Evolution of autoimmune diagnostics over the past 10 years: lessons learned from the UK NEQAS external quality assessment EQA programs.

Objectives: External quality assessment (EQA) programs play a pivotal role in harmonizing laboratory practices, offering users a benchmark system to evaluate their own performance and identify areas requiring improvement. The objective of this study was to go through and analyze the UK NEQAS "Immunology, Immunochemistry and Allergy" EQA reports between 2012 and 2021 to assess the overall level of harmonization in autoimmune diagnostics and identify areas requiring improvement for future actions.

Methods: The EQA programs reviewed included anti-nuclear (ANA), anti-dsDNA, anti-centromere, anti-extractable nuclear antigen (ENA), anti-phospholipids, anti-neutrophil cytoplasm (ANCA), anti-proteinase 3 (PR3), anti-myeloperoxidase (MPO), anti-glomerular basement membrane (GBM), rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), mitochondrial (AMA), liver-kidney-microsomal (LKM), smooth muscle (ASMA), APCA, and celiac disease antibodies.

Seasonal patterns of myositis-specific and myositis-associated autoantibodies in Italy: Seasonal patterns of myositis autoantibodies.

Objective: Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of systemic autoimmune disorders affecting skeletal muscles but also other organs. There are different forms of IIM, each with peculiar clinical manifestations and prognosis. Accordingly, several autoantibodies have been described in IIM, with different prevalence in the different forms of the disease.

Harmonization of anti-nuclear antibody testing (ANA) by indirect immunofluorescence assay: Results from ten years of UK NEQAS external quality assessment.

External quality assurance (EQA) programs play a pivotal role in monitoring laboratory practices, allowing each laboratory to evaluate the consistency of results across different methods as well the ability of individual laboratories to compare and improve over time their own performance. The objective of our study was to analyze the UK NEQAS EQA reports for the "Antibodies to Nuclear and Related Antigens" program from 2013 to 2023, to assess the overall level of harmonization of the responses for anti-nuclear antibody (ANA) testing by indirect immunofluorescence (IIF), in terms of both pattern and titer consensus. As a second aim, we analyzed the impact of the introduction in UK NEQAS EQA reports of the International Consensus on ANA Patterns (ICAP) nomenclature and of digital image recognition on the harmonization of the ANA HEp-2 IIF test.

Issues in autoantibody tests used in the classification criteria for autoimmune rheumatic diseases: the laboratory autoimmunologist's perspective.

Classification criteria of autoimmune rheumatic diseases are an important means to define homogenous groups of patients that can be compared across studies for clinical trials and research purposes. The measurement of autoantibodies is a relevant aspect in the definition of classification criteria, with a significant weight in the scores necessary to classify patients with autoimmune rheumatic diseases. The impact of autoantibodies has gradually increased over the years, contributing to the evolution and improvement of the classification criteria.