Full blood count (FBC) and differential
These are routinely trquested tests that are performed in order to count the number and relative proportion of each of the different types of cells in the blood stream. They give your doctor information about the size, shape, and relative maturity of the blood cells present. FBCs and differentials are snapshots of what is happening in the body at the time the blood is taken. They are used to detect cell abnormalities, determine their importance, help diagnose their cause, and to monitor response to treatment. Irregularities in cell counts, such as elevated WBC counts or low RBC counts, may be due to bone marrow disorders, but they may also be due to a variety of other temporary or chronic conditions.
Bone marrow aspiration/biopsy
If your doctor suspects a bone marrow disorder, they may then perform a bone marrow aspiration or biopsy to investigate the production and maturation of the different cell lineages present in the bone marrow.
When a doctor examines the sample from your bone marrow under the microscope, they will be able to see the number, size, and shape of your red and white blood cells and platelet precursors (megakaryocytes), determine the proportions of mature and immature cells, see any overgrowth of fibrous tissue, and detect any cancer cells from cancers that may have spread to the marrow. Most bone marrow disorders can be diagnosed during this examination.
Iron storage can also be estimated by a marrow examination, although if iron deficiency is suspected, further blood tests are usually requested to confirm the diagnosis (ferritin, iron and total iron binding capacity).
Flow cytometry is a technique that is used to measure cell surface antigens present on the different blood cell lineges. This can be performed on cells from the bone marrow, peripheral blood, or other body fluids. This technique involves incubating your blood cell antigens with specific antibodies which bind these markers. The binding of these antibodies can then be used to determine if the cell population is normal or abnormal.
These tests look at several different types of genetic abnormalities in blood cells.
- Karyotyping: looks for numerical and structural chromosomal abnormalities. Structural abnormalities include translocations in which part of one chromosome is transferred to different a location.
- Mutation analysis can be used to determine when specific changes arise to the genetic material. These include deletion and insertions to the DNA. This technique involves removing the DNA from the cell population in the bone marrow or the blood, manipulating the DNA to find the correct gene, and then using special tests that look for one of the abnormalities listed above in the isolated gene.
Lumbar puncture (spinal tap)
If leukaemia is found in the bone marrow, a lumbar puncture may be performed by the doctor as a follow-up test to look for leukaemic cells in the cerobrospinal fluid (CSF).
X-rays are sometimes used to look for signs associated with some bone marrow diseases, such as masses of cells in areas like the chest, spleen, and liver.