Increased proinflammatory cytokines in sera of patients with multifocal motor neuropathy

Abstract

Background: Multifocal motor neuropathy (MMN) is characterized by clinical improvement with intravenous immunoglobulin and the frequent detection of anti-ganglioside antibodies. However, the immunological background of the neuronal damage in MMN is still unclear.

Objective: The aim of this study is to investigate abnormalities in the cytokine and chemokine profiles of MMN patients.

Methods: Sera from 16 patients with MMN, 16 patients with sporadic amyotrophic lateral sclerosis (ALS), and 15 patients with other non-inflammatory neurological diseases (ONDs) were analyzed for 27 cytokines and chemokines using a multiplex bead array. We also checked whether the altered cytokine/chemokine profile in the MMN group differed significantly in the presence or absence of abnormal electrophysiological findings.

Results: Serum IL-1Ra, IL-2, G-CSF, TNF-α, and TNFR1 levels were significantly higher in the MMN group than in the ONDs group. Of these, G-CSF and TNF-α also showed significant increases compared to the ALS group. Serum G-CSF and TNF-α levels were significantly higher in MMN patients presenting with focal demyelination including conduction block than in patients without any focal demyelination.

Conclusions: Proinflammatory cytokines may contribute to peripheral nerve demyelination in MMN.

Keywords: Amyotrophic lateral sclerosis; Demyelination; Granulocyte colony-stimulating factor; Multifocal motor neuropathy; Tumor necrosis factor α.