Additional Tissue Sampling Trials Did Not Change Our Thyroid Practice.

This study aimed to determine whether additional tissue sampling of encapsulated thyroid nodules would increase the frequency of follicular thyroid carcinoma (FTC) diagnoses. We examined thyroid tissue specimens from 86 patients suspected of FTC (84.9% female; mean age, 49.0 ± 17.8 years). The number of tissue blocks created for pathological assessments ranged from 3 to 20 (mean, 9.1 ± 4.1); the numbers in the previous method recommended by the Japanese General Rules for the Description of Thyroid Cancer and additional blocks ranged from 1 to 12 (mean, 6.0 ± 2.8) and from 1 to 8 (mean, 3.1 ± 2.0), respectively. The additional blocks were subsequently examined to determine whether any diagnoses changed from those based on the previous method. Five patients were diagnosed with FTC using the previous method; however, additional tissue blocks led to the diagnosis of FTC in 6 patients, as 1 diagnosis was revised from follicular adenoma to FTC. It has been reported that increasing the number of tissue blocks used for pathological assessments can increase the frequency of FTC diagnoses; however, this was not clinically significant in thyroid carcinoma, which requires completion thyroidectomy and radioactive iodine treatment. It resulted in no benefits to the patient because all minimally invasive FTCs, follicular tumors of uncertain malignant potential (FT-UMP), and follicular adenomas are treated with lobectomy alone in Japan. Additional tissue sampling only had a slight impact on our thyroid practice; therefore, we decided to cease it.

IgG4 thyroiditis in the Asian population.

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibro-inflammatory condition that often causes the formation of tumefactive lesions. The discovery of IgG4-RD linked many well-known isolated conditions as a distinct multi-organ disease, and started an era of promoting investigation and treatment in relevant fields. In the thyroid gland, a subcategory of Hashimoto thyroiditis (HT) with IgG4-rich inflammation was first discovered and named IgG4 thyroiditis by our group. This subtype of HT presents with rapidly progressive clinical manifestations and destructive histopathological features underlying thyroid dysfunction, which are significantly different from the common type of HT. Moreover, other IgG4-rich thyroid conditions in patients with Graves' disease and systemic IgG4-RD have been described. These observations are most frequently reported in the Asian population for unknown reasons. Although recent studies demonstrated that IgG4 thyroiditis is a specific entity independent from IgG4-RD, recognition of this unique subset of thyroid disease has yielded important insights into understanding its pathogenesis and the development of novel therapeutic approaches.

Clinical value of the first automated TSH receptor autoantibody assay for the diagnosis of Graves' disease (GD): an international multicentre trial.

BACKGROUND: Most recently, a new rapid and fully automated electrochemiluminescence immunoassay for the determination of TSH receptor autoantibodies (TRAb) based on the ability of TRAb to inhibit the binding of a human thyroid-stimulating monoclonal antibody (M22) has been established. OBJECTIVE: To evaluate this assay system in clinical routine based on an international multicentre trial and to compare the results with other established TRAb assays. PATIENTS AND MEASUREMENTS: Totally 508 Graves' disease (GD), 142 autoimmune thyroiditis, 107 subacute thyroiditis, 109 nonautoimmune nodular goitre, 23 thyroid cancer patients and 446 normal controls were retrospectively evaluated. RESULTS: ROC plot analysis revealed an area under curve of 0.99 (95% CI: 0.99-1.0) indicating a high assay sensitivity and specificity. The highest sensitivity (99%) and specificity (99%) was seen at a cut-off level of 1.75 IU/l. Here, the calculated positive predictive value was 95%, whereas the negative predictive value was 100%. Applying the ROC plot-derived cut-off of 1.75 IU/l we found a sensitivity for TRAb positivity within the group of newly diagnosed GD patients of 97% which is in accordance to the sum of different nonautomated porcine TSH receptor-based assays with a sensitivity of 94% indicating an excellent analytical performance of the new assay format. Detailed comparison of the automated and the sum of manual assays revealed a near identical specificity. CONCLUSION: Our results demonstrate that this new assay system has a high sensitivity for detecting GD and specificity for discriminating from other thyroid diseases. This assay may represent the future technology for rapid fully automated TRAb detection.

Technical evaluation of the first fully automated assay for the detection of TSH receptor autoantibodies.

BACKGROUND: Graves' disease (GD) is mediated by autoantibodies which bind to the TSH receptor (TRAb). The aim of the present study was to evaluate the technical performance of the first fully automated immunoassay for TRAb detection. METHODS: The Elecsys Anti-TSHR immunoassay utilizes a porcine TSH receptor (TSHR) and the human thyroid stimulating monoclonal TSHR autoantibody M22. RESULTS: Intraassay and total imprecision CV were determined between 1.4%-14.9%, and 2.4%-28.8%, respectively. Using the 20% CV criteria the functional sensitivity was found at 0.73 IU/L. The median CV at the cut-off (1.75 IU/L) was found to be 11%. Comparison studies with five TRAb immunoassays yielded slopes and intercepts between 1.02-1.48, and -0.74-0.56, respectively. Correlation coefficients were determined between 0.895 and 0.978. ROC plot analysis of patients with GD, patients with other thyroid disorders and healthy controls revealed an AUC of 0.99 resulting in a sensitivity of 97% and a specificity of 99% at a TRAb level of 1.75 IU/L. CONCLUSION: The evaluation of the TRAb immunoassay generated homogeneous performance data and demonstrated a high degree of comparability to established TRAb assays. The automated TRAb assay represents a major improvement of thyroid testing in clinical practice.

Evaluation of a new rapid and fully automated electrochemiluminescence immunoassay for thyrotropin receptor autoantibodies.

BACKGROUND: Hyperthyroidism in Graves' disease is caused by autoantibodies to the TSH receptor (TSHR), and measurement of the TSHR autoantibody (TRAb) yields important information to diagnose and decide on the course of treatment of Graves' disease. We evaluated basic and clinical performance of a new, rapid, and fully automated electrochemiluminescence immunoassay Elecsys Anti-TSHR (Elecsys TRAb) for measuring serum TRAb. METHODS: For evaluation of basic performance of the assay, we carried out intra- and interassay precision studies using five serum pools and three serum pools, respectively, and the assay was compared with four commercial TRAb assays. Clinical performance of the assay was evaluated with sera from 298 patients with untreated Graves' disease, 220 patients with destructive (painless and subacute) thyroiditis, and 332 healthy volunteers. The optimal cutoff point, which was calculated by receiver operating characteristic (ROC) analysis with the above subjects, was then used to classify an independent sample set of 80 patients with untreated Graves' disease, and 152 patients with destructive thyroiditis. RESULTS: Intraassay coefficient of variation (CV) was 4.24% at 1.85 IU/L and interassay CV was 10.1% at 1.46 IU/L. All the correlation coefficient values calculated against four commercial assays were larger than 0.85. ROC analysis resulted in a specificity of 99.1% with a sensitivity of 97.0% at a decision limit of 1.86 IU/L from comparison with untreated Graves' disease and destructive thyroiditis. The cutoff point yielded a sensitivity of 87.5% and specificity of 96.7% with the independent sample set. CONCLUSION: In spite of the short measuring time of only 27 minutes, the assay showed the same or better results with the existing commercial products. The short measuring time would contribute to speedy, preconsultation diagnosis of thyroid disease, especially of Graves' disease.