**14. Conclusion**

Replacement therapy with immunoglobulin either via intravenous or via subcutaneous is in patients with immunodeficiencies are associated with reduced infection frequency and organ damage and increased life expectancy. IVIG has been widely used in US and Europe for many years. Monthly IVIG treatment offered steady-state IgG level throughout the dosing cycle, dedicated viral inactivation steps improved safety concerns, pooled analyses confirmed the efficacy and safety, benefits of therapy and adverse events has been welll established.

Recent advances in the basic science of immunoglobulins and meta-analyses of patient data have provided new approaches in using polyclonal IgG to treat patients with primary immunodeficiencies. The old fashion subcutaneuos IG infusion reintroduced to treat patients with immunodeficiencies. The subcutaneous-IG therapy was reported to be effective, safe and well tolerated in children and adults. In addition, the SCIG home therapy high treatment satisfaction (TS) scores and health-related quality of life (HRQOL) was advantages of SCIG. Subcutaneous infusions are recommended to patients who are small children or reactive to IVIG or have problem with vascular access. Practicing immunologists can use new concepts in tailoring their approach to treat patients with primary immunodeficiencies.
