Combined procedure better as myasthenic crisis treatment: Study
Lymphoplasmapheresis tops plasma exchange in study
Plasma exchange — a procedure that clears antibodies, such as those that cause myasthenia gravis (MG), from the blood — may be a better myasthenic crisis treatment when used in combination with a procedure used to remove white blood cells, a study found.
The combined procedure, called lymphoplasmapheresis, achieved better treatment outcomes than plasma exchange alone, in fewer treatment sessions. Both reduced the levels of MG-causing antibodies, but lymphoplasmapheresis appeared to perform better.
The study, “Comparison of Efficacy Between Lymphoplasmapheresis and Plasma Exchange in Myasthenic Crisis,” was published in Muscle & Nerve by a team of researchers led by Huan Yang, MD, PhD, of Central South University in China.
MG occurs when the body produces self-reactive antibodies that bind to proteins involved in nerve-muscle communication, disrupting the process. In most cases, these antibodies target acetylcholine receptors (AChRs) on the surface of muscle cells. This leads to MG symptoms such as muscle weakness and fatigue.
One treatment option for MG is plasma exchange, also known as plasmapheresis. In this procedure, a patient’s blood is passed through a machine to separate the plasma, which contains the disease-causing antibodies, from the blood cells. The blood cells are then mixed with fresh fluid and returned to the patient.
Testing lymphoplasmapheresis as myasthenic crisis treatment
Lymphoplasmapheresis combines plasma exchange with leukapheresis, a similar procedure that involves removing white blood cells from circulation. White blood cells are part of the body’s immune system, but they may be overactive in MG, contributing to lasting inflammation and antibody production.
Earlier work by Yang’s team showed that lymphoplasmapheresis is better than plasma exchange at easing MG symptoms and shortening the time spent in the hospital. Now, they tested it for cases of myasthenic crisis, a life-threatening complication that occurs when respiratory muscles become too weak, impairing a patient’s ability to breathe.
To find out if lymphoplasmapheresis is better than plasma exchange in this context, the researchers reviewed the medical records of 86 patients who had a myasthenic crisis and received either lymphoplasmapheresis or plasma exchange as a form of treatment.
Nearly two-thirds of the patients were women. Lymphoplasmapheresis was used to treat 47 patients, and plasma exchange was used in 39.
Researchers compared how long patients stayed in the hospital, how long they needed mechanical ventilation to help with breathing, and how long they were in intensive care. They also compared Quantitative MG (QMG) scores, a measure of muscle weakness in which higher scores indicate more severe symptoms.
On average, patients treated with lymphoplasmapheresis needed fewer sessions than those treated with plasma exchange (2.26 sessions vs. 3.87 sessions). Despite having fewer sessions, those treated with lymphoplasmapheresis needed fewer days on mechanical ventilation (8.5 days vs. 11.7 days) and had shorter stays in the intensive care unit (11.9 days vs. 15.9 days).
Functional outcomes were also better with lymphoplasmapheresis. On average, patients treated with lymphoplasmapheresis scored significantly less on the QMG scale at both one month (13.6 points vs. 16.4 points) and two months (11.1 points vs. 13.7 points) after the myasthenic crisis compared with patients treated with plasma exchange.
“The duration of efficacy for replacement therapy is about 1–2 months,” the researchers wrote. “We found that patients treated with [lymphoplasmapheresis] exhibited better functional outcomes up to 2 months following the crisis episode when compared to those treated with [plasma exchange].”
Both treatments were well tolerated and reduced the levels of anti-AChR antibodies and inflammatory molecules released into circulation. However, lymphoplasmapheresis appeared to perform better.
Lymphoplasmapheresis removes white blood cells and inflammatory molecules that contribute to disease, helping to control a myasthenic crisis faster than plasma exchange. It also appears to be more effective with fewer treatment sessions, the researchers found.
“The reduction in the number of exchanges brought about by [lymphoplasmapheresis] not only reduces the risk of serious adverse events during repeated invasive operation and replacement, but also reduces the burden of treatment costs, as well as reduces the consumption of clinical blood resources,” they wrote.
While more studies are needed to confirm these findings, lymphoplasmapheresis “may be a superior choice” for managing a myasthenic crisis, the scientists said.
“For medical centers, switching from [plasma exchange] to [lymphoplasmapheresis] is entirely feasible, as [lymphoplasmapheresis] does not require new machines, and the changes in procedure required by physicians are straightforward,” they wrote.
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