A-046 Evaluation of the Clinical Performance of Anti Thyroid Peroxidase II and Anti Thyroglobulin II Assays on the ADVIA Centaur System

Abstract Background Autoimmune thyroid diseases (AITD), including Hashimoto’s thyroiditis (HT) and Graves* disease (GD), are characterized by the presence of autoantibodies against thyroid-specific proteins, such as thyroid peroxidase (TPO) and thyroglobulin (Tg). These autoantibodies play a critical role in the diagnosis, monitoring, and management of these conditions. Elevated levels of anti-TPO antibodies (aTPO) together with anti-Tg antibodies (aTg) are commonly seen in more than 90% of patients with HT and GD, making them critical and widely used diagnostic markers for these conditions. Moreover, the presence of anti-Tg antibodies may interfere with the measurement of serum Tg level, leading to inaccurate results. Thus, anti-Tg testing accompanies every serum Tg measurement to ensure accurate diagnostic outcomes in the clinical setting. The ADVIA Centaur Anti-Thyroid Peroxidase II (aTPOII) and ADVIA Centaur Anti-Thyroglobulin II (aTgII) evaluate the clinical performance of these assays on the ADVIA Centaur system, providing insights into their diagnostic potential and utility in clinical practice. Methods Samples from approximately 360 subjects (=22 years of age) were prospectively collected from six US sites. Collection included =207 samples (numbers vary between aTPO and aTg) from clinically confirmed Hashimoto’s and Graves’ disease (AITD) per ATA guidelines, and 157 from non-autoimmune thyroid disease (NAITD) populations. Results from these samples were compared to clinical diagnosis (CD) to evaluate clinical sensitivity and specificity. Additionally, 210 samples were collected from other disease states such as silent painless thyroiditis, thyroid carcinoma, subacute thyroiditis, etc. Results from these samples, together with the =360 sample results, were used in method comparison analyses. Positive percent agreement (PPA) and negative percent agreement (NPA) were evaluated by comparing ADVIA Centaur aTgII and ADVIA Centaur aTPOII assay results to those from commercially available predicate devices, the Beckman Access aTg and Abbott Architect aTPO assays. Results The ADVIA Centaur aTPOII assay (cut-off=10.4 IU/mL) demonstrated a sensitivity of 71.5% (65.0, 77.2) and specificity of 89.2% (83.3, 93.1) to the CD of AITD or NAITD. Additionally, the aTPOII assay demonstrated a PPA of 91.0% (86.7, 94.0) and NPA of 100.0% (98.8, 100) when compared to results of the predicate device, Abbott Architect aTPO. The ADVIA Centaur aTgII assay (cut-off=1.8 IU/mL) demonstrated a sensitivity of 43.1% (36.6, 49.7) and specificity of 84.1% (77.6, 89.0) to the CD of AITD or NAITD. Additionally, the aTgII assay demonstrated a PPA of 96.9% (92.3, 98.8) and NPA of 90.8% (87.7, 93.1) when compared to results of the predicate device, Beckman Access aTg. Conclusion The ADVIA Centaur aTPOII and aTgII assays demonstrated acceptable sensitivity, specificity, and great concordance when compared with the predicate device. Both assays fulfill requirements for use to aid in the diagnosis of AITD. *For education and scientific exchange only. Not for sales or promotional use.