Improvement of severe and intravenous immunoglobulin-dependent multifocal motor neuropathy with conduction block after long-term rituximab

Introduction

Some patients suffering from multifocal motor neuropathy with conduction blocks (MMNCB) are still disabled after treatment with intravenous immunoglobulin (IVIg).

Case report

We report the benefits of a combination of rituximab (RTX) and IVIg in the case of a 72-year-old man with MMNCB.

Discussion

Despite an IVIg treatment, the patient had severe motor weakness of the four limbs which limited daily living activity. Azathioprine, mycophenolate mofetyl and cyclophosphamid did not improve the patient's status. Adjunction of rituximab to IVIg therapy increased muscle strength measured on MRC sum score and reduced disability evaluated on ONLS (Overall Neuropathy Limitation Scale) score in the long term (37 months). In spite of the improvement of his neurological status, the patient remained dependent on IVIg.

Conclusion

RTX could be proposed as a long-term complementary treatment for some severe cases of IVIg-dependent NMMBC. These results must be confirmed in a randomized controlled study.     

Association of antibodies to ganglioside complexes and conduction blocks in axonal Guillain‐Barré syndrome presenting as acute motor conduction block neuropathy

A close relationship between acute motor conduction block neuropathy and antibodies against the complex of GM1 and GalNAc‐GD1a has been reported. This study investigates the hypothesis that conduction block at the early phase of axonal Guillain‐Barré syndrome (GBS) is also associated with such ganglioside complexes. Sera were obtained from seven French patients with initial evidence of isolated conduction blocks that resolved or progressed to acute motor axonal neuropathy. Serum IgG to asialo‐GM1 and gangliosides of LM1, GM1, GM1b, GD1a, GalNAc‐GD1a, GD1b, GT1a, GT1b, and GQ1b as well as their complexes were measured. Five of seven patients progressed within the first month of disease to AMAN. One patient had IgG antibodies against the complex of asialo‐GM1 and each of the other ganglioside antigens. Another patient carried IgG antibodies against GM1 complex with GM1b, GD1a, and GT1a as well as asialo‐GM1 complex with GD1a and GT1a. None had IgG antibodies against GM1/GalNAc‐GD1a complex. Six patients had IgG against single antigens GM1, GD1a, GalNAc‐GD1a, GD1b, and asialo‐GM1. In three patients, a reduced reaction against GM1/GalNAc‐GD1a complex was observed. The presence of conduction block in axonal GBS is not always associated with anti‐GM1/GalNAc‐GD1a complex antibodies.