Time course of exhaled hydrogen peroxide and nitric oxide during chemotherapy

This study was designed to assess the effect of differential leukocyte depletion during chemotherapy by monitoring the levels of exhaled hydrogen peroxide H2O2 and nitric oxide (F(eNO)) present. In 39 patients with lung cancer (chronic obstructive pulmonary disorder up to stage II, median forced expiratory volume in one second 78% predicted), measurements were performed before a cycle of therapy (day 1), at least once during the cycle (day 8: n = 34; day 15: n = 19), and afterwards (days 21-29). There were significant changes in the level of H2O2, F(eNO) and peripheral blood cell differentials over the visits. The level of H2O2 was decreased only on day 15, with a median (difference between the upper and lower quartiles) fall of 31 (57)%, while F(eNO) was reduced only on day 8, by 22 (40)%. Neutrophil numbers were unchanged on day 8 and decreased by 59 (48)% on day 15, while monocyte numbers were decreased on day 8 by 87 (39)%. On days 21-29, values had returned to baseline. Taken together with previous findings, the parallel course of levels of exhaled hydrogen peroxide and neutrophil counts suggests that a major part of exhaled hydrogen peroxide is due to neutrophils via the conducting airways. In contrast, the production of exhaled nitric oxide seems to be primarily associated with monocytes.

Lung fibroblasts from patients with emphysema show markers of senescence in vitro

BACKGROUND

The loss of alveolar walls is a hallmark of emphysema. As fibroblasts play an important role in the maintenance of alveolar structure, a change in fibroblast phenotype could be involved in the pathogenesis of this disease. In a previous study we found a reduced in vitro proliferation rate and number of population doublings of parenchymal lung fibroblasts from patients with emphysema and we hypothesized that these findings could be related to a premature cellular aging of these cells. In this study, we therefore compared cellular senescence markers and expression of respective genes between lung fibroblasts from patients with emphysema and control patients without COPD.

METHODS

Primary lung fibroblasts were obtained from 13 patients with moderate to severe lung emphysema (E) and 15 controls (C) undergoing surgery for lung tumor resection or volume reduction (n = 2). Fibroblasts (8E/9C) were stained for senescence-associated beta-galactosidase (SA-beta-Gal). In independent cultures, DNA from lung fibroblasts (7E/8C) was assessed for mean telomere length. Two exploratory 12 k cDNA microarrays were used to assess gene expression in pooled fibroblasts (3E/3C). Subsequently, expression of selected genes was evaluated by quantitative PCR (qPCR) in fibroblasts of individual patients (10E/9C) and protein concentration was analyzed in the cell culture supernatant.

RESULTS

The median (quartiles) percentage of fibroblasts positive for SA-beta-Gal was 4.4 (3.2;4.7) % in controls and 16.0 (10.0;24.8) % in emphysema (p = 0.001), while telomere length was not different. Among the candidates for differentially expressed genes in the array (factor > or = 3), 15 were upregulated and 121 downregulated in emphysema. qPCR confirmed the upregulation of insulin-like growth factor-binding protein (IGFBP)-3 and IGFBP-rP1 (p = 0.029, p = 0.0002), while expression of IGFBP-5, -rP2 (CTGF), -rP4 (Cyr61), FOSL1, LOXL2, OAZ1 and CDK4 was not different between groups. In line with the gene expression we found increased cell culture supernatant concentrations of IGFBP-3 (p = 0.006) in emphysema.

CONCLUSION

These data support the hypothesis that premature aging of lung fibroblasts occurs in emphysema, via a telomere-independent mechanism. The upregulation of the senescence-associated IGFBP-3 and -rP1 in emphysema suggests that inhibition of the action of insulin and insulin-like growth factors could be involved in the reduced in vitro-proliferation rate.

Effect of freezing of sputum samples on flow cytometric analysis of lymphocyte subsets

Sputum samples should be processed shortly after induction to prevent cell degradation. For intermediate storage, freezing of homogenised samples or immediate fixation have been shown to be suitable for cytospins. The aim of this study was to investigate whether freezing or immediate fixation of sputum affect the analysis of lymphocyte subsets by flow cytometry. Selected plugs from 24 sputum samples were homogenised. One aliquot was processed immediately and analysed by flow cytometry. A second aliquot was homogenised, frozen at -20 C after addition of dimethylsulfoxide and stored for a median time of 6 days. In six samples a third aliquot was fixed in formalin after induction and stored for up to 72 h before further processing. Compared to immediate processing, percentages of total lymphocytes and T-suppressor cells were elevated after being frozen, with a minor decrease in the T4/T8 ratio. Proportions of total lymphocytes, T-helper and T-suppressor cells correlated between native and frozen samples, intra-class correlation coefficients being 0.74, 0.85 and 0.70, respectively. The formalin-fixed aliquots could not be analysed with the antibodies used. In conclusion, freezing seems to be a suitable technique to store sputum samples for flow cytometry of CD3, CD4 and CD8 lymphocyte subsets. Its effects were minor compared to the variation between subjects.

Comparison of exhaled nitric oxide analysers

Currently no published data are available concerning the comparability of different types of NO analysers, making inter-laboratory comparisons difficult. In two sets of experiments we compared 4 and 5 NO analysers, respectively, from 3 different manufacturers using different calibration regimes: calibration with (1) a separate recommended calibration gas for each analyser, (2) a single low concentration for all (394 ppb), and (3) a single high concentration (12.8 ppm). We measured three subjects with known low (L), moderate (M) and high (H) bronchial exhaled nitric oxide concentrations as well as standard gases (SG). In the first set of experiments, calibration regime 1 resulted in the largest differences between analysers (coefficient of variation (CV) for L, M, H, SG: 0.42, 0.22, 0.20, 0.14). The lowest CV between analysers was observed after calibration 2 (0.34, 0.19, 0.12, 0.02). Very similar results were obtained in the second set of comparisons. Thus, differences between analysers existed, but were mainly due to differences in recommended calibration gases/procedures. Only a small part was explainable by deviations from target flow. These differences need to be taken into account when comparing data between laboratories or replacing the calibration gas of an analyser, as well as for the establishment and interpretation of normal values.

Lung fibroblasts from patients with emphysema show a reduced proliferation rate in culture

Emphysema is characterised by a loss of alveolar structure, as reflected in elastic recoil and gas exchange. As fibroblasts play a key role in the maintenance of structure, the current authors hypothesised that their proliferation might be constitutively impaired in lung emphysema. Using explant cultures, lung fibroblasts were obtained from resected lungs of 10 patients with emphysema (median forced expiratory volume in one second (FEV1) 40% predicted) and 10 control patients (FEV1, 95% pred). The doubling time (DT) was measured over 4 days under standard conditions (10% foetal calf serum) prior and after cryopreservation. Additionally, in seven samples per group the total population doubling level (PDL) was determined. In emphysema, mean+/-sem DT was 33.6+/-2.8 h compared with 24.8+/-1.4 h in controls. The differences in DT were preserved after cryopreservation. Groups also differed in the initial slope of the PDL plot during long-term culture (up to 35 days). However, the median (range) maximum PDL did not differ significantly between groups (13.8 (7.4-22.6) versus 20.2 (11.2-25.5)). The current authors, therefore, suggest that the reduced proliferation rate in vitro of lung fibroblasts from patients with emphysema reflects a persistent, intrinsic failure of cellular replacement and maintenance in this disease, possibly in relation to pre-term aging.

[Non-invasive methods for monitoring airway inflammation: a comparison of expenditures, gain and clinical value]

Among the noninvasive procedures for the assessment of airway inflammation, the analysis of spontaneous sputum is currently the only method, the expenses of which are covered by health insurance in Germany. It can easily be used for semiquantitive cytological analyses by practising pneumologists. Recent data also indicate the usefulness of sputum induction, particularly in asthma diagnosis and therapy control, and demonstrate its capability of reducing total costs per patient. In contrast to sputum analysis, the measurement of exhaled nitric oxide (NO) yields a read-out without time delay. NO as associated with eosinophils also seems suitable for monitoring airway inflammation. The number of studies regarding NO, both its pathophysiological role and clinical use, is far greater than that regarding any other marker of exhaled air. Measurements are easy and fast, but the costs of analysers are still prohibitive in clinical practice. The analysis of other compounds of exhaled air, particularly those of exhaled breath condensate (EBC), offers fascinating perspectives, owing to the scope of markers that might be measured, and could enable the assessment of multivariate profiles that are useful for diagnosis and therapy control. Currently, however, the method still faces methodological questions, and data indicating its usefulness and cost-efficiency in clinical practice are scarce. Compared to NO, the expenses per measurement in clinical use are mainly due to the costs per marker detection after sampling, as well as storage and transport of samples. The on-site analysis of pH in the EBC could be a first step to circumvent this obstacle.

Direct measurement of BDP and 17-BMP in bronchial and peripheral lung tissue after inhalation of HFA- vs CFC-driven aerosols

Indirect assessments have shown a superior lung deposition of HFA-BDP (Ventolair/Qvar) compared to CFC-BDP (Aerobec). The aim of this study was to assess the concentrations of BDP and its metabolite 17-BMP in airways and peripheral tissue from resected lung specimens after inhalation of these BDP formulations. Immediately prior to surgery for lung cancer, 10 patients inhaled 1000 microg of either CFC-BDP (n = 5) or HFA-BDP (n = 5) Mouthwash was collected after inhalation, and serum before, during, and after surgery. There was no significant difference between CFC and HFA in the concentration of 17-BMP in bronchi (median, 4365 vs 4121 pg/g tissue). After CFC, concentrations of 17-BMP were lower in peripheral tissue (1424 vs 2089 pg/g; ANCOVA, p = 0.001) and in serum taken immediately after inhalation (688 vs 1219 pg/ml, p < 0.01). Furthermore, the CFC group showed a higher concentration of BDP in the mouthwash (17,660 vs 1320 ng/ml, p < 0.05), but the concentration of 17-BMP was lower (452 vs 1028 ng/ml, n.s.). These findings indicate a predominantly peripheral deposition of HFA-BDP, in line with previous data. They also provide evidence for a faster uptake and metabolism of HFA-BDP, probably because BDP is dissolved in HFA and has a smaller particle size distribution than the CFC suspensions.

Repeated ozone exposures enhance bronchial allergen responses in subjects with rhinitis or asthma

BACKGROUND

Single exposures to > 200 p.p.b. of ozone are capable of enhancing the early-phase lung function response to allergen.

OBJECTIVE

The aim of the present study was to compare the effect of single vs. repeated exposures to ozone on early and late-phase allergen responses.

METHODS

Eleven subjects with allergic asthma and 22 subjects with allergic rhinitis underwent single exposures to filtered air, 125 p.p.b. and 250 p.p.b. ozone, as well as repeated exposures to 125 p.p.b. ozone on four consecutive days. Twenty hours after the (final) exposure, subjects inhaled a single dose of allergen and a sputum induction was performed 6-7 h later.

RESULTS

In the subjects with rhinitis, the mean early-phase response of FEV1 and the number of > or = 20% reductions were significantly greater after exposure to 250 or 4 x 125 p.p.b. ozone compared with filtered air. In addition, most of the > or = 15% late-phase responses in FEV1 occurred after exposure to 4 x 125 p.p.b., as well as the strongest effects on sputum parameters. The rise in the number of eosinophils was statistically significant in both groups. Regarding the number of lymphocytes and the concentrations of mast cell tryptase, histamine or LDH, significance was, however, only reached in the asthma group.

CONCLUSION

Our data suggest that repeated exposure to ozone, at a peak ambient air level, can enhance both functional and inflammatory responses to inhaled allergen in subjects with pre-existing allergic airway diseases, and that these effects might reach a clinically relevant magnitude.

The relationship between airway hyper-responsiveness, markers of inflammation and lung function depends on the duration of the asthmatic disease

BACKGROUND

The combination of airway hyper-responsiveness, eosinophilic airway inflammation, and lung function impairment is considered as a hallmark of bronchial asthma. Since airway function might change with time in chronic asthma, the association between parameters which are characteristic of asthma could be different in subjects with different durations of the disease.

OBJECTIVE

We assessed whether in patients with asthma the relationship between airway hyperresponsiveness, non-invasive markers of airway inflammation, and baseline lung function depended on the duration of the disease.

METHODS

Sixty-six non-smoking patients with mild to moderate allergic asthma without corticosteroids were assigned to two groups, according to a duration of the disease (time interval since doctor's diagnosis) of either < or = 16 years (median 8 years; mean FEV1, 92.6% pred.; n = 34) or > 16 year (median 25 years; mean FEV1, 87.9% pred.; n = 32).

RESULTS

Groups did not differ statistically in PC20FEV1 of methacholine, sputum composition, levels of exhaled nitric oxide (NO), lung function parameters, or history of treatment. There were significant correlations between PC20FEV1, eosinophils and NO in patients with a duration of the disease < or = 16 year, but no relation to lung function. In contrast, patients with a duration > 16 year showed a correlation between PC20FEV1 of methacholine and lung function but not eosinophils or NO. In both groups, eosinophils and NO were associated with each other. These results were corroborated by the statistical procedure of factor analysis that revealed 'inflammation' and 'lung function' as major entities and found 'responsiveness' to be associated with only one of them in each group.

CONCLUSION

Our data demonstrate that with a shorter duration of the asthmatic disease airway hyper-responsiveness is associated with airway inflammation, whereas with a longer duration it is associated with impaired lung function, suggesting that in chronic asthma ongoing alterations become the primary determinant of functional characteristics.

Airway response to inhaled hypertonic saline in patients with moderate to severe chronic obstructive pulmonary disease

The present study aimed at delineating the mechanisms underlying the adverse response to hypertonic saline inhalation in patients with chronic obstructive pulmonary disease (COPD). Twenty patients (age, 48-70 yr; FEV(1), 29-58 %pred) inhaled, on two different days in randomized order, 200 microg salbutamol from an MDI and 20 min later either 0.9% or 3% saline from an ultrasonic nebulizer for a maximum of four consecutive 5-min periods. Forced expiratory (FEV(1)) and inspiratory (FIV(1)) volumes, inspiratory capacity (IC), intrathoracic gas volume (ITGV), and specific airway resistance (SRaw) were measured. Significant changes occurred in FEV(1), FIV(1), IC, ITGV, and SRaw with both concentrations (p < 0.05, each) and effects were stronger with 3% as compared with 0.9% saline (p < 0.05, each). The increase in dyspnea was associated with the changes in FIV(1), FEV(1), IC, and ITGV, in contrast to its decrease during bronchodilation, where only FIV(1) was important. Sputum analysis showed elevated concentrations of histamine after 3% as compared with 0.9% saline. These data indicate that the adverse lung function response to hypertonic saline is common in patients with moderate to severe COPD, involves both bronchoconstriction and lung hyperinflation, and could be mediated, at least partially, through activation of mast cells.