Favorable outcomes seen for very late-onset myasthenia gravis: Study
Early treatment, correct meds cited as crucial to better patient outcomes
Most people with very late-onset myasthenia gravis (MG) — patients in whom symptoms start to manifest at age 65 or older — who are positive for self-reactive antibodies against acetylcholine receptors, or AChRs, show significant clinical improvements within two years of disease onset, according to a new study from researchers in China.
The team found that starting treatment early and using the right medications were critical for better outcomes in these patients, noting that among treated individuals, “nearly half … showed significant improvement within [six] months.”
“The study shows that older patients with myasthenia gravis can recover well if they receive timely treatment,” the researchers wrote.
Titled “Short-term and long-term prognoses in AChR-Ab positive very-late-onset myasthenia gravis patients,” the study was published in the journal Therapeutic Advances in Neurological Diseases.
Myasthenia gravis starting after age 65 dubbed very late onset
In MG, a rare autoimmune disease, the immune system mistakenly attacks important proteins involved in nerve-muscle communication. For most patients, these autoimmune attacks are driven by self-reactive antibodies that target AChRs — proteins essential for coordinating muscle contraction.
People with MG can be classified into different groups based on when the disease’s symptoms begin to manifest. Usually, cases are classified as early-onset MG for individuals whose symptoms start before the age of 50, and late-onset MG for those whose symptoms start after the age of 50.
In recent years, there has been an increasing number of MG cases in which symptoms emerge in people who are ages 65 or older. Researchers have deemed these cases to be very late-onset myasthenia gravis. However, very little is known about the symptoms and disease progression in those with very-late onset MG.
“Current research on [very-late onset MG] prognosis remains limited, especially regarding factors influencing outcomes,” the researchers wrote.
To learn more, a team led by researchers at Xuanwu Hospital at Capital Medical University in Beijing assessed data from 93 people with very late-onset MG. The researchers tracked how factors like age, symptom severity, treatment timing, and medication type impacted clinical outcomes for these patients over six months, and over two years.
The team also analyzed the effect of age on disease outcomes by subdividing the patients into two age groups: the sub-very late-onset MG group and the super late-onset MG group. The sub-very late-onset MG group comprised 75 patients whose symptoms started between the ages of 65 and 74, while the super late-onset MG group involved 18 patients whose disease onset occurred at age 75 or older.
Researchers encourage clinicians to ‘focus on early intervention’
Overall, those with AChR-positive very late-onset MG had both short-term and long-term outcomes that were favorable. Approximately half (49.5%) achieved minimal symptom expression, or MSE, defined as an MG Activities of Daily Living (MG-ADL) score of zero or 1, within six months of disease onset. A total of 86% of patients attained the same outcome within two years.
MG-ADL is a measure of disease severity used to assess the impact of MG on a patient’s daily activities; its score ranges from zero to 24, with higher values indicating greater disease severity.
Similar proportions of sub-very late-onset MG patients and super late-onset MG patients achieved minimal symptom expression at six months, one year, and two years after disease onset, the data showed.
Managing the side effects of long-term immunotherapy in elderly MG patients remains a critical concern. … We generally recommend that elderly patients receive potent and rapid immunosuppressive therapy early in the disease course to minimize the total drug dose and occurrence of side effects.
Statistical analyses showed that very late-onset MG patients who had less severe disease — an MG-ADL score of four points or lower — and those treated with steroids were more likely to achieve MSE within six months of disease onset and have a more favorable short-term prognosis.
Patients who received treatment within a year of disease onset were more likely to achieve MSE within two years. Specifically, the researchers found that the use of steroids alone or in combination with immunosuppressants increased the likelihood of MSE at two years.
Given these findings, the researchers recommended that “doctors should focus on early intervention and appropriate medication to improve patient outcomes.”
The team also found that weakness in the muscles of the limbs or those in the head and neck — known as the bulbar muscles — were risk factors for a worse long-term prognosis.
Nearly half of the patients (46.2%) had side effects due to MG treatment, with similar rates seen in the two patient subgroups. Medication withdrawal occurred in 27.9% of the individuals who experienced side effects. No statistically significant difference in medication withdrawals was seen between the two patient subgroups, the researchers noted.
“Managing the side effects of long-term immunotherapy in elderly MG patients remains a critical concern,” the researchers wrote. “We generally recommend that elderly patients receive potent and rapid immunosuppressive therapy early in the disease course to minimize the total drug dose and occurrence of side effects.”
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