I.v. immunoglobulin reduces circulating proinflammatory cytokines in Guillain-Barré syndrome

Abstract

Background: Treatment with human i.v. immunoglobulin (IVIg) modifies the course of Guillain-Barré syndrome (GBS), but its specific mode of action is unknown. Cellular interactions mediated through the release of cytokines play a role in the pathogenesis of GBS and may be regulated by IVIg therapy.

Objective: To delineate possible immunoregulatory mechanisms of IVIg in patients with GBS.

Methods: Circulating levels of the proinflammatory cytokines, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, were assayed in 21 patients with GBS before and serially after IVIg therapy. Comparisons were made with serum concentration of the anti-inflammatory cytokines, soluble TNF-alpha receptor and IL-10. Serial measurements were also performed in 12 untreated patients with relatively mild disease and 7 patients treated by plasma exchange.

Results: Circulating levels of TNF-alpha and IL-1beta decreased after treatment with IVIg but remained relatively high in untreated patients and in those treated by plasma exchange. Clinical improvement in patients treated with IVIg was associated with a reduction in unbound TNF-alpha during the acute phase of the illness. Circulating levels of anti-inflammatory cytokines were not affected by IVIg treatment.

Conclusion: Data presented here suggest a novel mechanism of action of IVIg that involves selective modulation of circulating proinflammatory cytokines.