Comparison of Thyroid Function Tests by RIA / IRMA Based Commercial Kit and in House Method in Hypothyroid Patients

Abstract

The diagnosis of hypothyroidism is based on the com-bination of clinical presentation and laboratory tests. The current study focuses on the strategy for the dif-ferential diagnosis of hypothyroidism and a compari-son of thyroid function tests (TFTs) by commercial kit based RIA / IRMA (radioimmunoassay / immuno-radiometric assay) procedures with those by in – house method. The study encompasses 75 hypothyroid pati-ents whose clinical history were recorded and TFTs were performed on their serum samples by commercial kit based RIA / IRMA. Moreover, 40 samples were assayed again for TFTs by in – house RIA / IRMA procedures to check whether the results by both methods were comparable. It has been found that in most cases, hypothyroidism is a clinical diagnosis and estimation of TFTs is required for its confirmation but to reach the differential diagnosis of hypothyroidism, additional relevant investigations are required. Fur-thermore, when TFTs results by commercial kit based RIA / IRMA were compared with those by in – house RIA / IRMA procedures, no statistically significant difference was found between the two methods. This implies that in – house RIA / IRMA procedures may be applied in place of commercial kit based methods to perform TFTs provided the criteria for quality control are fulfilled.

Keywords:  Hypothyroidism, RIA, IRMA.