Reduced bronchial CD4+ T-cell density in smokers with occupational asthma

Abstract

Cigarette smoking may alter bronchial inflammation in asthma. Multicolour immunohistofluorescent examination on bronchial cryosections was used to examine bronchial inflammatory cell infiltrate in patients with occupational asthma. Monoclonal antibodies to CD3, CD4, CD8, T-cell receptor-d1, CD68 and human leukocyte antigen-DR were combined to identify Tcell subsets and macrophages in bronchial biopsies from 20 workers with occupational asthma (12 smokers and eight nonsmokers), 15 healthy workers (seven smokers and eight nonsmokers) and 10 nonsmoking, nonexposed controls.The increased subepithelial CD4+ T-cell density in nonsmoking asthmatics was not present in smoking asthmatics, who had the lowest CD4+ T-cell density of all groups. The decreased subepithelial CD4+ and CD8+ T-cell density correlated with a reduction in lung function, as measured by percentage predicted forced expiratory volume in one second, in smoking asthmatics only. Although smoking asthmatics had a significantly increased number of intraepithelial CD8+ T-cells and macrophages compared with nonsmoking asthmatics, the proportion of cd-T-cells was significantly decreased in both asthmatic groups.Smoking asthmatics had a distinctly different distribution of T-cell subsets compared with nonsmoking asthmatics. The accumulation of subepithelial CD4+ T-cells, which was observed in nonsmoking asthmatics, appeared to be inhibited in smoking asthmatics, suggesting a smokinginduced bronchial immune modulation, at least in occupational asthma in the aluminium industry.

CD8 and CD103 Are Highly Expressed in Asthmatic Bronchial Intraepithelial Lymphocytes

“…The investigations by Fournier et al [32], Ricciardolo et al [34] and Tavora et al [36] focused only on bronchial IELs and did not examine IELs versus LPLs. Reports by Power et al [33] and Sjaheim et al [35] compared phenotypes of IELs and LPLs in control subjects and showed that the CD4/CD8 ratio is lower in IELs than LPLs, similar to our observations. However, the CD4/CD8 ratios reported by both of these authors were lower than what we observed in control subjects.…”

Severe asthma exists despite suppressed tissue inflammation: findings of the U-BIOPRED study

“…A reduction in CD4 + lymphocytes, as observed by us, has been reported when comparing smoking and nonsmoking mild asthma with occupational asthma [29]. We also saw an increase in absolute numbers of neutrophils in the blood and a decrease in FeNO in the SAs/ex group compared with the SAn group.…”

“…These effects are also reported in milder asthma [30][31][32]. Other inflammatory changes observed in response to smoking in milder asthma include a reduction in blood [30] and sputum eosinophils [30,33], increases in sputum neutrophils [29], and increased submucosal CD8 + lymphocytes and macrophages in bronchial biopsies [34]; however, we did not see these differences in our severe asthma subjects.…”

Correlates of CD4+ and CD8+ Lymphocyte Counts in High-Risk Immunodeficiency Virus (HIV)-Seronegative Women enrolled in the Women’s Interagency HIV Study (WIHS)

“…It is possible that the higher number of both CD4 and CD8 cells in the peripheral blood of HIV-negative women who smoke are a consequence of cellular recruitment or redistribution as part of a normal response against the damaging agents present in inhaled tobacco smoke, as was suggested by Ekberg-Jansson et al [9]. Recently, investigators reported that tobacco smokers have reduced subepithelial bronchial CD4ϩ T-cell density [10]. The redistribution of CD4ϩ cells from bronchial lining to the periphery may be a plausible explanation for the increase in CD4ϩ cells reported in this communication as well as by others [11,12].…”

“…A total of 22 HIV negative women were excluded, because CD4 and CD8 cell counts were unavailable in these participants. Subjects in the original cohort contributed a median (range) of 11 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) visits and those in the new cohort contributed 3 (1-4) visits to the analysis. Baseline characteristics of the study participants are listed in Table 1.…”