Optimization of intravenous immunoglobulin in chronic inflammatory demyelinating polyneuropathy evaluated by grip strength measurement.

Background: Optimal dose and timing of repeated intravenous immunoglobulin therapy (IVIg) for intractable chronic inflammatory demyelinating polyneuropathy (CIDP) patients have not been determined. The aim of this study was to optimize dose and timing of IVIg for CIDP patients who need frequent IVIg using daily grip strength measurement.

Methods: Repeated IVIg were administered for two intractable CIDP patients. Grip strength was recorded at home every day to access the clinical change in symptoms, and dose and timing of IVIg were optimized based on the results.

Results: The decrement on grip strength was a sensitive indicator of symptom exacerbation. 100 g of IVIg had a limited effect for each patient. In one patient, symptoms maintained after monthly 60 g of IVIg. In another, 100 g of IVIg every 7 weeks resulted in a marked improvement. After receiving 20 g of IVIg weekly, each patient showed further improvement.

Conclusion: Optimal dose and timing possibly vary in each individual patient. Dose titration of IVIg is necessary to avoid over- and undertreatment. The daily self-monitoring of grip strength is a helpful tool for clinical assessment in CIDP.