Natural autoantibodies (NAAbs) are an important constituent of circulating immunoglobins. Some demonstrate polyspecific reactivity and high idiotypic connectivity. For example, they are reactive with DNA and cytoskeleton protein; others exhibit restricted binding specificity. Among several hypotheses, we have explored the possibility that NAAbs constitute a physiologic system in the organism that participates in the elimination of dead tissues and cellular debris by opsonization and phagocytosis.