Immunosuppressive Agents

Importance
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by inflammation and immune-mediated injury to multiple organ systems, including the mucocutaneous, musculoskeletal, hematologic, and kidney systems. Approximately 3.4 million people worldwide have received a diagnosis of SLE.

Observations
Approximately 90% of people with SLE are female. Although there are no uniformly accepted diagnostic criteria for SLE, the 2019 European Alliance of Associations for Rheumatology (formerly the European League Against Rheumatism)/American College of Rheumatology classification criteria developed for scientific study are an estimated 96.1% sensitive and 93.4% specific for SLE. These classification criteria include both clinical factors, such as fever, cytopenia, rash, arthritis, and proteinuria, which may be indicative of lupus nephritis; and immunologic measures, such as SLE-specific autoantibodies and low complement levels. Approximately 40% of people with SLE develop lupus nephritis, and an estimated 10% of people with lupus nephritis develop end-stage kidney disease after 10 years. The primary goal of treatment is to achieve disease remission or quiescence, defined by minimal symptoms, low levels of autoimmune inflammatory markers, and minimal systemic glucocorticoid requirement while the patient is treated with maintenance doses of immunomodulatory or immunosuppressive medications. Treatment goals include reducing disease exacerbations, hospitalizations, and organ damage due to the disease or treatment toxicity. Hydroxychloroquine is standard of care for SLE and has been associated with a significant reduction in mortality. Treatments in addition to hydroxychloroquine are individualized, with immunosuppressive agents, such as azathioprine, mycophenolate mofetil, and cyclophosphamide, typically used for treating moderate to severe disease. Three SLE medications were recently approved by the Food and Drug Administration: belimumab (for active SLE in 2011 and for lupus nephritis in 2020), voclosporin (for lupus nephritis), and anifrolumab (for active SLE).

Conclusions and Relevance
Systemic lupus erythematosus is associated with immune-mediated damage to multiple organs and increased mortality. Hydroxychloroquine is first-line therapy and reduces disease activity, morbidity, and mortality. When needed, additional immunosuppressive and biologic therapies include azathioprine, mycophenolate mofetil, cyclophosphamide, belimumab, voclosporin, and anifrolumab.