The 2015 guidelines for the laboratory diagnosis of rheumatic diseases by the All-Russian Public Organization «Association of Rheumatology of Russia»

Abstract

The paper gives the clinical guidelines for the laboratory diagnosis of rheumatic diseases (RDs) elaborated by the Association of Rheumatologists of Russia in terms of the international requirements for methodology of a system search and assessment of the quality of evidence. The main goal of the laboratory diagnosis of RDs is to obtain objective information on the presence and pattern of immunopathological changes in a patient, which is an important tool for the early diagnosis, assessment of activity and severity of the disease, and its prediction, and efficiency of performed therapy. The clinical informative value of laboratory studies is determined by calculating their diagnostic sensitivity and specificity and the likelihood ratio for positive and negative results. Serological antibody detection tests hold a central position in the laboratory diagnosis of RDs. The main diagnostic laboratory markers of the latter are antinuclear antibodies, rheumatoid factor, anticitrullinated protein antibodies, antineutrophil cytoplasmic antibodies, and antiphospholipid antibodies. The positive results of autoantibody detection include diagnostic criteria for systemic autoimmune RDs, are used to assess the activity and prognosis of these diseases, play an important role in the diagnosis of earlystage RD, permit identification of individual clinical and laboratory RD subtypes, and serve as predictors for RDs in the absence of its symptoms. Standard autoantibody profiles were elaborated; a list of primary (screening), secondary (confirming), and additional serological tests were made out to diagnose systemic autoimmune RDs. The important laboratory markers of RDs are acutephase indicators (erythrocyte sedimentation rate, C-reactive protein, etc.) that can assess the inflammatory activity of the disease, its progression pattern, and prognosis during the chronic inflammatory process, as well as therapeutic efficiency. Other laboratory biomarkers (immunoglobulins, immune complexes, cryoglobulins, complement components, cytokines, endothelial activation markers, lymphocyte subpopulations, genetic markers, bone and cartilage tissue metabolic parameters, etc.) are of less clinical value than autoantibodies and acute inflammatory phase parameters in diagnosing RD.