21. What Treatments are currently available?
Most therapeutic treatments for Mitochondrial Disease aim to either reduce damage to mitochondria, improve energy generation or remove toxin build up.
Supplements like cofactors (made by the body) or vitamins (from food) can help with this and are often prescribed by clinicians in combination as a ‘cocktail’ tailored to the individual patient.
Although there is still no clinical evidence that these supplements actually alter the course of the disease, there have been many anecdotal reports of improved wellbeing after taking these and as they appear to have few side effects, most doctors will agree they are worth trying.
Reducing Damage to Mitochondria
Antioxidants, can prevent damage to mitochondria by neutralizing highly charged molecules called ‘free radicles’ in the cell.
Coenzyme Q10 (CoQ10, Ubiqinone)
CoQ10 is produced by our bodies but is also found in foods like meat, poultry, nuts and green leafy vegetables. CoQ10 plays a key role in transporting electrons between complexes I, II and III of the mitochondrial respiratory chain, so in patients with Mitochondrial Disease where these complexes are affected, supplementation it is believed to have a therapeutic effect.
Coenzyme Q10 is also has antioxidant properties which could in addition help prevent mitochondrial damage.
This is a synthetic version of CoQ10, but is designed to penetrate the nervous system more easily.
It works in exactly the same way as CoQ10, as a transporter of electrons and as an antioxidant.
Initial studies of idebenone have suggested some beneficial effect patients with Friedreich Ataxia and LHON and a trial in patients with MELAS is underway.
Riboflavin (Water soluble vitamin B2)
This vitamin is a key building block in Complex I and II, and also helps in stabilizing the mitochondrial membrane. Early studies have shown riboflavin may be helpful in treating mitochondrial diseases where there is complex I involvement, particularly if the complex I deficiency is the result of a mutation in the ACAD9 gene.
Other antioxidants that may be of benefit to mitochondrial patients include selenium, vitamin C, vitamin E, and lipoic acid.
Improving Energy generation
Creatine is a small molecule that helps supply the body with extra energy during times of high demand.
Creatine is made in the body but can also be found in red meats and fish. The highest concentrations in our bodies are found in tissues with the highest energy demands like muscle and brain.
Some patients have a deficiency of creatine and it has been suggested that a dietary supplement of creatine may benefit this group. Even in those without creatine deficiency, supplementation may have a role in improving muscle strength during activity although there have not yet been any long term studies undertaken.
Removing toxin build up
When a person has Mitochondrial Disease, their mitochondrial respiratory chain is blocked by one or more processes not working correctly. This block can lead to a build up of chemicals in the cells which can be toxic to the body and cause secondary problems.
Sodium Bicarbonate & Dichloroacetate
The most common example of toxin build up in mitochondrial disease is pyruvate, which can accumulate outside the mitochondria if there is a problem in the respiratory chain. Our body then converts this pyruvate into lactic acid. If lactic acid is present at elevated levels for extended periods of time, it can cause direct damage to tissues like the brain and muscle. It is therefore beneficial to ensure that patients with mitochondrial disease should try and minimise the buildup of lactic acid.
In rare situations, individuals with specific types of mitochondrial disease may become critically unwell due to persistently elevated lactate levels. Intravenous hydration is the first line of treatment for such individuals. In emergency situations of profound lactic acidosis not responding to intravenous hydration, sodium bicarbonate and/or dichloroacetate may be considered. It is important to note that risks have been associated with the use of dichloroacetate (DCA).
In addition to lactic acid, other metabolites that normally feed into the respiratory chain can build up in the cells of people with mitochondrial diseases and cause problems.
Carnitine is a natural compound made in the body and can also be found in foods such as red meat, fish, poultry & milk. One of its roles is to clean up these extra metabolites by escorting them out of the cells and into the kidneys for excretion in the urine.
Carnitine deficiency has been observed in some patients with Mitochondrial Disease so it has been suggested that a dietary supplements might benefit this group.
Thiamine (Vitamin B1)
The use of thiamine has been established in the treatment of some forms of PDH deficiency and Kearns-Sayre syndrome but failed to demonstrate any benefit in a larger study of mitochondrial myopathies.
Treatments, Supportive Therapies & Monitoring
Good treatments exist for many of the associated complications of Mitochondrial Disease, for example:
- seizures can be managed with anti epileptic medications or the use of a ketogenic diet in some cases,
- heart failure, cardiomyopathy or arrhythmias can be managed with medications, pacemakers or defibrillators,
- L-Arginine may be beneficial in the management of acute stroke
- diabetes can be managed through careful diet and medication including insulin if required
- droopy eyelids (ptosis) can be alleviated by corrective surgery,
- endocrine dysfunctions can benefit from appropriate hormone replacement,
- folinic acid supplements may be beneficial in patients with Kearns-Sayre syndrome
- hearing loss can be restored or improved with the use of cochlear implants,
- although transplantation of single organs is usually not appropriate (as most mitochondrial diseases involve multiple organ systems), there are uncommon circumstances in which specific organ transplantation may be considered. These include Liver Transplants in patients with some mitochondrial depletion syndromes (with no neurological involvement), Heart Transplants in some patients with isolated cardiomyopathy, or Kidney transplants.
- Stem cell transplants in some MNGIE patients has given promising early results,
The goal of supportive therapy is not to change the underlying Mitochondrial Disease, but to preserve and maintain strength, mobility, and functioning.
Physiotherapy, occupational, visual, speech and respiratory therapies can all be beneficial to mitochondrial patients.
Although it may not be possible to treat all of the primary causes of mitochondrial diseases, early intervention is likely to improve outcome.
In some cases (particularly in adults) patients may actually be in greater danger from treatable complications than from the Mitochondrial Disease itself so it is wise to ensure that people living with a mitochondrial disease should make sure their condition is actively monitored.
Regular appointments, blood counts, EEG's, ECG's, Echo's, MRI's, can all prove hugely valuable in catching changes early, allowing intervention and treatment where possible.
Lifestyle & Exercise
Some individuals with mitochondrial diseases appear more sensitive to physiologic stressors such as minor illness, dehydration, fever, temperature extremes, surgery, anaesthesia, and prolonged fasting or starvation.
During such stress, rapid systemic decompensation may occur which may result in temporary or permanent worsening of the condition.
Preventive measures are aimed at avoiding (or at least not making any worse) such decompensation include:
- Eat regularly, avoid fasting and intentional weight loss
- stay well hydrated (early administration of oral and/or IV fluids & dextrose during illness)
- correcting lactic acidosis: this often responds to rehydration with intravenous fluids but in some circumstances administration of sodium bicarbonate is required. Dichloroacetate causes nerve damage and is reserved for very severe acidosis unresponsive to sodium bicarbonate and fluids.
- avoiding exposure to pharmacologic mitochondrial toxins (alcohol, cigarettes)
- providing cofactor and/or vitamin therapies.
- protection from infectious diseases.
Exercise has been shown to reduce the burden of unhealthy mitochondria, increase % of healthy mtDNA and improve endurance and muscle function.
Whenever possible, exercise is advised by clinicians but regimes should be supervised by a professional and patients should start at a very low intensity and brief duration and should progress gradually. Resistance exercise (using weights) can be performed by many patients and can increase strength.
Exercise regimes should be halted during an illness.