Predictors of successful transplantation for severe combined immunodeficiency

1. Factors that predict survival after stem cell transplant for severe combined immunodeficiency (SCID) include: age less than 3.5 months, no active infection at time of transplant, matched sibling donor. 

2. Factors that have a negative effect on survival after transplant for SCID include: active infection at time of transplant, donors other than a matched sibling.

Evidence Rating Level: 2 (Good)

Study Rundown: SCID refers to a group of conditions in which both components of the body’s adaptive immune system–T cells and B cells–do not function properly. Since the source of these defective immune cells is defective stem cells in the bone marrow, the treatment for SCID is to transplant healthy stem cells into the patient.  

For this study, the authors reviewed over 200 cases of SCID treated over a 10-year period from 2000 to 2009. They looked for factors which were associated with better survival after transplantation. Some factors they identified were: age at transplantation, infection status at transplantation, and source of donor stem cells. 

Children younger than 3.5 months at transplant appeared to do well regardless of the source of the stem cells. Children older than 3.5 months but who had had no previous infections did almost as well. Children with active infections at the time of transplantation did poorly. Donor cells from a matched sibling were the best for survival; umbilical cord blood was the worst. 

Click to read the study, published today in NEJM

Relevant Reading: Hematopoietic stem-cell transplantation for the treatment of severe combined immunodeficiency

In-Depth [retrospective cohort]: The authors identified 240 cases of SCID treated with hematopoietic-cell transplantation from 2000 to 2009. Overall 5-year survival was 74%, with the highest survival among children receiving a transplant before age 3.5 months (94%) or those receiving a transplant from a matched sibling (97%). Children who received a transplant after age 3.5 months and had active infection at the time of transplant had the lowest survival rate of only 50%.

Conditioning, a chemotherapeutic regimen to suppress the patient’s native bone marrow prior to the transplant, generally led to a lower survival rate compared to no conditioning. The negative effect of conditioning was most apparent on children with active infections. However, conditioning did appear to be associated with higher post-transplant T-cell counts and better B-cell function. As such, conditioning may be beneficial in certain select patients without active infection.  

More from this author: Early risk factor for progression of cystic fibrosis identified, Gut microbes implicated in stroke and heart attacks: new dietary link, New leukemia mutation offers therapeutic targets, Childhood ADHD associated with increased risk of suicide, A marker of aggressive liver cancer and potential therapeutic target identified

Image: PD

©2012-2014 2minutemedicine.com. All rights reserved. No works may be reproduced without expressed written consent from 2minutemedicine.com. Disclaimer: We present factual information directly from peer reviewed medical journals. No post should be construed as medical advice and is not intended as such by the authors, editors, staff or by 2minutemedicine.com. PLEASE SEE A HEALTHCARE PROVIDER IN YOUR AREA IF YOU SEEK MEDICAL ADVICE OF ANY SORT.