Mitochondrial DNA Profiling in Blood and CSF for ALS Insights

Analysis of mitochondrial DNA (mtDNA) has revealed insights into the pathogenesis of amyotrophic lateral sclerosis (ALS). This severe, often lethal, disease carries a significant healthcare cost, and the search for an effective treatment remains an important area of research. This study demonstrates the use of mtDNA profiling from both blood and cerebrospinal fluid to better understand and treat ALS.

Why It Matters

Amyotrophic Lateral Sclerosis (ALS) is a deadly disease affecting nerve cells in the brain and the spinal cord for which healthcare providers have yet to find the cause. The National ALS Registry uses several innovative methods to estimate newly diagnosed cases and existing cases of ALS in the United States. Researchers used both retrospective and prospective methods to estimate 32,893 cases of ALS in the US in 2022, and project a more than 10% increase in cases by 2030, totaling 36,308. The study’s authors believe the numbers represent an underestimation due to emerging treatments and better healthcare that will allow people with ALS to live longer and be diagnosed as a result.

Median survival in patients with ALS has consistently been reported to be less than 3 to 5 years. While a number of theories regarding the causes of the disease have been proposed, the exact cause of ALS remains unknown. Potential causes of the disease include glutamate excitotoxicity, oxidative stress, impairment of energy production by mitochondria, protein misfolding, astrocyte dysfunction, neuroinflammation, and other abnormalities leading to overall failure of homeostasis. Importantly, increasing evidence has demonstrated abnormal mitochondrial function in ALS. These findings suggest that mitochondrial dysfunction is involved in the pathophysiology of the disease.

mtDNA profiling in blood and CSF

Quantification of MtDNA in blood and CSF could be very useful. Elevated levels of mtDNA in CSF and blood are associated with severity and survival. The mtDNA signatures could be useful biomarkers for diagnosis and patient stratification for individualized treatments. Following these observations, clinical trials and experimental studies have found that individuals with ALS have a higher percentage of mtDNA variants and deletions than controls.

The study could help patients with ALS by giving doctors an early indicator of the disease’s rapid progression in individual patients. As researchers scratch for reasons why mtDNA stress leads to such rapid disease progression in ALS, this work could ultimately help the field to better understand the disease and improve patient outcomes by giving doctors a more reliable tool for monitoring the disease’s progression and intervene at the right time to improve quality of life for patients. Having such a tool could ease some of the burden and stress on both patients and their families as they struggle to care for loved ones whose diseases are so aggressive.

As mtDNA sequencing enters the clinical scene, it will challenge current frameworks of health system organisation. New guidelines and protocols will be needed as well as training of clinical staff to interpret results of mtDNA sequencing. Policy makers will have to weigh the costs of such technologies against the public health benefit. Given the complexity and strain that an ALS diagnosis places on the health system, this consideration is especially pertinent.

Who it affects

The implications of mtDNA profiling in ALS will positively affect patients and their families through more accurate diagnosis and more individualized treatment. While there is currently no cure for ALS, established evidence of medicines to slow disease progression, as well as treatment options to improve quality of life and length of survival for people with ALS, supports the concept that patients and their families will greatly benefit from the advancements in mtDNA profiling in ALS. Patients and families will work with a team of medical personnel and health care professionals including all types of physicians and pharmacists, as well as social workers and clinical psychologists. Home care and hospice nurses, physical, occupational, speech and respiratory therapists can also be part of the team that designs an individualized treatment and care plan for each patient with ALS. For the clinician, the discovery of new biomarkers will have the potential to improve diagnosis and treatment for this clinically poor-prognosis group of cancer patients for whom there are few effective clinical options.

This information, potentially, could be useful to other researchers as they study the mtDNA of people with ALS to understand the causes of the disease and work on treatments.

Possible Future Research Partners?

The National Institutes of Health (NIH) National Institute of Neurological Disorders and Stroke (NINDS) is the primary federal funder of research on the brain and nervous system – which includes ALS. In 2023, the NINDS published a 10-year Research Plan that outlines strategic priorities for future ALS research efforts to help move effective treatments – for diagnosis, treatment, management, prevention, and a cure – from the laboratory to patient use. The Accelerating Access to Critical Therapies for ALS Act authorizes NINDS to fund research related to expanded access to investigational new drugs for people with ALS who are not participating in a clinical trial.

Recent advances in our understanding of biology have identified several promising therapeutic targets for ALS research. Future studies are needed to determine whether treatments targeting these potential therapeutic targets will be effective in treating or slowing the progression of ALS. NINDS’ goals for future ALS research are to:

1. Understand the cellular mechanisms involved in the development and progression of the disorder
2. Investigate the influence of genetics and other potential risk factors
3. Identify biomarkers (biological measures of a disorder)
4. Develop new treatments

Patients, Patient Advocates, and Policymakers

This information is also relevant to family members and caregivers of people with ALS.

While there is currently little that can be done to treat or reverse the progression of ALS, some kinds of treatment may be possible in the future. Understanding the disease process more clearly may also be of use. There are some things that people with ALS and their families can do now. As the disease progresses, most people with ALS will need help with many daily activities. There are several national organizations focused on ALS and its effects on people with the disease and their families. In addition to these national organizations, there are organizations in each state serving patients and families. Many of these organizations are working with the National ALS Registry to create a database of all people with ALS in the United States.

In addition to these advances benefitting people with ALS, there will be those interested in how these advances can increase access and promote greater equity so that all people with ALS have access to the best in diagnosis and treatment today. There will also be a continued need for policymakers to support organizations such as NINDS in their leadership of research efforts to development better treatments for and a cure for ALS.

• The introduction of mtDNA profiling may change how clinicians assess and monitor ALS, leading to more accurate prognoses and personalized care plans.
• Enhancements in understanding mtDNA dynamics could expand research into targeted therapies, potentially leading to breakthroughs in treatment that transform patient longevity and quality of life.
• Healthcare systems may need to adapt their frameworks to incorporate new diagnostic practices, affecting clinician training, resource allocation, and patient access to specialized care.