Establishment of Reference Range for FT4 in Neonates
Background: Reference Intervals (RIs) are essential for clinical laboratory test interpretation and patient care. Reference intervals are indispensable in evaluating laboratory result. Every laboratory has to establish its own reference range. Methods for estimating a reference range is expensive difficult to perform, often inaccurate and non-reproducible. Despite the importance of RIs globally there are very few publications on RIs for neonates TFT, is primarily due to technical issues.
FT4, the unbound form of the thyroid hormone thyroxin (T4), is representative of thyroid status. Therefore, serum FT4 levels reflect the health of the thyroid gland and can assist in thyroid disease diagnosis. During fetal development, thyroid hormones are important in brain cell migration as well as differentiation of neurons, oligodendrocytes, astrocytes, and microglia Therefore, adequate levels of maternal T4 are important for appropriate fetal neurodevelopment. Neonatal screening can help in the timely diagnosis of newborn thyroid diseases such as congenital hypothyroidism and thus prevent developmental or growth problems.
Objective: To establish reference range for FT4 in neonates.
Methods: Samples are collected from OBG and NICU wards and test for serum FT4 is done by using electrochemiluminescence method in Roche Cobbas 601. Data obtained is analyzed based on CLSI guidelines for determining reference range for FT4. Medians, 2.5th, 5th, 95t, 97.5th percentile for free T4 is calculated. Range is calculated using median and 2.5th and 97.5th percentile values.
Result: This study established a reference range for FT4 in neonates based on CLSI guidelines and it is 1.4-4.1 ng/dl.
Conclusion: Clinical biochemistry results are always accompanied by reference range. Various factors such as age, sex, geography, method of estimation etc. will affect the reference range. The reference range for FT4 measure by electrochemiluminasence method in adults varies from that measured in neonates. In adults the reference range is 0.93-1.7 ng/dl and in neonates it is 1.4-4.1 ng/dl.
Liisa Lehtonen
To read the full article Download Full Article | Visit Full Article
Menu