Conditioning is associated with better thymopoiesis, donor B-lymphocyte chimerism, cessation of immunoglobulin therapy and normal QoL.
Hematopoietic stem cell transplantation (HSCT) cures the T-lymphocyte, B-lymphocyte and Natural Killer (NK) cell differentiation defect in IL2RG/JAK3 SCID. We evaluated long-term clinical features, longitudinal immunoreconstitution, donor chimerism and quality of life (QoL) of IL2RG/JAK3 SCID patients >2 years post-HSCT at our center. Clinical data were collated and patients/families answered PedsQL Generic Core Scale v4.0 questionnaires. We performed longitudinal analyses of CD3+, CD4+ naïve T-lymphocyte, CD19+ and NK cell numbers from pre-transplant until 15 years post-transplant. 31/43 (72%) patients survived. Median age at last follow-up was 10 years (range, 2-25). 21 (68%) had persistent medical issues, mainly on-going immunoglobulin replacement (14, 45%), cutaneous viral warts (7, 24%), short stature (4, 14%), limb lymphoedema (3, 10%) and bronchiectasis (2, 7%). Lung function was available and normal for 6 patients. Longitudinal analysis demonstrated sustained CD3+, CD19+ and NK cell output 15 years post-HSCT. CD4+ naïve lymphocyte numbers were better in conditioned versus unconditioned recipients (p 0.06). B-lymphocyte and myeloid chimerism were highly correlated, (rho 0.98, p < 0.001). Low toxicity MAC recipients have better B-lymphocyte/myeloid chimerism and are free from immunoglobulin replacement therapy. IL2RG/JAK3 SCID survivors free from immunoglobulin replacement have normal QoL.
- Submitted November 1, 2016.
- Accepted February 12, 2017.
- Copyright © 2017 American Society of Hematology