Introduction: HSCT is a therapeutic option for IEI. The aim is to describe the clinical outcomes and immune reconstitution of allogeneic HSCT in children with IEI, performed from 2001 to 2022.
Method: Descriptive study. Review of clinical records of 16 patients (p) who received 17 HSCT. All patients assisted in CIC Bezrodnik and four in joint follow-up at the Hospital de Niños Ricardo Gutierrez, until 31st May 2023.
Results: A total of 16p including 13 boys and 4 girls underwent HSCT. One patient received two HSCT. The mean age at transplant was 9,74years (0,83-17,66), 41% before 2yo. Underlying diagnosis was Combined Immunodeficiency, HyperIgM syndrome, Phagocytes defect, Immune-dysregulation, Bone Marrow Failure, Autoinflammatory Syndrome, and Very Early-Onset Inflammatory Bowel Disease. 16p(94%) had fully HLA-matched donors (15MUD, 1MRD), while one had a Mismatch unrelated donor. The mean follow-up time since HSCT was 3,75y (0,08-12,8). The total of p received myeloablative conditioning. Pre-HSCT clinical condition includes infections: bacterial 13(76%), fungal 6(35%), viral 5(29%), opportunistic 7(41%), parasites 1(5%), autoimmunity 9(52%), hyperinflammation 4 (23%), failure to drive 4(23%), chronic diarrhea 2(11%), lymphoproliferation 2(11%), no malignancy. First 3-months post-transplant complications were viral infections 12(70%), acute-GvHD 7(41%), haemolytic anemia 1(5%), Veno-occlusive disease 1(5%), 3p(17%) without any complication. Regarding immune-reconstitution, 8p(47%) achieved a complete immune reconstitution and 5p29% partial reconstitution after 2y post-HSCT, 2p(11%) lost graft, 2p(11%) not evaluable. A 50%(7/14) achieved CD4+Tcells values ​​greater than 250c/mm3 between 3-6months post-HSCT. The mean %Naïve CD4Tcell after 1y post-HSCT was 35%, however, patients with CMV reactivation values were 20%. Humoral reconstitution: 66%(8/12) could stop immunoglobulin replacement after 2y post HSCT (mean IgG levels: 929mg/dl). Overall survival (OS) was 93% (15/16).
Conclusions: Excellent OS and sufficient results of immune reconstitution were observed, despite the broad age range and the different IEI.