Ce Mapp

Predominant emphysema phenotype in chronic obstructive pulmonary disease patients

Patients with fixed airflow limitation are grouped under the heading of chronic obstructive pulmonary disease (COPD). The authors investigated whether COPD patients have distinct functional, radiological and sputum cells characteristics depending on the presence or absence of emphysema. Twenty-four COPD outpatients, 12 with and 12 without emphysema on high-resolution computed tomography scan of the chest, were examined. Patients underwent chest radiography, pulmonary function tests and sputum induction and analysis. Subjects with documented emphysema had lower forced expiratory volume in one second (FEV1), FEV1/forced vital capacity ratio, and lower carbon monoxide diffusion constant (KCO), compared with subjects without emphysema. Chest radiograph score of emphysema was higher, chest radiograph score of chronic bronchitis was lower, and the number of sputum lymphocytes was increased in patients with emphysema, who also showed a negative correlation between KCO and pack-yrs. Chronic obstructive pulmonary disease patients with emphysema, documented by high-resolution computed tomography scan, have a different disease phenotype compared with patients without emphysema. Identification of chronic obstructive pulmonary disease-related phenotypes may improve understanding of the natural history and treatment of the disease.

Mechanisms of occupational asthma

The mechanisms ofinduction or sensitization by which many occupational agents may induce asthma are largely unknown, but are believed to be mainly related to immunological sensitization. Some investigators believe that asthma is an allergic disease, i.e. a disease that develops and manifests itself through an IgE-mediated mechanism [1]. White it has not been firmly proven that asthma is causally related to immunotogical abnormalities, there is little doubt that allergic asthma is by far more frequent in atopic subjects [2,3]. and particularly that atopic subjects are at higher risk of developing occupational asthma induced by high molecular weight occupational sensitizers [4,5]. In addition, recent studies have shown that activated T-Iymphocytes, methacromatic cells and activated eosinophils are prominent in the bronchial mucosa of both mild allergic asthmatics and of subjects with occupational asthma induced by isocyanates, suggesting similar, probably immunologically-mediated mechanisms for both non-occupational and occupational asthma [6.7]. Immunology has expanded in recent years and it is difficult to keep up-to-date. Excellent reviews and books have been published to which the reader is referred [8-10].

Salbutamol plus beclomethasone dipropionate, but not salbutamol alone, completely prevent early and late asthmatic responses to allergen

The effect of a week treatment with inhaled salbutamol plus placebo (S+P) vs. salbutamol combined with beclomethasone dipropionate (S+BDP) on early and late asthmatic responses to inhaled allergen was studied in ten atopic patients in a randomized, double-blind, cross-over study. All patients had previously shown a dual type response to the specific bronchial provocative test (sBPT). Each patient performed two periods of treatment for a week, with a 15 day interval between them: (a) salbutamol 0.3 mg, tid + placebo; (b) salbutamol 0.3 mg+BDP 0.2 mg, tid; at the end of each treatment period, sBPT was performed and the last treatments were given 1.5-2 h before and 3-4 h after allergen challenge. S + BDP completely prevented both early and late responses to allergen, while S + P reduced but did not completely inhibit early and late responses. The difference between the two treatments was significant for early and late asthmatic responses. Non-specific bronchial hyperresponsiveness to methacholine was performed before each treatment period, after 6 days of treatment before sBPT and the day after sBPT at the end of the treatment period; there was only a mild increase in PD15FEV1 methacholine after 6 days of treatment with S + BDP in comparison with S + P treatment. These results suggest that salbutamol plus beclomethasone may be used effectively in the prophylaxis of early and late asthmatic reactions induced by allergen in sensitized subjects.

Eosinophil cationic protein (ECP), histamine and tryptase in peripheral blood before and during inhalation challenge with toluene diisocyanate (TDI) in sensitized subjects

To determine whether the measurement of specific markers of inflammatory cells in peripheral blood might be used to detect the inflammatory activity in the airways in asthma induced by toluene diisocyanate (TDI). we measured the levels of eosinophil cationic protein (ECP), histamine and tryplase in peripheral blood before and during inhalation challenge with TDI or methacholine in two groups of subjects who exhibited or did not exhibit an asthmatic reaction after exposure to toluene diisocyanate in the laboratory. When the subjects developed a late asthmatic reaction after exposure to TDI, the showed an increase in their ECP serum levels. By contrast, there were no signilicam changes in serum ECP levels after exposure to TDI in the control group or after methacholine challenge in either group. Tryptase levels in serum were not detectable before or during inhalation challenge with TDI or methacholinc. There was no significant increase in plasma histamine levels during inhalation challenge with TDJ or methacholine. These results suggest that eosinophils arc ‘activated’ in subjects who develop a late asthmatic reaction after exposure to TDI and that the measurement of ECP levels in peripheral blood may be a useful marker to monitor airway inflammation.

In-vitro exposure of guinea pig main bronchi to 2·5 ppm of nitrogen dioxide does not alter airway smooth muscle response

In order to investigate whether the oxidant airborne pollutant nitrogen dioxide (NO2) affects airway smooth muscle responsiveness, the contractile response of guinea pig main bronchi after in vitro exposure to 2.5 ppm of nitrogen dioxide was studied. Main bronchi were cannulated and exposed for 2 or 4 h to a constant flow of either NO2 or air. After exposure, bronchial rings were obtained and placed in a 37 degrees C jacketed organ bath filled with Krebs-Henseleit solution. Concentration-response curves were performed for acetylcholine (10(-9)-10(-3) M), substance P (10(-9)-10(-4) M), and neurokinin A (10(-10)-10(-5) M), and voltage-response curves (12-28 V) were performed for electrical field stimulation. There was no significant difference in either the smooth muscle maximal contractile response, or sensitivity between the bronchi exposed to NO2 and those exposed to air. We conclude that in vitro exposure to 2.5 ppm of NO2 does not alter airway smooth muscle responsiveness in guinea pigs.

Increased neurokinin-2 receptor expression in alveolar macrophages of smokers with COPD.

A Maciejczyk V Materna M Drag-Zalesińska A Wojnar M Pudelko W Kędzia M Spaczyński M Dietel M Zabel H Lage Institute of Pathology, Charité Campus Mitte, Berlin, Germany, Department of Histology and Embryology, University School of Medicine and Lower Silesian Centre of Oncology, Wrocław, Department of Obstetrics and Gynaecology and Department of Histology and Embryology, University School of Medicine, Poznań, Poland