My husband had joint pain for a couple of weeks. His ANA came back positive, but the RA factor came back < 20, with a ref range of < 21 as normal. His rbc sedation rate was normal. His dr is referring him to a rheumatologist due to the positive ANA.
His pain has been gone now for a few days. What does the < 20 mean? Since it was only one point under the ref range, is this still concerning?
Is it possible for a virus to cause a positive ANA? He was sick for a few days, had weird tingling, then the joint pain and stiffness that moved from his shoulders down thru the fingers and ankles, and now back to nothing in the span of about 3-4 weeks.
Yes indeed. A passing virus can cause a positive ANA test. The pattern of it is helpful to know as well. Even just having a positive ANA is not indicative of disease depending on the titre, or level. Same for that slightly positive RF factor. Autoimmune diseases are not diagnosed on the basis of lab work alone. A person must exhibit symptoms as well, long term. It sounds like your Dr might be being cautious. I wouldn't worry too much if his symptoms went away. Think of the referral as a trip to a specialist just to err on the safe side as if your husband had an xray with a smudge on it. You get referred to a specialist to make sure that it was indeed just a smudge, otherwise known as a false positive. I hope this helps and you have a very nice holiday if you are in the US.
His RF <20 just means his rheumatoid factor was less than 20-it could have been 2 or 3, so this definitely negative. It would be interesting to know the titer and pattern of his ANA. I would not be overly concerned, but he should follow up with the rheumatologist as there are other tests that can be helpful in evaluating him and getting a baseline for comparison should his symptoms recur.
Thanks ladybud!! I agree, we really need to know the actual titer for the ANA. I'm not sure why the test was ordered the way it was....it's almost like the doctor picked the wrong one or something. Strange. I did send the doctor a message asking if we could run more blood work. I'll report back if we get any new info. Thanks again!