Background: The study aimed to analyze the clinical features and risk factors for poor prognosis of Guillain-Barré syndrome (GBS) spectrum disorders in children positive for anti-tetrahexose monosialoganglioside (GM1) antibody.

Methods: We collected data for children with anti-GM1 antibody-positive GBS spectrum disorders in Affiliated Children's Hospital of Chongqing Medical University between July 2018 and March 2024; 1:1 matching was performed for combined anti-ganglioside or anti-sulfatide antibody. The patients underwent comparative clinical characterization to determine the antibody phenotype-clinical phenotype and to analyze the possible risk factors for the poor prognosis of the disorders.

Results: Thirty-seven pediatric patients were recruited. Anti-GM1 antibody-positive GBS spectrum disorders were preceded by a prodromal event (25 of 37, 67.6%). The first symptom was mainly limb weakness (20 of 37, 54.1%), which could be predominately accompanied by autonomic nerve involvement (21 of 37, 56.8%). Seven features showed statistically significant differences (P < 0.05) between the positive group and the negative one, including cranial nerve involvement, bulbar palsy, low lower limb muscle strength at discharge, axonal type of electrophysiological typing, and clinical typing of acute motor axonal neuropathy. The GBS disability scores at discharge and at one month after discharge were higher than those in the control group. The shorter time to peak (<7.5 days) was identified as an independent risk factor for poor short-term prognosis of the disorders.

Conclusions: Anti-GM1 antibody-positive GBS spectrum disorders have a relatively specific antibody phenotype-clinical phenotype. The shorter time to peak (<7.5 days) is an independent risk factor for poor short-term prognosis of the disorders in children.