CD8(+) T-cell lymphoproliferative disorder associated with Epstein-Barr virus in a patient with rheumatoid arthritis during methotrexate therapy.

A 75-year-old woman with rheumatoid arthritis (RA) who was receiving methotrexate (MTX) therapy developed Epstein-Barr virus (EBV)-associated CD8(+) T-cell lymphoproliferative disorder (LPD) and meningoencephalitis. She was successfully treated with acyclovir and corticosteroids plus MTX cessation. T-cell LPD is relatively rare in RA patients receiving MTX. To our knowledge, this is the first report of CD8(+) T-cell LPD with EBV genome occurring during MTX therapy for RA. EBV infection should be carefully monitored to assess severe EBV-associated complications.