title: Stability of symmetric idiotypic networks--a critique of Hoffmann's analysis.
abstract: Hoffmann (1982) analysed a very simple model of suppressive idiotypic immune networks and showed that idiotypic interactions are stabilizing. He concluded that immune networks provide a counterexample to the general analysis of large dynamic systems (Gardner and Ashby, 1970; May, 1972). The latter is often verbalized as: an increase in size and/or connectivity decreases the system stability. We here analyse this apparent contradiction by extending the Hoffmann model (with a decay term), and comparing it to an ecological model that was used as a paradigm in the general analysis. Our analysis confirms that the neighbourhood stability of such idiotypic networks increases with connectivity and/or size. However, the contradiction is one of interpretation, and is not due to exceptional properties of immune networks. The contradiction is caused by the awkward normalization used in the general analysis.
authors.forename: R J
authors.initials: RJ
authors.lastname: De Boer
authors.forename: P
authors.initials: P
authors.lastname: Hogeweg
mesh_terms: D000818:Animals; D007108:Immune Tolerance; D007130:Immunoglobulin Idiotypes; D008954:Models, Biological; D008962:Models, Theoretical
chemical_list: D007130:Immunoglobulin Idiotypes