Development of a high sensitivivy Immuno-PCR assay to detect and quantify low levels of thyroid stimulating hormone (TSH) in human serum samples

ABUD, J.E.; SANTAMARÍA, CG; CARDOZO, MA; LUQUE EH; RODRÍGUEZ HORACIO ADOLFO

Buenos Aires

Congreso; LXII Reunión Anual SAIC, Reunión Conjunta de Sociedades de Biociencias; 2017

SAIC

Measurement of TSH in human fluids is utilized as a ?first line? thyroid test, in order to assist clinical decision-making in thyroid disorders. Most of the current TSH methods used in clinical laboratories are two-site ?sandwich? heterogeneous immunoassays. The inter-methods variability is the largest at low TSH concentrations, due to lower analytical sensitivity of some immunoassay methods.The immuno-PCR (IPCR) technique combines the enormous sensitivity of the PCR with the versatility of ELISA-based methods by exchanging the signal-generating antibody-enzyme conjugate used in ELISA with an antibody-DNA conjugate (Figure 1). Typically, IPCR allows a 10 - 10000 fold increase in sensitivity over the analogous ELISA. ?Universal? IPCR is the most widely used format where avidin is used as a linker molecule between a biotinylated detection antibody and a biotinylated DNA probe. Therefore, IPCR is a methodology with potential higher analytical sensitivity than traditional TSH methods.The TSH-IPCR assay showed a significant increase in terms of the slope definition of sensitivity in low levels range, providing better quantitative resolution for a given amount of measurement error or, conversely, higher sensitivities can tolerate larger measurement errors for a given amount of quantitative resolution. This conclusion, together with other aspects of our results, support the potential of IPCR technique for being applied in clinical diagnosis of thyroid states.