Included Study Characteristics.

<p><sup>a</sup> Blood samples were obtained from 103 GBS cases for a previous study, but only 93 were available for the analyses in this study. An additional four cases were recruited between the end of the first study and the analysis for this study.</p><p><sup>b</sup> All participants were diagnosed with GBS; however, for this study they were divided into the AMAN and AIDP forms of GBS.</p><p><sup>c</sup> HLA typing was performed on a subset of randomly selected GBS cases from a larger cohort (n = 80) and compared to a pool of 202 healthy controls rather than the pool of 80 matched healthy controls recruited for the case/control section of the study.</p><p>Included Study Characteristics.</p>