Autoantibodies to chromogranin A are potential diagnostic biomarkers for non-small cell lung cancer

Cancer-associated autoantibodies show promise as sensitive biomarkers for the early detection of cancer. To test the immunogenicity of chromogranin A (ChgA) as a B cell autoantigen and to assess the potential applications of ChgA autoantibodies as novel biomarkers for the diagnosis of non-small cell lung cancer (NSCLC), we developed a high-content peptide microarray using ChgA peptides. Autoantibody profiling was carried out using sera from 168 individuals with NSCLC and 97 healthy controls. We present evidence for the occurrence of autoantibodies to ChgA peptides in patient sera and identified five highly responsive peptides in the NSCLC group using significance analysis of microarray (SAM). Receiver operating characteristic analyses showed that ChgA autoantibodies are valuable in the predictive diagnosis of NSCLC, suggesting that serum autoantibodies to ChgA-derived peptides are promising novel markers of NSCLC. Moreover, the high-content peptide microarray antibody profiling reported in this work provides a powerful tool to visualize the overall B cell response to ChgA peptides and should enable the rapid development of in-depth research into ChgA.