Successful Therapeutic Response of Intravenous Immunoglobulin in Guillain-Barre Syndrome with Onset More Than Two Weeks: A Case Report

Guillain-Barré Syndrome (GBS), with a global incidence of 1–2 cases per 100,000 population annually, remains the most common cause of acute flaccid paralysis. Standard treatment includes plasma exchange within 4 weeks or intravenous immunoglobulin (IVIg) within 2 weeks of symptom onset. However, IVIg may still benefit selected late-presenting cases. Here, we report a case a 17-year-old male presented with progressive bilateral limb weakness and paresthesia that began approximately 3 weeks before admission. He also experienced a brief syncope episode and defecation syncope, indicating possible autonomic involvement. On hospital day 3, after shared decision-making, the family opted for IVIg over plasma exchange. Laboratory tests on admission and prior to IVIg showed normal albumin and elevated C-reactive protein (CRP), resulting in a low CRP-Albumin Ratio (CAR = 0.12). Although CAR has not been validated in GBS, studies in Kawasaki disease suggest that lower CAR may be associated with a favorable response to IVIg. The patient received IVIg at 0.4 g/kg/day for 5 days, starting on hospital day 4 (approximately day 24 of symptoms). By day 3 of IVIg therapy, the patient showed improved limb strength and reduced paresthesia. The GBS disability score improved from 4 to 2 upon completion of treatment. This case supports the potential benefit of IVIg beyond the conventional 2-week window in GBS, particularly in patients with autonomic symptoms. The use of CRP-Albumin Ratio (CAR) as a potential supportive marker for predicting IVIg responsiveness in GBS warrants further investigation.