What are monocytes and what do they do?
The monocyte’s nucleus appears dark purple in the center of the cell and can take the shape of:
- A lumpy kidney bean.
- A horseshoe.
- A lopsided circle.
- A circle with an indentation.
What are the causes of high monocyte levels?
The disease conditions that cause high monocyte count are:
- Sarcoidos (unusual tiny, circular shaped bumps formation on the surface of the affected tissues)
- Chronic granulomatous disease (genetic disorder where immune system cells can not destroy specific types of bacteria, fungus etc.)
- Cushing’s syndrome (excess secretion of steroidal hormone like cortisol from adrenal gland)
What do monocytes do in a body?
Some conditions that can cause monocytosis include:
- Endocarditis, a heart valve infection
- Tuberculosis, a lung infection
- Syphilis, a sexually transmitted disease
- Collagen vascular disorders, an inflammation of the collagen and joints
- Sarcoidosis, an inflammatory disease
- Protozoan or rickettsial infections
- Bone marrow recovery
- Hematologic disorders, which affect your blood
What is the normal percent of monocytes?
The normal range of monocytes is usually between 2%-10% of your total white blood cell count. Having a high or low monocyte count doesn’t usually cause symptoms itself. However, you may notice symptoms of the condition that is affecting your absolute monocyte count.
What does it mean when your monocytes are high?
What Does a High Monocyte Count Mean? A high monocyte count — also called monocytosis — is often associated with chronic or sub-acute infections. It can also be linked with some types of cancer, especially leukemia. A high monocyte count can occur when you are recovering from an acute infection.
Should I be concerned if my monocytes are high?
If you have a high monocyte count, it's likely due to an infection or another medical cause. If your monocytes are elevated due to an infection, they will get back to normal levels when the infection resolves. If they are elevated due to a medical condition, you would need medical treatment.
What is a normal range for monocytes?
What is a normal range for my monocyte count? A normal monocyte count is between 2% and 8% of your white blood cell count. This equals about 200 to 800 monocytes per microliter of blood in healthy adults. If your monocyte count is outside those ranges, you're at risk of acquiring a monocyte-related condition.
What does it mean when your monocytes are low?
Having low levels of monocytes may mean your body is more susceptible to infection. If your white blood cell count is low, you may also have low absolute monocytes. Causes of a low white blood cell count can include: infection.
What cancers cause high monocytes?
Chronic myelomonocytic leukemia (CMML) is a rare type of cancer that begins in the blood-forming cells in the bone marrow, leading to abnormally high levels of white blood cells called monocytes. ... In most cases of CMML, the cause is unknown.More items...•
Does Covid 19 cause high monocytes?
Furthermore, increased proliferation of monocytes derived from patients with severe COVID-19 after in vitro challenge with lipopolysaccharide was discussed as an indicator for a release of immature myeloid cells from the bone marrow reminiscent of emergency myelopoiesis (137) and contributing to innate immune ...
What autoimmune diseases cause high monocytes?
A high monocyte count is a potential sign of many different medical conditions. It's often linked to infectious diseases like mononucleosis or an autoimmune disease like lupus. Some medications can cause monocytosis. It's also linked to conditions such as blood disorders and certain cancers.
What is the function of monocyte?
Monocytes are a critical component of the innate immune system. They are the source of many other vital elements of the immune system, such as macrophages and dendritic cells. Monocytes play a role in both the inflammatory and anti-inflammatory processes that take place during an immune response.
How are you tested for leukemia?
Blood tests. By looking at a sample of your blood, your doctor can determine if you have abnormal levels of red or white blood cells or platelets — which may suggest leukemia. A blood test may also show the presence of leukemia cells, though not all types of leukemia cause the leukemia cells to circulate in the blood.
What cancers cause low monocytes?
These types of cancers include leukemia, lymphoma, and multiple myeloma. Amounts of different white blood cells. Higher-than-normal numbers of lymphocytes or monocytes can indicate the possibility of certain types of cancers. Some cancers and their treatments may cause neutropenia.
How do you treat low monocyte count?
Regular exercise is an important component to overall good health and maintaining the right blood counts. There's some evidence to suggest exercise can help improve monocyte function, especially as you age. Since monocytes respond to inflammation, an anti-inflammatory diet might be beneficial.
Can stress cause low monocytes?
Even though acute stress decreases blood monocyte levels in humans (Brazaitis et al., 2014), it is still unclear whether this is in a subtype-dependent manner.
What are monocytes? What are their functions?
Monocytes protect against viral, bacterial, fungal, and protozoal infections. They kill microorganisms, ingest foreign particles, remove dead cells, and boost the immune response [ 3, 1, 4, 2 ]. However, they can also be involved in the development of inflammatory diseases like arthritis and atherosclerosis.
How do monocytes work?
In this post, we’ll take a closer look at how monocytes work and how they may be implicated in disease [ 5, 6, 7 ]. Monocytes can kill microbes, boost your immunity, and remove dead cells. Once they enter your tissues, they become macrophages.
Why are monocytes high?
The most common causes of high monocytes (monocytosis) are chronic infections and inflammation. In turn, high monocytes can worsen inflammation and clog your blood vessels. Many health conditions can also cause low monocyte levels (monocytopenia), including autoimmune diseases and nutrient deficiencies.
What are the conditions that can cause high monocyte levels?
However,several other conditions can also be associated with monocytosis, such as heart disease, depression, diabetes, and obesity [ 21, 22, 47 ]. The conditions most commonly associated with high monocyte levels are:
What is high monocyte count?
High Levels of Monocytes (Monocytosis) Monocytosis is a condition in which the number of monocytes circulating in the blood is increased to more than 0.8×109/L in adults.
What is the role of monocytes in a low level?
Takeaway. Further Reading. Monocytes are the largest of all white blood cells and play an important role in the defense against germs and in inflammation.
What is the largest type of white blood cell?
Monocytes are the largest type of white blood cell. Approximately 2 to 10% of white blood cells are monocytes [ 1 ]. These immune cells circulate in the blood for several days before they enter the tissues, where they become macrophages or dendritic cells [ 1, 2 ].
Why are monocytes important?
Like other white blood cells, monocytes are important in the immune system’s ability to destroy invaders, but also in facilitating healing and repair. Monocytes are formed in the bone marrow and are released into peripheral blood, where they circulate for several days. They comprise about 5% to 10% of the circulating white blood cells in healthy ...
What percentage of white blood cells are monocytes?
They comprise about 5% to 10% of the circulating white blood cells in healthy individuals. Monocytes are probably best known for their role in serving as something akin to reserve forces in the military.
How do monocytes fight infection?
From above, we know that some monocytes transform into macrophages in the tissues that are like Pac-Man, gobbling up bacteria, viruses, debris, and any cells that have been infected or are sick.
What are the two types of white blood cells called?
Some of them may be called up if needed, to form the precursors of two other types of white blood cells: tissue macrophages and dendritic cells . But monocytes also have other roles in infection and disease, some of which have nothing to do with tissue macrophages and dendritic cells.
Why are monocytes high?
An increase in monocytes may be due to an infection by bacteria, fungus, or virus. It can also be a response to stress. Elevated monocyte counts may be due to a problem with blood cell production. In certain cases, the excess is due to a malignancy, such as certain types of leukemia.
Where do monocytes migrate?
In the Spleen. A good number of human monocytes are believed to migrate into tissues throughout your body where they may reside or give rise to macrophages that perform essential functions to fight infection and clean up dead cells.
Why do monocytes increase in CBC?
An increase in monocytes may be due to an infection by bacteria, fungus, or virus.
What are the functions of monocytes?
Function. Monocytes and their macrophage and dendritic cell progeny serve three main functions in the immune system. These are phagocytosis, antigen presentation, and cytokine production. Phagocytosis is the process of uptake of microbes and particles followed by digestion and destruction of this material.
What are the different types of monocytes?
There are at least three types of monocytes in human blood: 1 The classical monocyte is characterized by high level expression of the CD14 cell surface receptor (CD14 ++ CD16 − monocyte) 2 The non-classical monocyte shows low level expression of CD14 and additional co-expression of the CD16 receptor (CD14 + CD16 ++ monocyte). 3 The intermediate monocyte with high level expression of CD14 and low level expression of CD16 (CD14 ++ CD16 + monocytes).
What are some examples of processes that can increase a monocyte count?
Examples of processes that can increase a monocyte count include: A high count of CD14 + CD16 ++ monocytes is found in severe infection ( sepsis) In the field of atherosclerosis high numbers of the CD14 ++ CD16 + intermediate monocytes were shown to be predictive of cardiovascular events in at risk populations.
How long do monocytes stay in the blood?
Monocytes circulate in the bloodstream for about one to three days and then typically move into tissues throughout the body where they differentiate into macrophages and dendritic cells. They constitute between three and eight percent of the leukocytes in the blood.
How do monocytes differentiate into dendritic cells?
In vitro, monocytes can differentiate into dendritic cells by adding the cytokines granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin 4. Such monocyte-derived cells do, however, retain the signature of monocytes in their transcriptome and they cluster with monocytes and not with bona fide dendritic cells.
What is the name of the cell that differentiates into macrophages and dendritic cells?
Anatomical terms of microanatomy. 3D Rendering of a monocyte. Monocytes are a type of leukocyte, or white blood cell. They are the largest type of leukocyte and can differentiate into macrophages and conventional dendritic cells.
What is the geometry of monocyte nucleus?
The archetypal geometry of the monocyte nucleus is ellipsoidal; metaphorically bean-shaped or kidney-shaped, although the most significant distinction is that the nuclear envelope should not be hyperbolically furcated into lobes. Contrast to this classification occurs in polymorphonuclear leukocytes.
What is the purpose of monocytes?
Treatment. Tips for healthy levels. Bottom line. Share on Pinterest. Monocytes are a type of white blood cell. They help fight bacteria, viruses, and other infections in your body. Along with other types of white blood cells, monocytes are a key element of your immune response.
Why are monocytes important?
Monocytes, along with other types of white blood cells, are a vital part of your immune system. They help protect you against infection and illness. If your monocytes are higher than they should be, your doctor will work with you to find the cause and start any treatments that may be necessary.
What does it mean when your monocytes are high?
When your monocyte level is high — known as monocytosis — it means your body is fighting something. Some conditions that can cause an increase in the monocytes in your blood are: viral infections, such as infectious mononucleosis, mumps, and measles. parasitic infections. chronic inflammatory disease.
What is the most common sign of chronic myelomonocytic leukemia?
chronic inflammatory disease. tuberculosis (TB), a chronic respiratory disease caused by a type of bacteria. Having too many monocytes is also the most common sign of chronic myelomonocytic leukemia. This is a type of cancer that begins in the cells that produce blood in bone marrow.
How many types of white blood cells are there?
There are five types of white blood cells, each with a specific purpose. Your bone marrow produces monocytes and releases them into your bloodstream. Once they reach tissues in your body, they’re called macrophages. There, they isolate and gobble up germs and other harmful microorganisms.
How to know how many monocytes are in your blood?
To know how many monocytes are circulating in your blood, you’ll need a blood differential test. This test determines the level of each type of white blood cell in your blood. It can also tell if some types of white blood cells are abnormal or immature. The blood differential test is done the same way as most other blood tests.
What type of cells secrete chemicals to help fight allergies and infectious agents?
Here’s a bit about the other types of white blood cells: Basophils secrete chemicals to help fight allergies and infectious agents. Eosinophils attack parasites and cancer cells and assist with allergic response. Lymphocytes produce antibodies against bacteria, viruses, and other invaders.
What are monocytes?
Monocytes are cells of the immune system that represent immune effector cells with chemokine receptors and pathogen recognition receptors that circulate through blood or remain localized in lymphoid organs. These cells account for about 5% of the total circulating nucleated cells in human blood and have a half-life ...
Why are monocytes important?
Monocytes are essential for both the innate immune system and the adaptive immune system as these differentiate into macrophages and dendritic cells. Monocytes are one of the master cells of the immune system as these can perform a group of different functions performed by different immune cells. These can recognize danger signals ...
What is the subset of monocytes that express MHC class II?
Besides, human blood also contains another smaller subset of monocytes that are distinguished by surface molecule expression. CD14+CD16+CD64+ monocytes are a subset of highly phagocytic monocytes that express high levels of MHC class II. This subset is also called the transitional monocytes that can activate T cells.
What are the two subsets of monocytes?
Monocytes found in humans can be divided into two subsets on the basis of the expression of CD14 and CD16. CD14 is a component of the lipopolysaccharide receptor complex, whereas CD16 is the TcγRIII immunoglobulin receptor. Both of these monocytes express distinct chemokines, immunoglobulins, adhesion proteins, and scavenger receptors.
Why are monocytes heterogeneous?
Monocytes are highly plastic and heterogenous as these can change their functional phenotypes depending on the environmental stimuli.
What are mononuclear phagocytic cells?
These are mononuclear phagocytic cells of the immune system, which are described by different morphological and physiological characteristics depending on the stage of differentiation of the cells. Monocytes. Created with BioRender.com.
How do monocytes move through the vascular surface?
In order to enter the affected areas, monocytes should first bind to the endothelium and then move through the vascular surface. Finally, the monocytes adhere to the endothelium and finally make their way through the endothelial cells by the process of diapedesis.
What are monocytes called?
After a few hours, monocytes move from the blood to tissues — such as lung, liver, or spleen tissue — and are then called macrophages . Monocytes are one of the five different types of white blood cells. The others include: Lymphocytes create antibodies to fight against viruses and bacteria.
Where are monocytes produced?
What Are Monocytes? Monocytes are a type of white blood cell. They are produced in the bone marrow and then enter the bloodstream. They fight certain infections and help other white blood cells remove dead or damaged cells and fight cancer cells.
What is a high monocyte count?
A high monocyte count — also called monocytosis — is often associated with chronic or sub-acute infections. It can also be linked with some types of cancer, especially leukemia. A high monocyte count can occur when you are recovering from an acute infection. Some conditions that can cause monocytosis include:
What causes monocytosis?
Some conditions that can cause monocytosis include: Endocarditis, a heart valve infection. Tuberculosis, a lung infection. Syphilis, a sexually transmitted disease. Collagen vascular disorders, an inflammation of the collagen and joints. Sarcoidosis, an inflammatory disease.
What percentage of white blood cells are monocytes?
Monocytes normally make up between 2% and 8% of your total white blood cells. The complete range of normal white blood cells includes: Neutrophils: 2500 to 8000 per mm3, between 55% and 70% of total white blood cells. Lymphocytes: 1000 to 4000 per mm3, between 20% and 40% of total white blood cells. Monocytes: 100 to 700 per mm3, between 2% and 8% ...
What is the test for monocytes?
Monocytes are measured with a blood test called a white blood count (WBC) differential. It's often part of a complete blood count (CBC). A CBC does tests on the red blood cells, white blood cells, and platelets in your blood. A CBC is a routine part of an annual physical exam.
How to tell if a WBC is normal?
A WBC differential is done by collecting a sample of your blood from a vein or by pricking your finger.
Why are monocytes important?
Monocytes and other kinds of white blood cells are necessary to help the body fight disease and infection. Low levels can result from certain medical treatments or bone marrow problems, while high levels can indicate the presence of chronic infections or an autoimmune disease.
Where do monocytes form?
Monocytes form in bone marrow from myelomonocytic stem cells before entering the bloodstream. They travel throughout the body for a few hours before entering the tissue of organs, such as the spleen, liver, and lungs, as well as bone marrow tissue. Monocytes rest until they’re activated to become macrophages.
How do monocytes become macrophages?
Monocytes rest until they’re activated to become macrophages. Exposure to pathogens (disease-causing substances) can start the process of a monocyte becoming a macrophage. Once fully activated, a macrophage can release toxic chemicals that kill harmful bacteria or infected cells.
Why do people have high monocytes?
High absolute monocyte count. The body may make more monocytes once an infection is detected or if the body has an autoimmune disease. If you have an autoimmune disease, cells such as monocytes go after healthy cells in your body by mistake. People with chronic infections tend to have elevated levels of monocytes, too.
What is CBC in medical?
A standard complete blood count (CBC) will include a monocyte count. If you have an annual physical that includes regular blood work, a CBC is fairly standard. In addition to checking your white blood cell count (including monocytes), a CBC checks for: 1 red blood cells, which carry oxygen to your organs and other tissue 2 platelets, which help clot the blood and prevent bleeding complications 3 hemoglobin, the protein that carries oxygen in your red blood cells 4 hematocrit, a ratio of red blood cells to plasma in your blood
What percentage of white blood cells are monocytes?
Typically, monocytes make up 2 to 8 percent of total white blood cell count. Absolute monocyte test results can range slightly, depending on the method used for the test and other factors. According to Allina Health, a non-profit healthcare system, normal results for absolute monocytes fall into these ranges: Age range.
What is CBC in blood work?
How absolute monocyte count is determined. A standard complete blood count (CBC) will include a monocyte count. If you have an annual physical that includes regular blood work, a CBC is fairly standard. In addition to checking your white blood cell count (including monocytes), a CBC checks for:
What is the function of monocytes?
Advertisement. Monocytes are a type of white blood cell, and their function is to fight infections, germs, and inflammation, and to keep your immune system healthy. Doctors check blood test results for low or high monocyte levels to help diagnose various health conditions. For example, high monocyte count can mean that your body is fighting ...
Why are monocytes high?
Because infections and inflammation cause your immune system to send out white blood cells to destroy germs and microbes, a high monocyte count is often more common than low monocyte levels. Let’s look at what it means when monocytes are high.
What causes low monocytes?
A vitamin B12 deficiency can cause low absolute monocyte count in a regular complete blood cell count lab test. If the low mono count is due to a vitamin B12 deficiency you will also show signs of anemia like lack of energy, brain fog, muscle weakness, or mood swings.
Why is my monocyte count low?
Low monocytes in a blood test result may be accompanied by unexplained weight loss. This is also often a symptom of leukemia, and doctors will need to perform additional tests to find the cause of low mono count along with weight loss.
What does it mean when your blood test shows high monocytes?
Interestingly, severe mood swings and depression could mean that blood test results show high monocyte levels. According to the Journal of Psychiatric Research, elevated white blood cell count, including monocytes, is often seen in lab test results of people who suffer from depression. 7
Why do mono levels drop?
Stress. If you are under a lot of emotional or psychological stress, it could be that you see a temporary drop in mono levels. Stress can affect your body in many ways and make you feel fatigued, put up your blood pressure, cause gastrointestinal problems, and weaken your immune system.
When to use monocytes for CBC?
Mary Territo from the Division of Hematology and Oncology at UCLA, blood testing for monocyte count as part of a CBC is usually done if a person shows signs of infection or an autoimmune disorder. 2. However, doctors don’t just use the number of absolute monocytes to help diagnose health conditions.
Function
Types
- Now it is known that different subsets of monocytes have different markers or protein tags on the outside, and these subsets may also behave differently. Three different kinds of human monocytes are now described:
Terminology
- The terms inflammatory and anti-inflammatory are also used to describe human monocytes, based on the particular protein tags, or receptors, found on the outside of these cells. It is not yet certain in humans, however, what proportion of monocytes are mobile enough to go in and out of tissues, and evidence suggests there may be kinds of monocytes that can engulf and digest, or …
Causes
- A good number of human monocytes are believed to migrate into tissues throughout your body where they may reside or give rise to macrophages that perform essential functions to fight infection and clean up dead cells. The spleen has all major types of mononuclear phagocytes, including macrophages, dendritic cells, and monocytes. In this way, the spleen can be an active …
Definition
- Innate immunity refers to the immunity you are born with, not the more targeted immunity you might develop after, say, a vaccine or after recovering from an infectious illness. The innate immune system works through different mechanisms, including phagocytosis and inflammation. Macrophages can engage in phagocytosis, a process by which they engulf and destroy debris a…
Diagnosis
- When you have a CBC blood test done with a differential count, the white blood cell monocytes are counted and the number is reported, as well as what percentage of total white blood cells are monocytes.
Clinical significance
- In humans, monocytes have been implicated in a number of diseases including microbial infection, shock, and rapidly emerging organ injuries, osteoporosis, cardiovascular disease, metabolic diseases, and autoimmune diseases. However, how it is that different kinds of monocytes behave in various human diseases is still an area of active research. The line of cell…
Risks
- Listeria monocytogenes is a species of bacteria that can cause listeriosis, a notorious foodborne illness. Listeria precautions are one of several given during pregnancy, since listeria can cause meningitis in newborns; pregnant mothers are often advised not to eat soft cheeses, which may harbor listeria.
Health
- It turns out that monocytes can help fight infection, but they can also become Trojan horses, by transporting bacteria into the brain, and that is a concern with listeria. The listeria gets inside the monocytes, but then the monocytes are unable to kill the bacteria and they multiply.
Overview
Monocytes are a type of leukocyte, or white blood cell. They are the largest type of leukocyte and can differentiate into macrophages and conventional dendritic cells. As a part of the vertebrate innate immune system monocytes also influence adaptive immune responses and exert tissue repair functions. There are at least three subclasses of monocytes in human blood based on their phenotypic rece…
Structure
Monocytes are amoeboid in appearance, and have nongranulated cytoplasm. Thus they are classified as agranulocytes, although they might occasionally display some azurophil granules and/or vacuoles. With a diameter of 15–22 μm, monocytes are the largest cell type in peripheral blood. Monocytes are mononuclear cells and the ellipsoidal nucleus is often lobulated/indented causing a bean-shaped or kidney-shaped appearance. Monocytes compose 2 % to 10 % of all le…
Development
Monocytes are produced by the bone marrow from precursors called monoblasts, bipotent cells that differentiated from hematopoietic stem cells. Monocytes circulate in the bloodstream for about one to three days and then typically migrate into tissues throughout the body where they differentiate into macrophages and dendritic cells.
Subpopulations
There are at least three types of monocytes in human blood:
1. The classical monocyte is characterized by high level expression of the CD14 cell surface receptor (CD14 CD16 monocyte)
2. The non-classical monocyte shows low level expression of CD14 and additional co-expression of the CD16 receptor (CD14 CD16 monocyte).
Function
Monocytes are mechanically active cells and migrate from blood to an inflammatory site to perform their functions. As explained before, they can differentiate into macrophages and dendritic cells but the different monocyte subpopulations can also exert specific functions on their own. In general, monocytes and their macrophage and dendritic cell progeny serve three main functions in the immune system. These are phagocytosis, antigen presentation, and cytoki…
Clinical significance
A monocyte count is part of a complete blood count and is expressed either as a percentage of monocytes among all white blood cells or as absolute numbers. Both may be useful but these cells became valid diagnostic tools only when monocyte subsets are determined. Monocytic cells may contribute to the severity and disease progression in Covid-19 patients.
See also
• Complete blood count
• Hematopoiesis
• Lymphocyte
• Neutrophil granulocyte
• Phagocyte
External links
• Histology image: 01702ooa – Histology Learning System at Boston University
• Human Monocytes — Prof. Dr. Ziegler-Heitbrock
• Circulation of Body Fluids