Can you have a positive blood test for arthritis if you are in remission?

Hmm.. Not sure to which arthritis you are referring, but if rheumatoid arthritis the answer is yes. The rheumatoid factor will always remain positive whether symptoms are present or not. Ankylosing spondylitis hla b27 test also will remain positive. Those two tests are not a measure of disease activity, just the presence of the disease in an individual.