Naranjo Hernández A, Rodríguez González T, Rodríguez-Lozano C, Ojeda Bruno S, Francisco Hernández F, Sánchez-García F, Bilbao Cantarero A
Sección de Reumatología, Hospital Nuestra Señora del Pino, Las Palmas de Gran Canaria.
Rev Clin Esp. 1997 Apr;197(4):232-6.
Rheumatoid factor (RF) is one of the most characteristic laboratory parameters in rheumatoid arthritis (RA), and its specificity for this disease increases when the titer is high. We investigated the diagnoses associated with high titers of RF and whether they are associated with a poor prognosis of RA.
Patients with RF titers higher than 300 IU/ml were studied (nephelometry) during a three-year period in a general hospital. Patients with RA were compared with other group of patients with RA and RF lower than 300 IU/ml regarding functional capacity, presence of nodules, HLA-DR4 and radiologic status, in a retrospective cohort study.
RF was quantitated in 2,181 patients and was higher than 300 IU/ml in 79 cases; 63 among patients in this group (80%) had RA, and the remaining patients inflammatory diseases of the connective tissue (four patients), palindromic rheumatism (two), liver disease (two), infection (one) and neoplasm (one). In two cases the diagnosis was arthrosis and in one case arthralgia of unknown origin. RA with RF higher than 300 IU/ml had a higher frequency of rheumatoid nodules than RA with RF lower than 300 IU/ml (p = 0.01; RR: 2.26; 95% CI: 1.18-4.35). The index of functional capacity and rate of HLA-DR4 and erosions was similar in both RA groups.
In a patient with a high RF titer, RA should be first ruled out, followed by other inflammatory diseases, collagenosis and liver diseases. The likelihood of finding a healthy patient with arthrosis or soft tissue rheumatism was very low. In RA, rheumatoid nodules were significantly associated with RF with titers higher than 300 IU/ml.
类风湿因子（RF）是类风湿关节炎（RA）最具特征性的实验室指标之一，当滴度升高时其对该病的特异性也会增加。我们研究了与高滴度RF相关的诊断情况以及它们是否与RA的不良预后相关。
在一家综合医院对RF滴度高于300 IU/ml的患者（采用散射比浊法）进行了为期三年的研究。在一项回顾性队列研究中，将RA患者与另一组RF低于300 IU/ml的RA患者在功能能力、结节的存在情况、HLA - DR4以及放射学状态方面进行了比较。
对2181例患者进行了RF定量检测，其中79例患者的RF高于300 IU/ml；该组患者中有63例（80%）患有RA，其余患者患有结缔组织炎性疾病（4例）、回纹型风湿症（2例）、肝脏疾病（2例）、感染（1例）和肿瘤（1例）。有2例诊断为关节病，1例诊断为不明原因的关节痛。RF高于300 IU/ml的RA患者类风湿结节的发生率高于RF低于300 IU/ml的RA患者（p = 0.01；相对危险度：2.26；95%可信区间：1.18 - 4.35）。两个RA组的功能能力指数、HLA - DR4指数和侵蚀率相似。
对于RF滴度高 的患者，应首先排除RA，其次是其他炎性疾病、胶原病和肝脏疾病。发现患有关节病或软组织风湿症的健康患者的可能性非常低。在RA中，类风湿结节与RF滴度高于300 IU/ml显著相关。
