Abatacept for rheumatoid arthritis complicated by disseminated cryptococcosis: a case report

A 78-year-old man developed disseminated cryptococcosis with central nervous system involvement as encapsulated yeast cells were detected in transbronchial biopsy and skin biopsy specimens, and cerebrospinal fluid. Cryptococcus neoformans was confirmed by culture. He had been treated with low-dose prednisolone and methotrexate for rheumatoid arthritis. He started receiving antifungal therapy with intravenous liposomal amphotericin B followed by oral fluconazole. Methotrexate was discontinued. Approximately 4 months after the course of intravenous liposomal amphotericin B was completed, he complained of pain and swelling of the right wrist, which suggested that rheumatoid arthritis was worsening. Abatacept therapy was initiated along with antifungal therapy, and his symptoms relieved. After 24 months of antifungal therapy, although he was still receiving oral fluconazole, he was doing well and the serum cryptococcal antigen had become negative. Disseminated cryptococcosis is an important opportunistic infection associated with low-dose methotrexate for rheumatoid arthritis. Abatacept therapy may be feasible in strictly selected patients with rheumatoid arthritis complicated with cryptococcosis concomitantly with intensive anti-fungal therapy.