title: Monocyte chemoattractant protein production in red cell incompatibility.
abstract: BACKGROUND
  Mononuclear phagocytes play a central role in hemolytic transfusion reactions by erythrophagocytosis and production of inflammatory mediators. Factors that affect the number or function of monocyters would be expected to alter the clinical course of hemolytic transfusion reactions, and thus the production of monocyte chemoattractant protein-1 (MCP-1), a recently described chemotactic and activating cytokine specific for monocytes, was investigated in two distinct settings of red cell (RBC) incompatibility.
  
  
  METHODS
  Fresh heparinized whole blood was incubated with ABO-compatible or -incompatible RBCs. Isolated peripheral blood mononuclear cells were incubated with anti-D-coated or uncoated RBCs. MCP-1 was measured in the plasma or culture medium by enzyme-linked immunosorbent assay. MCP-1 gene expression was detected by Northern blot analysis of buffy coat or mononuclear cell total RNA.
  
  
  RESULTS
  Significant levels of MCP-1 protein in plasma or medium were detected 24 hours after the addition of incompatible RBCs, but not in the first 6 hours. Nonimmune hemolysis of added RBCs did not stimulate MCP-1 production. The inactivation of complement by heat treatment of plasma prior to the addition of RBCs to whole blood did not prevent MCP-1 production. Nor did neutralizing antibodies to tumor necrosis factor prevent MCP-1 production in ABO incompatibility. MCP-1 production was associated with increased steady-state levels of white cell MCP-1 mRNA, which occurred more rapidly in ABO than Rh incompatibility.
  
  
  CONCLUSIONS
  The monocyte-specific chemotactic cytokine MCP-1 is produced by peripheral blood leukocytes in response to RBC incompatibility. MCP-1 may act in a positive feedback loop to recruit and activate monocytes during hemolytic transfusion reactions, thus contributing to the maintenance of these reactions.
authors.affiliation: Department of Pathology, University of Michigan Medical School, Ann Arbor.
authors.forename: R D
authors.initials: RD
authors.lastname: Davenport
authors.forename: M
authors.initials: M
authors.lastname: Burdick
authors.forename: R M
authors.initials: RM
authors.lastname: Strieter
authors.forename: S L
authors.initials: SL
authors.lastname: Kunkel
mesh_terms: D000017:ABO Blood-Group System; D001483:Base Sequence; D001787:Blood Group Incompatibility / Q000378:metabolism*; D018932:Chemokine CCL2; D002630:Chemotactic Factors / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D012204:Rh-Hr Blood-Group System; D065227:Transfusion Reaction
chemical_list: D000017:ABO Blood-Group System; D018932:Chemokine CCL2; D002630:Chemotactic Factors; D012204:Rh-Hr Blood-Group System