Treatment of patients with primary antibody deficiencies in Germany

Background: Primary antibody deficiencies are the most common forms of primary immunodeficiencies (PID). Recurrent bacterial infections and the risk of progressive structural tissue damage are the most serious complications of these diseases. Substitution therapy with polyvalent immunoglobulins (Ig) has been established as the standard therapy in PID for several decades now. Methods: During summer 2002 German PID treaters were interviewed in a survey in order to assess the present status of immunoglobulin therapy in German patients with antibody deficiencies. A disease questionnaire was used during standardized interviews. Information was sought on tile treating physician and center, the kind of immunodeficiency and its complications. Furthermore, details on the Ig therapy, routine diagnostic procedures and concomitant medication were asked. Results: 13 pediatricians and 5 specialists for internal medicine who treated a total of about 230 patients with CVID/XLA participated in the interviews. Most of the patients received Ig substitution therapy, most frequently as intravenous immunoglobulin (IVIG) infusions in a hospital outpatient setting. Approximately 14% of the substituted patients received subcutaneous immunoglobulin (SCIG), mostly as self-infusions at home. At the time of the interviews SCIG had not yet been licensed in Germany. The mean monthly dose was 0.4 g per kg bodyweight, both in IVIG and SCIG treatment and most centers aimed at trough IgG levels of 5 to 6 g/l. Conclusions: The majority of centers followed current guidelines concerning monthly immunoglobulin doses and desired IgG trough levels, but often aimed at the lower end of these recommendations.