Efficacy and safety of intravenous immunoglobulin retreatment amongst Guillain-Barré syndrome patients who poorly responded to initial IVIG cycle: a systematic review.

INTRODUCTION: Small cross-sectional studies and case reports observed improvement after administration of second IVIG dose (SID) amongst Guillain-Barré Syndrome (GBS) patients not responsive to initial IVIG cycle. Nevertheless, recent clinical trial and larger observational studies did not find any positive effects of SID. Instead, an increased risk of thromboembolism and mortality was noted. The conclusions of these studies however were not robust as confounding and selection bias were present.

METHODOLOGY: Two neurologists conducted the search process (KBA and MBP) using the following terms in Medline: [(" Guillain-Barré Syndrome"[MeSH Terms] or GBS or Acute Motor Axonal Neuropathy or Acute Motor Axonal Neuropathy or Acute Inflammatory Demyelinating Polyneuropathy) AND (Poorly Responsive or Poor Prognosis or Progressive)] AND [("Intravenous Immunoglobulin"[MeSH Terms] or IVIG or IGIV) AND (second dose or retreatment or SID)].

RESULTS: Only 7 articles were included in this review. In terms of primary outcomes, although the cross-sectional study found improvement in GBS DS score at 4 weeks (Median GBS DS: 3 vs 5, p = 0.033) and the 2 case series observed improvement after SID, no significant differences between the control and intervention groups were found in the cohort [Early SIV OR: 0.7 (95% CI 0.16-3.04), Late SIV OR: 0.66 (CI: 0.18-2.5)] and clinical trial studies (Adjusted OR: 1.4 (95% CI:0.6-3.3, p = 0.45). Moreover, 4 patients who died in the clinical trial were from the intervention group.

CONCLUSION: Based on studies with research designs of higher quality, SID is not effective in the management of GBS patients who poorly responded to initial IVIG. Nevertheless, an adequately powered, randomized, double-blinded, placebo-controlled clinical trial, using GBS-DS of 3 and above after first IVIG dose should be done to effectively establish the efficacy and safety of SID as intervention for this cohort of patients.