Lactoferrin in rheumatoid arthritis and systemic lupus erythematous.

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are prototypes of autoimmune diseases. In order to assess the inflammatory status in these conditions, lactoferrin, stored in specific granules of neutrophils, was measured in serum samples of patients with SLE and RA. In RA, the mean serum lactoferrin level (1221.397 +/- 289.476 ng/ml) was significantly higher than that in normal individuals (753.364 +/- 124.063 ng/ml). Surprisingly, there were no significant differences between active SLE (672.682 +/- 356.154 mg/ml) and inactive SLE (642.267 +/- 270.456 ng/ml). Still, no differences were found between normal volunteers, active SLE and inactive SLE. Serum lactoferrin in SLE correlated significantly with CRP (Rs = 0.4089, p less than 0.01), but not with complement level and ANA titers. Thus in RA serum lactoferrin was highly elevated and this indicated that PMN in systemic circulation was activated. In SLE the correlation of CRP with lactoferrin reflected the role of later protein in inflammation.