[New diagnostic and evaluative tests for rheumatoid arthritis].
To prevent joint destruction, it is important to diagnose RA early and to consider the prognosis. For this purpose, several new laboratory tests, such as IgG-RF, anti-agalactosyl IgG antibodies (CARF), and matrix metalloproteinase-3 (MMP-3), have become available for diagnosing RA. RF has a tolerable sensitivity of 68.5% for RA, but low specificity of 77.1%, and also 76.0% for patients with other rheumatic diseases and chronic inflammatory disease, respectively. CARF showed slightly higher sensitivity but low specificity for other rheumatic diseases and chronic inflammatory patients. In contrast, anti-cyclic citrullinated peptide antibody (anti-CCP), a new diagnostic test for RA, demonstrated significantly high specificity for other rheumatic diseases, and also for chronic inflammatory disease patients. Anti-CCP was superior to other laboratory tests by ROC analysis. Moreover, both CARF and anti-CCP had higher sensitivity of 66.7%, 61.5%, respectively, for the diagnosis of early RA than RF. On the other hand, MMP-3 is thought to be not only an evaluative test for the activity of RA because of its significant correlation with CRP, but also has potential as a prognostic test to identify joint damage from RA. Anti-CCP was also reported to associate with the progression of joint damage and may be also used as a prognostic test. We next examined the efficiency of RA diagnosis made by combining these laboratory tests. The specificity of RF was not as high as anti-CCP but reached 92% when combined with MMP-3. Thus, it is concluded that anti-CCP is superior to other laboratory tests in sensitivity and specificity, and that these combination assays are useful in the early diagnosis of RA.
Hayashi
Nobuhide
N
Department of Clinical Laboratory, Kobe University Hospital, Kobe 650-0017.
Nishimura
Kunihiro
K
Morinobu
Akio
A
Kumagai
Shunichi
S
D001172:Arthritis, Rheumatoid / Q000175:diagnosis*; D001323:Autoantibodies / Q000097:blood*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D019278:Matrix Metalloproteinase 3 / Q000097:blood*; D010456:Peptides, Cyclic / Q000276:immunology*; D012217:Rheumatoid Factor / Q000097:blood*; D012680:Sensitivity and Specificity
D001323:Autoantibodies; D007074:Immunoglobulin G; D010456:Peptides, Cyclic; C064155:agalactosyl IGG; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor; D019278:Matrix Metalloproteinase 3