OBJECTIVE: Although there is evidence for a pathogenic role of humoral factors in multifocal motor neuropathy (MMN), plasma exchange (PE) is assumed to be an ineffective treatment. We set out to elucidate possible reasons for this apparent contradiction. METHODS: A retrospective analysis of seven patients with MMN, who underwent 4 to 18 sessions of PE. Clinical response, electrophysiological parameter and anti-ganglioside antibody titers were reviewed. RESULTS: Two patients, who had anti-ganglioside antibodies, exhibited transient clinical responses to PE, manifested by improved neurological function. Whereas electrophysiological parameters continued to worsen in all patients, anti-ganglioside antibody titers declined during PE, but increased after PE. CONCLUSION: PE is of limited therapeutic value in patients with MMN, who do not respond to established treatment options. It may only be useful as an adjunctive treatment in a subset of patients. The transient decrease of anti-ganglioside-antibodies titers suggests that pathogenic humoral factors in MMN are only temporarily reduced. Further, PE treatment alone is insufficient to prevent axons from continuing degeneration, which may explain the failure of PE to substantially influence the disease course of patients with MMN.
OBJECTIVE: Although there is evidence for a pathogenic role of humoral factors in multifocal motor neuropathy (MMN), plasma exchange (PE) is assumed to be an ineffective treatment. We set out to elucidate possible reasons for this apparent contradiction. METHODS: A retrospective analysis of seven patients with MMN, who underwent 4 to 18 sessions of PE. Clinical response, electrophysiological parameter and anti-ganglioside antibody titers were reviewed. RESULTS: Two patients, who had anti-ganglioside antibodies, exhibited transient clinical responses to PE, manifested by improved neurological function. Whereas electrophysiological parameters continued to worsen in all patients, anti-ganglioside antibody titers declined during PE, but increased after PE. CONCLUSION: PE is of limited therapeutic value in patients with MMN, who do not respond to established treatment options. It may only be useful as an adjunctive treatment in a subset of patients. The transient decrease of anti-ganglioside-antibodies titers suggests that pathogenic humoral factors in MMN are only temporarily reduced. Further, PE treatment alone is insufficient to prevent axons from continuing degeneration, which may explain the failure of PE to substantially influence the disease course of patients with MMN.
Authors: Lotte Vlam; W-Ludo van der Pol; Elisabeth A Cats; Dirk C Straver; Sanneke Piepers; Hessel Franssen; Leonard H van den Berg Journal: Nat Rev Neurol Date: 2011-11-22 Impact factor: 42.937