What Is the MuSK Antibodies Test?

The MuSK Abs, Serum test detects antibodies against Muscle-Specific Kinase (MuSK) in your blood. These antibodies are associated with a type of autoimmune myasthenia gravis (MG)—a condition that causes muscle weakness due to a breakdown in communication between nerves and muscles.

MuSK is a protein that plays a key role in forming and maintaining the connection between nerve endings and muscle fibers. When the immune system creates antibodies that attack MuSK, it can lead to impaired nerve-muscle signaling and muscle fatigue.

Why Is This Test Important?

This test is especially helpful in diagnosing seronegative myasthenia gravis—cases where patients have MG symptoms but test negative for acetylcholine receptor (AChR) antibodies. MuSK antibodies are found in about 5–8% of MG patients, particularly in those with:

• Facial, throat, and respiratory muscle weakness

• Rapid symptom progression

• Less eye-related symptoms compared to AChR-positive MG

Mutated citrullinated vimentin (MCV) antibody is a specific type of autoantibody that has gained attention in the context of rheumatology, particularly in the diagnosis and management of rheumatoid arthritis (RA). Citrullination is a post-translational modification of proteins, which is a normal process in cell death and differentiation.

In a complete blood count (CBC) the MXD # refers to the combined count of mixed white blood cells which includes monocytes, eosinophils and basophils. This helps to understand the relative and absolute numbers of these less common white blood cells which can be important in diagnosing various conditions.

→ Monocytes: These cells fight off bacteria, viruses and fungi. They also remove dead or damaged tissues and regulate immune responses.

→ Eosinophils: These cells are involved in parasitic infections and allergic reactions and asthma.

→ Basophils: These cells are involved in inflammatory responses and allergic reactions.

In a complete blood count (CBC) the MXD # refers to the combined count of mixed white blood cells which includes monocytes, eosinophils and basophils. This helps to understand the relative and absolute numbers of these less common white blood cells which can be important in diagnosing various conditions.

→ Monocytes: These cells fight off bacteria, viruses and fungi. They also remove dead or damaged tissues and regulate immune responses.

→ Eosinophils: These cells are involved in parasitic infections and allergic reactions and asthma.

→ Basophils: These cells are involved in inflammatory responses and allergic reactions.

Mycobacterium avium (M. avium) is a gram-positive, slow-growing bacteria with high guanine and cytosine content. It is present mainly in cattle and transmitted to humans by drinking unpasteurized animal milk. M. avium, M. bovis and M. tuberculosis are the most common human acquired mycobacteria.

Mycophenolic Acid is an antifungal, antibacterial, and antiviral mycotoxin acid. It is produced by the Penicillium fungus. 

Mycophenolic Acid is an immunosuppressant which inhibits the proliferation of B and T lymphocytes. Mycophenolic Acid exposure can increase the risk of opportunistic infections such as clostridia and Candida. 

Mycophenolic Acid is associated with miscarriage and congenital malformations when the woman is exposed in pregnancy.

Mycophenolic Acid is an antifungal, antibacterial, and antiviral mycotoxin acid. It is produced by the Penicillium fungus. 

Mycophenolic Acid is an immunosuppressant which inhibits the proliferation of B and T lymphocytes. Mycophenolic Acid exposure can increase the risk of opportunistic infections such as clostridia and Candida. 

Mycophenolic Acid is associated with miscarriage and congenital malformations when the woman is exposed in pregnancy.

Mycophenolic Acid is an antifungal, antibacterial, and antiviral mycotoxin acid. It is produced by the Penicillium fungus. 

Mycophenolic Acid is an immunosuppressant which inhibits the proliferation of B and T lymphocytes. Mycophenolic Acid exposure can increase the risk of opportunistic infections such as clostridia and Candida. 

Mycophenolic Acid is associated with miscarriage and congenital malformations when the woman is exposed in pregnancy.

Mycoplasma hominis is from the Tenericutes phylum.

Tenericutes are cell wall-less bacteria that do not synthesize precursors of peptidoglycan. Tenericutes consist of four main clades designated as the Acholeplasma, Spiroplasma, Pneumoniae and Hominis clusters. Tenericutes are typically parasites or commensals of eukaryotic hosts.

Mycoplasma hominis is a fastidious bacterium, which usually colonizes the lower urogenital tract and may cause systemic infections in neonates and genital infections in adults. It can also be the cause of serious extra-genital infections, mainly in immunosuppressed or predisposed subjects.

What is Mycoplasma pneumoniae – IgG?

Mycoplasma pneumoniae is a type of bacteria that commonly causes respiratory infections, especially atypical pneumonia—a milder, slower-developing form of pneumonia often referred to as "walking pneumonia." It is also associated with sore throat, prolonged cough, sinusitis, and bronchitis. In some cases, it can contribute to more serious complications such as asthma exacerbations, ear infections, or skin rashes.

The IgG antibody test detects long-term immune response to Mycoplasma pneumoniae. IgG antibodies typically appear several weeks after infection and may remain in the bloodstream for months or even years, indicating past exposure or infection.

What Does a Medium Result Mean?

A medium IgG result reflects a moderate level of antibodies, which may suggest:

• A recent past infection, with IgG levels still stabilizing

• A waning immune response from an older infection

• Borderline reactivity, possibly requiring repeat testing or further evaluation

A medium result alone does not indicate whether the infection is active—it should be considered alongside symptoms and other lab markers, especially IgM.

Mycoplasma Pneumoniae Antibody (IgG) testing plays a pivotal role in the serological diagnosis of infections caused by the bacterium Mycoplasma pneumoniae, a common agent of atypical pneumonia and other respiratory tract infections.

This antibody is a specific type of immunoglobulin G (IgG), which the human immune system produces in response to an infection with this organism.

The presence and levels of Mycoplasma pneumoniae IgG antibodies in a patient's blood are measured to determine whether they have been exposed to the pathogen, either in the recent past or as a more distant infection. Typically, the body starts producing these antibodies 1-2 weeks after the initial infection, and their levels peak around 4-6 weeks post-infection.

Mycoplasma Pneumoniae Antibody (IgM) testing is a crucial diagnostic tool for identifying acute infections caused by Mycoplasma pneumoniae, a common bacterium responsible for causing atypical pneumonia and other respiratory tract infections. The IgM antibodies are among the first to be produced by the immune system in response to an infection, typically appearing within the first couple of weeks after exposure to the pathogen.

In the context of Mycoplasma pneumoniae infection, the presence of IgM antibodies is indicative of a recent or ongoing infection, making this test particularly useful in the early stages of the disease. Patients infected with Mycoplasma pneumoniae often present with symptoms like cough, fever, sore throat, and sometimes more severe respiratory issues.

The "Mycoplasma pneumoniae IgA" test is a specific blood test designed to detect the presence of Immunoglobulin A (IgA) antibodies against Mycoplasma pneumoniae, a bacterium that causes respiratory infections, most notably a form of pneumonia often referred to as "walking pneumonia." Unlike typical pneumonia, walking pneumonia caused by Mycoplasma pneumoniae is generally milder and can sometimes manifest with symptoms so slight that individuals might not even realize they are ill, hence the name "walking." The body produces IgA antibodies as part of its immune response to a Mycoplasma pneumoniae infection. These antibodies are a type of protein that the immune system uses to help fight off infections, specifically at mucosal sites such as the lungs and throat in this case.

Mycoplasma pneumoniae is a small bacterium transmitted via organism-containing droplets.

Mycoplasmas are the smallest free-living microbes known.

Mycoplasma refers to a genus of bacteria that lack a cell wall, which makes them immune to common antibiotics such as penicillin. Mycoplasma pneumoniae, Mycoplasma arthritidis and ureaplasma are common human pathogens.

Myelin is the protective sheath surrounding nerves. Myelin basic protein (MBP) is believed to be important in the process of myelination, the building of myelin sheaths. Thus, MBP is often a target in the demyelination process in various neuroimmune disorders.

Known Cross-Reactions:

Chlamydia pneumonia, herpes – streptococcal protein; gliadin