Falling white cell count

Today I went back to the hospital for an extra clinic appointment after my diarrhoea attack last week. My neutrophils have fallen to 0.52, which is really bad, almost neutropenic. You may recall that the white cells consist of of lymphocytes that attack viruses and neutrophils that attack bacteria. My worst times in hospital were caused by e-coli infection when I was neutropenic, so I am a quite worried.

There are three possible causes of the drop in neutrophils: a) my neutrophils are pretty much all donor produced, but I do have some residual host immune system which is attacking the neutrophils; b) it is a common side effect of imatinib (Glivec) to lower blood counts; c) my leukaemia has returned.

Clearly, option c would be a disaster. The doctor thinks it is unlikely, because my platelets and haemoglobin are fine, and a relapse of leukaemia would normally knock all the counts. They have sent blood for a BCR-ABL test, that will show if there are leukaemia cells in my blood. The test takes a couple of weeks to be done, although they will try to expedite it for me. The doctor would also like a bone marrow biopsy, but since I am not so keen on the procedure we decided to wait for the results of the blood tests, although she said that if the blood tests are negative for a relapse of leukaemia, I might need the bone marrow biopsy anyway because it is a good way of seeing if the low blood counts are caused by my host immune system (and this can be treated if it is the case).

Rather than concentrate on finding the cause in the short term, I (and the doctor) am more concerned about infection. Accordingly, I had
a shot of GCSF today (the stem cell growth hormone) to try and boost my neutrophils, and also I will take a reduced dose of Glivec. I am going back to the hospital on Thursday to get another blood count, and hopefully my neutrophils will have recovered.

This all reminds me of the week before my transplant, when my red count dropped a lot in one day, and the doctor was worried it was caused by a relapse of leukaemia and took a bone marrow biopsy that day. I guess that whenever these symptoms occur (drop in blood counts), this is always a possible cause.

Assuming this is not a relapse of leukaemia, it seems there is a war raging inside me, over which I have very little control. On the one side is the donor immune system, attacking me (GVHD) and hopefully killing my host bone marrow, and on the other side the remnants of host immune system are attacking my donor immune system!