**6. PR progression to RA**

According to research in Japan, Anti-CPA in PR patients who developed RA was higher than those who did not develop RA in a future life [15]. According to a British case study of 39 patients of PR 19 showed progression to RA. Another study also indicated that most cases of PR progressed to other chronic arthritis and 35\60 progressed to RA [43]. The reason for this progression is multifactorial and one of the factors for this progression is a misdiagnosis of PR as there is no specific test and diagnosis is made mostly on physician's judgment and others may include progression duration which may vary from months to20 years [14, 44, 45].
