In this preliminary screening of tissues, we propose to characterize B cells in the pancreas of cadavers that are autoantibody positive. Pancreas of non-autoantibody positive cadavers will be studied as controls. We propose to use immunohistochemistry to analyse cell surface marker expression, together with an analysis of the microantomical distribution of B cells and their relationship to other cells. We will attempt to locate specific antibody producing cells. We will be particularly interested in a population of large B cells with dendritic processes that often connect with T cells. These cells, which are normally located in thymus and in T cell zones of organized lymphoid tissues may be antigen presenting B cells.