Low white blood cells

Yes.

I took azathioprine at a daily dose of 150 mg, then 100 mg, then 50 mg. Finally discontinued it because even at the lowest dose my white blood cell count was depressed. And it didn't seem to help my UC symptoms.

I never noticed any increase in susceptibility to infections, though.

I was glad to get off it, because I also worried about general suppression of the immune system.

If our blood numbers become concerning, then either we reduce dosage or discontinue. It depends how bad those numbers are. Any dosage reduction or discontinuation will take a minimum of 6-weeks to show a difference within our blood test results. Often it can take 8-weeks for our numbers to turn in the right direction.

When we take thioprines (azathioprine/Imuran or 6MP), our goal is to reduce the WBCs to a lower but safe range. WBCs are elevated during flares, directly cause inflammation within the body, and the less WBCs we have the less inflammation can be caused. Some of us metabolize the medication too well, and it suppresses WBCs more than expected. It's known as myelosuppression, which can happen at any time during our treatment course, and that's why these medications require ongoing blood work to look for this. Thioprines work by slowing the rate in which WBCs and others (platelets, RBCs, etc.) are created. When created at a slower rate, we get a lesser amount over time. Thioprines can do nothing about our current blood makeup, but regular clearance of existing WBCs means that there are less reinforcements. The affect of thioprines isn't just on WBCs, in myelosuppression they can impact RBCs, platelets, neutrophils, etc.

Yes, I had this happen once with 6MP a number of years ago. My neutrophils were dropping month-over-month further below the normal range. My gasteroenteroligist called it neutropenia (chronic, low neutrophils) and had me cut my dosage from 75mgs a day to 50mgs a day, and about 8 weeks later my numbers returned to normal. I am still on 6mp today, and am even back to 75mgs a day without issue today.

With WBCs within the 2's, you do have to be a bit more careful about infections requiring antibiotics (UTI, Bronchitis, sinus infections, etc). Generally being in the 3's is fine, and some doctors purposely keep us in the 3's, slightly below normal range, for optimum affect. Being in the 2's an infection could start to become worrisome and has a chance of spreading to other areas of the body (a.k.a. a sepsis which is serious). Greater odds, but far from guaranteed. Just practice good hand washing techniques after touching common vectors, like doornobs and other areas frequently touched by others, and avoid those with a contagious infection. And if you suspect you have an infection requiring antibiotics then seek out antibiotics earlier rather than wait another week to confirm. Heathcare professionals follow recommended CRC hand washing procedures, and whenever immunosuppressed, it is a good practice to know and follow: /www.cdc.gov/handwashing/when-how-handwashing.html

My wbc count comes back low about 1-2 times a year. My old doctor had me take a break for 2 weeks and then check blood again, then went back to original dose. My new doctor doesn’t seemed concerned when it happens and even had me go from blood tests every 6 weeks to every 6 months. Last blood test my wbc was low and I didn’t change anything. This time it was normal again. I asked him about it being low and he said if all other tests were good, there was no concern.

I'd ask about a retest. Sometimes we can get bad numbers from one draw. I'd expect a couple bad test results before making big changes.

alltheway said...
Thanks for your response. Do you know what your levels were like when they were lowest? I'm just wondering whether or not mine are exceptionally low. I have also not noticed an increase in susceptibility to infection- I have just been worrying since getting the blood test back.

Azathioprine has worked exceptionally well for my UC so I would like to be able to stick with it as well.

The lowest value for my white blood cell count was 3.0 thousand / uL. Quest Diagnostics sets the "normal" reference range as 3.8-10.8 thousand / uL. After discontinuing azathioprine, my WBC count went up to about 5.5, in the normal range.