The chemotherapy used in HSCT is designed to destroy the immune system. The subsequent stem cell transplant is designed to grow back a new immune system.

For this purpose, the immune system presence is measured by total white blood cell count (WBC). When the WBC is below a certain threshold, the body is in a state called, “neutropenia.” This is a dangerously low WBC, in which the body is highly susceptible to infection.

WBC is proportional to the number of neutrophils in the blood, or absolute neutrophil count (ANC). “Neutropenia may be characterized clinically as mild neutropenia with an ANC of 1000-1500/μL, moderate neutropenia with an ANC of 500-1000/μL, or severe neutropenia with an ANC of less than 500/μL.” * The measurement is the total number per microliter or square millimeter.

Yesterday, I think they said that my blood test showed an ANC of 1200 (I will double-check this tomorrow), so I was mildly neutropenic. Today, it’s probably lower, and soon, it will start to raise back up as stem cells in my body grow into new white blood cells. To track my ANC, I’ll have blood tests every other day until I complete my treatment here. I’ll continue to get somewhat regular tests for a few months after I return home to be sure I’m headed for normal levels.

As one of the patients in my group said, “this is what we paid for, to become neutropenic.” I agree. This is when the MS-infected immune system becomes depleted, and we get to grow back a brand new one.

A couple days ago, I tried to cut my carbamazepine (Tegretol) dose by a third to check my resulting pain levels. (My primary MS symptom is pain.) That was a bad idea. A few hours later, I found myself gobbling down the rest to make up the remainder of the dose. I guess I got a little cocky because my pain levels have generally been lower since the first chemotherapy. No worries. There’s still two years of recovery ahead of me, so I need to remember to buck the urge for immediate satisfaction.

Anyway, I’ve been getting a daily shot of the stem cell mobilization medication, filgrastim, and I’m generally just waiting things out in isolation at this point. My sister, Ruth, is here to assist. Equipped with her surgical face mask, she went to Walmart today to do some grocery shopping. She also bought me a Wahl hair trimmer (total body grooming kit).

Goodbye body hair. It’s been falling out for a couple days, so time to get proactive. Most of the other patients are already bald.

* Dale DC, Cottle TE, Fier CJ, et al. (2003) Severe chronic neutropenia: treatment and follow-up of patients in the Severe Chronic Neutropenia International Registry. Am J Hematol 72(2):82–93.