Frequency of URTIs higher when MG is treated with rituximab
Rate of URTIs about equal among MG patients, general population
People with myasthenia gravis (MG) are just as likely to have upper respiratory tract infections (URTIs) as people in the general population, a study in Saudi Arabia suggests.
Certain treatments used to manage MG, such as rituximab, an antibody-based therapy sometimes used off-label for that purpose, might increase the frequency of these types of infections, however.
“The findings of this study suggest that the frequency of URTI is not significantly different between patients with MG and the general population,” wrote the researchers, who said “further research is warranted to validate these findings and explore associations between rituximab and URTI.”
The study, “Frequency of upper respiratory tract infections in patients with myasthenia gravis compared to the general population,” was published in Clinical Neurology and Neurosurgery.
MG is a chronic autoimmune condition where the communication between nerves and muscles is disrupted, leading to weakness in various muscle groups. The disease is caused by self-reactive antibodies being produced that target proteins involved in nerve-muscle communication.
Many patients rely on immunosuppressive therapies to manage their symptoms, but these treatments can weaken the body’s ability to fight off infections. Rituximab works to lower the number of antibody-producing immune B-cells in the body. While it can help lower the levels of the self-reactive antibodies that drive MG, it can also weaken the body’s ability to mount an immune response and increase patients’ susceptibility to infections.
Link between rituximab use, URTIs in MG
“Nonetheless, it remains uncertain whether the frequency of URTI is higher among patients with MG compared with the general population,” wrote the researchers, who investigated how frequently MG patients had URTIs compared with people from the general population. They examined data from monthly questionnaires completed by 50 MG patients and 111 people from the general population over six months.
The questionnaires were designed to assess the presence of URTI symptoms in the previous month. If the participants reported at least two symptoms, one of them being either cough, runny nose, recurrent sneezing, or sore throat within a specific month, they were considered to have had a URTI during that month.
Most MG patients (70%) reported at least one URTI during the study period, a rate similar to the general population (82%). But the frequency of URTIs was higher among MG patients undergoing treatment with rituximab (93%) than in those not receiving the medication (61%).
“Treatment with rituximab showed a statistically significant association with URTI in patients with MG,” the researchers wrote.
This wasn’t seen with other immunomodulating therapies, such as the corticosteroid prednisone or the nonsteroidal immunosuppressant azathioprine.
The study’s findings were limited by the small sample size and the six-month observation period, which didn’t cover all seasonal variations, the researchers said.
“Further, URTI is commonly a mild, self-limited infection, potentially leading to inaccurate reporting when relying on patient-reported questionnaires instead of direct physician evaluations,” they wrote, noting the limitations don’t allow for a complete generalization of the study’s results. Further research is needed to validate the findings and explore the link between specific MG treatments and infection risks.
“Physicians need to adopt proactive measures in monitoring and managing infections in patients receiving immunomodulating therapies and educate patients regarding the importance of adhering to preventive measures and the potential risks of MG relapse associated with infections,” the researchers wrote.
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