142 Approaching cytopenias in systemic lupus erythematosus: what does the bone marrow reveal?

Abstract

BackgroundCytopenias are a common manifestation in systemic lupus erythematosus (SLE), and it is fundamental to determine their etiology in order to establish an adequate therapeutic strategy. The aim of this study was to determine the relevance of bone marrow aspirations (BMA) and biopsies while studying the cause of cytopenias in SLE patients, as well as describing associated clinical and laboratory features.MethodsWe 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.ResultsWe included 101 patients; 81.2% were women. Median age was 32 years. Leukopenia (<3000 cells/µl) was found in 47.5% of patients; with lymphopenia (<1000 cells/L) being a common finding (71.3% of patients). Moderate-to-severe thrombocytopenia (<50 K/µl) was present in 28.7% of patients. Finally, 25.8% of patients presented with pancytopenia.In 72.3% of patients, bone marrow interpretation, along with clinical and laboratory findings, lead to a conclusive diagnosis. The most common final diagnoses were disease activity (24.8%) and drug-associated toxicity (28.7%). The agreement between the initial diagnostic impression and the conclusion after BMA was performed was 45.5%.We analyzed factors associated with the most common etiologies (table 1). Regarding BMA findings, when cytopenias were secondary to disease activity, it was more frequent for the bone marrow to 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).After multivariate analysis, a neutrophil count <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<1000 cells/µl (OR 4.05; 95% CI 1.15–14.19, p=0.029) were found to be independent risk factors for myelotoxicity.Abstract 142 Table 1Clinical and serologic characteristics of patients with SLE and cytopenias secondary to disease activity or drug-associated myelotoxicity at the time of the bone marrow aspirateCharacteristicDisease activity (n=25)Drug-associated myelotoxicity (n=28)p Time since SLE diagnosis (months) 12 (0–348) 54.5 (0–372) 0.038 History of disease activity- Mucocutaneous- Hematologic- Renal - Serositis80%100% 44% 28%86%96.4% 78.6% 32.1%0.7191 0.012 0.774Hemoglobin (g/dL)8.6 (3.9–15.4)9.5 (6.7–15.7)0.674 Neutrophils (cells/μl) - Normal (>1500) - Mild neutropenia (1000–1499) - Moderate neutropenia (500-999) - Severe neutropenia (<500) 76% 16% 4% 4% 35.7% 17.9% 7.1% 39.3% 0.004 Lymphopenia (<1000 cells/µl)68%70%1Platelets (K/µl)- Normal (>100)- MIld thrombocytopenia (50-99)- Severe thrombocytopenia (<5...