No abstract

The methods used for anti-F-actin antibody detection have different diagnostic performances. Both IIF methods, the one on rat tissues and the other on VSM47 cell line, are highly specific for AIH-1. In contrast, ELISA and especially ID show positive results in control population, although usually at low levels (with the single exception of PBC patients). Therefore, having a high positive predictive value, both IIF methods are reliable tools for the specific detection of AIH-associated anti-F-actin autoantibodies, whereas the immunometric assays might be integrated into the diagnostic scheme as second level tests upon improvement of their respective cut-offs to confirm anti-F-actin positivity in case of SMA positivity.

The unexpected isolated sIgE reactivity to nJug r 2 found by ImmunoCAP ISAC™ 112 is frequently related to reactivity to cross-reactive carbohydrate epitopes and it is lacking clinical significance.

PurposeThyrotropin receptor (TSHR) autoantibodies (TRAbs) are a hallmark of Graves’ disease (GD). The aim of this study was to evaluate the diagnostic accuracy of a new third generation automatic fluorescence enzyme immunoassay for TRAb measurement in GD, in comparison with two current IMAs.MethodsSera of 439 subjects (57 patients with untreated GD, 34 with treated GD, 15 with GD and Graves’ orbitopathy, 52 with multinodular non-toxic goiter, 86 with Hashimoto’s thyroiditis, 20 with toxic adenoma or toxic multinodular goiter, 55 with non-thyroid autoimmune diseases and 120 normal controls) were tested for TRAbs with the ELiA™ anti-TSH-R assay (ThermoFischer Scientific, Uppsala, Sweden), the TRAK™ RIA, Brahms (Thermo Scientific, Hennigsdorf, Germany) and the Immulite™ TSI assay (Siemens Healthcare, Llanberis, UK).ResultsSensitivity and specificity of the ELiA™ anti-TSH-R assay, TRAK™ RIA and Immulite™ TSI assay were 94.7% and 99.6, 100 and 98.2%, 100 and 98.2%, respectively. Spearman’s coefficient and Passing-Bablok regression showed a satisfactory correlation between EliA™ and TRAK™ [rho: 0.925; 95% CI: 0.883-0-953. Intercept: − 0.875 (95% CI: − 2.411 to 0.194); slope: 1.086 (95% CI: 0.941 to 1.248)], and between ELiA™ and TSI™ [rho: 0.947; 95% CI: 0.912 0.969. intercept: 1.085 (95% CI: 0.665 to 2.116); slope 1.315 (95% CI:1.116 to 1.700)].ConclusionsThe diagnostic performance of ELiA™-TSH-R assay is comparable to that of some current TRAb assays. It may be adopted into clinical practice for the differential diagnosis of hyperthyroidism, to screen for transient hyperthyroidism, and to monitor disease activity and treatment effects.

A high diagnostic accuracy of the sIgE to allergen components measurement with Immulite™ 2000 and a high agreement with ImmunoCAP™ platforms were shown in this study.