Plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy.
BACKGROUND
Chronic inflammatory demyelinating polyradiculoneuropathy is an uncommon progressive or relapsing paralysing disease caused by inflammation of the peripheral nerves. If the hypothesis that it is due to autoimmunity is correct, removal of autoantibodies in the blood by plasma exchange should be beneficial.


OBJECTIVE
To evaluate the efficacy of plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy.


METHODS
We searched the Neuromuscular Disease Group Register (December 2003), and MEDLINE (January 1966 to January 2003), EMBASE (January 1980 to January 2003), CINAHL (January 1982 to December 2002) and LILACS (January 1982 to January 2003). We also scrutinised the bibliographies of the trials, and contacted the trial authors and other disease experts.


METHODS
Randomised or quasi-randomised controlled trials in participants of any age comparing plasma exchange with sham treatment or no treatment. A trial showing no significant difference in the benefit from plasma exchange with intravenous immunoglobulin has been included in a separate Cochrane review.


METHODS
Two authors selected the trials, extracted the data and assessed methodological quality independently. Where possible data were combined according to the methods of the Cochrane Neuromuscular Disease Review Group.


RESULTS



METHODS
one crossover trial including 18 participants showed 2 (95% confidence interval (CI) 0.8 to 3.0) points more improvement after four weeks in an 11-point disability scale with plasma exchange (10 exchanges over four weeks) than with sham exchange. Rapid deterioration after plasma exchange occurred in eight of 12 who had improved.


METHODS
when the results of this trial and another with 29 participants treated in a parallel group design trial were combined, there were 31 points (95% CI 16 to 45) more improvement in an impairment scale after plasma exchange (six exchanges over three weeks) than after sham exchange. There were significant improvements in both trials in an electrophysiological measure, the proximally evoked compound muscle action potential, after three or four weeks. Non-randomised evidence indicates that plasma exchange induces adverse events in 3% to 17% of procedures. These are sometimes serious.


CONCLUSIONS
Evidence from two small trials showed that plasma exchange provides significant short-term benefit in about two-thirds of patients with chronic inflammatory demyelinating polyradiculoneuropathy but rapid deterioration may occur afterwards. Adverse events related to difficulty with venous access, use of citrate and haemodynamic changes are not uncommon. More research is needed to identify agents which will prolong the beneficial action of plasma exchange.
Mehndiratta
M M
MM
Neurology, G.B.Pant Hospital, Professor, Department of Neurology, D-II, Kidwai Nagar-west, New Delhi, India, 110023.
Hughes
R A C
RA
Agarwal
P
P
D006801:Humans; D010951:Plasma Exchange; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic