Since the last entry I've been back to work, and then I've stopped. To begin with I started working two half days on Tuesday and then Thursday. The first day in work was quite tiring despite not really doing any 'work'. I had to sift through the 1500 e-mails that had accumulated in my inbox during my absence. After arriving home that afternoon I just crashed out and went to sleep.

The Thursday was better, I wasn't so tired after the day at work. The following Tuesday was even better, but I received a call from my supervisor two days later on Thursday morning telling me that he'd come down with the flu. As we sit adjacent to each other I didn't come in to work, and in fact didn't go to work the following week either as he wasn't the only person there to have a cold. This would be one of the issues to clarify at my consultation, as I wasn't sure if it was sensible to return to work when colds and flus are becoming more prevalent during the winter months. It's strange talking about the winter months, because it feels like the entire year has flown past. I remember lying in hospital during the short cold winter days in January and February, and now we're nearly at the same stage at the other end of the year.

At the consultation, the big question was whether the PCR had continued to drop or had it risen again. Well, it turned out the the PCR did indeed rise again, this time to the level of 2.5. Bear in mind that the 'threshold' for action is 0.2 then became quickly apparent that the donor lymphocyte infusions or DLI would be necessary.

This involves contacting the donor through their registry which in this case is in Germany and requesting her to come in and give some lymphocytes. Lymphocytes are one of two types of white cells (the other being granulocytes or myeloid white cells). The lymphocytes are key to ridding the body of leukaemia after a bone marrow transplant as they will seek out the remaining cells with the chromosomal abnormalities that are are characteristic of CML with the Philadelphia chromosome. However the same lymphocytes are also responsible for causing graft vs host disease (GVHD) which can cause unwanted complications. Therefore there is a fine line to tread between having enough lymphocytes in the body to fight the leukaemic cells and not getting to much GVHD.

The BMT protocol at Hammersmith Hospital is to subdue the effectiveness of the lymphocytes in the early phases to lessen the risks of severe GVHD. In the process though there is a higher possibility of relapse in the months following the transplant. The PCR count of 2.5 has spotted the increase in leukaemic cell activity and therefore we need more lymphocytes to fight these faulty cells, hence asking the donor for more cells. As it has been eight months since the transplant with very little GVHD, there is a lower risk of the GVHD returning following the DLI, but then there is the desired effect of the lymphocytes killing off the faulty white cells.

The process for the donor is very straight forward. Her blood is circulated through a machine that extracts the excess lymphocytes from her system, and these are then injected into my arm. Simple. No anaesthetic or long stays in hospital. I'm then monitored for any GVHD and the PCR tests continue and hopefully the PCR count falls. As the initial DLI is a small dose there may not be any change, in which case a larger quantity of lymphocytes are given. The process is repeated with a larger amount if the previous amount doesn't yield more favourable results. This is a very successful treatment which was pioneered at the hospital, and I'll be meeting its chief exponent at my next appointment.

That's when I'll post the next update to the diaries.