Fig. 4.

The anti-apoptotic effect of synovial fluid is reduced by depletion of lactoferrin. Peripheral blood neutrophils were incubated with medium alone (control), or with synovial fluid from seven different RA patients which had been immunodepleted for lactoferrin (LTF) using an anti-lactoferrin monoclonal antibody (LTF) or mock-depleted using an isotype control immunoglobulin (Mock). Apoptosis was measured by active caspase 3 staining after 20 h in culture. Control and immunodepleted data were compared using a paired Student's t-test and *P < 0.03.