Generating highly-resolved quantitative profiles of human immune responses remains a significant challenge because clinical samples are often limited in size, and cells of particular interest (e.g., autoreactive T cells) can be rare. This talk will describe an approach for analyzing large populations of single cells for both phenotypic, surface-expressed markers and secreted factors such as cytokines and antigen-specific antibodies. A soft lithographic technique called microengraving is employed to allow concurrent detection of cytokines and antibodies from peripheral blood mononuclear cells. Application of the approach to examine B cells from a recent-onset Type I diabetic subject showed the frequency of proinsulin-reactive B cells to be ~0.5% of the circulating B cells tested. Extensions for detection of multiple analytes simultaneously will be presented.