Subcutaneous immunoglobulin therapy for adult patients with primary immunodeficiency disease: Qatar experience

Introduction: Subcutaneous immunoglobulin (SCIG) and intravenous immunoglobulin (IVIG) are used for the treatment of primary immunodeficiency (PIDD). SCIG is as effective as IVIG in preventing infections.(1) However, SCIG has advantages over IVIG as it causes fewer systemic reactions and can be infused at home by the patient leading to improved quality of life.(2) Methods: We retrospectively analyzed adult patients with PIDD who received SCIG in an Adult Allergy Clinic in Qatar. Patients who received IVIG before SCIG and are naïve to IgG replacement were included. We compared Serum IgG levels, the number of antibiotic courses received, and the number of hospital admissions one year before and one year after starting SCIG. SF36 score was used to compare health-related quality of life scores before SCIG and after one year of SCIG. Results: Twenty patients were included in the study, of which 17 were on prior IVIG replacement, and three were naive to replacement. SCIG replacement resulted in the maintenance of serum IgG levels in those who received IVIG prior. SCIG resulted in a statistically significant reduction in the number of antibiotics prescribed and hospitalization in the naïve subgroup but no substantial change in the prior IVIG group. 6/20 patients developed side effects like injection site pain, swelling, and headache. No patients developed significant systemic side effects. 10/20 patients discontinued the SCIG therapy, four patients due to side effects, and others due to noncompliance and financial reasons. SF36 Score was compared for the five patients in IVIG prior group and showed no significant improvement in individual score but improvement in the overall score (p=0.003) Conclusions: In our experience, SCIG therapy effectively prevents recurrent infection in PIDD patients, and patients did not experience any significant systemic side effects. There is a substantial improvement in the quality of life. However, compliance continues to be a problem.