Eosinophils are considered to play a central pathogenetic role in asthma. We previously reported that sputum eosinophilia was observed in patients with cough variant asthma (CVA), as well as in "classic" asthma with wheezing. This study was undertaken to further investigate the involvement of eosinophils in CVA. The serum eosinophil cationic protein (ECP) level, the percentage of eosinophils in bronchoalveolar lavage (BAL) fluid, and the number of eosinophils in bronchial biopsy specimen were examined in 14 patients with CVA, 21 with classic asthma, and in seven healthy controls. For the two asthmatic groups, the clinical severity was classified with scores of 1-3. Pulmonary function and bronchial responsiveness were not significantly different between the patients with classic asthma and those with CVA. BAL, tissue eosinophil and serum ECP were all significantly increased in both classic asthma and CVA when compared with the controls but were not different between classic asthma and CVA. In both groups of asthmatics, the clinical severity significantly correlated with serum ECP and tissue eosinophils. In conclusion, eosinophilic inflammation is involved in cough variant asthma as well as in classic asthma. Anti-inflammatory treatment may be essential in patients with CVA, as in those with classic asthma.

Patients with bronchiectasis suffer from sputum production, recurrent exacerbations, and progressive airway destruction. Erythromycin is effective in diffuse panbronchiolitis, another suppurative airway disorder, although its efficacy is unknown in idiopathic bronchiectasis. A double-blind placebo-controlled study was therefore conducted to evaluate the effects of 8-week administration of low dose erythromycin (500 mg b.i.d.) in steady-state idiopathic bronchiectasis. Patients in the erythromycin group (n=11, 8 female, mean age 50+/-15 yrs), but not the placebo group (n=10, 8 female, mean age 59+/-16 yrs) had significantly improved forced expiratory volume in one second, forced vital capacity and 24-h sputum volume after 8 weeks (p<0.05). There was no parallel improvement in sputum pathogens, leukocytes, interleukin (IL)-1alpha and IL-8, tumour necrosis factor-alpha, or leukotriene B4. The results of this pilot study show that low-dose erythromycin improves lung function and sputum volume in bronchiectasis. Further studies are indicated to evaluate the efficacy of long-term erythromycin therapy in bronchiectasis.

We have investigated the efficacy of a clarithromycin-containing four-drug regimen for Mycobacterium avium complex (MAC) pulmonary disease in 46 patients without acquired immunodeficiency syndrome (AIDS). The patients were 14 males and 32 females with a mean age of 60.9 +/- 11.5 yr. Patients received 10 mg/kg/d of clarithromycin plus ethambutol, rifampin, and initial kanamycin and subsequent quinolone for 24 mo. Seven patients (15.2%) were dropped in the first 6 mo. Among 39 patients who received more than 6 mo of therapy, 28 patients (71.8%) converted their sputa to negative: 26 of 31 patients (83.9%) infected with clarithromycin-susceptible strains and two of eight patients (25.0%) with resistant or intermediate strains. The timing of sputum conversion was 3.6 +/- 1.9 mo, with a range of 2 to 9 mo. The conversion rate was significantly lower in patients who were infected with clarithromycin-resistant or intermediate strains, who had had prior therapy (55.0% versus 89.5%), or who were acid-fast bacilli (AFB) smear-positive at entry (60.7% versus 100%). The age and sex of patients, the species of pathogen (M. avium or M. intracellulare), type and extent of the disease, and the use of kanamycin did not significantly affect the conversion rate. Although the regimen was efficacious for newly treated patients, frequent adverse reactions and a low conversion rate of sputum in retreated patients are problems that remain to be solved.

Mycobacterium avium complex (MAC) pulmonary disease with nodules and bronchiectasis is increasing. But the usefulness of computed tomography (CT) and bronchoscopy for diagnosis and the significance of MAC isolation from respiratory secretions are still unclear. For a 4-yr period, we prospectively examined the role of bronchoscopy with bronchial washing and transbronchial lung biopsy in 26 patients who had clusters of small nodules in the periphery of the lung associated with ectatic changes of the draining bronchi on the CT scan. None of them was infected with human immunodeficiency virus. Thirteen of the 26 patients (50%) had cultures positive for MAC, six in the sputum and 13 in the bronchial washing. Epithelioid granuloma was demonstrated in eight of 13 patients with culture-positive MAC and in two of 13 patients in whom MAC was culture-negative. Rapidly growing mycobacteria were cultured in the two patients. Seven of the eight biopsy-positive patients received treatment and responded by sputum conversion and/or radiographic improvement. We found that the CT finding was a useful clue to suspect MAC pulmonary disease and that the bronchial washing was more sensitive than the routine expectorated sputum for MAC isolation. Demonstration of granuloma in more than half of the MAC-positive patients would suggest that MAC may have invaded the lung tissue rather than colonized in the airways.

I In nt te er ra ac ct ti io on n o of f P Ps se eu ud do om mo on na as s a ae er ru ug gi in no os sa a w wi it th h h hu um ma an n r re es sp pi ir ra at to or ry y m mu uc co os sa a i in n v vi it tr ro o Transmission electron microscopy (TEM) showed that uninfected organ cultures had normal ultrastructure. TEM of infected organ cultures at 8 h showed significant epithelial damage: 43.9±10% of cells extruding from the epithelial surface, 17.7±3% of cells with loss of cilia, 32.9±10.2% of cells with mitochondrial damage, and 11.6±3% of cells with cytoplasmic blebbing. P. aeruginosa only infrequently adhered to normal epithelium, but adhered to areas of epithelial damage and to basement membrane. Scanning electron microscopy (SEM) of organ cultures up to 2 h found P. aeruginosa only infrequently associated with mucus. SEM at 4 h revealed P. aeruginosa predominantly associated with mucus and extruded damaged epithelial cells, but also occasionally associated with cilia, and very occasionally with unciliated cells. SEM also revealed loss of epithelial tight junctions in P. aeruginosa infected organ cultures, and P. aeruginosa were frequently seen in the gaps between epithelial cells. An extracellular matrix, possibly of bacterial origin, was seen bridging the space between bacteria and cell surface.We conclude that P. aeruginosa infection of this organ culture caused tissue damage and that P. aeruginosa preferentially adhered to mucus, damaged epithelium and basement membrane.