Prevalence and Risk Factors Associated with Neutropenia in Hospitalized Patients with Systemic Lupus Erythematosus

ABSTRACT

OBJECTIVE: This study estimated the prevalence and explored possible risk factors associated with neutropenia in hospitalized patients with systemic lupus erythematosus (SLE). METHODS: This review included 160 admissions of 85 SLE patients between 2006 and 2013. Neutropenia was defined as absolute neutrophil count (ANC) below 1,500/mm³. The baseline characteristics of the patients were compared between patients who experienced neutropenia and those who did not. Clinical and serological factors related to neutropenia episodes during admission were analyzed. RESULTS: Thirty-five (21.9%) neutropenic episodes were found among the 160 admissions. Most of the neutropenic episodes were mild to moderate. Severe neutropenia of ANC <500/mm³ occurred in 3.1% of the cases. Patients with neutropenia had higher frequencies of ANA (100.0% vs. 86.8%, p=0.042) and anti-double stranded DNA (87.5% vs. 60.4%, p=0.008), and satisfied more SLE classification criteria at the time of diagnosis than those without (5.1 vs. 4.6, p=0.009). Anemia, leukopenia, thrombocytopenia and low complement levels were frequently accompanied with neutropenia. Chronic kidney disease (odds ratio, 11.17; 95% confidence interval, 1.46∼85.27; p=0.020) was associated with neutropenia. CONCLUSION: This study demonstrates that neutropenia is frequent in hospitalized patients with SLE, and patients with neutropenia have more hematologic and immunologic abnormalities. Renal damage was more frequent among those presenting with neutropenia.