October 14, 2008
NEWBORN SCREENING FOR PRIMARY IMMUNODEFICIENCY DISEASE
By: Saul Spigel, Chief Analyst
You asked whether the legislature has considered adding primary immunodeficiency disease to the state's array of newborn screening tests and what factors it might consider in making such a decision.
Neither the legislature nor the Public Health Department has considered adding primary immunodeficiency disease to the list of genetic and metabolic diseases and conditions for which newborns in Connecticut are screened. Scientists have identified over 70 primary immunodeficiency diseases, but, to date, a newborn screening test has been developed for only one—severe combined immunodeficiency disease (SCID)—and that just recently.
In 2007, Wisconsin began a four-year pilot program to evaluate a statewide newborn screening program for SCID using this new test. Screening began in January 2008. The screening is estimated to cost $5.50 per child. State officials have tentatively concluded that screening costs are reasonable and that cost-effective treatment is available for newborns who are diagnosed with SCID.
Massachusetts will begin an optional SCID newborn screening in February 2009, and Illinois is currently evaluating whether to offer screening.
SCID is not one of the 29 diseases for which the American College of Medical Genetics recommends newborn screening. Among the factors the legislature might consider in deciding whether to require or offer optional SCID screening statewide are the cost to the state for equipment and personnel and whether (1) SCID prevalence warrants statewide screening, (2) the benefits of early detection outweigh the cost of screening and false positives, (3) providers who can provide follow-up services are available, and (4) successful treatment options are available.
PRIMARY IMMUNODEFICIENCY (PI) DISEASES
PI disease results from a genetic defect that affects the body's immune system. Because the immune system is so complex, different mutations result in PI diseases that present in numerous forms with varying symptoms. To date, over 70 types of PI diseases have been identified. Some forms are so mild they may not be recognized for years. Others, like SCID, are deadly.
Children with PI are subject to numerous infections because their immune systems cannot fight them. They typically get one infection after another and often get multiple infections at the same time. Weakened by infection, these children may fail to gain weight and can fall behind in growth and development. They are subject to pneumonia, osteomyelitis, cellulitis, and menigitis, among other infectious diseases. Serious infections can require repeated hospitalizations and lead to death.
PI diseases can be diagnosed with a variety of blood tests. Once diagnosed (and after any infections are cleared up), they are correctable with bone marrow transplants (especially for young children) and enzyme and antibody replacement therapy.
The number of people with PI is unknown. The National Institute of Child Health and Human Development reports that about 400 children are born annually in the U.S. with a serious PI. The most common estimate of SCID prevalence is about 1:100,000 births, but some experts believe that ratio is too low because it does not account for babies who die before SCID can be diagnosed. Some experts believe about 100 infants with SCID are born in the U.S. each year (Puck, “Population-Based Newborn Screening for Severe Combined Immunodeficiency: Steps Toward Implementation,” Journal of Allergy and Clinical Immunology, v.120, #4, October, 2007).
WISCONSIN SCID SCREENING PILOT PROGRAM
Wisconsin is currently in the second year of a four-year pilot program to test whether a recently developed screening test for SCID can be used on a statewide basis. It is the first state to conduct such testing. The pilot is a collaboration among the Children's Hospital of Wisconsin, Wisconsin State Laboratory of Hygiene, and the Jeffrey Modell Foundation. A $250,000 Modell Foundation grant, which was matched by the Children's Hospital and the Medical College of Wisconsin, provided the pilot's initial funding.
The pilot's first year (2007) involved (1) determining whether SCID testing met the state's criteria for inclusion in the newborn screening program, (2) developing the testing procedure and protocols and a system for following up positive screening results, and (3) testing the screening tool on unidentified samples. As Table 1 shows, the Newborn Screening Umbrella Committee and the state Department of Health and Family Services determined that SCID met their five criteria for inclusion in the newborn screening program.
Table 1: Criteria and Findings for Including SCID in Newborn Screening Program
Disorder prevalence warrants screening
SCID prevalence estimated at 1:65,000
Early detection benefits outweigh adverse consequences of false positives and screening costs
SCID morbidity and mortality is significant; preliminary studies indicated very low false positive rates
Potential exists for successful treatment
Early bone marrow transplants (within the first 3.5 months of life) are 75% to 95% successful
Screening methodology is adaptable to mass screening
State laboratory can effectively handle 300 to 400 screenings a day
Test cost is comparable to other established tests
SCID test costs about $6, which is comparable to hypothyroidism and adrenal hyperplasia tests
Source: Wisconsin State Laboratory of Hygiene
The screening portion of the pilot program began in January 2008. Approximately 70,000 babies are born in Wisconsin each year. The state lab estimates the SCID screening will cost $5.50 per child for an annual screening cost of about $385,000 (other sources state the screening will cost $6 to $8). During 2008, the existing $69.50 newborn screening fee will cover this cost. (The fee is the amount the state lab charges hospitals to analyze the blood samples; it is included in the parents' hospital bill.) The sponsors anticipate receiving grants to cover the screening cost in subsequent years, but if they do not it will be added to the state fee. As in Connecticut, this fee includes the cost of confirmatory tests for positive screens, tracking, and follow-up counseling. Connecticut's newborn screening fee is currently $28, and about 44,000 babies are born each year.
Based on the first three months of testing, the state laboratory tentatively concluded that:
1. the SCID test's cost is within the newborn screening program's cost parameters;
2. the test can be used as part of routine newborn screenings; and
3. the $120 cost of the test used to confirm a positive screening and make a definitive diagnosis is reasonable.
The Wisconsin lab estimates that screening decreases total medical costs. It estimates that the hospital costs for three surviving babies diagnosed with SCID later in infancy were $2.2 million each, while a bone marrow transplant for one baby diagnosed early because its sibling had SCID cost $364,000.
SCID TESTING IN OTHER STATES
Massachusetts will begin a three-year pilot program in February 2009 that offers optional SCID screening. Based on previous pilots, the director of the state screening program anticipates 98% of parents will opt for the screening. The state's existing $54.75 newborn screening fee will not change during the pilot period thanks to an initial $378,000 grant from the Centers for Disease Control and Prevention. In addition to paying for screening costs, some of the money is being used to develop an alternative or ancillary SCID test and for staff training.
Children with positive SCID screens will be referred to tertiary care centers that a SCID workgroup deem capable of diagnosing and treating the disease. The workgroup is a consortium of newborn screening program staff and clinicians with expertise in SCID. It anticipates that standard payment mechanisms (including third party payers) will adequately cover diagnostic and treatment costs.
Illinois is considering an SCID screening program. As of September 18, 2008, the Public Health Department's Genetic and Metabolic Diseases Advisory Committee was still reviewing the concept.