The National Cancer Center said Tuesday its researchers confirmed that two elderly patients with diffuse large B-cell lymphoma in complete remission after combined immunochemotherapy developed the Guillain-Barré syndrome after receiving Pfizer–BioNTech Covid-19 vaccines.
Guillain-Barré syndrome is a rare inflammatory disease that affects the peripheral nerves and often comes accompanied by rapidly progressive muscle weakness and paresthesia in the extremities. There have been reports that Guillain-Barré syndrome occurred after prior infection or influenza vaccination, and the disease is one of the adverse reactions of special interest after Covid-19 vaccination.
Um Hyun-seok, the director of an affiliated hospital, led the team. In addition, Professors Hyun Jae-won of the Department of Neurology, Jeong Jun-young of the Department of Infectious Diseases, and Park So-hyun of the Department of Nuclear Medicine participated in the study.
The team stressed that as most of the national vaccination programs were for infants and children, there is no precedent for extensive vaccination for the elderly.
“That may explain why the researchers could observe closely rare side effects that may occur in elderly patients with underlying diseases,” the center said. “It is necessary to carefully observe the side effects of vaccination that may occur in patients with B-cell lymphoma who have abnormal B-cell function involved in antibody-related humoral immunity.”
However, the team stressed that although this case shows a temporal relationship between vaccination and Guillain-Barré syndrome, it does not prove a causal relationship and requires additional researches.
Therefore, the researchers conducted a glucose analog positron emission tomography test to rule out the possibility of lymphoma recurrence due to acute paralysis in patients who had diffuse large B-cell lymphoma and received complex immunochemotherapy.
In the process, they could observe the inflammatory response of the peripheral nerves related to the site of acute paralysis.
“This is meaningful as it is the world's first positron emission tomography report of a patient with Guillain-Barré syndrome findings,” the center said.
Nevertheless, the research team concluded that the benefits of the Covid-19 vaccination are greater as the incidence of Guillain-Barré syndrome after vaccination is very low, with one to two cases per 100,000 people, and occurs mainly in older adults, especially those with Covid-19 infection and underlying diseases.
Lancet Neurology published the study results in its latest issue.