Mitochondrial Medicine Society Updates Patient Care Guidelines

Experts from multiple disciplines have released updated guidelines for the treatment and management of patients with mitochondrial diseases.

The review, “Patient care standards for primary mitochondrial disease: a consensus statement from the Mitochondrial Medicine Society,” appeared in Genetics in Medicine — the official journal of the American College of Medical Genetics and Genomics.

Mitochondrial disorders are caused by defects in the mitochondria genome, or in the nuclear DNA in genes that affect mitochondrial function. At specialized mitochondria centers, clinicians address the different manifestations of mitochondrial disease in a comprehensive manner.

In 2015, the Mitochondrial Medicine Society (MMS) developed consensus criteria to help diagnose mitochondrial disease. An MMS follow-up survey of 207 clinicians — including neurologists, geneticists and metabolic experts from across the globe — showed interest in additional guidelines for further assistance on patient care. In fact, most clinicians knew the previously published MMS guidelines and found them useful in managing patients.

As such, the MMS appointed a working group to develop a new consensus statement that expands and complements, but does not replace, the 2015 statement, “Diagnosis and Management of Mitochondrial Disease.” This group included 35 professionals from Australia, Canada, Great Britain, Italy, the Netherlands and the United States specializing in genetics, cardiology, endocrinology, neurogenetics and pediatric neurology.

“The panel developed recommendations using the Delphi method, which [utilizes] expert opinions to make a knowledge-based decision when insufficient information is available,” authors wrote. The open-access revision includes a summary of the recommended screening guidelines and specialist consultations including cardiology, endocrinology, gastroenterology and hematology to consider.

For example, a previous study reported cardiac involvement in 30 patients of patients with mitochondrial disease. Other studies reported a variation of 20 to 40 percent.

In light of this, screening guidelines propose measuring blood pressure and performing electrocardiograms at diagnosis (if not previously obtained) and repeat it at one- to two-year intervals. Of note, the number of echocardiograms may be reduced in low-risk patients after several years of monitoring. Cardiac magnetic resonance imaging and Holter recording are performed as needed, depending on symptoms. In Holter recording, patients wear a monitor that measures their hearts’ electrical activity to detect abnormalities.

The review also includes an updated list of medications that must be used with caution, or even avoided, in mitochondrial patients.

“The following medications should be avoided in patients with mitochondrial disease when possible and, if given, they should be used with caution: valproic acid; statins; metformin; high-dose acetaminophen; and selected antibiotics, including aminoglycosides, linezolid, tetracycline, azithromycin and erythromycin,” authors wrote.

“We hope that these recommendations also raise awareness of the complete spectrum of symptoms and findings in mitochondrial disease and aid in the diagnosis, management, and monitoring of co-morbid conditions,” the study concluded.