THU0260 SYSTEMIC LUPUS ERYTHEMATOSUS AND CYTOPENIAS: THE KEY FINDINGS IN BONE MARROW
Authors: Ana Barrera-Vargas, Jonathan Campos-Guzmán, Samuel Govea-Peláez, Aldo García-Ramos, Roberta Demichelis-Gómez, Christianne Bourlon, Javier Merayo-Chalico, Jorge Alcocer-Varela
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Cytopenias are common in systemic lupus erythematosus (SLE), and it is fundamental to determine their etiology in order to establish an adequate therapeutic strategy. <h3>Objectives:</h3> To describe the findings in the bone marrow aspirations (BMA) and biopsies of patients with SLE and cytopenias, as well as clinical and laboratory features associated with the etiology of the hematological abnormalities. <h3>Methods:</h3> We performed a retrospective study in a third-level hospital in Mexico City. We included patients who fulfilled ACR criteria for SLE, presented with cytopenias and had a BMA and biopsy performed between 2000 and 2016. We described the main aspirate and biopsy findings, and also analyzed the final diagnosis and its association with clinical, laboratory and serological features. <h3>Results:</h3> We included 101 patients; median age was 32 years and 81.2% were women. Leukopenia (&lt;3000 cells/µl) was found in 47.5% of patients, with 29.7% having moderate or severe neutropenia (&lt;1000 cells/µl). Lymphopenia (&lt;1000 cells/μl) was a common finding (71.3% of patients). Moderate-to-severe thrombocytopenia (&lt;50 K/µl) was present in 28.7% of patients. Finally, 25.8% of patients presented with pancytopenia. Regarding bone marrow findings, there was erythroid dysplasia in 50.5% of patients, granulocytic dysplasia in 28.7% and megakaryocytic dysplasia in 16%. Myelofibrosis was found in 2.6%. An increase in plasma cells (≥5%) was found in 21.8%. In 72.3% of patients, bone marrow interpretation was conclusive. The most common diagnoses were disease activity (24.8%) and drug-associated myelotoxicity (28.7%). When compared to other etiologies, in patients with cytopenias secondary to disease activity, it was more frequent for the bone marrow be hypercellular (56 vs 23%, p=0.006) and to have increased megakaryocytes (40 vs 17.4%, p=0.048). Conversely, granulocytic dysplasia was less common in this group of patients (17.4% vs 54.3%, p=0.036) We analyzed factors associated with both activity and toxicity as final diagnoses (Table 1). After multivariate analysis, a neutrophil count &lt;1000 cells/µl was a protective factor for disease activity (OR 0.021; 95% CI 0.001-0.428, p 0.012). On the other hand, a history of renal activity (OR 4.3; 95% CI 1.3-14.2, p=0.024) and neutrophils less than 1000 cells/µl (OR 4.05; 95% CI 1.15-14.19, p=0.029) were found to be independent risk factors for myelotoxicity. <h3>Conclusion:</h3> The main causes of cytopenias in our SLE patients were disease activity and bone marrow toxicity. Our findings suggest that when patients present with less than 1000 neutrophils/µl, it is unlikely for the cytopenias to be secondary to disease activity. Our study reinforces the diagnostic utility of BMA and biopsy, and the associations we described may assist clinicians to determine the etiology of cytopenias in SLE patients, in order to make appropriate therapeutic decisions. <h3> Disclosure of Interests:</h3> Ana Barrera-Vargas: None declared, Jonathan Campos-Guzmán: None declared, Samuel Govea-Peláez: None declared, Aldo García-Ramos: None declared, Roberta Demichelis-Gómez: None declared, Christianne Bourlon: None declared, Javier Merayo-Chalico Speakers bureau: Pfizer, Jorge Alcocer-Varela: None declared&nbsp;