Haruko Taniguchi

Significance of IL‐1β and IL‐1 receptor antagonist (IL‐1Ra) in bronchoalveolar lavage fluid (BALF) in patients with diffuse panbronchiolitis (DPB)

We evaluated the effect of erythromycin therapy on pulmonary function tests and the airway inflammatory response of patients with DPB. The number of neutrophils in BALF obtained from DPB patients was significantly higher than that of healthy volunteers. Treatment with erythromycin (600 mg/day for 12.9 γδ+9.5 months (mean γδ+s.d.)) significantly reduced the total number of cells and neutrophils in the airway, and significantly improved pulmonary function tests. The levels of IL‐1β and IL‐8 were significantly higher in DPB compared with healthy volunteers (P < 0.05, P < 0.05, respectively). IL‐1 Ra in patients is considered to have a weak inhibitory activity for IL‐1β, with approximately five‐fold concentration of IL‐1β compared with that in healthy volunteers (approx. nine‐fold concentration of IL‐1β). Erythromycin therapy significantly reduced these cytokines to levels comparable to those of healthy volunteers, and produced a trend toward reduction in the level of IL‐1Ra in BALF. The level of IL‐1β correlated significantly with the concentration of neutrophils in BALF (r= 0.72, P < 0.01), as well as with the level of IL‐1Ra (r= 0.688, P < 0.05) and IL‐8 (r= 0.653, P < 0.05). A nearly significant or significant correlation was observed between the concentration of neutrophils and levels of IL‐1Ra or IL‐8 in BALF (r= 0.526, P= 0.053 or r= 0.776, P < 0.01, respectively). There was also a significant relationship between FEV, and the concentration of neutrophils in BALF (r= 0.524, P < 0.05). Our results suggest that the relative amounts of IL‐1β and IL‐1Ra or IL‐8 may contribute, at least in part, to the neutrophil‐mediated chronic airway inflammation in patients with chronic airway disease, and long‐term erythromycin therapy may down‐regulate the vigorous cycle between the cytokine network and neutrophil accumulation, with resultant reduction of neutrophil‐mediated inflammatory response.

Elevated IL-5 levels in pleural fluid of patients with paragonimiasis westermani

To investigate the pathogenic mechanisms of eosinophilic pleural effusion in patients with paragonimiasis, we measured the levels of IL‐5, granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) and interferon‐gamma (IFN‐γ) in pleural effusions. Samples were obtained from 11 patients with Paragonimus westermani infection. In addition, samples from 12 patients with pleural transudates, 16 with tuberculous pleurisy, seven with empyema and 20 with lung cancer were also examined. Eosinophilia was remarkable in peripheral blood (range 4–34%, median 23·4%) and pleural fluid (range 0–95%, median 71%) of paragonimiasis patients. IL‐5 concentrations in pleural effusions of paragonimiasis were markedly higher than those in other groups. Although marked elevation of GM‐CSF and IFN‐γ levels was observed in pleural effusion of empyema and tuberculosis patients, it was marginal in the pleural effusion of paragonimiasis patients. In paragonimiasis patients, IL‐5 levels in the pleural effusion correlated well with the percentage of eosinophils in peripheral blood and pleural fluid. Such a correlation was not observed between GM‐CSF levels in pleural effusion and percentages of eosinophils in pleural fluid or peripheral blood. Our findings suggest that in paragonimiasis IL‐5 in the local inflammatory site is particularly important in mediating eosinophilia in peripheral blood and pleural effusion.

Expression of CD44 variants in lung cancer and its relationship to hyaluronan binding.

We examined the expression of CD44 variant forms and their binding to hyaluronan (HA) in lung cancer cell lines. There was no relationship between the level of expression of CD44 variants and HA binding in different lung cancer cell lines. The expression of CD44v6 and CD44E in some cell lines was not always associated with HA binding. There was no relationship between the tissue pathological type and CD44 expression or HA binding. Deglycosylation by neuraminidase induced CD44-HA binding in human lung cancer cell lines. Our findings suggest that the HA binding ability of CD44, which is negatively regulated by glycosylation, might be a more important factor in tumorigenesis or metastasis than the expression of CD44 variant forms.

Recombinant granulocyte colony-stimulating factor induces production of human neutrophil peptides in lung cancer patients with neutropenia

Human neutrophil peptides (HNPs) 1, 2 and 3 are antimicrobial peptides localized in the azurophil granules of neutrophils. We investigated the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the biosynthesis of HNPs 1-3 using a sensitive radioimmunoassay and Northern blot analysis. Seven patients with lung cancer were first treated with various anticancer agents for 3 days (days 1-3) followed by treatment with rhG-CSF (2 microgram/kg weight/day) for 7 days (days 8-14). Chemotherapy caused neutropenia but the neutrophil count increased biphasically between days 8 and 14. Chemotherapy did not change the baseline plasma concentration of HNPs 1-3 (74.1+/-2.1 pmol/ml) but the concentration increased from day 12, 5 days after commencement of rhG-CSF therapy, to reach a peak value of 430.8+/-57.0 pmol/ml on day 15, 1 day after the last administration of rhG-CSF. Baseline HNPs 1-3 content per neutrophil was 0.59+/-0.02 fmol, decreased to 0.30+/-0.07 fmol on day 9, then increased to 0.78+/-0.07 fmol on day 15. Analyses of peripheral blood neutrophils by Northern blot and reverse-phase high-performance liquid chromatography showed that the amounts of HNPs 1-3 mRNA and precursors of HNPs 1-3 markedly increased in response to rhG-CSF. Our results indicate that recombinant hG-CSF does not only increase neutrophil count but stimulates HNPs 1-3 biosynthesis in neutrophils, thus enhancing the host defense system of compromised hosts with neutropenia.

Characterization of CD44 expressed on alveolar macrophages in patients with diffuse panbronchiolitis

Interleukin (IL)‐8 may play an important role in neutrophil infiltration in the airways of patients with diffuse panbronchiolitis (DPB). Furthermore, alveolar macrophages could produce IL‐8 subsequent to CD44‐hyaluronic acid (HA) interaction. The purpose of this study was to evaluate the contribution of CD44 expressed on alveolar macrophages to the pathogenesis of DPB. We examined the concentration of soluble CD44 (sCD44) in bronchoalveolar lavage fluid (BALF) and CD44 expression on macrophages in BALF from patients with DPB before and after low‐dose, long‐term macrolide therapy. We also assessed the HA‐binding ability of alveolar macrophages as a functional analysis of the CD44 molecule. The sCD44 concentration in BALF was significantly lower in patients with DPB than in healthy volunteers. Percentages of alveolar macrophages expressing low CD44 (CD44 low+) and HA‐nonbinding alveolar macrophages were higher in patients with DPB compared with healthy volunteers. Furthermore, macrolide therapy normalized CD44 expression and HA‐binding ability of macrophages in BALF from DPB patients. Our findings suggest that alveolar macrophage dysfunction could result from abnormalities of CD44 expression in patients with DPB and that these events could contribute to the pathogenesis of DPB.