Benefits, challenges and prospects of newborn screening for primary immunodeficiency

More than ten years of implementation of newborn screening for severe combined immunodeficiency (SCID) using a T-cell receptor excision circle (TREC) and in recent years the TREC/ kappa-deleting recombination excision circle (KREC) assay have shown a number of advantages, which are not only the proper detection of SCID, to achieve better treatment outcomes and survival of children, as well as expanded knowledge on the prevalence of SCID, other diseases associated with T- and B-lymphopenia, but also allowed to detect new mutations associated with PID. The challenges include the inability to diagnose SCID with T-cell dysfunction and normal levels of T-lymphocytes and other SCIDs using the TREC assay, cytomegalovirus infection, that significantly worsens hematopoietic stem-cell transplantation prognosis (HSCT), economic issues, especially in low- and middle-income countries, and certain ethical issues. Considering the good worldwide experience, there are many reasons for a wider implementation of the newborn screening program for SCID in the world, including the Eastern Europe.