Children’s Hospital of Richmond at VCU was recently chosen as a site for screening severe combined immunodeficiency screening. What does this mean for families in Virginia? Dr. Brant Ward provides the answers in this SCID Q&A.
What is SCID?
Severe combined immunodeficiency (SCID), also known as “bubble boy disease”, is an inherited syndrome characterized by failure of the immune system to develop. Infants are born without crucial cells that coordinate the immune responses to bacteria, viruses, and other infections. As a result, affected infants are at significant risk of contracting life-threatening infections.
Without treatment, children with SCID will die within the first two years of life due to overwhelming infection.
How is SCID treated?
Treatment of SCID requires replacement of the baby’s immune system with fully functional immune cells. Typically, this is done through transplantation of bone marrow cells from an unaffected donor. After transplantation, a new immune system develops from the donor’s cells, allowing the baby to fight off infections on their own. In some cases, replacement of a critical enzyme by weekly injection may be effective in restoring immune function. Finally, correction of the underlying genetic defect using gene therapy is possible for some forms of SCID, though only on a research basis.
Why is newborn screening for SCID important?
It is clear that treatment of infants at the earliest possible age, before they develop infections, is associated with significantly better chances for survival. Moreover, earlier treatment can be associated with up to 75 percent less overall cost to the health care system, which can reach millions of dollars per year for undiagnosed infants. Unfortunately, routine blood tests may fail to pick up SCID. Additionally, babies with SCID typically appear completely normal at birth, since they were protected from infection in the womb by the mother’s immune system. Furthermore, a family history of immune deficiency is apparent in less than 20 percent of affected infants. Thus, newborn screening is an important way to save on health expenditures and, more importantly, save additional lives. Of note, SCID is the only condition on the newborn screening panel for which standard treatment offers the possibility of a complete cure.
What’s the process for screenings?
In general, the process to screen for SCID is no different than for other conditions and will be included in Virginia’s state-wide newborn screening panel as of June 3, 2015. At 24-48 hours of age, spots of blood are collected on a special filter paper card, which is then sent to the state laboratory. A technique called real-time polymerase chain reaction is then used to measure small snippets of DNA, called TRECs, from the dried blood spot. TRECs are associated with the development of T cells, a type of immune cell that is absent in SCID. Therefore, a low TREC level is indicative of SCID and triggers a positive screen. Once a positive screen is identified, the Virginia Department of Health will contact the infant’s primary care provider (PCP). The PCP will then refer the baby, preferably within one to two days, to one of several regional Immunology centers for confirmation of the diagnosis and follow up care.
Why was CHoR chosen for the SCID screenings?
CHoR was chosen as one of the regional immunology diagnostic centers due to our faculty’s extensive knowledge and experience treating immunological disorders. Our immunologists currently follow and treat nearly one hundred pediatric and adult patients with various immunodeficiencies, and they were an integral part of the team that helped bring SCID screening to Virginia. Additionally, CHoR provides the only pediatric bone marrow transplantation program in Virginia. CHoR’s bone marrow transplant team has considerable experience in treating children with malignant disorders and non-malignant disorders, including immune deficiencies.
With the combined talents of our immunologists and transplant specialists—along with a full team of case managers, genetic counselors, infectious diseases experts, nursing staff, and pulmonologists—ChoR will be a premier center for the diagnosis and treatment of SCID in Virginia.
How many children are diagnosed every year?
In the past, SCID was considered to be extremely rare, with its various forms together afflicting only 1 in every 100,000 infants. With the development of newborn screening for SCID, it has become clear that the disorder is at least twice as common as previously thought, affecting about 1 in 50,000 live births. In the days before newborn screening, it is likely that many of the infants with SCID died from infections before the diagnosis was made or even considered. Based on the birth rate in Virginia, an estimated two to four babies will be born with SCID each year.
With the recent development of TREC testing, it is now possible to identify babies with SCID immediately after birth, when treatment is most successful. The test has been validated in several other states, and a majority of states currently screen for SCID or will do so in the near future. By instituting this screening program, Virginia will remain at the forefront of modern medicine and help ensure the health of its citizens.
Who should providers call if they have a potential SCID patient?
Call the SCID Provider Hotline at (804) 628-SCID (7243).