Sensitivity and specificity of tritiated thymidine incorporation and ELISPOT assays in identifying antigen specific T cell immune responses

摘要

Background Standardization of cell-based immunologic monitoring is becoming increasingly important as methods for measuring cellular immunity become more complex. We assessed the ability of two commonly used cell-based assays, tritiated thymidine incorporation (proliferation) and IFN-gamma ELISPOT, to predict T cell responses to HER-2eu, tetanus toxoid (tt), and cytomegalovirus (CMV) antigens. These antigens were determined to be low (HER-2eu), moderate (tt), and robustly (CMV) immunogenic proteins. Samples from 27 Stage II, III, and IV HER-2eu positive breast cancer patients, vaccinated against the HER-2eu protein and tt, were analyzed by tritiated thymidine incorporation and IFN-gamma ELISPOT for T cell response. Results Linear regression analysis indicates that both stimulation index (SI) (p = 0.011) and IFN-gamma secreting precursor frequency (p Conclusion These data underscore the importance of taking into consideration the performance characteristics of assays used to measure T cell immunity. This consideration is particularly necessary when determining which method to utilize for assessing responses to immunotherapeutic manipulations in cancer patients.