Methods: Immunoglobulin supplementation and mesurement of trough/steady-state serum IgG level
Results: We report the effectiveness of subcutaneous IgG supplementation in a female patient with myotonic dystrophy and low IgG plasma levels (2.79 g/L) likely due to high IgG catabolism. Over the course of her illness, the patient experienced recurrent infections. Initial treatment with intravenous immunoglobulin (IVIG) resulted in a variety of unfavourable side effects, likely due to high requirements (0.75 g/kg/month) to achieve adequate IgG serum level. The patient was subsequently switched to subcutaneous IgG (SCIG). Adequate IgG serum level was achieved with a dose of 100 mg/kg/week without side effect. Since the start of IgG supplementation, no infections were reported.
Conclusions: Subcutaneous once-weekly IgG administration appears to be more effective than once-monthly IVIG regimen in a patient with high IgG catabolism.