The current standards for laboratory diagnosis of rheumatic diseases and their use in real clinical practice

Abstract

The use of the current standards for laboratory diagnosis of rheumatic diseases (RD) in clinical practice was analyzed on the basis of the data obtained at the Laboratory for the Immunology and Molecular Biology of Rheumatic Diseases, V.A. Nasonova Research Institute of Rheumatology, Russian Academy of Medical Sciences, in 2012. A total of 19,900 patients with RD were examined; 90,364 tests (mean 4.5 tests per patient), 57,338 (63.6%) autoantibody tests, 11,661 (12.9%) acute-phase inflammatory protein tests, and 21,365 (25.5%) tests for other biomarkers were carried out. There were also 27,026 (30%) tests for antinuclear antibodies; 7,027 (7.8%) for rheumatoid arthritis, 8,194 (9.1%) for cyclic citrullinated peptide antibodies, 8,353 (9.2%) for antiphospholipid antibodies, and 2,550 (2.8%) tests for antineutrophil cytoplasmic antibodies. C-reactive protein was measured in 10,845 (12.0%) tests; IgG, IgG4, IgM, and IgA in 7,178 (7.9%); complement in 4,978 (5.5%); cryoglobulins in 2,578 (2.9%); lymphocyte subpopulations in 950 (1.1%); and antistreptolysin O in 1,156 (1.3%). Autoantibodies and acute-phase indicators were shown to be of the greatest clinical value among the laboratory biomarkers of RD. In real clinical practice, the diagnostic sensitivity and specificity of and positive and negative likelihood ratios for laboratory tests can differ from those when examining specially selected groups of patients and healthy individuals. In this connection, the use of laboratory tests and the assessment of their results require strict compliance with presumptive diagnosis and the data of a thorough clinical examination of patients.