Successful rituximab treatment in a seronegative rheumatoid arthritis patient with concurrent cold agglutinin syndrome and immune thrombocytopenia.

Cold agglutinin disease, a subtype of cold-type autoimmune hemolytic anemia, is referred to as cold agglutinin syndrome (CAS) when it develops secondary to other conditions. Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by the peripheral destruction of platelets. While both CAS and ITP can occur in patients with rheumatoid arthritis (RA), their concurrent manifestation in a single patient has not been reported, leaving the optimal treatment strategy for such a complex case unclear. Given that rituximab has been reported to be effective in treating RA, CAS, and ITP, it may be a promising treatment option for cases where these three conditions co-occur. We present the first case of RA complicated by both CAS and ITP, where the patient achieved complete remission with rituximab therapy. Furthermore, our review of the literature identified three cases of CAS and three cases of ITP in RA patients, all successfully treated with rituximab. These findings highlight the potential efficacy of rituximab in managing this challenging and potentially life-threatening combination of autoimmune diseases.