CIRCULATING ADHESION MOLECULES IN-TUBERCULOSIS

Leucocyte-endothelial adhesion molecules have been implicated in the p athogenesis of inflammatory diseases. To evaluate their role as marker s of disease activity in tuberculosis, we have used an antigen capture ELISA to measure the serum concentrations of circulating intercellula r adhesion molecule-1 (cICAM-1), E-selectin (cE-selectin) and vascular cell adhesion molecule-1 (cVCAM-1) in 34 patients with active tubercu losis (27 with pulmonary disease and seven with lymph node disease) be fore the commencement of standard chemotherapy, 15 subjects who had pr eviously completed treatment for pulmonary tuberculosis, and 27 health y volunteers. Circulating ICAM-1 and E-selectin levels were significan tly elevated in patients with active tuberculosis when compared to tho se with treated disease (P less than or equal to 0.01), and healthy co ntrols (P < 0.02). Circulating VCAM-1 was raised in patients with acti ve or old pulmonary tuberculosis (P<0.02 versus healthy controls) but not in those with tuberculous lymphadenitis. Significant correlations were observed between the levels of cICAM-1 and cE-selectin (p = 0.63, P=0.0001), and between cICAM-1 and cVCAM-1 (p=0.28, P=0.016). Taking the mean + 2 s.d. of the serum level in healthy controls as the upper limit of normal range, circulating ICAM-1 had the best discriminative power in identifying active tuberculosis, being elevated in about 80% of patients but was raised in only 6.7% of subjects with treated disea se and in 3.7% of normal subjects. Our data support the possibility th at three adhesion molecules may be involved in the pathogenesis of tub erculosis and cICAM-1 may be a useful marker of disease activity.