Non-transference of biological reference interval of TSH by electrochemiluminescence immunoassay: an Indian population perspective

• Published in: Clinica chimica acta Vol. 423; pp. 130 - 134
• Main Author: Sarkar, Rajarshi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 23.08.2013
• Subjects: Adult; Biological reference interval; Cobas; Electrochemiluminescence; Female; Humans; Immunoassay - standards; India; Luminescence; Male; Middle Aged; Reference Values; Thyrotropin - blood; TSH; Young Adult; India; TSH; Biological reference interval; Electrochemiluminescence; Cobas; India
• ISSN: 0009-8981; 1873-3492; 1873-3492
• DOI: 10.1016/j.cca.2013.04.020

Although TSH measurement by electrochemiluminescence immunoassay has become commonplace in India, significant discrepancy has been observed on interpretation of the test results when the manufacturer supplied biological reference interval (BRI) criteria were applied. This report determined whether the manufacturer's BRI (Roche Cobas) is transferable to the Indian population. Three hundred seventy-eight age- and sex-matched healthy subjects were selected from an urban Indian population. TSH reference measurements were acquired, and the reference data were statistically analysed. BRI of the Indian urban reference population was determined by non-parametric means. BRI was found to be 1.134 to 7.280μIU/ml. BRI thus calculated was found to be significantly different from that mentioned by the manufacturer (0.27 to 4.20μIU/ml), which, needless to mention, has profound clinical implications in this part of the globe. •Reference data were analysed for partitioning, normality, symmetry and outlier tests.•A non-parametric analysis computed a TSH reference interval of 1.134–7.280 μIU/ml.•Indian reference TSH data differed from the Western population data (0.27–4.20 μIU/ml).•Iodine deficiency in India might cause this rightward shift of TSH reference interval.•Clinical implications of this finding are quite significant.