Lactoferrin, anti-lactoferrin antibodies and inflammatory disease.

The nucleophilic properties of human lactoferrin (Lf) were demonstrated by immunofluorescence microscopy using cryostat rat tissue sections, and the nuclear/perinuclear distribution of Lf in ethanol-fixed human neutrophils was visualized with rabbit anti-human Lf, producing a P-ANCA/GS-ANA staining pattern. Prevention of complement activation by Lf was confirmed in a haemolytic assay. Antibodies (IgG) against human Lf were studied by ELISA in sera from patients with Crohn's disease, ulcerative colitis, primary sclerosing cholangitis, rheumatoid arthritis, systemic lupus erythematous and primary Sjögren's syndrome. Anti-Lf antibodies were found in high frequency in ulcerative colitis and primary sclerosing cholangitis, but only occasionally in the other conditions.