serum rheumatoid factor

例句：

1. 1. The doctor ordered a blood testto check for the serum rheumatoid factor.
   医生要求做血液检测以检查血清风湿因子。
2. 2. This patient has beendiagnosed with rheumatoid arthritis, which requires monitoring for the serumrheumatoid factor.
   这名患者被诊断出患有类风湿关节炎，需要监测血清风湿因子。
3. 3. The test results showedthat the patient had elevated levels of theserum rheumatoid factor, indicatingan active infection.
   测试结果显示，患者的血清风湿因子水平升高，表明存在活跃的感染。