Rheumatoid factor

And then we have a whole laundry list of autoimmune antibodies that we can look for.

And there's very sensitive ones like ANA and rheumatoid factor.

And these are much more sensitive, but not very specific, but they can lead you kind of in the right direction.

And then lastly, we can order some initial imaging like chest x-ray to look for pneumonias or even an abdominal ultrasound to maybe look at an abscess or possible kidney infection or something like that.