Myasthenia Gravis Plasma & Serum Samples
Fresh frozen tissue and matched biofluid samples are collected from unique patients diagnosed with myasthenia gravis (MG).
Myasthenia Gravis (MG) Overview
In MG disease, antibodies destroy the communication between nerves and muscle, resulting in weakness of the skeletal muscles.
Usually MG affects the voluntary muscles of the body, especially those that control the eyes, mouth, throat and limbs.
The disease can strike anyone at any age, but is more frequently seen in young women (age 20 and 30) and men aged 50 and older.
These muscles are responsible for functions involving breathing and moving parts of the body, including the arms and legs.
In myasthenia gravis (MG) disease condition that causes the muscles tends to tire and weaken easily, because there is a problem with how the nerves stimulate the contraction of muscles.
For example, if someone has myasthenia gravis (MG), they may notice that during a meal, their jaw muscles become tired and weak, interfering with their ability to chew food. After they have rested for a little while, the muscles may become strong again, allowing them to resume eating.
There is no known cure for myasthenia gravis (MG), but with current therapies, most cases of MG are not as “grave” as the name implies and can be managed.
Available treatments can control symptoms and often allow patients to have a relatively high quality of life. Most individuals with the condition have a normal life expectancy.
Signs and Symptoms of Myasthenia Gravis (MG)
Symptoms of myasthenia gravis (MG) vary widely. Fatigue is the most common symptom in MG patients, however in some patients, only the eye muscles are affected, while in others, it can impact many muscles, including those that control breathing.
Double vision, drooping in one or both eyelids, or both are an early signs in most of the MG patients. This can cause eyesight problems, this condition is known as ocular myasthenia gravis. In some of the MG patients the throat and face muscles are the first to be affected.
Following are the most common symptoms of myasthenia gravis (MG):
- Facial muscle involvement causing a mask-like appearance; a smile may appear more like a snarl.
- Visual problems, including drooping eyelids (ptosis) and double vision (diplopia).
- Trouble swallowing or pronouncing words.
- Muscle weakness and fatigue may vary rapidly in intensity over days or even hours and worsen as muscles are used (early fatigue).
- Weakness of the neck or limbs.
Myasthenia Gravis (MG) Crisis
A myasthenic crisis is a medical emergency that occurs when the muscles that control breathing weaken to the point where patients require a ventilator to help them breathe.
Myasthenic crisis can involve the upper airway muscles, respiratory muscles, or a combination of both muscle groups. resulting in dyspnea.
Almost half of the patients may have no obvious cause for their myasthenic crisis. Certain medications have been shown to cause myasthenia gravis (MG.
However, sometimes these medications may still be used if it is more important to treat an underlying conditions.
Causes of Myasthenia Gravis (MG)
Myasthenia Gravis (MG) is not inherited and it is not a contagious disease. It generally develops later in life when antibodies in the body attack normal receptors on muscle. This blocks a chemical needed to stimulate muscle contraction.
Under normal conditions, nerves direct the muscles to work by sending a message through an area called a receptor. The chemical that delivers the message is called acetylcholine.
When acetylcholine binds to a nerve receptor, the muscle knows to contract. In myasthenia gravis (MG), your body attacks its acetylcholine receptors.
A temporary form of myasthenia gravis (MG) may develop in the fetus when a woman with myasthenia gravis (MG) passes the antibodies to the fetus. Generally, it resolves in 2 to 3 months.
In the case of myasthenia gravis (MG), antibodies block, attack or destroy the acetylcholine receptors needed for muscle contraction.
Exactly what causes the body to begin producing the antibodies that destroy acetylcholine receptors is unknown. In some cases, the process seems to be related to the thymus gland, which helps produce antibodies.
The thymus gland is located in the upper chest beneath the breastbone, appears to play a key role.
Diagnosis of Myasthenia Gravis (MG)
Diagnosis can be difficult, however, because MG shares symptoms with other diseases. A neurologist may need to confirm the diagnosis.
- Reflexes
- Muscle strength
- Muscle tone
- Touch
- Sight
- Coordination
- Balance
Following are some of the diagnostics tests performed to get conclusive diagnosis of myasthenia gravis (MG).
- Edrophonium Test: Your doctor injects you with a chemical called edrophonium chloride (Tensilon)
to see if it improves your muscle strength. If it does, that’s a sign you might have myasthenia gravis (MG). - Ice Pack Test: If a patient have a drooping eyelid, the doctor may put an ice pack on it for 2 minutes to see if the low temperature has an effect on it.
- Blood Tests: A patients blood is drawn and send it to a lab to check for certain antibodies that affect muscle nerve receptors to check for myasthenia gravis (MG).
- MuSK Antibody Test: Recently, a second antibody called the muscle-specific kinase anti-MuSK antibody has been found in about 30% to 40% of patients with myasthenia gravis who do not have acetylcholine receptor antibodies.
- LRP4 Antibody Test: Also recently, low-density lipoprotein receptor-related protein LRP4 has been identified as the agrin receptor.
- Repetitive nerve stimulation: This test uses electrodes on the muscles to send small electrical pulses to see if the patients nerves react to the signals.
- Single-fiber electromyography (EMG) Test: A doctor puts a thin wire electrode through your skin and into a muscle. It can test the electrical activity between the brain and the muscles.
- Imaging Tests: A doctor may suggest a CT scan or MRI to look more closely for a tumor on the patients thymus that could be causing symptoms.
- Pulmonary Functioning Tests: The doctor will perform PFT to tests the patients breathing to check if the lungs are affected by myasthenia gravis (MG).
Other methods to confirm the diagnosis include a version of nerve conduction study, which tests for specific muscle “fatigue” by repetitive nerve stimulation.
This test records weakening muscle responses when the nerves are repetitively stimulated by small pulses of electricity.
Repetitive stimulation of a nerve during a nerve conduction study may demonstrate gradual decreases of the muscle action potential due to impaired nerve-to-muscle transmission.
Prevention of Myasthenia Gravis (MG)
MG cannot be prevented. However, the patient can take steps to stop a flare-up of symptoms or prevent them from developing complications.
These include practicing careful hygiene to avoid infections, and treating them immediately if they do develop.
It is also advisable to avoid extreme temperatures and overexertion. Effective stress management can also reduce the frequency and severity of the symptoms.
Treatment of Myasthenia Gravis (MG)
There is no cure for myasthenia gravis (MG), generally, it can be managed with immunosuppressants or cholinesterase inhibitors. These therapies can help reduce and improve muscle weakness.
Treatment options depend on the patients:
- Age
- Severity of the symptoms
- How fast the disease is progressing
- Overall health and medical history
- Tolerance to handle specific medicines, procedures and therapies
- Preference
Following are some of the medications used for the treatment of myasthenia gravis (MG) that help reduce and improve muscle weakness:
- Cholinesterase (ChE) Inhibitors. These medications boost the communication between the nerves and the muscles. They can help strengthen muscles.
- Corticosteroids: Corticosteroids such as prednisone mute the immune system and slow the release of antibodies that could be helping block your nerve receptors.
- Immunosuppressants: Your doctor may add immunosuppressants to your corticosteroids to help reduce your immune system response.
If the patients have sudden worsening of symptoms, or is scheduled for surgery or other available therapies, the doctors may recommend the following intravenous (IV) therapies:
- Plasmapheresis: This procedure is like dialysis, because it filters the blood. Patients blood goes through a machine that removes certain antibodies. Typically, plasmapheresis treatment can only be given for few weeks before the effects start to wear off.
- Intravenous immunoglobulin (IVIg): This therapy injects new antibodies into the patients bloodstream. These antibodies alter the immune system response to help with symptoms. Results typically last about 3-6 weeks.
- Monoclonal antibodies: Option of monoclonal antibodies treatment is recommend only if other treatments haven’t worked. They can have serious side effects.
Some cases of myasthenia gravis (MG) may go into remission, either temporarily or permanently, and muscle weakness may disappear completely.
Stable, long-lasting complete remissions are the goal of thymectomy and may occur in about 50 percent of individuals who undergo this procedure.
Research are under way to find more effective treatments for MG. One of the treatment options could be Autologous hematopoietic stem cell transplant (HSCT).
Complications of Myasthenia Gravis (MG)
In a myasthenic crisis, the respiratory muscles become so weak that the patient cannot breathe properly.
This potentially life-threatening complication requires emergency treatment with mechanical breathing assistance. Plasmapheresis and immunoglobulin therapies can help.
Other diseases include:
- Thyroid problems: These include overactive or underactive thyroid. The thyroid gland is a small gland in the front of the neck that secretes hormones that regulate metabolism.
- Lupus: This is an autoimmune disease that can lead to inflammation, swelling, and damage to joints, skin, kidneys, blood, the heart, and lungs.
- Rheumatoid Arthritis: This is a chronic progressive and disabling condition that causes inflammation and pain in the joints, the tissue around the joints, and other organs in the human body.
This critical patient’s clinical data includes information relating to their past and current disease, treatment history, lifestyle choices, biomarkers and genetic information.
- Peripheral whole-blood,
- Amniotic fluid
- Bronchoalveolar lavage fluid (BAL)
- Sputum
- Pleural effusion
- Cerebrospinal fluid (CSF)
- Serum (sera)
- Plasma
- Peripheral blood mononuclear cells (PBMC’s)
- Saliva
- Buffy coat
- Urine
- Stool samples
- Aqueous humor
- Vitreous humor
- Kidney stones (renal calculi)
- Other bodily fluids from most diseases including cancer.
日本のお客様は、ベイバイオサイエンスジャパンBay Biosciences Japanまたはhttp://baybiosciences-jp.com/contact/までご連絡ください。