Banchuin N, Janyapoon K, Sarntivijai S, Parivisutt L
Department of Microbiology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand.
Asian Pac J Allergy Immunol. 1992 Jun;10(1):47-54.
An indirect ELISA for the determination of each isotype (IgM, IgG, IgA, IgD, IgE) of rheumatoid factors (RF) was performed with sera obtained from 77 patients with either classical or definite rheumatoid arthritis (RA) and 319 controls, using rabbit IgG as the antigen. The results were compared with those of a commercial latex agglutination test, using denatured human gamma globulin as the antigen for rheumatoid factor determination. At the cut-off level at which positive results were found in less than 5% of normal controls, ELISA for IgM RF determination had sensitivity, specificity, efficiency, positive predictive value and negative predictive value of 46.75%, 98.12%, 88.13%, 85.71%, 88.41%, while those for IgA RF were 46.75%, 93.42%, 84.34%, 63.16%, 87.91% and for IgG RF were 59.74%, 92.16%, 85.86%, 64.78%, 90.46%, respectively. These indices by latex agglutination test were 83.11%, 93.73%, 91.67%, 76.19% and 95.83%, respectively. IgD RF titre greater than or equal to 1:5 was detected in 19/77 RA patients and 4/200 normal controls while IgE RF titre greater than or equal to 1:5 was detected only in 7/77 RA patients. Thus, ELISA did not appear to have any advantage over latex agglutination test for diagnosis of RA.
采用兔免疫球蛋白G（IgG）作为抗原，运用间接酶联免疫吸附测定法（ELISA）对77例患有典型或确诊类风湿性关节炎（RA）的患者以及319名对照者的血清进行检测，以确定类风湿因子（RF）的各同种型（IgM、IgG、IgA、IgD、IgE）。将结果与商业乳胶凝集试验的结果进行比较，后者使用变性人γ球蛋白作为测定类风湿因子的抗原。在正常对照中阳性结果出现比例低于5%的临界值水平下，ELISA法测定IgM RF的灵敏度、特异性、效率、阳性预测值和阴性预测值分别为46.75%、98.12%、88.13%、85.71%、88.41%，测定IgA RF的相应指标分别为46.75%、93.42%、84.34%、63.16%、87.91%，测定IgG RF的相应指标分别为59.74%、92.16%、85.86%、64.78%、90.46%。乳胶凝集试验的这些指标分别为83.11%、93.73%、91.67%、76.19%和95.83%。在77例RA患者中有19例检测到IgD RF滴度大于或等于1:5，在200名正常对照者中有4例检测到；而仅在77例RA患者中的7例检测到IgE RF滴度大于或等于1:5。因此，ELISA法在RA诊断方面似乎并不比乳胶凝集试验具有任何优势。
