Efficacy of abatacept for Felty's syndrome

The First Case of Felty's Syndrome Complicated by COVID-19 Infection

Felty's syndrome (FS) is an uncommon disorder with a poor prognosis, and most patients die from infections caused by neutropenia. Currently, there is no standardized treatment strategy, and treatment options are based on case reports and clinical experience. To date, no cases of FS complicated by coronavirus disease-2019 (COVID-19) have been reported. This article reports a successful case of FS complicated by COVID-19. We emphasized treating rheumatic diseases with immunosuppressive therapy at appropriate doses based on strong and effective anti-infection when co-infected.

Felty's syndrome

Felty's syndrome was first described in 1924 by the US-American physician Augustus Roi Felty as a triad of rheumatoid arthritis, splenomegaly and leucopenia. Even nearly 100 years later, this rare syndrome is still paralleled by diagnostic and therapeutic challenges and its pathogenesis is incompletely understood. Neutropenia with potentially life-threatening infections is the main problem and several pathomechanisms like Fas-mediated apoptosis, anti-neutrophil antibodies, anti-G-CSF antibodies, neutrophil consumption in the context of NETosis and suppression of granulopoiesis by T-LGLs have been suggested. Felty's syndrome has various differential diagnoses as splenomegaly and cytopenia are common features of different infectious diseases, malignancies and autoimmune disorders. Additionally, benign clonal T-/NK-LGL lymphocytosis is increasingly noticed in Felty's syndrome, which further complicates diagnosis. Today's treatment options are still sparse and are largely based on case reports and small case series. Methotrexate is the mainstay of therapy, followed by rituximab, but there is less evidence for alternatives in the case of adverse reactions or failure of these drugs. This article gives an updated review about Felty's syndrome including its pathogenesis and treatment options.

The Use of Abatacept for the Treatment of Felty Syndrome in Rheumatoid Arthritis

Felty syndrome is characterized by a triad of rheumatoid arthritis, neutropenia, and splenomegaly that typically occurs in patients with seropositive rheumatoid arthritis. We report a case of an 81-year-old man with a 22-year history of rheumatoid arthritis who developed pancytopenia and neutropenia for one month. An abdominal ultrasound revealed splenomegaly. A bone marrow biopsy excluded large granular lymphocytic leukemia, thus Felty Syndrome was diagnosed. He was treated with a maximum tolerated dose of methotrexate (15 mg once a week) for two months with no improvement in absolute neutrophil count. The patient was given abatacept 1000 mg intravenously every four weeks with improvement in hemoglobin, leukocyte, and platelet counts and absolute neutrophil counts from 0.2 to 2.4 K/µl.