P162 Incidence of Neutropaenia and Infections in Lupus Patients on Immunosuppression

Abstract Background/Aims Neutropaenia occurs in 20-40% of patients with systemic lupus erythematosus (SLE) and is attributed to a combination of autoimmune and complement-mediated destruction of white cells, increased neutrophil apoptosis and medication side-effects. Commonly when patients become neutropaenic (<2x10^9/L), immunosuppressant doses are reduced or discontinued. However, studies have not consistently shown an increased risk of infection in SLE patients that suffer neutropaenia while taking immunosuppressants. This retrospective case note review aimed to examine the association between degree of neutropaenia and rates of infection in SLE patients. Methods Data was collected for 100 patients attending an SLE clinic in a tertiary London hospital between May 2019 and August 2020. Patients completed a questionnaire reporting the number and nature of infections they had suffered in the previous year, and whether antibiotics and/or hospitalisation was required. Clinical data was collected by retrospective review of electronic patient records including immunosuppressant therapy and neutrophil counts. Sustained neutropaenia was defined as a neutrophil count <2x10^9/L for >3 months, and severe neutropaenia defined as a neutrophil count of < 1x10^9/L). Results 95% of patients were female with a median age of 42 years (range 18-87). 55 (55%) of our patients were prescribed an immunosuppressant - 32 mycophenolate mofetil, 14 azathioprine, 4 rituximab, 4 methotrexate, 4 ciclosporin, 3 cyclophosphamide and 1 leflunomide. This cohort was more likely to develop neutropenia (n = 19, 35% vs n = 10, 22%, OR 1.8, p = 0.13), report one or more infections (n = 29, 53% vs n = 19, 42%), require antibiotics (n = 19, 35% vs n = 10, 22%) or inpatient treatment (13% vs 7%). However, immunosuppressed patients with neutropaenia >1x10^9/L (8/19) did not experience more infections than those without neutropaenia (21/36) (42% vs 58%, OR 0.5, p = 0.2). Chest, urine and upper respiratory tract were the most commonly reported infections. 29 (29%) patients had sustained neutropaenia, with only 2 (2%) patients experiencing severe neutropaenia - both latter patients experienced recurrent viral infections and were only taking hydroxychloroquine. Conclusion Immunosuppressive therapy was correlated with an increased prevalence in the absolute number of reported infections, antibiotic prescriptions and hospital admissions. Although there were more cases of infection and neutropenia in patients receiving immunosuppressants, rates of infection were not higher amongst neutropenic patients whose counts were above 1x10^9/L. Our data suggest that the increased risk of infection in our patients receiving immunosuppressants may be independent of the risk of neutropenia. Rates of infection, antibiotic use and hospital admission were not increased in patients with sustained neutropenia. There were few cases of severe neutropenia in our cohort, and in the absence of immunosuppressant use, this may have been driven by the SLE itself. Disclosure S. Manou-Stathopoulou: None. W. Hann: None. A. Pakozdi: None. R. Rajakariar: None. M. Lewis: None. A. Cove-Smith: None. D. Pyne: None.