Guillain-Barré syndrome with T-cell receptor gene clonal rearrangement following COVID-19 vaccination: a case report.

The occurrence of Guillain-Barré syndrome (GBS) following coronavirus disease 2019 (COVID-19) vaccination have been documented; however, its pathogenesis remains unclear. We present a case of GBS associated with T-cell receptor (TCR) clonal rearrangement after COVID-19 vaccination. A previously healthy 60-year-old man developed fever, skin rash, general fatigue, and generalized urticaria after receiving his third vaccine dose (Spikevax, Moderna). No adverse events occurred after his first and second doses (COMIRNATY, Pfizer). Within 4 weeks of vaccination, the patient experienced progressive limb weakness and gait instability, and was referred to our hospital. Nerve conduction studies revealed increased distal latency, reduced compound muscle action potential amplitudes, decreased motor nerve conduction velocities, and diminished sensory nerve action potentials. Positron emission tomography-computed tomography showed systemic lymphadenopathy, splenomegaly, and increased splenic and bone marrow uptake. Bone marrow biopsy and peripheral blood analysis demonstrated TCR clonal rearrangement, which resolved by day 115 post-vaccination. Based on clinical progression, electrophysiological findings, and worsening neurological symptoms, a diagnosis of GBS was made. This case suggests that aberrant T-cell clonal expansion may contribute to GBS development following COVID-19 vaccination. To our knowledge, this is the first report describing TCR gene clonal rearrangement following COVID-19 vaccination.