Giving patients with severe Guillain-Barre syndrome a repeat dose of intravenous immunoglobulin is unlikely to provide a clinical benefit and may do harm, Dutch researchers say.

Their randomised controlled trial in 59 hospitals in the Netherlands between 2010 and 2018 is the first to examine the efficacy and safety of giving a second dose of intravenous immunoglobulin (IVIg).

About one quarter of nonresponders receive a second dose, a practice which appears to be based only on a small uncontrolled case series and results from a phase 2 trial that found higher IVIg doses were more effective than low ones, the researchers say.

The patients in the trial had a poor prognosis after their first IVIg treatment, defined as a score of six or higher on the modified Erasmus Guillain-Barre syndrome Outcome Score, the authors reported in the Lancet Neurology.