Predictive factors of efficacy of rituximab in patients with anti-MAG neuropathy.

OBJECTIVE

To identify factors associated with efficacy of rituximab (RTX) infusions in patients with anti-myelin associated glycoprotein (MAG) neuropathy.

METHODS

33 patients with anti-MAG neuropathy treated with RTX were retrospectively evaluated. All patients underwent neurological, biological, and electrophysiological examinations. Good response was defined as an improvement of at least one point of the Overall Neuropathy Limitation Scale (ONLS) at 6months or at the last follow-up. Disease evolution was defined as sub-acute if the ONLS increased by at least 2 points the year before therapy.

RESULTS

Ten patients (30%) were improved 6months after RTX and 6/20 (30%) at the last follow-up (mean 42months). Response to RTX was significantly associated with subacute evolution and proximal weakness of the lower limbs at the onset of disease. Improvement was not correlated with electrophysiological data and anti-MAG antibodies titers.

DISCUSSION

This study suggests that RTX may be efficacious in a sub-population of patients with anti-MAG neuropathy, particularly in those with proximal weakness of the lower limbs or sub-acute evolution.