The rapid plasma reaction test, which is a blood test, is used in patients with syphilis. If a patient with syphilis has a rapid plasma reaction test, it is used in the course of treatment and is not used alone, but as a specific serologic test for syphilis. This is a non-specific test for syphilis, because non-syphilis patients can also have a positive rapid plasma reactin test or a high titer. In the case of syphilis, it is useful to determine whether treatment is needed. In addition, it can determine the effectiveness of treatment. When the titer is high, after applying antibiotics such as penicillin, the titer of the rapid plasma reactin test will gradually decrease to a certain level, and the treatment will indicate an effect. So this is a test to observe the effect of treatment during the treatment of syphilis patients.