Exame de reticulócitos: para que serve e como é feito? Entenda de uma vez por todas!

Summary

This video explains the reticulocyte count exam, a blood test used to measure immature red blood cells (reticulocytes) in the bloodstream. The test helps assess bone marrow function and can indicate various types of anemia, such as hemolytic anemia or deficiencies in iron and vitamin B12. High reticulocyte levels suggest the body is compensating for blood loss, while low levels may point to bone marrow suppression. The video also discusses how the test is performed and the various medical conditions that it can help diagnose, making it an essential tool for understanding blood health.

Takeaways

• 😀 Reticulocytes are immature red blood cells that haven't fully matured and still contain RNA.
• 😀 The reticulocyte count test measures the percentage of these immature cells in the blood, providing insight into bone marrow activity.
• 😀 Immature red blood cells are typically formed in the bone marrow and should mature before entering the bloodstream to function properly.
• 😀 When the body experiences blood cell destruction (hemolysis), the bone marrow increases production, sometimes releasing reticulocytes prematurely.
• 😀 Reticulocytes are essential for assessing the cause of anemia, as an increased count suggests hemolytic anemia and a decreased count points to possible deficiencies or bone marrow issues.
• 😀 The reticulocyte count is often part of a broader blood test, such as a hemogram, to evaluate overall blood health and diagnose anemia.
• 😀 A higher than normal reticulocyte count can indicate anemia caused by excessive red blood cell destruction or diseases like sickle cell anemia and thalassemia.
• 😀 A low reticulocyte count may suggest an iron, B12, or folate deficiency, or an issue with the bone marrow's ability to produce red blood cells.
• 😀 The reticulocyte test is often combined with additional tests, such as serum iron, ferritin, and vitamin B12 levels, to pinpoint the specific type of anemia.
• 😀 In addition to anemia diagnosis, a reticulocyte count can provide clues to more serious conditions like leukemia, lymphoma, or bone marrow disorders.
• 😀 The test uses a special stain (like blue cresyl) to highlight the RNA in reticulocytes, which distinguishes them from fully mature red blood cells.

Q & A

What are reticulocytes and how do they differ from mature red blood cells?

Reticulocytes are immature red blood cells (RBCs) that still contain residual RNA, which prevents them from carrying oxygen effectively. Unlike mature RBCs, which have no nucleus or RNA and are fully functional in oxygen transport, reticulocytes are not yet capable of performing this primary function due to the genetic material present in them.

Why are reticulocytes produced in the bone marrow?

Reticulocytes are produced in the bone marrow as part of the normal process of red blood cell formation. The bone marrow is responsible for creating all blood cells, including RBCs, leukocytes (white blood cells), and platelets. Reticulocytes are the last stage before RBCs mature and enter the bloodstream.

How does the presence of reticulocytes in the blood relate to anemia?

The presence of reticulocytes in the blood indicates that the body is producing new red blood cells, often due to a loss of mature RBCs (such as from hemolysis or blood loss). If there are too many reticulocytes, it suggests the body is compensating for RBC destruction or loss. On the other hand, a low reticulocyte count could indicate a bone marrow disorder or a deficiency in key nutrients like iron or B12.

What role does the reticulocyte count play in diagnosing anemia?

The reticulocyte count helps to assess bone marrow activity and RBC production. A high reticulocyte count can indicate a hemolytic anemia (where RBCs are destroyed prematurely), whereas a low count can suggest anemia due to insufficient production in the bone marrow, possibly caused by deficiencies in nutrients like iron, vitamin B12, or folate.

How is the reticulocyte count test performed?

The reticulocyte count is usually done as part of a hemogram, where a small blood sample is taken from the patient. The blood is then examined under a microscope, often using a special stain like Cresyl Blue to highlight the residual RNA in reticulocytes. This allows for the quantification of reticulocytes as a percentage of total RBCs.

What is Cresyl Blue staining and why is it used in the reticulocyte count?

Cresyl Blue is a special stain used to highlight the residual RNA in reticulocytes. Reticulocytes contain genetic material, and the dye binds to this RNA, allowing it to be visualized under a microscope. This staining helps differentiate reticulocytes from mature red blood cells and provides a clearer count during testing.

What are the normal reference values for reticulocyte count?

Normal reference values for reticulocyte count typically range from 0.5% to 1.5% of total red blood cells. A value above 3% is generally considered abnormal and may suggest an issue such as hemolysis or a response to blood loss.

What conditions could lead to an increased reticulocyte count?

An increased reticulocyte count may indicate conditions such as hemolytic anemia, acute blood loss, or recovery from anemia. It is also seen in situations where the bone marrow is compensating for the destruction or loss of red blood cells, for example, in the case of autoimmune diseases, infections, or certain types of cancer.

What conditions might cause a decrease in reticulocyte count?

A decrease in reticulocyte count can be caused by conditions such as iron deficiency anemia, pernicious anemia (due to a lack of vitamin B12), aplastic anemia (where the bone marrow fails to produce enough blood cells), or bone marrow suppression due to chemotherapy or radiation therapy.

How can a reticulocyte count help guide treatment for anemia?

A reticulocyte count helps determine whether the bone marrow is actively producing new red blood cells. If the count is low, it may suggest a need for nutritional supplementation (e.g., iron, vitamin B12, or folic acid) or treatment for an underlying bone marrow disorder. Conversely, a high reticulocyte count might lead to further investigation into the cause of RBC destruction or blood loss.