[Antecedent Infections in Guillain-Barré Syndrome: Knowledge in Clinical Practice]

Guillain-Barré syndrome (GBS) is a post-infectious disease in which a diversity of pathogenetic factors and clinical features is surely determined by the type of preceding infections. It is necessary in clinical practice and research to identify the antecedent infectious agent in each case. Several lines of evidence indicate that the ganglioside-like epitopes on the infectious agents induce the production of anti-ganglioside autoantibodies and thereby cause GBS. This makes it possible to evaluate the causal significance of the pathogen by examining the cross-reactivity of the detected autoantibodies with outer antigens of the pathogens, although such an investigation is practical only when the pathogen is successfully isolated from the patients. The term "antecedent infection" should be strictly used in the situation in which the infection is thought to be closely related to the development of GBS but not for the situation without findings that suggest such a relationship. Simple but non-validated criteria for the judgment of antecedent infection in each GBS case are proposed in this review in order to prevent numerous and unreliable suspicions of "new" and "unknown" prior infectious agents of GBS, which are only built on the precedence in the disease.