D. Caccavo et al., Increased levels of lactoferrin in synovial fluid but not in serum from patients with rheumatoid arthritis, INT J CL L, 29(1), 1999, pp. 30-35
Citations number
35
Categorie Soggetti
Medical Research Diagnosis & Treatment
Journal title
INTERNATIONAL JOURNAL OF CLINICAL & LABORATORY RESEARCH
Lactoferrin is a multifunctional immunoregulatory protein, stored in specif
ic granules of neutrophil granulocytes, from which it is released following
cell activation. As activated neutrophils play a crucial role in the destr
uction of synovial joints in rheumatoid arthritis, we evaluated lactoferrin
concentration in synovial fluid and sera from 21 patients with rheumatoid
arthritis and 11 patients with osteoarthritis. We also measured lactoferrin
levels in sera from 12 healthy controls. Lactoferrin was measured by a sol
id-phase inhibition immunoassay. Median lactoferrin levels were significant
ly higher in synovial fluid from rheumatoid arthritis than from osteoarthri
tis patients (P=0.0002). In contrast, no significant difference was found b
etween serum lactoferrin from patients with rheumatoid arthritis or osteoar
thritis compared with normal controls. In patients with rheumatoid arthriti
s, lactoferrin concentrations were higher in synovial fluid than in sera (P
=0.036). In both rheumatoid arthritis and osteoarthritis no correlation was
found between serum and synovial fluid lactoferrin (P=0.51 and P=0.5, resp
ectively). In synovial fluid from patients with rheumatoid arthritis, lacto
ferrin concentrations correlated with neutrophil granulocyte count (P<0.000
1), but neither serum nor synovial lactoferrin levels correlated with disea
se activity (P=0.32 and P=0.25, respectively). In conclusion, lactoferrin i
s a reliable marker of neutrophil activation at sites of inflammation in rh
eumatoid synovitis, but does not represent a marker of disease activity.