No abstract

Subjects >= 18 yr of age with serum alpha1-antitrypsin (alpha1-AT) levels <= 11 microM or a ZZ genotype were followed for 3.5 to 7 yr with spirometry measurements every 6 to 12 mo as part of a National Heart, Lung, and Blood Institute Registry of Patients with Severe Deficiency of Alpha-1-Antitrypsin. Among all 1,129 enrollees, 5-yr mortality was 19% (95% CI: 16 to 21%). In multivariate analyses of 1, 048 subjects who had been contacted >= 6 mo after enrolling, age and baseline FEV1% predicted were significant predictors of mortality. Results also showed that those subjects receiving augmentation therapy had decreased mortality (risk ratio [RR] = 0.64, 95% CI: 0. 43 to 0.94, p = 0.02) as compared with those not receiving therapy. Among 927 subjects with two or more FEV1 measurements >= 1 yr apart, the mean FEV1 decline was 54 ml/yr, with more rapid decline in males, those aged 30 to 44 yr, current smokers, those with FEV1 35 to 79% predicted, and those who ever had a bronchodilator response. Among all subjects, FEV1 decline was not different between augmentation-therapy groups (p = 0.40). However, among subjects with a mean FEV1 35 to 49% predicted, FEV1 decline was significantly slower for subjects receiving than for those not receiving augmentation therapy (mean difference = 27 ml/yr, 95% CI: 3 to 51 ml/yr; p = 0.03). Because this was not a randomized trial, we cannot exclude the possibility that these differences may have been due to other factors for which we could not control.

Samples of iris ciliary body, choroid and retina from normal eyes and from 2 cases of sympathetic ophthalmitis (one acute and one late stage fibrosis) were examined for the expression of the VLA integrins beta 1 and alpha 1-6, and the integrin beta 3, in addition to ICAM-1, VCAM-1, ELAM-1 and CD44 using an APAAP staining technique. The expression of VLA-4, VLA-5, VCAM-1, ICAM-1, and CD44 was significantly increased and ELAM-1 was slightly increased in acute sympathetic ophthalmitis in comparison to fibrotic and normal eyes. VLA-6 was moderately increased in acute and fibrotic cases and VLA-2 VLA-3 and beta 3 were moderately expressed on all tissues examined. The differential expression of molecules known to be involved in lymphocyte activation and adhesion in acute sympathetic ophthalmitis suggests that certain adhesion molecules play a role in the pathogenesis of intraocular inflammation and may be suitable targets for immunotherapy.

Endotoxin (lipopolysaccharide, LPS) is known to induce inflammatory responses, such as monocyte/macrophage adherence, migration, and accumulation. Recruitment and accumulation of macrophages during infection and inflammation are regulated by integrin-mediated cell-extracellular matrix interactions. In the present report, we studied the effects of LPS on the expression of VLA-5 (alpha 5 beta 1), VLA-3 (alpha 3 beta 1), and VLA-2 (alpha 2 beta 1) integrins and fibronectin (FN) by human alveolar macrophages in an attempt to understand the mechanism by which LPS regulates macrophage adhesion to matrix proteins. Bronchoalveolar lavage macrophages were treated with varying concentrations of Escherichia coli LPS for different times and evaluated for expression of the integrins and FN by immunofluorescence, immunoelectron microscopy, autoradiography, and radioimmunoassay. Immunofluorescent and immunoelectron microscopic observations showed that VLA integrins were constitutively expressed on the cell surface and concentrated on the microvilli and pseudopodia of the macrophages. The effects of LPS on expression of the integrins were dose and time related. VLA-5 expression was increased after 30 min of stimulation by LPS, suggesting that LPS may induce rapid secretion of the integrin. However, incubations with LPS longer than 30 min decreased VLA-5 expression in a dose-dependent pattern. LPS also caused dose-related decreases in the expression of VLA-3 and VLA-2 integrins and increases of intracellular FN 24 h after stimulation. The results suggest that a prolonged exposure to LPS may impede VLA integrin-mediated migration and result in local accumulation of macrophages in the lung.