I have been on azathioprine for 8 months. I am having a great response so far. I have seen a lot of posts talking about it taking 3 months to work on that was spot on for me. I have near complete mucosal healing as evidenced by a flex sig 5 months after starting. Anyway my blood has always been good but last week my wbc was 4.9. Is that low and should I be concerned?. The lab reference for normal is 3.5 to 10.8. In the past my wbc has always been closer to the high end and 4.9 just seems low. Btw I am currently taking 150 mg and I weigh 172. My wbc over the past 7 months has went from 8 to 4.9 and my rbc and platelets have not changed at all since starting aza. Thanks for any encouraging words you guys may have