A case of newly onset rheumatoid arthritis successfully treated with methotrexate under the anti-retrovirus therapy against HIV infection.

Abstract

The patient was a 70-year-old woman. In July 2018, she developed pneumocystis pneumonia and was diagnosed with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). Antiretroviral therapy (ART) was continued, the HIV-RNA load was suppressed, and the CD4+cells count was maintained. In 2024, the polyarticular pain and swelling persisted. HIV-associated arthropathy, reactive arthritis, and other diseases were excluded. The patient was diagnosed with rheumatoid arthritis (RA) according to the ACR/EULAR 2010 Rheumatoid Arthritis Classification Criteria. Joint radiography revealed narrowing of the wrist joint, and joint ultrasonography showed synovial thickening and power doppler signals, supporting the diagnosis of RA. Methotrexate was initiated, and remission was achieved and maintained. After starting MTX, HIV-RNA load increased transiently but rapidly decreased after that. CD4+cells count was maintained. Patients with HIV have underlying immune dysfunction, and RA requires treatment with immunosuppressants (DMARDs), which makes treatment challenging. Recently, HIV infection has been considered a factor that makes the diagnosis of RA difficult. When symptoms suggestive of RA are observed in HIV-infected patients, it is important to make a thorough differential diagnosis and determine a treatment plan based on the characteristics of RA complicated by HIV infection.