Serum Biomarkers for Identifying Acute Chest Syndrome Among Patients Who Have Sickle Cell Disease and Present to the Emergency Department

• Published in: Pediatrics (Evanston) 2005-09, Vol.116 (3), p.e420-e425
• Main Authors: Naprawa, James T, Bonsu, Bema K, Goodman, Deborah G, Ranalli, Mark A
• Format: Article
• Language: English
• Subjects: Acute Disease; Adolescent; Anemia, Sickle Cell - blood; Anemia, Sickle Cell - complications; Area Under Curve; Biomarkers - blood; Chest Pain; Child; Endothelin-1 - blood; Female; Humans; Interleukin-6; Leukocyte Count; Lung Diseases - blood; Lung Diseases - diagnosis; Lung Diseases - etiology; Male; Phospholipases A - blood; Phospholipases A2; Sensitivity and Specificity; Syndrome
• ISSN: 0031-4005; 1098-4275
• DOI: 10.1542/peds.2004-2107

To compare the accuracy of biomarkers for identifying acute chest syndrome (ACS) in patients with sickle cell disease presenting to a pediatric emergency department (ED). We conducted a 13-month-long (2002-2003) cohort study with nested case-control in patients with sickle cell disease presenting to the pediatric ED with vaso-occlusive crises or fever in which we compared levels of secretory phospholipase A2 (sPLA2), endothelin-1, interleukin-6 (IL-6), and peripheral white blood cell count (WBC) in cases that were complicated by ACS and in control subjects with uncomplicated illnesses. For diagnosis, a test was considered to be accurate when the area under its receiver operator characteristic curve (AUC) was >0.70. Laboratory tests with AUC values > or =0.70 were entered into a binary recursive partitioning model for diagnosis. For the period of study, samples from 72 visits were obtained from 51 patients who presented with vaso-occlusive crises (range: 1-4 visits per patient; 15 were enrolled more than once). ACS complicated 19 of 72 visits (26%, 95% confidence interval: 17%-38%). At an AUC value of 0.79, only the sPLA2 test was accurate for diagnosing ACS. AUC values for peripheral WBC, endothelin-1, and IL-6 were 0.68, 0.51, and 0.52, respectively. Binary recursive partitioning retained only sPLA2 at a cutoff of 13.7 ng/mL to be accurate for diagnosis. This cutoff had a sensitivity of 74% (14 of 19), a specificity of 87% (46 of 53), a positive likelihood ratio of 5.6, and a negative likelihood ratio of 0.18. Secretory phospholipase A2 but not endothelin-1, IL-6, or WBC is an accurate test for identifying present or incipient ACS in young patients who present to the ED with sickle cell pain crises.