Jónsson T, Steinsson K, Jónsson H, Geirsson A J, Thorsteinsson J, Valdimarsson H
Department of Immunology, National University Hospital, Reykjavik, Iceland.
Rheumatol Int. 1998;18(3):119-22. doi: 10.1007/s002960050069.
The diagnostic value of measuring rheumatoid factor (RF) by agglutination or isotype-specific enzyme-linked immunosorbent assay (ELISA) was compared. The study included 70 patients with rheumatoid arthritis (RA) and 205 patients with various other rheumatic conditions. Of the RA patients, 74% were RF-positive by agglutination and 90% had one or more RF isotypes elevated by ELISA compared to 14% and 22%, respectively, of the other patients. Strikingly, 70% of the RF-positive RA patients had an elevation of two or more RF isotypes compared to only 16% of the other RF-positive patients (P < 0.0001). Furthermore, a combined elevation of IgM and IgA RF was found in 52% of the RF-positive RA patients, but only in two (4%) of the other RF-positive patients (P < 0.0001). It is concluded that a combined elevation of IgM and IgA RF is highly specific for RA and is very rarely found in rheumatic diseases other than RA. Isotype-specific RF assays are therefore diagnostically superior to agglutination tests. The detection of the RA-specific RF isotype pattern may be particularly helpful early in the course of RA even before the disease is fully differentiated.
比较了通过凝集法或同型特异性酶联免疫吸附测定（ELISA）检测类风湿因子（RF）的诊断价值。该研究纳入了70例类风湿关节炎（RA）患者和205例患有各种其他风湿性疾病的患者。在RA患者中，74%通过凝集法检测为RF阳性，90%的患者有一种或多种RF同型通过ELISA检测升高，相比之下，其他患者的这一比例分别为14%和22%。令人惊讶的是，70%的RF阳性RA患者有两种或更多种RF同型升高，而其他RF阳性患者中这一比例仅为16%（P<0.0001）。此外，52%的RF阳性RA患者发现IgM和IgA RF联合升高，但其他RF阳性患者中只有2例（4%）出现这种情况（P<0.0001）。结论是，IgM和IgA RF联合升高对RA具有高度特异性，在RA以外的风湿性疾病中很少见。因此，同型特异性RF检测在诊断上优于凝集试验。在RA病程早期，甚至在疾病完全分化之前，检测RA特异性RF同型模式可能特别有帮助。
