A randomized controlled trial of IV immunoglobulin in patients with postpolio syndrome.

OBJECTIVE: To investigate in a single-center randomized control trial whether a single IVIg course improves short-term outcome in patients with postpolio syndrome (PPS).

METHODS: Fifty-one patients with PPS were randomly allocated to receive 2g/kg IVIg body weight or placebo infused over 5 consecutive days. The primary endpoint was health-related quality of life (HRQoL) limited to the physical component score (PCS) in the Short-Form-36 (SF-36). Secondary endpoints included the SF-36 mental component score (MCS), 6-minute walk test, visual analog scale, 101-numeric rating, and fatigue severity scale. Muscle strength was graded according to the Medical Research Council scale and by dynamometer. Primary and secondary outcome variables were tested double-blind at baseline, 2months, and 4months.

RESULTS: At two months, although SF-36 PCS scores were similar in both arms, the role physical (RP) domain improved significantly in the treatment arm (p=0.05) and so did the composite MCS (p=0.015), and role emotional (RE) subscale (p=0.02). No differences were found in the remaining outcome measures. At 4months, none of the outcome variables differed significantly between groups.

CONCLUSIONS: Although the study did not reach the primary endpoint, we showed that a single IVIg course improves HRQoL related to mental activity, as measured by the SF-36 composite MCS, and role limitations including RP and RE SF-36 subscales at 2months, in patients with PPS. A single IVIg course leaves, gait, muscle strength, fatigue and bodily pain unchanged in patients with PPS.

CLASSIFICATION OF EVIDENCE: Class I evidence indicates that IVIg did not change SF-36 PCS, and Class II evidence indicates that IVIg improved scores on the SF-36 MCS, RP, and RE.