- "Understanding Severe Chronic Neutropenia" by Audrey Anna Bolyard, R.N.,B.S., Tammy Cottle, Carole Edwards, R.G.N./R.S.C.N., Bsc., Sally Kinsey, M.D., Beate Schwinzer, Ph.D., Cornelia Zeidler, M.D.

When a diagnosis of neutropenia is suspected (e.g. with recurrent infections which may occur on a cyclical basis) physicians will begin by taking a Complete Blood Count/Full Blood Count and proceed to further tests if necessary. These examinations will be extended to include the bone marrow of the patient. The most important investigations performed are explained below.

The blood investigation, Complete Blood Count (CBC) or Full Blood Count (FBC), is the same thing and these terms are interchangeable.

Blood Count Monitoring

As already mentioned, the first investigation on suspicion of neutropenia is a CBC/FBC. By this procedure the neutrophil count is measured. If the neutrophil count is low it is normal to repeat the CBC/FBC to be certain that the neutropenia continues. In patients with SCN the neutrophil count may vary slightly, but in contrast to cyclic neutropenia it always remains at a very low level.

Sometimes the neutrophil count can be normal because of a cyclical change, but at other times it is very low. In this case your physician may suspect cyclic neutropenia, then he/she will arrange for blood samples (CBC/FBC) to be taken three times per week for at least six weeks to see whether there is a regular cyclical pattern of neutrophil counts.

Other Blood Tests

Your physician will also do a blood test to exclude autoimmune neutropenia by testing for antibodies.

Bone Marrow Aspirate/Thephine Biopsy

If your physician thinks from the blood tests that you have a type of neutropenia, then it is important to do a bone marrow examination to confirm the diagnosis by looking at the marrow cells under the microscope.

Bone marrow cells are usually taken from the large pelvic bone, the ilium, or, sometimes also from the flat breastbone, the sternum. This is usually done with the patient asleep under general anaesthetic or under local anaesthetic with sedation. The actual technique may vary between treating centres. Your physician will explain exactly how the procedure will be done for you.

There are two different methods to examine bone marrow. Firstly, marrow cells can be taken out like taking a blood sample from a vein (bone marrow aspirate), but this time from the middle of the bone. Secondly, a small piece of the solid, bonier part of bone marrow is taken (bone marrow biopsy) and processed differently, to look at the architecture of the marrow structure.

Cytogenetic Evaluation and Molecular Testing

It is important to monitor the cytogenetics of the marrow cells. Any morphological abnormality of the marrow cells may be preceded by a change in cytogenetics.

There are additional techniques by which some cytogenetic changes can be monitored; your physician will explain these to you.

SCN is a very rare disorder. Some treating centres are actively involved in research of SCN and may wish to discuss other investigations.

Investigation in Other Conditions

To be certain about the diagnosis of conditions that are not limited to the blood system like Shwachman-Diamond syndrome and Glcogen-Storage Disease, it will be necessary to do different investigations, in addition to blood tests. Your physician will explain what further tests are required. Sometimes this may even involve being seen by another specialist.