Education Rounds archive

Nathalie Lepage, PhD

  1. A new era in Down syndrome screening: integrated risk assessment. Improved utilization of second trimester sample.

    The field of prenatal screening for Down syndrome has dramatically expanded since its implementation with only second trimester AFP. The risk assessment has been modified with the addition of ultrasound markers to the biochemical markers in both first and second trimesters of pregnancy. The presentation will evaluate the screening performance of most available options, including the full integrated screening. It will also look at options of adding additional diseases, such as pre-eclampsia, in the context of prenatal screening.

  2. Prenatal screening - the futuristic approach

    The advancement of the protocols for prenatal screening for Down syndrome has brought about major improvement of screening performance. The detection rate and false positive rate have dramatically improved from the second trimester triple test (implemented in most centers in the mid -1980s) to the integrated prenatal screening more recently implemented in some centers worldwide (using a combination of first trimester and second trimester biochemical markers and first trimester ultrasound marker). The screening performance is now approaching a detection rate of 90% with a false positive rate of 2%.

    The development of markers based on nucleic acid (fetal DNA, fetal RNA) is bringing possibilities of a change in paradigm and diagnosis of fetal Down syndrome from maternal plasma. The challenges with this emerging technology will be discussed.

Sihe Wang, PhD

  1. Autoverification of Clinical Laboratory Results

    Patient safety issues have been the focus of the national medical community since the 2000 publication of “To Error Is Human” by the Institute of Medicine. The laboratory community has been researching the means to reduce laboratory related errors. Additionally, the clinical laboratory community is dealing with the significant shortage of medical technologists as discussed in the August 2005 issue of Clinical Laboratory New. One approach towards improving these situations is to reduce human involvement in the testing process and opt for total automation. It is especially important to a comprehensive hospital or commercial laboratory in which high throughput requires quick validation of test results on a total automation line. In a smaller laboratory, autoverification is also an important first step to reduce human error in result reporting. Setting up an autoverification program and creating appropriate rules in the autoverification algorithm is challenging, but essential to the success of such a program. Staff involvement and reception are also critical to successful implementation. Autoverification in general includes rule generation, logistics, and staff involvement.

  2. Development and Validation of LC-MSMS Assays for Patient Care

    LC-MSMS has unique advantages over immunochemistry in clinical laboratory services and has reasonably high sensitivity and very high specificity, important for measuring many analytes including steroids. It can also measure multiple analytes in a single run simultaneously. LC-MSMS assays are relatively easy to set up and modify with long-term financial benefit. However, it also presents pitfalls which include matrix effect, interference, and in-source transformation. Therefore, proper development and rigorous validation are necessary before introducing such an assay into patient care.

David Grenache, PhD

  1. Contemporary issues in fetal lung maturity testing

    Premature birth continues to be a significant cause of infant morbidity and mortality and a common disorder among preterm infants is neonatal respiratory distress syndrome (RDS) caused by a deficiency of pulmonary surfactant. This presentation describes RDS including its pathophysiology, management, treatment, and also provides a review of currently available laboratory tests for the assessment of fetal lung maturity. Contemporary issues that affect both laboratorians and physicians are also described.
  2. The analytical and clinical complexities of human chorionic gonadotropin tests

    Human chorionic gonadotropin (hCG) is most often used as a biomarker for diagnosing intrauterine and ectopic pregnancies but it also has clinical utility in oncology applications. hCG exists in many different molecular forms and this variation influences both its clinical utility and its detection and measurement by qualitative and quantitative hCG assays. In order to appropriately utilize hCG tests and interpret their results, both physicians and laboratorians need to be aware of the strengths and limitations of hCG immunoassays.

Nathalie Lepage, PhD

  1. Prenatal screening for Down syndrome and open neural tube defects- Update on quality assessment sonographers

    Over the past few years, the field of prenatal screening for Down syndrome has changed. In the past, the risk assessment was only performed in the second trimester of pregnancy using three biochemical markers; this assessment has been modified with the addition of ultrasound markers to the biochemical markers. With the addition of ultrasound markers, the epidemiological monitoring of quality has also been changed. The presentation will discuss the specific issues related to monitoring quality assessment of nuchal translucency, measured by sonographers and reported by sonologists.