A Decade of Progress and Persistent Challenges in Autoimmune Diagnostics: Insights from UK NEQAS (2012–2021)

External Quality Assessment (EQA) programs play a crucial role in monitoring laboratory performance, identifying inconsistencies, and promoting the adoption of best practices in autoimmune diagnostics. Over the past decade, this field has undergone substantial evolution, driven by technological advances, enhanced standardisation, and increasing efforts toward harmonisation. This review examines findings from two recent studies assessing the decade-long evolution of autoimmune testing through data from the UK National External Quality Assessment Service (UK NEQAS) programmes. The results highlight considerable progress in the adoption of novel immunoassay technologies and improvements in test standardisation. However, challenges persist, particularly in achieving full harmonisation across laboratories and methodologies.