The bone marrow is the factory where blood cells are made. Some types of chemotherapy slow down the factory and not as many blood cells are made. This can cause low levels of the three main types of blood cells:
White blood cells (fight infection)
Red blood cells (carry oxygen to the body)
Platelets (help to stop bleeding)
We check your child’s blood counts using a laboratory test called a Complete Blood Count or CBC. Blood counts are often lowest 7-10 days after chemotherapy is given, which is called the “nadir.”
Type of Blood Cell
White blood cell normal range: 4.0-10.5 k/uL
Red blood cell normal range: 4.2-5.6 M/uL
Platelets normal range: 160-370 K/uL
Leukopenia (Low White Blood Cell Count)
White blood cells fight infection. When your child has a low white blood cell count, the risk of infection increases. This is called leukopenia.
There are different types of white blood cells that have different jobs.
Neutrophils: Fight infection
Lymphocytes: Make antibodies to fight infection
Monocytes: Fight infection by killing and removing bacteria
Basophils and eosinophils: Respond during allergic reactions
A term you will hear often is Absolute Neutrophil Count or ANC. The ANC is the total number of neutrophils in the white blood cell count. A low neutrophil count is called neutropenia.
When your child’s ANC is less than 500, the risk of infection is high. During this time, it is very important to avoid crowds, avoid people who are sick, and focus on good handwashing.
If your child has a fever while their ANC is low, they may need to be admitted to the hospital for antibiotics. Chemotherapy may need to be delayed until the ANC increases.
Anemia (Low Red Blood Cell Count)
Red blood cells carry oxygen through the body. There are two tests that measure the number and function of red blood cells.
Hemoglobin: A protein in the red blood cells that carries oxygen.
Hematocrit: The percentage of blood made up of red blood cells.
When these tests results are low, the body is not able to carry as much oxygen around the body. This is called anemia. A blood transfusion may be given if your child’s hemoglobin is too low.
Symptoms of Low Hemoglobin
Energy levels decreasing through the day or needing more rest periods
Increased tiredness
Shortness of breath
Headache
Fast heart rate
Pale skin and/or pale gums
Dizziness
Call if your child is having any these symptoms. A blood transfusion is needed when the hemoglobin is less than 7 (or with a higher hemoglobin with symptoms of anemia).
Thrombocytopenia (Low Platelet Count)
Platelets stop bleeding in the body by forming clots. When your child has a low platelet count, the body is not able to clot well and the risk of bleeding increases. This is called thrombocytopenia.
Signs of a Low Platelet Count
Easy or excessive bruising, especially in locations that bruising is not expected
Petechiae (small, pinpoint spots on the skin)
Bleeding from the nose or gums
Black stools or vomit may mean blood is in the stomach or bowel)
Call if your child is having any these symptoms. A platelet transfusion is needed when the platelets are less than 10 (or with higher platelet counts with symptoms of bleeding).