This document provides guidelines for the use of automated cell counting to enumerate lamellar bodies in amniotic fluid. It describes the different counting technologies used in automated cell counters as well as methods laboratorians can use to verify/validate the lamellar body count (LBC) test.
CLSI Publishes New Guideline: Assessment of Fetal Lung Maturity by the Lamellar Body Count (C58-A)
Wayne, Pennsylvania, USA—December 2011—The Clinical and Laboratory Standards Institute (CLSI) recently published Assessment of Fetal Lung Maturity by the Lamellar Body Count; Approved Guideline (C58-A). This document provides guidelines for the use of automated cell counting to enumerate lamellar bodies in amniotic fluid. It describes the different counting technologies used in automated cell counters as well as methods laboratorians can use to verify/validate the lamellar body count (LBC) test.
“Premature birth is a significant cause of infant morbidity and mortality, and a common disorder among premature infants is neonatal respiratory distress syndrome caused by a deficiency of pulmonary surfactant,” explains David G. Grenache, PhD, DABCC, FACB, Associate Professor of Pathology, University of Utah, and Medical Director, Special Chemistry, ARUP Laboratories, USA, and Chairholder of the document development committee. “Lung disorders rank as the sixth cause of neonatal death in the United States. The most widely used fetal lung maturity (FLM) test is the commercially available surfactant/albumin ratio, which is being discontinued at the end of this year. Laboratories that currently offer this test need to consider another rapid FLM test as a potential replacement. The LBC is the most likely test to fill this need.”
Dr. Grenache adds, “The LBC test is performed using an automated cell counter to enumerate the number of lamellar bodies in amniotic fluid, and has been demonstrated to be as clinically useful as the surfactant/albumin ratio in predicting lung maturity. Because it is a ‘laboratory-developed test,’ laboratorians who wish to validate and implement LBC need to be aware of the many preanalytical, analytical, and utilization issues that are associated with it. C58 addresses these issues.”
Key highlights in C58 include:
Lamellar body counting has proven to have many advantages over other tests of FLM, including rapid turnaround time, low reagent cost, and excellent clinical performance. As such, laboratory directors, medical technologists, laboratory supervisors, and pathologists, as well as in vitro diagnostic manufacturers involved in the development of devices and materials related to LBC testing, will benefit from using this guideline.
CLSI is a volunteer-driven, membership-supported, nonprofit organization dedicated to developing standards and guidelines for the health care and medical testing community through a consensus process that balances the perspectives of industry, government, and the health care professions. For additional information, visit the CLSI website at www.clsi.org or call 610.688.0100.
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