Irrespective of the fact that Myeloid and Lymphoid both have the same suffix “–oid,” they are different from each other. Both the terms refer to the components of a certain organ or structure found in the human body. Myeloid refers to the structure of bone marrow, and lymphoid refers to the lymph or lymphatic system.
Myeloid vs Lymphoid
The main difference between myeloid and lymphoid is that the former term is used to define the structure or an illness that originates inside the bone marrow, whereas the latter term is used to refer to a component in the human body or the disease that occurs in the lymph or lymphatic system.
Myeloid is a term used to define the structure that originates in the bone marrow of a human body and refers to an illness related to blood or occurring in the bone marrow. When there is a severe lack of red blood cells in the body, it leads to cancer in the bone marrow.
Lymphoid is a term used to define the composition of a human body known as lymph or lymphatic system, and the term also used while describing a cancerous disease in the lymphatic system known as lymphoid leukemia. The lymphatic system of the human body is mainly responsible for its immune protection.
Comparison Table Between Myeloid and Lymphoid
| Parameters of Comparison | Myeloid | Lymphoid |
| Definition | A structure that originated in the bone marrow is known as the Myeloid. | The lymph and lymphatic system are known as Lymphoid. |
| Other definition | Myeloid is also used to define the illness occurring in the bone marrow. | Lymphoid is also used to define the illness occurring in the lymphatic system. |
| Disease development | It can occur in both RBC and WBC. | It occurs in the WBC only. |
| Subtypes | Myelodysplastic syndrome | Hairy cell leukemia |
| Types of malignancies | AML and CML. | ALL and CLL. |
What is Myeloid?
Myeloid term is used to describe the bone marrow structure in a human body, and the bone marrow contains myeloid cells, which are multipotent type stem cells. The myeloid cells produce many types of blood cells in the body, which namely are red blood cells (RBC), granulocytes like monocytes, neutrophils, eosinophils, basophils, and platelets.
There are two types of malignancies that occur in the bone marrow known as acute myelogenous/myeloid leukemia (AML) and chronic myelogenous/myeloid leukemia (CML). These two types of cancer happen due to the rapid growth of abnormal cells. Acute myelogenous/myeloid leukemia (AML) is a fast-growing form of blood or bone marrow cancer.
Chronic myelogenous/myeloid leukemia (CML) occurs in the blood-forming cells of bone marrow, and later with the span of time, it spreads to the bloodstream and therefore, as the blood reaches other parts of the body, the disease spreads in the whole body. There is another type of disease relating to myeloid known as Myelodysplastic Syndrome (MDS), in which there is an abnormal behavior shown by the bone marrow as it produces a fewer amount of functioning red blood cells (RBC), white blood cells (WBC), or platelets in the body. The cells in the blood and bone marrow seem to be abnormal when diagnosed.
What is Lymphoid?
Lymphoid that is used to describe the lymph or lymphatic system of the body contains lymphoid cells, which are a type of multipotent, hematopoietic progenitor cells. The lymphoid cells are mainly responsible for producing T and B lymphocytes along with natural killer cells. T lymphocytes play a major role in boosting immunity.
B lymphocytes produce antibodies which play a major role in humoral immunity. Natural killer cells help to respond against virally infected cells. There are two types of malignancies that occur in the lymphoid cells known as acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL). These two types of cancer happen due to the production of immature lymphoblasts in a large amount.
In acute lymphoblastic leukemia (ALL), the healthy cells which produce functioning lymphocytes are replaced rapidly, and thus, the cells remain immature. These immature cells then flow in the bloodstream to different body parts where the cells divide and grow, which results in various symptoms. Chronic lymphocytic leukemia (CLL) is a slow-growing cancer disease that occurs when there is an abnormal lymphocyte growth that obstructs the normal cells, in turn making it difficult to fight any infection.
The subtype of CLL, also known as hairy cell leukemia (HCL), occurs when there is a large production of B cells.
Main Differences Between Myeloid and Lymphoid
- The term Myeloid refers to the structure which originated or is related to the bone marrow, whereas the lymphoid term refers to the lymph or lymphatic system of the body.
- The term myeloid is also used to refer to a cancerous illness that is related to or occurs in the bone marrow, whereas on the other hand, the term lymphoid is also used to refer to an illness relating to or which occurs in the lymphatic system.
- The myeloid disease develops and attacks both the white blood cells (WBC) as well as the red blood cells (RBC), whereas on the other hand, the lymphoid disease known as lymphoid leukemia attacks and develops in the white blood cells (WBC) only.
- Myelodysplastic syndrome is the subtype of myeloid-related disease in which the bone marrow produces very less amount of functioning RBC, WBC, or platelets, and on the other hand, hairy cell leukemia is the subtype of chronic lymphatic leukemia in which the bone marrow produces too many B cells.
- In myeloid, AML and CML are the main types of malignancies, whereas in lymphoid ALL and CLL are the main types of malignancies.
Conclusion
Myeloid, which refers to the bone marrow structure, contains myeloid cells that are responsible for producing red blood cells, which carry oxygen throughout the body along with granulocytes, monocytes, and platelets in the body. Lymphoid, which refers to the lymph or lymphatic system, contains lymphoid cells which are responsible for producing T and B lymphocytes and natural killer cells that protect the body from foreign bodies. These two terms are different based on the type of blood cells they produce. Both the terms refer to a type of cancerous illness that occurs in the respective organs and destroys the cells of that certain component.
References
- https://www.nejm.org/doi/full/10.1056/nejm199909303411407
- https://www.nejm.org/doi/full/10.1056/NEJMra1406184
- https://www.nejm.org/doi/full/10.1056/NEJM199904293401706
- https://ashpublications.org/blood/article-abstract/107/9/3481/133476