Gosh, I could have sworn I replied yesterday but I guess I never hit submit! Here it goes again!
I had a positive PPD back in 1990. Back then (way before Crohn's dx or symptoms) it was explained to me that I had been exposed to the TB virus and was carrying it around (latent) and it could activate at any time. I was given the choice to either watch it and treat if it ever activated or treat as a precaution. I chose the latter and took Izoniazid (INH) for a year. Once a PPD is positive, it will always be positive. So now I just get chest x-rays. I've been on whatever immune suppressing drug (Remicade, Humira and now Tysabri) and never had a problem.
I recommend you see a pulmonary specialist to treat the latent TB. I am not sure you will be able to take Remicade without treatment of the TB.
Also, a word of warning that I was not given... do not allow another skin test! If you were positive the first time, it will be positive again. Each time it gets worse. It is an allergic reaction and like all allergic reactions they get worse with each exposure. I didn't know that and allowed the person to retest. My bump was as big as a golf ball the second time around! I've had clinical trial people try to get me to do a PPD and I refuse.
--40 year old female, dx as UC in '04 (1st symptoms in '03), switched to Crohn's in '05, 1 fistula, crohn's colitis, limited to large intestine
--rejected (reaction/didn't work): Asacol, AZA, 6-MP, MTX, Remicade, Humira, prednisone
--stuck on methylprednisolone, tried Prochymal in Phase III study (can't wait til it's approved!)
--started Tysabri 3/21/08
--single mom to 10-year-old girl