Leukopenia is a condition wherein the leukocyte count in the blood is low. Low WBC or White Blood Cells indicate decrease in disease fighting cells circulating in the blood. Some of the common causes for low WBC count:
Viral infections Any viral infections may disrupt bone marrow function for a short duration thus producing low counts of white blood cells. Infections like typhoid, influenza may lower the white blood cell count.
Congenital disorders may weaken bone marrow function, a WBC spectrum test can confirm any such congenital disorder.
Kostmann's syndrome is a congenital disorder wherein the neutrophil production is low.
Myelokathexis Neutrophils fail to enter the blood stream.
Infectious disease HIV destroys the WBC and leaves the person susceptible to infections.
Vitamin or mineral deficiencies
Autoimmune disorders may destroy white blood cells or bone marrow cells.
Aplastic anemia In this condition the bone marrow does not produce enough of any of the cells including white blood cells. This condition may set in all of a sudden or can develop and progress gradually. Few drugs, pregnancy, radiation therapy or chemotherapy can trigger this condition.
Lupus is an auto immune disease wherein the body fights with its own immune system thus destroying white blood cells.
Chemotherapy and radiation therapy are used to kill cancerous cells. They however destroy healthy white blood cells thus leaving the patient with low WBC count. This is one major reason why cancer patients are unable to fight diseases or infections in general.
Leukemia is a type of cancer wherein the body produces too many white blood cells that are abnormal. These white blood cells are not active white blood cells that can fight infections. People down with leukemia have low white blood cell count as their bone marrow is producing more of the abnormal white blood cells.
Cancer may also damage the bone marrow.
Hyperthyroidism An overactive thyroid can produce lower number of white blood cells. The medication used for thyroid can reduce the white blood cell count in the blood.
Liver disorder/Spleen disorder Hypersplenism, in which blood cells are destroyed prematurely by the spleen. An enlarged spleen also known as splenomegaly can trigger low white blood cell count.
Bone Marrow Aspiration
Bone marrow refers to the spongy tissue that is found inside the larger bones such as spine, breast bone, hips, ribs, legs and skull. Marrow has two parts – both solid and liquid. If the solid portion of the bone is sampled, it is called biopsy. Aspiration procedure is used to collect the liquid part of the marrow.
Both the procedures show whether the bone marrow is healthy and making normal amounts of blood cells. This procedure is normally used by doctors to diagnose and monitor blood and marrow diseases, including cancer. In bone marrow aspiration, the doctor uses a needle to draw a sample of the fluid portion. For a biopsy, a larger needle is used to take the sample of the solid part.
Most often bone marrow aspiration and bone biopsy is done at once. Together, they make the bone marrow examination. Although they are different procedures, they offer complementary information about bone marrow cells.
Why is it done?
Bone marrow aspiration and biopsy offer detailed information about the condition of the bone marrow and blood cells. In case the blood tests indicate that cell counts are abnormal, and information is not sufficient about a suspected problem, this is done. The doctor may perform bone marrow exam to diagnose a disease condition involving the bone marrow or blood cells:
Pre bone marrow aspiration procedure
It is imperative to inform the doctor about any medications and supplements the patient is consuming. This can increase the risk of bleeding after a bone marrow aspiration. In case of anxiety or worry, better talk to the health care provider so that a sedative medication could be given before the aspiration in addition to a numbing agent through local anesthesia at the site where the needle is inserted.
Bone marrow aspiration is done in a hospital, a clinic or in a doctor's room. A specialist in blood disorders – a hematologist – or an oncologist, who is a specialist in cancer does the procedure with a nurse and a trained technologist. It usually takes about half an hour for the exam and if any intravenous sedation is given, extra time is taken for pre and post procedure care.
The patient's blood pressure and heart rate are checked. Some form of anesthesia is administered before the bone marrow aspiration as it can be painful. For many, local anesthesia is sufficient. You will be fully awake during the aspiration, but the site is numbed to reduce pain. If you are quite anxious, intravenous IV sedation is given before the marrow procedure.
Bone marrow aspiration procedure
The area for inserting the biopsy needle is marked and cleaned. The bone marrow fluid (aspirate) is usually collected from the top ridge of the back of the hipbone, and if it is done from the breast bone or the front of the hip near the groin. In young children and kids, the sample is taken from the lower leg bone, just below the knee. The patient will be made to lie down on the abdomen or side.
The bone marrow aspiration is usually done before the biopsy. A small incision is made to insert the needle easier. A hollow needle is inserted through the bone and into the bone marrow. Several samples are taken and aspiration takes only a few minutes. While the health care team ensures that sufficient quantity of sample is drawn, sometimes a 'dry tap' may occur, that is fluid cannot be withdrawn. The needle is moved for another attempt.
Post aspiration procedure
After the bone marrow exam, pressure is applied to the where the needle was inserted to stop the bleeding. A smaller bandage is placed on the site. If local anesthesia had been administered the patient is asked to lie back for 10-15 minutes and apply pressure on the biopsy site. In case, IV sedation had been given, you are taken into a recovery area as sedatives may cause impaired judgment, memory lapses or slowed response.
Tenderness may be felt for a week or more after the bone marrow exam, and the doctor administers pain reliever. You need to keep the bandage dry for 24 hours and not shower or bathe, or swim or use the hot tub. It is okay to get the aspiration site wet after 24 hours. In case bleeding soaks through the bandage, or does not stop even with direct pressure, consult the doctor. The doctor also needs to be contacted if there is persistent fever, worsening pain, swelling at the procedure site and increasing redness or drainage at the procedure site. Also it is advised to avoid rigorous activity for a couple of days to minimize bleeding and discomfort.
Results from bone marrow aspiration
The sample is sent to a laboratory for analysis. The results are available in a few days. The pathologist or hematologist evaluates the samples to check the health of the marrow and if it has enough healthy blood cells and also for abnormal cells. The doctor confirms or rules out a diagnosis and how advanced the disease is or if the treatment is working. Sometimes, follow-up tests are done.
Risks of bone marrow examination
This is a safe procedure and complications are rare. But some complications include:
Excessive bleeding which can happen in people with low platelet count.
Infection in those with weakened immune systems.
Discomfort that could be long lasting in the biopsy site.
Heart and lung problems can be caused due to penetration of the breastbone.
Sedation can cause allergic reaction, nausea and irregular heartbeats in some.
Uses of bone marrow exams
These are used for many conditions including:
While problems with bone marrow can create lasting and serious health problems, bone marrow exams, such as aspiration and biopsy are important to help determine the status and extent of problems in the cells to evaluate and determine further treatment and management.
Complete Blood Count
A Complete Blood Count test CBC is a diagnostic test to measure the following in blood - the number of red blood cells, the number of white blood cells, Platelets and the total amount of hemoglobin in blood. Hematocrit (HCT) is the fraction of blood composed of red blood cells.
A Complete Blood Count normally includes the following components:
A CBC test provides information on measurements such as average red blood cell size or MCV, Hemoglobin per blood cell or Mean Corpuscular Hemoglobin MCH, hemoglobin concentration or the amount of hemoglobin relative to the size of the cell, per red blood cell or MCHC and platelet count.
Why Complete Blood Count test?
This is a complete lab test and is used to detect or monitor different health conditions. A doctor may require this test for various reasons: As a routine check up
If the patient exhibits symptoms such as fatigue, weight loss, fever or any other signs of infection, weakness, bruising, bleeding or signs of cancer
Blood count results may change if you are receiving treatment for medicines and radiation
To monitor any chronic health problem that can change your blood count results such as chronic kidney disease.
Results of CBC
Though blood count may vary with altitude, in general the normal ranges are given below. But it should be noted that these ranges may vary slightly from one laboratory to another. Various laboratories use varied measurements or test different samples. It is best to have it interpreted by a health care provider.
Red blood cell indices:
MCV (Mean Corpuscular Volume): 80 to 95 femtoliter
MCH (Mean Corpuscular Hemoglobin): 27 to 31 pg/cell
MCHC (Mean Corpuscular Hemoglobin Concentration): 32 to 36 gm/dL
RBC (erythrocyte) count:
Male: 4.7 to 6.1 million cells/mcL
Female: 4.2 to 5.4 million cells/mcL
WBC (leukocyte) count:
4,500 to 10,800 cells/mcL
Male: 40.7 to 50.3%
Female: 36.1 to 44.3%
Male: 13.8 to 17.2 gm/dL
Female: 12.1 to 15.1 gm/dL
Platelet (thrombocyte) count:
150,000 to 450,000/dL
What abnormal results mean?
An abnormal result means elevated RBC, hemoglobin or Hematocrit. These may be due to various factors including lack of adequate water and fluids due to severe diarrhea, excessive sweating or if diuretics are used to treat hypertension.
Low RBC, hemoglobin or hematocrit is also a sign of which result due to blood loss on account of heavy menstrual periods over long periods of time, bone marrow failure from radiation, infection or tumor, Hemolysis or breakdown of red blood cells, chronic kidney disease, ulcerative colitis or rheumatoid arthritis, leukemia, multiple myeloma, long term infections such as hepatitis, poor diet and nutritional deficiencies of iron, Vitamin B6, Vitamin B12 and folate.
High levels of Hematocrit can be the result of dehydration, diarrhea, erythrocytosis or myeloproliferative disorders such as Polycythemia Vera.
Lower than normal white blood cell count, or Leukopenia (Leucopenia), can be the result of alcohol abuse and liver damage, autoimmune diseases, bone marrow failure due to infection, tumor, radiation or fibrosis, chemotherapy medicines, disease of liver or spleen, enlarged spleen, infections caused by viruses such as AIDS or medications.
High WBC count is called leukocytosis which can result from certain medicines such as corticosteroids, infections, diseases such as rheumatoid arthritis or allergy, leukemia and severe emotional and physical stress, tissue damage
High platelet count may be due to bleeding - diseases such as cancer, iron deficiency, problems with the bone marrow.
Low platelet count may be due to anemia, disorders where platelets are destroyed during pregnancy, enlarged spleen, bone marrow failure (for example, due to infection, tumor, radiation, or fibrosis), Chemotherapy medicines used to treat cancer.
Disease of the platelets is known as Thrombocytopathy, which could be due to lower Platelet counts (a condition called as Thrombocytopenia or Thrombopenia), or due to a decrease in function (called as Thrombasthenia) or an increase in the number of platelet (addressed as Thrombocytosis). Normal platelet counts do not necessarily indicate normal functioning. In some cases the platelet counts may appear normal but the platelets themselves are dysfunctional. Aspirin inhibits cyclooxygenase-1 (COX1) which results in the disruption of platelet function affecting coagulation. Normal platelet function will be restored only when the affected platelets have been replaced which can take a week.
Precaution : At the time of drawing the blood, it is necessary to clean the venipuncture site with alcohol.
Bibliography / Reference
Collection of Pages - Last revised Date: February 17, 2019