Abstract
Connective tissue diseases (CTDs) comprise a heterogeneous group of autoimmune conditions characterized by diverse clinical manifestations and autoantibody profiles, posing significant diagnostic challenges. This systematic review and meta-analysis evaluated the diagnostic performance of automated connective tissue disease screening assays, commonly known as CTD screens, in diagnosing systemic rheumatic diseases. Eleven studies, including cohort and case-control designs, involving a total of 2384 CTD-positive patients, 8972 controls without CTD, and 679 healthy blood donors, were analyzed. The results demonstrated a pooled sensitivity of 79.36% and specificity of 90.79% for Elia(®) CTD-screen, and a sensitivity of 87.23% and specificity of 83.56% for QuantaFlash(®) CTD-screen. These tests exhibited varied sensitivity across individual CTDs, with excellent specificity for distinguishing CTD patients from healthy controls. Despite their utility, CTD screens should not be solely relied upon for diagnosis due to limitations in positive predictive value, particularly in low-prevalence populations. Clinical context and expert rheumatological evaluation remain indispensable. Optimizing the use of CTD screens can enhance diagnostic efficiency, reduce unnecessary testing, and mitigate patient anxiety and healthcare costs. Further research focusing on integrating these assays with clinical evaluation is recommended.