Efgartigimod Combined With Steroid Treatment for HAM/TSP: A Case Report.

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive neurological disorder with limited treatment options. We report a 54-year-old female with decade-long, progressive HAM/TSP, previously refractory to rituximab, who experienced worsening spastic paraparesis and neurogenic bladder dysfunction. She showed remarkable improvement in spasticity, bladder function, and quality of life following combination therapy with efgartigimod and corticosteroids. This case highlights efgartigimod's potential as an adjunctive therapy for refractory HAM/TSP, suggesting a new immune modulation strategy and warranting further research into combination treatments.