What is Reticulocyte Count?
Reticulocytes are relatively immature red blood cells (RBCs) produced by the bone marrow. This test is used to determine the amount of reticulocytes in the blood and is a measure of bone marrow function or activity. It is suggested by a doctor if he suspects any symptoms of anemia such as fatigue, headache and weakness. Various conditions such as liver cirrhosis, erythroblastosis fetalis, bone marrow failure and folate deficiency can lead to different types of anemia.
This test is used to diagnose different types of anemia including aplastic anemia, hemolytic anemia, pernicious anemia and Iron deficiency anemia.
Why is Reticulocyte Count done?
The Reticulocyte Count Test is performed:
· To evaluate bone marrow activity to produce red blood cells
· To diagnose and distinguish between different types of anemia
· To determine the cause of abnormal results appearing in tests like Complete Blood Count (CBC), Hematocrit Test, etc.
· To monitor treatment efficacy and recovery of bone marrow activity after chemotherapy, bone marrow transplant, treatment for iron deficiency and folate deficiency anemia, or treatment for renal failure
What does Reticulocyte Count Measure?
Red blood cells or RBCs are the type of blood cells responsible for carrying oxygen from the lungs to the different parts of the body with the help of an iron-containing pigment called hemoglobin. RBCs are produced from the hematopoietic stem cells (stem cells which form blood cells). These stem cells differentiate to produce reticulocytes, which are released into the circulation where they eventually form RBCs. The nuclei of the hematopoietic cells degenerate during their differentiation and maturation into RBCs. The mature RBCs have no genetic material but the reticulocytes which are immature RBCs contain some genetic material in the form of RNA.
The lifespan of a RBC in circulation is 120 days. Under normal conditions, RBCs lost due to degradation after their lifespan or through bleeding are constantly replaced by the bone marrow to maintain RBC count in blood within a stable range.
The RBC count may be affected due to a number of conditions like hemolysis, heavy bleeding, diseases of the bone marrow, liver, or kidneys as well as treatment procedures like chemotherapy. This also affects the reticulocyte count.
The Reticulocyte Count Test measures the number and percentage of reticulocytes available in circulation. This helps to determine the ability of the bone marrow to supply the necessary amount of RBCs required by the body normally as well as in response to RBC loss due to bleeding. It also helps to diagnose conditions affecting the RBCs as well as those affecting the bone marrow and causing abnormal RBC production.
Interpreting Reticulocyte Count results
· Adults: 0.5% to 2.5%
· Children: 2% to 6%
Reticulocyte count may vary from person to person depending on a number of other factors. Hence, Reticulocyte Count Test is performed and interpreted together with other tests like CBC, Hematocrit, Iron Tests, etc. to determine the cause of abnormalities, if any.
Higher than normal reticulocyte count may indicate:
· Hemolytic anemia (anemia due to destruction of RBCs)
· Excessive bleeding
· Bleeding disorders in newborns
· Kidney diseases causing increased secretion of hormone erythropoietin
· Cigarette smoking
Lower than normal reticulocyte count may indicate:
· Bone marrow failure due to infections, cancer, chemotherapy, etc.
· Liver cirrhosis
· Iron deficiency anemia
· Pernicious anemia (vitamin B12 or folate deficiency)
· Aplastic anemia (anemia due to bone marrow damage)
· Kidney diseases causing decreased secretion of hormone erythropoietin