CLSI Releases Newborn Screening Document

Clinical and Laboratory Standards Institute (CLSI) has released NBS06-A-Newborn Blood Spot Screening for Severe Combined Immunodeficiency by Measurement of T-cell Receptor Excision Circles; Approved Guideline.

Severe combined immunodeficiency (SCID) is a lethal disorder not evident at birth. This document addresses its detection by population-based newborn screening (NBS), which uses dried blood spot (DBS) specimens to measure T-cell receptor excision circles (TREC).

TREC may be used to reveal the presence of SCID, and this presymptomatic detection is required for effective treatment.

This guideline, which is intended for use by NBS clinicians, laboratory personnel, producers of laboratory products related to NBS, and those involved with the oversight of NBS programs, facilitates the incorporation of SCID NBS into the routine operation of existing NBS programs.

Methodologically, it focuses on measuring TREC in DBS specimens by real-time quantitative polymerase chain reaction, the method currently in use by all NBS laboratories.

Both startup and operating NBS programs benefit from the use of NBS06, which contains detailed protocols for screening and follow-up.

"There is the potential for a cure with early detection of SCID," said Harry Hannon, PhD, and Roshini Sarah Abraham, PhD, D(ABMLI); Chairholder and Vice-Chairholder of the NBS06-A document development committee. "Newborn screening can save lives from this devastating disorder."

NBS06 conveys detailed information for laboratory practice, including calibration, quality control, and proficiency testing. It also addresses program issues such as short-term follow-up (ie, notification and tracking to establish or rule out a diagnosis).

The guideline includes clinical and immunological background on SCID and other immunodeficiency disorders that may present with low or no TREC content in newborns.

This guideline also boasts several appendixes that showcase information vital to the document, including the first comprehensive tabulation of primary and secondary conditions detected by the TREC assay, and an exemplar generic flow chart for TREC assays in NBS.

SCID NBS is technologically evolving with respect to both laboratory practices and outcome measures. NBS06 provides the foundation for refinements in the future.

The participation and close collaboration of all NBS programs is critical to the success of this endeavor.