Dear Carol and anyone else with a similar problem.

Neutropenia.

Neutrophils are normally the commonest type of white blood cells in the blood. Their function is to eat bacteria and other small items. They spend only 6 hours in the blood, being on the way to the tissues where they do most of their work.

Down the microscope they look a little larger than CLL cells. Their nucleus is lobulated with 2-5 lobes. The rest of the cell is filled with small granules which contain the enzymes that digest whatever they eat. They are called neutrophils because when stained with a mixture of red and blue dyes, the granules are colored purple as opposed to the eosinophils that stain red and the basophils that stain dark blue.

The normal numbers are between 2500 and 8000 per cu mm (or 2.5 and 8.0) though there are variations with age and race and among cigarette smokers.

Often they are reported as percentages, but this is very misleading; what matters is the absolute number of neutrophils.

Mild neutropenia 1000-2000 /cu mm is very common and can mean almost anything. unless the fall is progressive no action is usually taken. When the count gets less than 1000 then we get interested. In CLL neutropenia is part of the marrow failure process like anemia and thrombocytopenia and means that the disease is advancing and treatment is necessary. There is an autoimmune cause (like ITP or hemolytic anemia) but it is very rare (although it is seldom looked for). Severe neutropenia is usually caused by chemotherapy and it is managed in exactly the same way as when it occurs following chemotherapy for anything else.

A neutrophil count of less than 500 is temporary and depending on the type of chemotherapy is unlikely to last for more than 1-2 weeks. Usually the patient is isolated, and uncooked food likely to carry bacteria is avoided - salads, fruit etc. Any raised temperature is taken seriously and appropriate antibiotics started. We now use prophylactic antibiotics in patients with temporary neutropenia less than 500. and our choice is ciprofloxacin. We are worried about gram negative infections that can make patients very ill very quickly. If an infection is established the there is a round of empirical antibiotics that starts in out unit with gentamicin and tazobactam followed by ceftazadine and vancomycin, followed by amphoterecin, but every hospital has its own schedule that depends in the type of organisms common in that locality.

As I say severe neutropenia is not usually a concern in CLL, but it could be after chemotherapy (especially CHOP or FNCR or even FC) and it is always a concern during a transplant.