Embodiments herein described provide devices for identifying and collecting rare cells or cells which occur at low frequency in the body of a subject, such as, antigen-specific cells or disease-specific cells. More specifically, the devices are useful for trapping immune cells and the devices contain a physiologically-compatible porous polymer scaffold, a plurality of antigens, and an immune cell-recruiting agent, wherein the plurality of antigens and the immune cell recruiting agent attract and trap the immune cell in the device. Also provided are pharmaceutical compositions, kits, and packages containing such devices. Additional embodiments relate to methods for making the devices, compositions, and kits/packages. Further embodiments relate to methods for using the devices, compositions, and/or kits in the diagnosis or therapy of diseases such as autoimmune diseases or cancers.
