PW03-034 – How to classify autoinflammatory diseases?

Results We propose a clinically-oriented definition: “autoinflammatory diseases are diseases with clinical signs of inflammation, associated with elevated acute phase reactants and due to a dysfunction in the innate immune system, genetically determined or triggered by an endogenous factor”. It is hard to find natural properties able to underlie a useful classification of autoinflammatory diseases, and inflammatory diseases as a whole, into disjoint and exhaustive categories. The notion of continuum is therefore appealing. However, a single continuum from purely autoinflammatory to purely autoimmune diseases oversimplifies, and even distorts, reality. How to locate, for instance, the disease caused by a deletion in PLCG2 (the gene encoding phospholipase Cg2) that associates autoinflammatory symptoms to both common variable immunodeficiency and autoimmune features? Here we have an overactivation of both the innate and the adaptive immune system, associated with a deficiency of the adaptive immune system. More than one dimension is needed to properly represent the immunological dysfunctions underlying inflammatory diseases. Furthermore, a classification of inflammatory diseases should also make sense of the clinical, pathological and biological phenotypes.