Background: Subcutaneous Immunoglobulin G (SCIgG) has not been widely used in pediatric kidney transplant patients. There are many benefits of SC vs intravenous infusions (IV) including no IV access needed, home infusion, less adverse effects, and less “wear off” effects since there is more frequent dosing.
Objective: Retrospective chart review to assess the efficacy and tolerability of SCIgG in pediatric kidney transplant patients treatmented for antibody mediated rejection (AMR).
Methods: All patients were treated for AMR at the discretion of the treating physician. Each patient was prescribed a 20% SCIgG formulation that was dosed at 0.5g/kg/month divided and given twice a week at home. Patients received training, supplies, and SCIgG from the pharmaceutical company either in their home or in clinic.
Results: Patient 1: 15 y.o. male with posterior urethral valves (PUV) received a living unrelated kidney transplant in 2016.  He developed mixed AMR and acute cellular rejection (ACR) in 2018. He was treated with solumedrol, thymoglobulin, pheresis, rituximab, and IVIgG while inpatient. He then developed BK Viremia and persistent donor specific antibodies (DSA).  He was started on SCIgG in November of 2020. BK viremia resolved and DSA and GFR stabilized. He remains stable on SCIgG.
Patient 2: 17 y.o. male who received a living related kidney transplant in April of 2013 secondary to PUV. He was treated for AMR in November 2015 with solumedrol, rituximab, bortezomib, and IVIgG.  Repeat kidney biopsy showed resolution of the C4d staining, but persistent mild peritubular capillaritis. Unfortunately, his DSA began to increase again, so he was started on SCIgG in March of 2018. He had an estimated schwartz GFR of 34ml/min/1.73m2 at initiation of SCIgG. Treatment stabilized GFR and DSA until August of 2021 when he started dialysis.  
Patient 3: 19 y.o. male with Pierre Robin sequence and PUV who received a deceased donor kidney transplant in October of 2020. In December of 2021 he was  treated for AMR. He received pheresis, bortezomib, rituximab, and thymoglobulin. Because of reoccurrence of DSA he was started SCIgG in June of 2022. DSA resolved.
Conclusion/Discussion: Our patients do not report any infusion reactions and actually report they prefer the home infusion despite increased needle sticks. Insurance approved all treatments. When IgG is administered SC, it diffuses into the SC space, then into the lymphatic system and finally into the blood stream via the thoracic duct. This results in a decreased peak concentration compared with IVIgG, which is likely why there are less adverse events associated with SCIgG.  There is a more reliable steady state concentration since it is given twice a week.  Patients are able to avoid costly admissions, across state travel, and long infusions in outpatient centers with this treatment. Parent-administered twice-weekly SCIgG therapy is a well-tolerated and effective alternative to monthly IVIG therapy for children.