Luigi Carratù

Increased Endothelin-Like Immunoreactive Material on Bronchoalveolar Lavage Fluid from Patients with Bronchial Asthma and Patients with Interstitial Lung Disease

Endothelin (ET) is an endothelial regulatory peptide present also in pulmonary tissue where it exerts several biological actions both on bronchial and vascular smooth muscle cells. It has been shown to increase in bronchoalveolar lavage fluid (BALF) from asthmatic patients; but changes in other chronic respiratory disease have not been well studied. We measured by a radioimmunoassay (RIA) ET-immunoreactive (IR) levels on BALF (BALF-ETIR, pg/ml) from 5 normal subjects (NS), 5 patients with chronic extrapulmonary disease (ED) without signs of lung involvement, 5 patients with allergic bronchial asthma (BA), 10 patients with idiopathic lung fibrosis (ILF) and 9 patients with miscellaneous interstitial lung disease (MILD). In 5/5 NS and 4/5 ED BALF-ETIR was lower than sensibility of RIA test used (0.8 pg/ml). BALF-ETIR was dosable in all patients with bronchopulmonary disease; means were 2.45 pg/ml in BA, 12.37 pg/ml in ILF, 2.90 pg/ml in MILD--Wilcoxons rank test (two tailed) versus NS, p < 0.05. There was an inverse correlation between BALF-ETIR values and the degree of ventilatory impairment (forced vital capacity % of predicted value, r = -0.61 p < 0.01; forced expiratory volume in 1 s % of predicted value, r = -0.71 p < 0.01) and the level of arterial pressure of O2 (PaO2; r = -0.75 p < 0.01); a positive correlation was found with number of neutrophils/ml of BALF (r = 0.52 p < 0.01)--Spearmans rank correlation. Though rarely detected on BALF from normal lungs, ET increases on BALF in patients with bronchopulmonary disease, raising the question of its involvement in pathogenic mechanisms or evolution of bronchial asthma and interstitial lung disease.

IgA immune response against the mycobacterial antigen A60 in patients with active pulmonary tuberculosis

Searching for IgG and IgM against the mycobacterial antigen A60 has been recognized as a potential diagnostic tool for pulmonary tuberculosis. The role of detection of anti-A60 IgA in improving diagnostic accuracy of serology is not well known. In this study we measured with ELISA serum levels of both anti-A60 IgG and IgA in 216 subjects. 88 healthy volunteers (44 PPD- and 44 PPD+), 44 patients suffering from nontuberculous lung disease and 15 subjects with healed pulmonary tuberculosis constituted the control population; 69 patients with active pulmonary tuberculosis (35 cavitary forms, 26 productive forms and 8 miliary forms) were examined. The sensitivity of IgG test was 73.9% in pulmonary tuberculosis (77.1% in cavitary forms, 65.4% in productive forms, 87.5% in miliary forms); the specificity of the test was 95.9%. For the IgA test we observed a sensitivity of 72.5% (74.3 in cavitary forms, 69.2% in productive forms, 75.0 in miliary forms) and a specificity of 93.9%. Combination of the two tests increased the sensitivity to 84.0% (+10.1% compared to IgG test, +11.5% compared to IgA test); the specificity decreased to 92.5% (-3.4% vs. IgG test; -1.4 vs. IgA test). In conclusion, the combined use of evaluation of anti-A60 IgG and IgA increases the accuracy of serological diagnosis of pulmonary tuberculosis.

Increased 24-Hour Endothelin-1 Urinary Excretion in Patients with Chronic Obstructive Pulmonary Disease

Abnormalities in endothelin-1 (ET-1) pulmonary metabolism have been reported in patients with pulmonary hypertension, asthma and chronic obstructive pulmonary disease (COPD). In this study we have evaluated the 24-hour urinary excretion of ET-1 in COPD patients both during acute exacerbation and stable phase of the disease. ET-1 plasma and urinary levels were measured in 13 COPD patients on admission to the hospital for an acute exacerbation and at the recovery period. Ten healthy volunteers were also studied. Determination of plasma and 24-Hour urinary ET-1 levels were carried out with a radioimmunoassay test. Plasma ET-1 levels in COPD patients were similar during exacerbation and recovery and were not significantly different from those in the healthy subjects. 24-hour urinary excretion of ET-1 was increased in COPD patients during acute exacerbation; it decreased during recovery, but remained elevated when compared to normal subjects. A negative correlation was found between arterial oxygen pressure and ET-1 excretion; no correlation was found between plasma and urinary ET-1 values. In conclusion, COPD patients excrete higher amounts of ET-1 compared to healthy subjects. Urinary ET-1 values are further increased during acute exacerbation of the disease.

The effect of platelet‐activating factor (PAF) on nasal airway resistance in healthy subjects is not mediated by nitric oxide

Background: The nose is an important source of nitric oxide (NO) in man, but the relevance of NO production to the response to inflammatory mediators is not clear.

Exhaled nitric oxide after inhalation of isotonic and hypotonic solutions in healthy subjects.

Airway nitric oxide (NO) homoeostasis is influenced by chemical and mechanical stimuli in humans; airway epithelium, which is an important site of NO production, is sensitive to osmotic challenge. The effect of inhaled hypotonic solutions on exhaled NO (eNO) is not known. In this study we evaluated the effect of ultrasonically nebulized distilled water (UNDW), a hypotonic indirect stimulus, on eNO levels. A total of 10 non-smoking healthy subjects were enrolled in the study. eNO was detected by chemiluminescence, and specific airway conductance (sGaw) was measured by plethysmography. Bronchial challenges with UNDW and with an isotonic solution were performed according to a double-blind experimental design. Baseline levels of eNO were 28.1+/-14.7 p.p.b. UNDW did not cause any significant change in sGaw (from 0.190+/-0.029 to 0.181+/-0.036 cm H(2)O x s(-1)). With respect to baseline values, the eNO concentration decreased significantly after inhalation of 8 or 16 ml of UNDW (from 26.0+/-13.1 to 17.2+/-8.5 and 16.6+/-7.7 p.p.b. respectively; P<0.001, n=10). After bronchial challenge with UNDW, eNO was significantly reduced in comparison with after inhalation of the isotonic solution. In five subjects, pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor NO synthesis, decreased NO levels from 21.7+/-8.5 to 10.0+/-3.3 p.p.b. Subsequent inhalation of 16 ml of UNDW did not cause any further decrease in NO levels (10.1+/-3.7 p.p.b.; not significant compared with L-NAME). We conclude that inhalation of aqueous solutions decreases eNO levels in healthy subjects, and that this effect is not associated with any significant change in airway calibre. The UNDW-induced decrease in eNO is not enhanced by pretreatment with the NO synthase inhibitor L-NAME, suggesting that inhaled solutions may interfere with the airway NO pathway in humans.

Effect of Amiloride on Human Bronchial Ciliary Activity in vitro

Amiloride (AM) reduces mucociliary transport in the frog palate in vitro preparation, whereas in vivo inhalation of AM enhances mucociliary and cough clearance in cystic fibrosis patients. AM influences the bioelectric properties of the respiratory mucosa, and since electrical activity and ciliary activity are strictly related in the beating cell, an effect on ciliary function cannot be excluded. We have, therefore, investigated the effect of AM (10(-7) to 10(-3) M) in vitro on the ciliary activity of ten samples of healthy human bronchial epithelium at 37 degrees C. The baseline ciliary beat frequency was 13.7 +/- (SD) 1.0 Hz. At concentrations of AM of 10(-4) and 10(-3) M, small statistically significant (p less than 0.01) increases in ciliary beat frequency were recorded only after 1 min of exposure to the drug, with changes of +8.2 and +7.6%, respectively. We conclude that (1) AM affects the ciliary activity of the beating cell, but (2) because of the weakness and short duration of the effect, it is unlikely that AM plays a major role on mucociliary transport.

Endobronchial administration of iodine-131 B72.3 monoclonal antibody in patients with lung cancer.

We tested the feasibility of endobronchial administration of radiolabelled monoclonal antibodies (MoAbs) and the biodistribution of the radiotracer. Ten patients with histological confirmed adenocarcinoma or squamous cell carcinoma were studied. Nine received 470 μCi (103 μg) of Iodine-131-B72.3, a monoclonal antibody reacting against TAG 72 antigen, while one patient received 502 μCi (291 μg) of 131I-4C4, an indifferent antibody used for comparison in a negative control study. The radiolabelled antibody was administered through a flexible fiberoptic bronchoscope and placed on the tumour mass under visual monitoring. Scans with a large field-of-view gamma-camera showed retention of 131I-B72.3 at the tumour site up to 6–9 days in six of eight patients. No other organs were visualized with the exception of faint activity in the gastrointestinal tract, bladder and thyroid. On the contrary, the indifferent antibody 131I-4C4 was not retained at the tumour site 6 days after MoAb administration, and more prominent activity was found in the gastrointestinal tract. In one patient the study was not technically adequate because of failure of the delivery system. The vascular compartment contained less than 3% of the administered dose. We conclude that endobronchial administration is a feasible technique and allows stable and specific targetting of bronchial tumours. Furthermore, the low activity found in the plasma and other organs suggests that this approach may be used to deliver therapeutic doses of MoAbs to lung cancers.