CTD Screen Testing with the CTD screen (Phadia AB) was conducted on a Phadia 250 instrument (Phadia AB). ENA, and LIA are potentially useful diagnostic methods for predicting AARDs. Combining CTD screen with LIA might be effective for AARD patients. 1. Introduction Autoantibodies are closely related to clinical manifestations or the prognosis of patients with antinuclear antibody- (ANA-) associated rheumatoid diseases (AARDs), including systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sj?gren’s syndrome (SS), and mixed connective tissue disease (MCTD), who generally suffer from diffuse organ damage [1, 2]. Antinuclear antibodies (ANAs), a kind of autoantibody, are directed against a variety of nuclear antigens. The detection of ANAs is useful for diagnosing patients with AARDs [3, 4]. Indirect immunofluorescence (IIF) assays with cultured human epithelial carcinoma cells (HEp-2 cells) have been regarded as a platinum standard method [5]. However, IIF is usually a labor-intensive and time-consuming process and exhibits poor reproducibility due to the subjective interpretation of results [4, 6]. Enzyme immunoassays (EIAs) have been developed as alternatives to IIF for ANA screening and are widely used in clinical laboratories, enabling automation and quantitation of ANA screening [7]. The connective tissue disease (CTD) screen (Phadia AB, Uppsala, Sweden) used in this study is a recently launched EIA-based assay employing 17 different human recombinant antigens. After the initial screen for ANAs, autoantibodies to extractable nuclear antigen (ENA) are frequently detected because of their diagnostic and prognostic significance. Identification of anti-ENA antibodies plays a critical role in the diagnosis and management of AARD [1, 8]. EliA ENA assays (Phadia AB) for detecting autoantibodies to dsDNA, U1RNP, Sm, Ro/SSA, La/SSB, Scl-70, Pm-scl, Jo-1, and CENP Terfenadine have been introduced in the form of several different EIA packages, and collection immunoassays (LIAs) have been widely applied for confirmatory screening [9]. Little information is available regarding evaluation of the performance of these autoantibody assays simultaneously for autoantibodies and consequent antibody-disease associations. Further, most previous population studies involved patients in Europe or the USA. In this study, we evaluated the current diagnostic performance of an automated CTD screening assay in patients with AARDs. The diagnostic power of the assay was compared with that of the HEp-2 cell-based IIF, EliA ENA, and LIA assessments in a large Terfenadine Asian populace. We also investigated the diagnostic overall performance of the CTD screen in combination with the other three autoantibody assays for each AARD. 2. Materials and Methods 2.1. Study Design Terfenadine A total of 1115 sera from patients who frequented two university hospitals in Korea for AARD evaluation were collected to demonstrate the diagnostic overall performance of Terfenadine the CTD screen (Phadia AB, Uppsala, Sweden), as well as IIF (Fluoro HEPANA test, MBL Co., Nagoya, Japan), EliA ENA (Phadia AB), and LIA (Euroimmun AG, Lbeck, Germany) screening. The samples were collected randomly, and results from the same patients were not included repeatedly. This study was approved by the impartial Institutional Review Table of Severance Hospital and Kosin University or college Gospel Hospital. Because residual serum samples were obtained from patients during routine screening for the detection of autoantibodies in our clinical laboratory, this study was Terfenadine exempted from the requirement for informed individual consent. The specimens were retrospectively classified according to predefined diagnoses as follows: total AARD (= 112), SLE (= 67), SSc (= 21), SS (= 19), Rabbit Polyclonal to RAB18 MCTD (= 5), and control (= 1003). The total AARD value was derived from the number of patients with SLE, SSc, SS, or MCTD. The controls were consecutive patients who consulted the rheumatology clinics and for whom the rheumatologists considered it necessary to.