. The automated solution for ALK IHC quality control management provides a convenient solution without the consumption of scarce tissue for IHC testing in day-to-day pathology practice. The availability of standardized protocols for the detection of ALK rearrangements using the BP6165 concentrated antibody on the LYNX480 PLUS platform will expand the number of laboratories that can reliably and consistently determine the eligibility of patients with lung adenocarcinoma for treatment with ALK tyrosine kinase inhibitors.