[Subcutaneous gammaglobulin in common variable immunodeficiency. First experience in Spain]

Weekly home-based subcutaneous immunoglobulin (SCIg) therapy is an alternative to intravenous immunoglobulin (IVIg) in the treatment of patients with primary antibody deficiencies. The objective of this study was to investigate the efficacy, safety, related quality of life and cost effectiveness of SCIg in our area.

Observational and descriptive study including paediatric patients with common variable immunodeficiency (CVID) receiving SCIg in our hospital (November 2006 to April 2008). Obtained data were compared with those from the last year with IVIg.

Eleven patients with CVID were included. Median age was 15 years. The median trough serum IgG level was 622 mg/dl with IVIg. In patients in whom the SCIg dose was maintained or reduced compared to IVIg, the median trough serum IgG level was 850 mg/dl (p < 0.0005). Annual rate of infection was 2.22 per patient-year, without significant differences to IVIg (p = 0.212). There were 58 treatment-related adverse events (AE) reported with SCIg (45 local AE and 13 systemic AE). The most frequent treatment-related adverse event was infusion-site reaction. Switching to home-based subcutaneous IgG treatment led to significant improvements in quality of life and substantial cost savings.

We conclude that subcutaneous administration of 16% SCIg is a safe and cost-effective alternative to IVIg for replacement therapy of primary antibody deficiencies. Median trough serum IgG levels were higher with SCIg. Local AE were common but mild and the incidence decreased over time. Quality of life is significantly improved.