About NMOSD
Neuromyelitis Optica, also known as “Devic’s Disease,” is an autoimmune disorder in which immune system cells and antibodies mistakenly attack and destroy myelin cells in the optic nerves and the spinal cord. The damage to the optic nerves produces swelling and inflammation causes pain and loss of vision; the damage to the spinal cord causes weakness or paralysis in the legs or arms, loss of sensation, and problems with bladder and bowel function. NMOSD occurs in two forms: a single attack extending over a month or two, or a more common relapsing form in which the person experiences multiple attacks.
Patients usually experience their first symptoms in childhood or adolescence. Patients as young as 16 months have been diagnosed with NMOSD. The average age for diagnosis amongst children is 10 years old.
Children with NMOSD usually present with “attacks” of new neurological symptoms appearing within a few hours or days. Children with NMOSD can have attacks with symptoms such as blurred vision, or loss of vision in one or both eyes. Other symptoms are weakness or numbness of the arms or legs. Some children experience confusion or extreme lethargy at their attacks. Other possible symptoms including vomiting, fever or seizures.
Approximately 65% of children with NMOSD have antibodies to aquaporin-4 (AQP4), also known as NMO-IgG. AQP4 antibodies are sometimes present at the first symptom or can manifest over time. About 15% of children with NMO have MOG antibodies (see section below). About 15% of children are negative for both antibodies.
Although there are no FDA approved treatments for adults or children with NMOSD, children are usually offered immunomodulatory treatments. Attacks are treated with a short course (usually up to a week) of intravenous steroids, IVIG or plasmapheresis. It is important to prevent new attacks in children with established NMOSD, and treatment with mycophenolate mofetil (CellCept) or rituximab is usually offered.
Treatments
Preventative treatment of NMOSD and MOG antibody associated diseases
CellCept
CellCept (Mycophenolate mofetil) is an oral immunosuppressant. It inhibits an enzyme in the body that contributes to the production of specific purines. These purines are necessary for certain white blood cells, specifically T- and B-cells, to carry out an attack against offending material. This leads to less damage of myelin and neurons in the brain.
CellCept is a pill that is taken by mouth. It should be taken one hour before or two hours after food for best absorption. Tablets should not be crushed, chewed, or cut and capsules should not be opened. Tablets and capsules should be swallowed whole. A solution is also available for younger children.
Certain medications interact with the absorption of CellCept and should not be given at the same time. These include the following:
- Avoid taking antacids containing aluminum or magnesium (i.e. Maalox®, Mylanta®) at the same time as CellCept, as these will affect how much drug the body will absorb. If antacids are needed, CellCept should be taken at least one hour before or two hours after taking antacids
- Avoid taking calcium supplements or iron supplements at the same time as CellCept as these will also affect how much drug the body will absorb. If such supplements are needed, CellCept should be taken at least one hour before or two hours after taking these supplements
- Make sure to contact your doctor prior to starting any new medications. Common side effects include: increased risk of infection, nausea, stomach pain, diarrhea, weakness, dizziness, difficulty sleeping, and increased liver function tests (increasing the dose slowly reduces these effects)
Rituximab
Rituximab (Rituxan) is an intravenous immunosuppressant. It is an antibody to a population of immune cells called B cells. B cells cooperate with T cells to cause attack on the myelin, neurons, or other cells in the brain. Rituximab is used as a treatment for MS, NMOSD, and MOG-antibody associated diseases in children.
Rituximab is given by intravenous infusion approximately every six months. The exact duration between treatments may be tailored to the specific patient and situation. Usually, the first dose is administered in two half doses, two weeks apart.
Rituximab is usually given along with intravenous steroids, antihistamines, and antacids to prevent infusion or allergic reactions. Rituximab infusions are usually given in an infusion unit by trained nursing staff.
Make sure to contact your doctor prior to starting any new medications.
Common side effects include: infusion reactions including rash, tiredness, and sometimes rarely, breathing difficulties. Long-term side effects include increased risk of infection, nausea, stomach pain, diarrhea, weakness, dizziness, difficulty sleeping, and increased liver function tests (increasing the dose slowly reduces these effects).