White blood cell count

I am 46 year old female. I had my CBC in 11/2008 and my white blood cell count was 3.7. I was then informed that it was 3.6 in June 2006. Yet in may 2006 just less than a month it was 5.2. I have been trying to figure out what made it drop. I am having another in a few days and have been taking B12 supplements hoping that's what it is. Yet I am wondering how it could have dropped so suddenly. I was in the hospital in may 2006 for chest pains, then they took a cbc, had a ekg done and stress test with some form of dye injected into my veins. I had some sort of heart scan and excercise test. They did give me some sort of cocktail they called it when I got there. Thye found nothing abnormal with my heart, Now I am wondering if the dye they gave me or the heart scan could have been the problem with the drop in WBC and it remained like that until now. They never said anything to me in 2006. I have ordered my med records to see what they gave me for medications. I have read on line that radioactive agents can lower WBC is this true and maybe even the scan they did might have?

[J.M. Keyes, MD]

Hi there,
I am unaware of radioactive dye for stress testing causing a long term decrease in white blood cells.  The causes of leukopenia (decreased wbcs) are numerous, including (among others)  infection, autoimmune disorgers, cancers, idiopathic, and endocrine disorders.  It can also be lab error.  Depending on the lab, your number may be just below the normal range, and nothing to worry about.
I would follow up for a repeat, and talk to your doctor about any symptoms you may have.  This, along with possible other lab results/testing will hopefully give you a definitive answer.

Good luck,
JMK MD