Methodological aspects of anti-nuclear antibodies detection: EFLM, EASI, ICAP AND RAMLD recommendations

Abstract

This is a review of international and Russian recommendation for the study of anti-nuclear antibodies (ANA) in autoimmune inflammatory rheumatic diseases (AIRD) and autoimmune liver diseases (ALD), including a description of the most important methodological aspects. The main purpose of laboratory diagnostics of AIRD and ALD is to obtain objective information about the presence and immunopathological changes, which is an important tool for early diagnosis, assessment of activity, severity, prognosis of the disease and the effectiveness of therapy. The positive results of ANA determination are the main laboratory markers of AIRD and ALD, being among the diagnostic criteria for diseases. The ‘gold standard’ and primary screening method for determining ANA in serum is the indirect immunofluorescence assay (IFA). Antigen-specific solid phase assays methods are used as confirmatory tests. Standardization of the ANA determination contributes for reducing the intra- and inter-laboratory variability of the results, helps to optimize the interaction between laboratory specialists and clinicians in matters of prescribing and clinical interpretation of ANA tests. Solving the problem of ANA detection standardization is important because of the growing number of laboratories performing these tests and an increased referring for this investigation from rheumatologists and another medical specialist.