Subcutaneous Immunoglobulin (SCIG) in Responders to Intravenous Therapy with Chronic Immune Thrombocytopenia (ITP)

Introduction. Immune thrombocytopenia (ITP) is characterized by platelet destruction due to the presence of platelet antibodies. This phenomenon is associated with impaired platelet production by bone marrow. Short-course corticosteroids and high-dose intravenous immunoglobulins remain the first-line treatments. Aim of this study was to test if SCIG is equally effective and can be less expensive than hospital-based IVIG in treating chronic-ITP

Methods

Seven-ITP patients aged between 13-52 years were given liquid intravenously immunoglobulin (IVIg) stabilized with proline in a dose of 400 mg/kg per day for 5 consecutive days.The median time since ITP diagnosis was 18 months (range, 16 – 38) Median (range) baseline platelet count 19 (3 – 32) x 109/L.,median of 2 (1 – 3) prior ITP therapies. Furthermore, none of of the subjects was a good candidate for TPO-receptor agonists (romiplostim and eltrombopag) because of age or other comorbidities.6 / 6 had a good response to the first 5 day course of gammaglobulin therapy, (platelet count ≥50 × 10(9) /l and ≥2× baseline). The peak platelet count occurred within 7 days from the beginning of the therapy. Only in one patient the platelet count peak took place after 12 days. During the first year of treatment, only one of seven initial responder patients achieved CR(defined as platelet count ≥ 100 * 10^9/L measured on two occasions > 7 days apart and the absence of bleeding) and was excluded from the study. After a loading dose of 2 g/kg over 2 days of IVIg, home SCIG of 8 gr total weekly dose was started by 87,3% (6/7) to maintain platelet counts in the target range of 50–100x109/L.

Results

5/6 patients reached the target. One patient achieved CR during the maintenance therapy.No untoward reactions necessitating cessation of therapy were encountered during this study. The most common side effect observed was headache.

Conclusion

Application of SCIG was well tolerated, easy to manage, and led to stabilization of the disease course.The therapy facilitates home therapy, as the infusion technique is easy for children, adults and elderly people to learn and there is no need for venous access. SCIG home therapy leads to significantly improved life situations for the patients; the SCIG home therapy regimen in particular reduces the costs of treatment. Overall costs per patient were strongly reduced in SCIG in comparison to IVIg.SCIG may represent an effective new therapeutic option in chronic ITP.