Search PubMed⌕ Search

Biomedical subjects

Anne Marie Comeau

Publications and source records attributed to Anne Marie Comeau.

13 recordsLinked to original sources

Pilot programs in newborn screening.

The term "pilot study" has been used over the years to describe the evaluation of the many elements involved in deciding whether a proposed condition should be added to a newborn screening (NBS) panel, and until recently, was unilaterally used to describe the evaluation of the assay to be used before the condition was officially adopted by a state for its newborn screening panel. Since Guthrie's introduction of screening for PKU, each time a new condition was added to the panel, the screening assay itself was validated through a population-based trial, in which the test was performed with de-identified samples to avoid association between the test result and the infant. This is considered by the laboratory as the "pilot phase" of adding a new condition. To advance the science of NBS, especially to accommodate new technologies that may provide new types of information (genetic versus physiological) for each new condition, pilot programs are essential. Involvement of the clinical community serves to improve these evaluations and provides the needed clinical validation of decisions made as a result of it. This paper describes the historical context of pilot programs in population-based NBS that utilize laboratory-based markers as indicators of concern; specifically, three applications that demonstrate different approaches to the use of pilots in adding conditions to a NBS panel are described.

Diffusion of Innovation↗

Early pulmonary manifestation of cystic fibrosis in children with the DeltaF508/R117H-7T genotype.

We report 3 cystic fibrosis newborn screen-positive infants with the DeltaF508/R117H-7T genotype who had Pseudomonas aeruginosa detected in oropharyngeal cultures early in life and a fourth who had pulmonary symptoms and Gram-negative growth on multiple oropharyngeal cultures. All 4 patients were followed prospectively from the time of genetic diagnosis. As many regions implement newborn screening for cystic fibrosis, there is concern regarding which mutations should be included in genetic panels used to make the cystic fibrosis diagnosis. Some have recommended that mutations not specifically associated with classic cystic fibrosis be excluded. Our cases highlight the importance of considering keeping so-called mild mutations on cystic fibrosis newborn screening panels and the need to follow children with these mutations closely.

Age of Onset↗

Challenges in implementing a successful newborn cystic fibrosis screening program.

OBJECTIVE: To identify necessary components of a successful cystic fibrosis (CF) newborn screening (NBS) program. STUDY DESIGN: The approach to CF NBS used by the Massachusetts NBS program was examined. RESULTS: Several key components were identified that should be addressed when a state has made the decision to screen, and well in advance of actual implementation. These components include (1) inclusion of CF center directors in the development process; (2) logistics of choosing a screening algorithm relative to practices in place and community wishes; (3) projections of medical service needs from specific algorithms; (4) identification of critical reporting components; (5) identification of critical follow-up components; and (6) recognition of educational needs. CONCLUSIONS: Careful examination of a wide variety of issues is needed to ensure optimal implementation of NBS for CF.

Aftercare↗

Communications systems and their models: Massachusetts parent compliance with recommended specialty care after positive cystic fibrosis newborn screening result.

OBJECTIVE: To evaluate compliance with recommendations for sweat testing/specialty evaluation and genetic counseling after a positive cystic fibrosis newborn screening (CF NBS) result. STUDY DESIGN: All infants with positive CF NBS results require a diagnostic sweat test at a CF center. Results that were "screen positive and diagnosis negative" prompted family genetic counseling. Parent compliance with follow-up protocol recommendations was retrospectively analyzed relative to the communications model in place at a particular CF Center. RESULTS: At each of the 5 MA CF centers, 95% of the CF NBS-positive infants completed recommended sweat testing. In contrast, there was wide disparity in compliance (32%-90%) with completion of genetic counseling between CF centers. CONCLUSION: CF centers that escorted parents through the 2 recommended follow-up steps in 1 day had higher compliance with the second step (genetic counseling) than centers that required a return visit for genetic counseling.

Aftercare↗

Sweat testing infants detected by cystic fibrosis newborn screening.

OBJECTIVE: Describe and define limitations of early pilocarpine iontophoresis (sweat testing) for cystic fibrosis (CF) newborn screening (NBS). STUDY DESIGN: Population-based results from follow-up of CF NBS-positive newborns. RESULTS: Insufficient quantity of sweat is more likely if the sweat test is done too early, but testing is generally successful after 2 weeks of age. Sweat chloride levels drop over the first weeks of life. CF carriers have higher sweat chloride concentrations than non-carriers. CONCLUSIONS: Sweat testing can be performed effectively after 2 weeks of age for CF NBS-positive newborns. Earlier testing has a higher risk of insufficient sweat for completing testing.

Age Factors↗

Diagnostic dilemmas resulting from the immunoreactive trypsinogen/DNA cystic fibrosis newborn screening algorithm.

OBJECTIVE: To quantitate the proportion of infants identified through cystic fibrosis (CF) newborn screening (NBS) by an immunoreactive trypsinogen (IRT)/DNA screening algorithm who have an unclear diagnosis as defined by the findings of an elevated IRT level and either 1) 2 CF gene (CFTR) mutations detected and sweat chloride level <60 mEq/L; or 2) 0 or 1 CFTR mutations and a "borderline" sweat chloride level >or=30 and <60 mEq/L. STUDY DESIGN: Using the 4-year cohort of CF-affected infants recently described by the Massachusetts CF NBS program, we identified and described the number of infants with the diagnostic characteristics (diagnostic dilemmas) aforementioned. RESULTS: Of infants with positive results on CF NBS who had 1 CFTR mutation detected and a borderline sweat chloride concentration, nearly 20% displayed a second CFTR mutation on further evaluation. Of all infants with positive CF NBS results considered affected with CF, 11% had a diagnosis that fell into 1 of the diagnostic dilemma categories aforementioned. CONCLUSIONS: Four problematic diagnostic categories generated by CF NBS are defined. In the absence of data on the natural history of such infants, careful follow-up is recommended for infants in whom a definitive diagnosis is elusive.

Algorithms↗

Newborn screening for cystic fibrosis: evaluation of benefits and risks and recommendations for state newborn screening programs.

In November 2003, CDC and the Cystic Fibrosis Foundation cosponsored a workshop to review the benefits and risks associated with newborn screening for cystic fibrosis (CF). This report describes new research findings and outlines the recommendations of the workshop. The peer-reviewed evidence presented at the workshop supports the clinical utility of newborn screening for CF. Demonstrated long-term benefits from early nutritional treatment as a result of newborn screening for CF include improved growth and, in one study, cognitive development. Other benefits might include reduced hospitalizations and improved survival. Mixed evidence has been reported for pulmonary outcomes. Newborn screening in the United States is associated with diagnosis of CF a median of 1 year earlier than symptomatic detection, which might reduce the expense and anxiety associated with workup for failure to thrive or other symptoms. Certain psychosocial risks for carrier children and their families (e.g., anxiety and misunderstanding) are associated with newborn screening. Exposure of young children to infectious agents through person-to-person transmission in clinical settings, although not an inherent risk of newborn screening, is a potential cause of harm from early detection. Involving specialists in CF care and infection control, genetic counseling, and communication can minimize these potential harms. Although screening decisions depend on a state's individual resources and priorities, on the basis of evidence of moderate benefits and low risk of harm, CDC believes that newborn screening for CF is justified. States should consider the magnitude of benefits and costs and the need to minimize risks through careful planning and implementation, including ongoing collection and evaluation of outcome data.

Algorithms↗

Integration of new genetic diseases into statewide newborn screening: New England experience.

Using a data set of newborn screening specimens tested by the New England Newborn Screening Program (NENSP) between January 1999 and February 2003, we analyzed the number of infants with positive newborn screening results and determined how many positive screening results were due to a recent multiplex expansion of services in some of the states. We found that for the subset of the 4-year cohort for which there was a 233% increase in the number of disorders screened (from 9 to 30 disorders), there was a 31% increase in the number of affected infants identified by the screen. We project that if all states in the program expanded their services and if the incidence of disorders is similar across states, there would be an observed 45% increase in the number of infants detected by the screen and a 43% increase in the number of infants for whom the screening algorithm would require some contact with the infants' health care provider. Furthermore, of those requiring contact, we project a 300% increase in the number of screened-positive infants who would be referred to tertiary care centers for a diagnostic evaluation. Increased contact with the medical community from additions to newborn screening as demonstrated in this report emphasizes the need for an approach in which the newborn screening program assures coordinated communications between birth units, laboratory, primary health care providers, and specialists.

Child Health Services↗

Population-based newborn screening for genetic disorders when multiple mutation DNA testing is incorporated: a cystic fibrosis newborn screening model demonstrating increased sensitivity but more carrier detections.

OBJECTIVES: Newborn screening for cystic fibrosis (CF) provides a model to investigate the implications of applying multiple-mutation DNA testing in screening for any disorder in a pediatric population-based setting, where detection of affected infants is desired and identification of unaffected carriers is not. Widely applied 2-tiered CF newborn screening strategies first test for elevated immunoreactive trypsinogen (IRT) with subsequent analysis for a single CFTR mutation (DeltaF508), systematically missing CF-affected infants with any of the >1000 less common or population-specific mutations. Comparison of CF newborn screening algorithms that incorporate single- and multiple-mutation testing may offer insights into strategies that maximize the public health value of screening for CF and other genetic disorders. The objective of this study was to evaluate technical feasibility and practical implications of 2-tiered CF newborn screening that uses testing for multiple mutations (multiple-CFTR-mutation testing). METHODS: We implemented statewide CF newborn screening using a 2-tiered algorithm: all specimens were assayed for IRT; those with elevated IRT then had multiple-CFTR-mutation testing. Infants who screened positive by detection of 1 or 2 mutations or extremely elevated IRT (>99.8%; failsafe protocol) were then referred for definitive diagnosis by sweat testing. We compared the number of sweat-test referrals using single- with multiple-CFTR-mutation testing. Initial physician assessments and diagnostic outcomes of these screened-positive infants and any affected infants missed by the screen were analyzed. We evaluated compliance with our screening and follow-up protocols. All Massachusetts delivery units, the Newborn Screening Program, pediatric health care providers who evaluate and refer screened-positive infants, and the 5 Massachusetts CF Centers and their affiliated genetic services participated. A 4-year cohort of 323 506 infants who were born in Massachusetts between February 1, 1999, and February 1, 2003, and screened for CF at approximately 2 days of age was studied. RESULTS: A total of 110 of 112 CF-affected infants screened (negative predictive value: 99.99%) were detected with IRT/multiple-CFTR-mutation screening; 2 false-negative screens did not show elevated IRT. A total of 107 (97%) of the 110 had 1 or 2 mutations detected by the multiple- CFTR-mutation screen, and 3 had positive screens on the basis of the failsafe protocol. In contrast, had we used single-mutation testing, only 96 (87%) of the 110 would have had 1 or 2 mutations detectable by single-mutation screen, 8 would have had positive screens on the basis of the failsafe protocol, and an additional 6 infants would have had false-negative screens. Among 110 CF-affected screened-positive infants, a likely "genetic diagnosis" was made by the multiple-CFTR-mutation screen in 82 (75%) versus 55 (50%) with DeltaF508 alone. Increased sensitivity from multiple-CFTR-mutation testing yielded 274 (26%) more referrals for sweat testing and carrier identifications than testing with DeltaF508 alone. CONCLUSIONS: Use of multiple-CFTR-mutation testing improved sensitivity and postscreening prediction of CF at the cost of increased referrals and carrier identification.

Algorithms↗

Multicenter evaluation of use of dried blood and plasma spot specimens in quantitative assays for human immunodeficiency virus RNA: measurement, precision, and RNA stability.

Eleven laboratories evaluated the use of dried blood and plasma spots for quantitation of human immunodeficiency virus (HIV) RNA by two commercially available RNA assays, the Roche Amplicor HIV-1 Monitor and the bioMerieux NucliSens HIV-1 QT assays. The recovery of HIV RNA was linear over a dynamic range extending from 4,000 to 500,000 HIV type 1 RNA copies/ml. The Monitor assay appeared to have a broader dynamic range and seemed more sensitive at lower concentrations. However, the NucliSens assay gave more consistent results and could be performed without modification of the kit. HIV RNA was stable in dried whole blood or plasma stored at room temperature or at -70 degrees C for up to 1 year. Dried blood and dried plasma spots can be used as an easy and inexpensive means for the collection and storage of specimens under field conditions for the diagnosis of HIV infection and the monitoring of antiretroviral therapy.

Antiviral Agents↗

Newborn screening for cystic fibrosis.

CF newborn screening benefits growth and prevents malnutrition in children with CF. Increasing evidence suggests long-term pulmonary benefits, but these data are still accumulating. With a standardized approach to clinical care for these pre-symptomatic patients, we should be able to ask questions about the optimal treatment strategy for therapies that are currently available, perhaps through randomized clinical trials in this group. For developing therapies, Massachusetts will have identified its CF patients before they have sustained significant malnutrition and lung injury, and it may be these patients who will benefit most from therapies still on the horizon.

Costs and Cost Analysis↗