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Biomedical subjects

Ronald H Laessig

Publications and source records attributed to Ronald H Laessig.

10 recordsLinked to original sources

Newborn screening for cystic fibrosis in Wisconsin: nine-year experience with routine trypsinogen/DNA testing.

OBJECTIVE: To describe the development and follow-up confirmatory results of the routine cystic fibrosis (CF) newborn screening (NBS) program in Wisconsin. METHODS: CF NBS has been performed on a routine clinical basis in Wisconsin since July 1994. The 2-tiered immunoreactive trypsinogen (IRT)/DNA technique was used on dried blood on filter paper spots. From July 1994 to February 2002, mutation analysis was for the DeltaF508 allele. Beginning in March 2002, multimutation analysis of 25 CF mutations was performed. Infants with a positive result on NBS were seen in certified CF centers for sweat testing by means of quantitative pilocarpine iontophoresis, and families received genetic counseling. RESULTS: From July 1994 to February 2002, there were 120 cases of CF detected by means of NBS (509,794 infants screened), with 53 DeltaF508 homozygotes and 67 compound heterozygotes. There were 8 clinically diagnosed cases of CF (no DeltaF508 allele). The CF incidence was 1:3983 (95%CI, 1:3373-1:4774). From March 2002 to June 2003, multimutation analysis identified 21 cases of classic CF (90,142 infants screened). Sweat tests were successfully performed in infants younger than 1 month. CONCLUSIONS: Early diagnosis of CF through NBS was successfully performed, with an estimated sensitivity rate of 99% using the IRT/25 CFTR multimutation assay.

Age Factors↗

Memories, memories.

Explore the source record for details and available documents.

Clinical Chemistry Tests↗

Multiplexed genetic analysis using an expanded genetic alphabet.

BACKGROUND: All states require some kind of testing for newborns, but the policies are far from standardized. In some states, newborn screening may include genetic tests for a wide range of targets, but the costs and complexities of the newer genetic tests inhibit expansion of newborn screening. We describe the development and technical evaluation of a multiplex platform that may foster increased newborn genetic screening. METHODS: MultiCode PLx involves three major steps: PCR, target-specific extension, and liquid chip decoding. Each step is performed in the same reaction vessel, and the test is completed in approximately 3 h. For site-specific labeling and room-temperature decoding, we use an additional base pair constructed from isoguanosine and isocytidine. We used the method to test for mutations within the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The developed test was performed manually and by automated liquid handling. Initially, 225 samples with a range of genotypes were tested retrospectively with the method. A prospective study used samples from >400 newborns. RESULTS: In the retrospective study, 99.1% of samples were correctly genotyped with no incorrect calls made. In the perspective study, 95% of the samples were correctly genotyped for all targets, and there were no incorrect calls. CONCLUSIONS: The unique genetic multiplexing platform was successfully able to test for 31 targets within the CFTR gene and provides accurate genotype assignments in a clinical setting.

Autoanalysis↗

Has compliance with CLIA requirements really improved quality in US clinical laboratories?

BACKGROUND: The Clinical Laboratory Improvement Amendments of 1988 (CLIA'88) mandate universal requirements for all U.S. clinical laboratory-testing sites. The intent of CLIA'88 is to ensure quality testing through a combination of minimum quality practices that incorporate total quality management concepts. These regulations do not contain established, objective indicators or measures to assess quality. However, there is an implicit assumption that compliance with traditionally accepted good laboratory practices--following manufacturers' directions, routinely analysing quality control materials, applying quality assurance principles, employing and assessing competent testing personnel, and participating in external quality assessment or proficiency testing (PT)--will result in improved test quality. METHODS: The CLIA'88 regulations do include PT performance standards, which intentionally or unintentionally, define intra-laboratory performance. Passing PT has become a prime motivation for improving laboratory performance; it can also be used as an objective indicator to assess whether compliance to CLIA has improved intra-laboratory quality. RESULTS: Data from 1994 through 2002 indicate that the percentage of laboratories passing PT has increased. In addition to PT performance, subjective indicators of improved quality--frequency of inspection deficiencies, the number of government sanctions for non-compliance, and customer satisfaction--were evaluated. CONCLUSIONS: The results from these subjective indicators are more difficult to interpret but also seem to show improved quality in US clinical laboratories eleven years post-CLIA'88.

Clinical Laboratory Techniques↗

Analysis of the costs of diagnosing cystic fibrosis with a newborn screening program.

OBJECTIVES: To compare the cost of diagnosing cystic fibrosis (CF) through a newborn screening program with the traditional method and to estimate the cost of CF diagnosis if a national newborn screening program is implemented. STUDY DESIGN: Surveys were conducted to determine the annual number of sweat tests in 1991 and in 2000 after implementation of statewide screening. A national survey of sweat test costs was used to estimate the annual expense for diagnosing CF in the United States through newborn screening. RESULTS: Since the introduction of newborn screening for CF, the numbers of sweat tests ordered annually have decreased from 1670 to 804 (including 134 follow-up tests from screening). The current estimated annual cost of Wisconsin CF newborn screening and diagnosis is $4.58 per newborn infant. The estimated annual cost per newly diagnosed CF infant using the traditional method is $4.97 per newborn infant. If no additional sweat tests were ordered outside of the newborn screening program, the estimated annual cost of a Wisconsin CF newborn screening and diagnosis is $2.66 per newborn and $2.47 per newborn for a national CF newborn screening program. CONCLUSIONS: A CF newborn screening program provides a potentially cost-saving alternative to the traditional method of diagnosis of CF.

Chlorides↗

Polybrominated diphenyl ethers (PBDEs): new pollutants-old diseases.

Polybrominated diphenyl ethers (PBDEs) are a class of recalcitrant and bioaccumulative halogenated compounds that have emerged as a major environmental pollutant. PBDEs are used as a flame-retardant and are found in consumer goods such as electrical equipment, construction materials, coatings, textiles and polyurethane foam (furniture padding). Similar in structure to polychlorinated biphenyls (PCBs), PBDEs resist degradation in the environment. Less brominated PBDEs like tetra-, penta- and hexa- demonstrate high affinity for lipids and can accumulate in the bodies of animals and humans. Breast milk from North American women contained much higher amounts of PBDEs than levels in breast milk from Swedish women, indicating that North American exposures to PBDEs may be particularly high. Evidence to date suggests that tetra- and penta-BDEs are likely to be the more toxic and bioaccumulative of the PBDE compounds, compared to octa- and deca-congeners. PBDEs are sold as mixtures, under names such as "pentabromodiphenyl ether" and "octabromodiphenyl ether." The pentabromo product is a mixture of tetra-BDEs and penta-BDEs in approximately equal amounts. Pentabromo consists of PBDEs that are believed to be the most toxic. This mixture has been banned by the European Union, but is still used in North America. The United States is the leading producer and user of pentabromo. In August 2003, the State of California passed a bill to phase out the use of penta- and octa-PBDE by 2008. The toxicology of PBDEs is not well understood, but PBDEs have been associated with tumors, neurodevelopmental toxicity and thyroid hormone imbalance. The neurotoxic effects of PBDEs are similar to those observed for PCBs. Children exposed to PBDEs are prone to subtle but measurable developmental problems. It is presumed that PBDEs are endocrine disruptors, but research in this area is scant. Further studies are imperative in a multitude of health and environmental disciplines to determine the adverse effects and mode of action of this widespread emerging pollutant on human health.

Animals↗

Screening newborns for congenital disorders.

The Newborn Screening Laboratory at the Wisconsin State Laboratory of Hygiene (WSLH) tests all newborn babies in the state of Wisconsin for 26 congenital disorders. The screening is mandated by state statute (253.13) and attempts to identify those babies at highest risk for any of the screened-for congenital disorders. The Newborn Screening Laboratory at the WSLH is part of the state's newborn screening program, a cooperative effort between the Wisconsin Department of Health and Family Services, state birthing hospital staff, several public and private specialty clinics, primary care providers, and parents. Screening occurs within the first hours (median 38 hours) of life when a few drops of blood from the baby's heel is collected, applied to a special paper, dried, and sent to the WSLH for analysis. Those babies determined to have at-risk test results get repeat testing to confirm the initial test results and, if warranted, the baby is referred to a specialty clinic for a diagnostic work-up and treatment if necessary. Since its inception in the early 1960s, newborn screening in Wisconsin has saved approximately 1300 children from serious mental or other medical problems.

Congenital Abnormalities↗

Newborn screening with tandem mass spectrometry: examining its cost-effectiveness in the Wisconsin Newborn Screening Panel.

OBJECTIVE: To examine the cost-effectiveness of tandem mass spectrometry (MS/MS) in a neonatal screening panel for 14 fatty acid oxidation and organic acidemia disorders in the Wisconsin Newborn Screening Program. STUDY DESIGN: An incremental cost-effectiveness analysis with a hypothetical cohort of 100,000 infants was performed. A threshold of $50,000/QALY (quality-adjusted life-year) was used to determine whether screening for medium-chain acyl-CoA dehydrogenase deficiency (MCAD) alone is cost-effective or whether additional disorders would need to be incorporated into the analysis to arrive at a conclusion regarding the overall cost-effectiveness of MS/MS. RESULTS: Under conservative assumptions, screening for MCAD alone yields an incremental cost-effectiveness ratio of $41,862/QALY. With the use of more realistic assumptions, screening becomes more cost-effective ($6008/QALY) and remains cost-effective so long as the incremental cost of screening remains under $13.05 per test. Adding the incremental costs of detecting the 13 other disorders on the screening panel still yields a result well within accepted norms for cost-effectiveness ($15,252/QALY). CONCLUSIONS: In Wisconsin, MS/MS screening for MCAD alone appears to be cost-effective. Future analyses should examine the cost-effectiveness of alternative follow-up and treatment regimens for MCAD and other panel disorders.

Acyl-CoA Dehydrogenase↗