NEUTROPHIL CD11B EXPRESSION IN PATIENTS WITH VENOUS DISEASE

Objective: To determine whether neutrophil CD11b, a marker of neutroph il adhesion, differs in patients with varying degrees of severity of v enous disease, and to compare the values obtained with those of age-ma tched normal control subjects. Design: Prospective study, measuring wh ite cell count and neutrophil CD11b expression in whole blood using a fluorescent-labelled monoclonal antibody in a flow cytometer. Setting: The Middlesex Hospital Vascular Laboratory, a referral centre for the investigation of venous disease. Patients: Ten patients with uncompli cated varicose veins, 10 patients with skin changes of lipodermatoscle rosis (LDS), and 20 age-matched control subjects with no history or cl inical finding of venous disease. Results: Higher levels of CD11b were found in patients with uncomplicated varicose veins compared with the ir controls (median 4.6 cf. 1.43 for normal controls, p = 0.005, Mann- Whitney U-test, difference between medians 2.7, 95% confidence interva l 1 to 4.6), and lower levels in patients with LDS (median 1.22 cf. 1. 53 for normal controls, p = 0.028, Mann-Whitney U-test, difference bet ween medians 0.45, 95% confidence interval 0.02 to 1.3). There was no difference in the white cell or neutrophil count between the patient a nd control groups. Conclusions: This study demonstrates increased neut rophil surface CD11b expression in patients with uncomplicated varicos e veins, but decreased levels in patients with LDS. This might be due to up-regulation of CD11b in some neutrophils with subsequent adhesion , so that only those with low expression remained in the peripheral ci rculation. Alternatively, this might represent either down-regulation or chronic exhaustion of neutrophil CD11b in these patients.