Outcomes of patients with severe combined immunodeficiency treated with hematopoietic stem cell transplantation with and without preconditioning.
BACKGROUND
The effect of pretransplantation conditioning on the long-term outcomes of patients receiving hematopoietic stem cell transplantation for severe combined immunodeficiency (SCID) has not been completely determined.


OBJECTIVE
We sought to assess the outcomes of 23 mostly conditioned patients with SCID and compare their outcomes with those of 25 previously reported nonconditioned patients with SCID who underwent transplantation.


METHODS
In the present study we reviewed the medical records of these 23 consecutive, mostly conditioned patients with SCID who underwent transplantation between 1998 and 2007.


RESULTS
Eighteen patients (median age at transplantation, 10 months; range, 0.8-108 months) received haploidentical mismatched related donor, matched unrelated donor, or mismatched unrelated donor transplants, 17 of whom received pretransplantation conditioning (with 1 not conditioned); 13 (72%) patients engrafted with donor cells and survive at a median of 3.8 years (range, 1.8-9.8 year); 5 (38%) of 13 patients require intravenous immunoglobulin; and 6 of 6 age-eligible children attend school. Of 5 recipients (median age at transplantation, 7 months; range, 2-23 months) of matched related donor transplants, all 5 engrafted and survive at a median of 7.5 years (range, 1.5-9.5 year), 1 recipient requires intravenous immunoglobulin, and 3 of 3 age-eligible children attend school. Gene mutations were known in 16 cases: mutation in the common gamma chain of the IL-2 receptor (IL2RG) in 7 patients, mutation in the alpha chain of the IL-7 receptor (IL7RA) in 4 patients, mutation in the recombinase-activating gene (RAG1) in 2 patients, adenosine deaminase deficiency (ADA) in 2 patients, and adenylate kinase 2 (AK2) in 1 patient. Early outcomes and quality of life of the previous nonconditioned versus the present conditioned cohorts were not statistically different, but longer-term follow-up is necessary for confirmation.


CONCLUSIONS
Hematopoietic stem cell transplantation in patients with SCID results in engraftment, long-term survival, and a good quality of life for the majority of patients with or without pretransplantation conditioning.
Patel
Niraj C
NC
Department of Pediatrics, Section of Allergy and Immunology, Baylor College of Medicine, Texas Children's Hospital, Houston, Tex 77039, USA.
Chinen
Javier
J
Rosenblatt
Howard M
HM
Hanson
I Celine
IC
Krance
Robert A
RA
Paul
Mary E
ME
Abramson
Stuart L
SL
Noroski
Lenora M
LM
Davis
Carla M
CM
Seeborg
Filiz O
FO
Foster
Samuel B
SB
Leung
Kathryn S
KS
Brown
Betty S
BS
Ritz
Jerome
J
Shearer
William T
WT
D002648:Child; D002675:Child, Preschool; D005260:Female; D006086:Graft vs Host Disease / Q000276:immunology; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D008297:Male; D011788:Quality of Life; D016511:Severe Combined Immunodeficiency / Q000601:surgery*; D019172:Transplantation Conditioning; D016896:Treatment Outcome
D007070:Immunoglobulin A; D007074:Immunoglobulin G