Low TRECs in a premature infant |
If a replicate is low, the baby is referred for flow cytometry. |
TRECs are repeated until >37 weeks corrected gestational age; if low at that point, referral is made to an immunologist. |
Reassessment when the baby reaches term. |
The ideal time interval between a positive TREC result and a formal immunologic assessment |
Under 2 weeks, less if TRECs are undetectable; a baby with low TRECs should not receive live vaccines. |
Within 2 weeks. (The mean time from any abnormal TREC assay to flow cytometric evaluations in Wisconsin is about 7 days; if the TREC is zero; the mean time is 2 days.) If the TREC is zero, the family is cautioned to avoid sick contacts and isolate the baby. |
2 weeks. The family should be cautioned to isolate and protect the baby |
The ideal time between the definitive diagnosis of SCID and transplantation |
2 weeks to 4 months. The workup is overseen by a designated Immunology Referral Center, which coordinates referral to a transplant center. |
Once the diagnosis is established, a referral is made to a transplant center. The timing is dictated by donor availability. |
3–6 months |
If the gene defect is not known, is the transplant protocol modified to accommodate potential DNA repair defects? |
Radiation sensitivity testing is available for all California SCID infants. DNA damaging conditioning regimens are particularly dangerous in patients with radiation-sensitive SCID. |
Reduced intensity conditioning is preferred. Infants without a molecular diagnosis are tested for radiation sensitivity, although if clinically indicated, transplantation is not delayed based on the pending results. |
Reduced intensity conditioning is preferred. |