Long-term continuous ambulatory peritoneal dialysis reduces the expression of CD11b, CD14, CD16, and CD64 on peritoneal macrophages.
OBJECTIVE
To characterize phenotypically the macrophages from nocturnal peritoneal effluent (NPE) in patients on continuous ambulatory peritoneal dialysis (CAPD), and to determine the influence of the length of this therapy on macrophage (M phi) function.


METHODS
Cross-sectional descriptive study.


METHODS
Fifty-five patients on CAPD who were classified into short-, medium-, and long-term groups according to their time on CAPD. Peritoneal macrophages (PM phi) were also characterized in 7 patients at the time of catheter placement, and there were 13 normal controls.


METHODS
Macrophages were collected from NPE by centrifugation.


METHODS
Membrane receptor expression was evaluated by flow cytometry analysis.


RESULTS
Flow cytometry analysis revealed that the expression of CD11b, CD16, CD64, and CD14 on NPE macrophages was reduced during the course of CAPD treatment, reaching levels which represented a 40%-50% reduction of the cell surface expression detected at the start of the treatment or on normal control macrophages. Both normal and CAPD PM phi expressed CD4, CD69, and CD71 very weakly and lacked CD25. No changes in HLA-DR or in other adhesion protein (CD11a, CD11c, CD18, CD54) expression were detected, and levels were similar in both patients and normal controls.


CONCLUSIONS
Our results show that long-term CAPD might affect Fc gamma receptor-mediated phagocytosis by reducing the expression of CD16, CD64, and CD11b. Lower CD11b and CD14 expression would also impair PM phi adhesion to mesothelial structures.
Cárcamo
C
C
Servicio de Hematología, Hospital La Paz, Madrid, Spain.
Fernández-Castro
M
M
Selgas
R
R
Jiménez
C
C
Molina
S
S
Vara
F
F
D000328:Adult; D000368:Aged; D001202:Ascitic Fluid / Q000166:cytology*; D018821:CD18 Antigens / Q000032:analysis; D002469:Cell Separation; D005260:Female; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D016167:Integrin alphaXbeta2 / Q000032:analysis*; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D018950:Lipopolysaccharide Receptors / Q000032:analysis*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D016177:Macrophage-1 Antigen / Q000032:analysis*; D008264:Macrophages / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D017452:Receptors, IgG / Q000032:analysis*
D018821:CD18 Antigens; D006684:HLA-DR Antigens; D016167:Integrin alphaXbeta2; D018950:Lipopolysaccharide Receptors; D016169:Lymphocyte Function-Associated Antigen-1; D016177:Macrophage-1 Antigen; D017452:Receptors, IgG; D018799:Intercellular Adhesion Molecule-1