Newborn screening by enzyme immunoassay using dry blood spot for diagnosis of metabolic disorders

Abstract

Background: Newborn screening (NBS) is the test used to diagnosis the metabolic and other disorders within 72 h of birth. The early identification of the disorder helps in early treatment which prevents neonates from life-threatening health problem, mental retardation, and serious lifelong disabilities. Objectives: Universal NBS using heel-prick dried blood spot (DBS) samples has become an integral part of public health system in developed countries. There are about 99.9% of newborns that are screened every year in western countries. Whereas, in India the less 1% of newborns are screened due to the ignorance and not knowing the importance of NBS. Very few states in India had started the program in government. Awareness among the professionals and public about the NBS has to be created and extended. Materials and Methods: The Newborn DBS samples were received from Government Vellore Medical College Hospital, Government Hospitals at Tirupattur, Gudiyatham and 104 primary health centers. Samples should be collected within 72 h from the newborn. Screening of human thyroid-stimulating hormones, 17-OHP, glucose-6-phosphate dehydrogenase, Galactose, and IRT are done using the Enzyme Immunoassay (EIA) method using their respective conjugate, Conjugate Diluent, Substrate solution TMB Chromogen, washing solution 10 ×, 1 × 50 ml Stopping solution and measured using micro plate photometer. Point of care testing (POCT) requires only 1 drop (10 μL) of blood from the pricked heel of the baby, and it can be performed 5–10 min at bedside. Results: NBS is done using the EIA method which reports between 8 and 12 days. Comparing point of care (POCT) with EIA, the results of POCT are compatible and satisfactory and it completes in 5 days. Conclusion: The proper implementation of “point of care” testing will help to identify the positive cases early and prevents the baby from permanent disability.