Identification of PTX3 and S100A9 As Serum Diagnostic and Therapeutic Response Biomarkers of NK/T Cell Lymphoma Patients

NK/T cell lymphoma (NKTCL) patients are frequently misdiagnosed as chronic nasosinusitis, which delays therapy and leads to poor prognosis. Our study aims to explore serum biomarkers to differentiate NKTCL patients from healthy individuals. Pretreatment and posttreatment serum samples from 16 newly-diagnosed NKTCL patients were collected. Serum samples from 16 matched healthy individuals were also collected. Comparative proteomic approach were utilized to identify the differentially expressed proteins. Enzyme-linked immunosorbent assay (ELISA) was performed to validate the candidate biomarkers. Receiver operating characteristic curve (ROC) analysis was employed to examine their sensitivity and specificity. Compared with healthy controls,109 upregulated and 82 downregulated proteins were identified in pretreatment serums of NKTCL patients. Among the differentially expressed proteins, PTX3 and S100A9 were selected as candidate biomarkers for further validation. ELISA assay showed that NKTCL patients present higher serum levels of PTX3 (p<0.0001) and S100A9 (p<0.0001) than normal controls. Moreover, the diagnostic sensitivity and specificity of PTX3 alone (cutoff point: 0.592ug/L), S100A9 alone (cutoff point: 51.16ng/ml), PTX3 in combination S100A9 were 78.87% and 84.44%, 73.24% and 80.0%, 74.65% and 93.33%, respectively. Furthermore, we found that posttreatment serum levels of PTX3 and S100A9 declined remarkably in treatment-sensitive NKTCL patients (p<0.001), while no significant changes were observed in treatment-resistant patients (p>0.05). In conclusion, serum PTX3 in combination with S100A9 could serve as potential biomarkers for NKTCL diagnosis and treatment response evaluation. Further confirmation of PTX3 and S100A9 in a larger cohort of patients will promote their clinical use.