Home therapy with subcutaneous immunoglobulins for patients with primary immunodeficiency diseases.

The most frequently encountered patients with primary immunodeficiency disease (PID) are those with antibody deficiencies. These patients require life-long immunoglobulin (IgG) replacement therapy to prevent severe and reoccurring infections. IgG is traditionally administered intravenously (IVIG) on an outpatient basis, although in some Scandinavian countries subcutaneous administration of IgG (SCIG) as home self-infusion has become the predominant mode of delivery. Compared with IVIG, SCIG therapy leads to a more physiologic IgG profile since the large variations between peak and trough levels of serum IgG are blunted by slow absorption and maintenance of closer equilibrium between intra- and extravascular compartments. SCIG therapy has been shown to be as effective as IVIG in preventing infections and has a better safety profile, with fewer systemic side effects. While local tissue reactions are common with SCIG, they are usually mild, tend to improve over time and typically do not interfere with therapy. Switching to SCIG therapy from IVIG can lead to significant improvements in health-related quality of life, appears to be more convenient for the patient, and can make it easier for the patient to travel. In those patients with difficult vascular access and intolerable side-effects with IVIG therapy, SCIG therapy may be the only treatment option. Selected patients can be expected to benefit greatly from SCIG therapy, although implementation of a successful home-treatment program requires proper education, training, and supportive care.