title: Activated monocytes and platelet-monocyte aggregates in patients with sickle cell disease.
abstract: Tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) increase endothelial surface receptors that mediate the adherence of sickle erythrocytes to the endothelium. Increased circulating levels of these cytokines have been found in patients with sickle cell disease (SCD). Monocytes are a source of both of these inflammatory mediators; we therefore determined whether circulating monocytes were activated in SCD, as defined by intracellular expression of these cytokines. Blood was also assayed for the presence of platelet-monocyte aggregates (PMAs), as platelet adherence is one possible mechanism for monocyte activation. The median percentages of monocytes expressing intracellular TNF-alpha and IL-1beta in SCD patients were 6.8 (2.8-17.3) [median (range)] and 14.1 (1.3-44.8), respectively. In African-American controls the corresponding percentages were 0.3 (0.1-0.5) and 0.4 (0.1-3.0), and in Caucasians 0.2 (0.1-0.5) and 0.8 (0.8-1.9) (P < 0.001, Kruskal-Wallis). The mean percentage (+/- SD) of PMA was 14.0 +/- 8.3 for Caucasian controls, 25.7 +/- 7.3 for African-American controls, and 45.7 +/- 21.6 for patients with SCD (P < 0.001, RM ANOVA; P < 0.05, Newman-Keuls posthoc test). We conclude that there are increased circulating PMAs and monocyte activation in patients with SCD.
authors: Division of Hematology and Oncology, UC Davis School of Medicine, CA, USA. ted.wun@ucdmc.ucdavis.edu
authors: Ted
authors: T
authors: Wun
authors: Miguel
authors: M
authors: Cordoba
authors: Arun
authors: A
authors: Rangaswami
authors: Anthony W
authors: AW
authors: Cheung
authors: Teresa
authors: T
authors: Paglieroni
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications; D044383:Black People; D001792:Blood Platelets / Q000473:pathology*; D002449:Cell Aggregation; D002648:Child; D005260:Female; D005898:Glass; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000209:etiology; D007375:Interleukin-1 / Q000097:blood; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000737:chemistry / Q000187:drug effects / Q000473:pathology*; D010973:Platelet Adhesiveness; D019851:Thrombophilia / Q000097:blood / Q000209:etiology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D044465:White People; D001741:Black or African American
chemical_list: D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D006493:Heparin