Expression of lactoferrin on neutrophil granulocytes from synovial fluid and peripheral blood of patients with rheumatoid arthritis.
OBJECTIVE
To analyze lactoferrin expression on synovial fluid (SF) and peripheral blood neutrophils of patients with rheumatoid arthritis (RA) and to compare it with the lactoferrin expression on neutrophils from patients with osteoarthritis (OA).


METHODS
Paired samples of peripheral blood and SF were obtained from 14 patients with RA and 9 patients with OA. Lactoferrin expression was evaluated on cell surfaces by cytofluorimetric analysis utilizing both polyclonal antibodies and the monoclonal anti-lactoferrin antibody AGM 2.29. Data are presented as mean fluorescence intensity.


RESULTS
In patients with RA, the expression of membrane lactoferrin was significantly increased on SF neutrophils in comparison with those in peripheral blood. This increase was found using both polyclonal antibodies and AGM 2.29 (p = 0.0001, p = 0.0017, respectively). In patients with OA, the difference was not significant. In addition, lactoferrin expression on SF neutrophils of patients with RA was significantly increased compared with that found on SF neutrophils of patients with OA (polyclonal antibodies, p = 0.0015; AGM 2.29, p = 0.005). In patients with RA, no correlation was found between lactoferrin expression and disease activity.


CONCLUSIONS
Our results provide evidence for an activation of neutrophil granulocytes at site of inflammation in RA and indicate that lactoferrin surface expression represents a reliable neutrophil activation marker.
Caccavo
Domenico
D
Department of Clinica Medica, Immunologia e Malattie Infettive, University of Bari, Rome, Italy.
Garzia
Pierluigi
P
Sebastiani
Gian Domenico
GD
Ferri
Giovanni Maria
GM
Galluzzo
Sara
S
Vadacca
Marta
M
Rigon
Amelia
A
Afeltra
Antonella
A
Amoroso
Antonio
A
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007781:Lactoferrin / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018375:Neutrophil Activation; D009504:Neutrophils / Q000378:metabolism*; D010003:Osteoarthritis / Q000276:immunology / Q000378:metabolism; D012720:Severity of Illness Index; D013582:Synovial Fluid / Q000166:cytology / Q000276:immunology*
D007781:Lactoferrin