Revue francaise des maladies respiratoires最新文献

Hypersensitivity pneumonitis is one model of environmental pulmonary disease. If the clinical and radiological pictures are now well established the risk of allergic disorders in the community can only be appreciated by large epidemiological enquiries which ought to be carried out with the utmost vigor, yet may be deceptive. As regards diagnosis, one should take note on the one hand of: --respiratory function tests showing the involvement of the alveoli and the interstitium in the pathological process but also that of the peripheral bronchioles, that is the distal lung as a whole. --On the other hand systemic immunological studies (search for precipitating antibodies to allergens, always considered to be a diagnostic test of major value) may nonetheless be reinforced by cell counts lymphocytes) or skin tests and even provocation tests. --The study of bronchoalveolar lavage yields very important information: An increase in the number of cells, notably " T " lymphocytes, biochemical disturbances characterized by an increase in protein and lipid levels with qualitative changes in the phospholipids: a fall in the lecithin and a rise of the other fractions which lead to an increase in the microviscosity of alveolar liquid. Finally an aetiological study is required to identify the allergen in the ambient atmosphere of the patient or worker and if possible, an experimental study trying to reproduce the pathological lesions and the immunological disturbances. Finally the treatment should consist of excluding the offending agent. Steroid therapy is justified in acute situations with disturbed function, but this does not prevent a final outcome of irreversible fibrosis.

Different sources of oxygen can be used in patient's homes: gas cylinders, portable liquid oxygen or a concentrator. The choice regarding source is related to the aims (nocturnal oxygenation, oxygen for rehabilitation), the length of daily treatment and the desire for patient autonomy. The selection flow rate during the day, the night and/or during exercise depends essentially on the physiological consequences of oxygen administration, planned in a precise fashion for periods not exceeding 24-48 h. Three types of tests may be retained: 1. A 30 minute day test, 2. A prolonged night study, 3. A polygraphic study. First, the short, resting, day-time, 30 minutes test measuring output from variations of PaO2, PaCO2 and pH before and after 30 minutes of inhalation; simultaneous measurements of PAP (but haemodynamic variations during the test do not carry long term predictive values). Secondly, long term studies at night: these trials may either include simple measurements, such as oxygen saturation with an ear oxymeter or more complex polygraphic measurements. Nowadays for the simple measurements with ear oxymetry, one night on ambient air and one on oxygen seems adequate in providing vital information regarding nocturnal hypoxia and its correction. Thirdly, respiratory polygraphs which provide better information on the mechanism of hypoxia but are much more difficult to use in daily practice. These polygraph studies should be reserved only for high risk sufferers, the obese and snorers. Among the exercise tests necessary to confirm that the benefit of oxygen therapy outweighs the disadvantage of carrying a portable oxygen system, is the Mac Gavin test (distance walked in 12 minutes) completed by doing blood gases to assess the indications and the efficacy of the portable system.

Prognosis in patients having undergone surgery for a bronchial carcinoma (oat cell. carcinoma excluded) was studied by comparing, with two statistical methods, a group of 178 patients surviving five years and more (group I) and a group of 178 patients who died within five years (group II). The two groups had undergone treatment during the same period. Comparison of the two groups suggested that the following factors were indicators of a good prognosis: ratio weight-height within normal limits without recent weight loss, fortuitous detection of the carcinoma; normal aspect on bronchoscopy; T1 N0 type without vascular extension, limited exeresis. Recurrences of the carcinoma were generally observed in group II but could be present in group I. The differential prognosis between pulmonary metastases and a "new" bronchial carcinoma was difficult. Survival was finally determined by the frequency of recurrences and metastases. By a correspondences factorial analysis it was possible to separate and to define the main characteristics of the patients with a good prognosis and a long survival and of those with a poor prognosis and a short survival. However this proved to be exact in only 30% of the individual cases because occurrence of metastases was generally unforeseable. From these data it appears that surgery alone is indicated in only one kind of tumours; T1 N0 carcinomas detected by routine examinations.

Biological data acquired in recent years has thrown new light on the pathogenesis of pulmonary fibrosis. The key element in the genesis of fibrosis may be the alveolar macrophage which, under the influence of different stimuli, secretes numerous factors, attracting polymorphonuclear leukocytes and eosinophils, stimulating fibroblasts and activating lymphocytes. Pulmonary fibrosis induced by inhalation of inorganic particles seems to proceed by identical mechanisms, with certain differences relating to the nature of each mineral. The morphological, cytological and immunological characteristics which defend the lung from silicosis and asbestosis are particularly discussed. The in vitro reactivity of several cell types (alveolar macrophages, mesothelial cells in culture, fibroblasts) equally has revealed differences between quartz and chrysotile. Nevertheless this in vitro response is difficult to interpret compared to an in vivo response: they vary according to the cellular system used and the physico-chemical state of the particular mineral (chrysotile and leached chrysotile by oxalic acid for example). The fibrosing action of other particles (talc, metals) is also reviewed. As opposed to an inflammatory granuloma secondary to the stimulation of alveolar macrophages which represents the usual response to mineral particles, there is also an immunological granuloma of the sarcoid type which may lead to secondary fibrosis: beryllium and talc in certain circumstances may act by this mechanism.

Broncho-alveolar lavage (LBA) was performed in 17 pneumoconiotics. The liquid obtained was analysed after gentle centrifugation to remove the cellular element, so that biochemical factors might be sought contribution to the evolution and progressive transformation to fibrosis. The percentage of liquid gathered was generally greater. Among the glycosidases found in all the 17 LBA analysed, the beta-D-glucuronidase, which was not detected in the LBA control subjects, was also found during the course of other pulmonary disorders. The elastolytic activity was characterized in 12 out of 17 LBA. In part it could originate from alveolar macrophages. An elevated number of macrophages (greater than 20 X 10(6) for the whole lavage) allied to the presence of elastolytic activity was found in 7 of 8 patients presenting with a pneumoconiosis and signs of progressive pulmonary disease. The collagenase and cathepsin B were present in the LBA of certain pneumoconiotics, but the significance of their presence is still unknown. The three major antiproteases of the serum exist in the LBA of pneumoconiosis. The quantity of alpha 1-antiprotease has identified a group of 6 patients whose LBA showed raised alpha 1-antiprotease, an elastolytic activity and for 5 of them progressive outcome.

Almitrine stimulates breathing by activating peripheral chemoreceptors and was given orally in a dose of 200 mg/day to nine patients with sleep apnoea syndrome, after a single blind placebo sequence. No reduction in the number of respiratory events per hour of sleep was observed. On the other hand Almitrine led to a significant fall in the mean duration of respiratory events (p less than 0.02). This fall occurred principally in the obstructive apnoea group and in those with mixed apnoea only during light slow wave sleep. These results are in agreement with the hypothesis that the arousal response to hypoxia mediated by the chemoreceptors could be responsible for the termination of sleep apneas.

Cell typing of sub-populations of lymphocytes is facilitated by using monoclonal antibodies (OKT); with this technique we determined the relative proportions of "helper" T-lymphocytes (OKT4) and "Suppressor" T-lymphocytes (OKT8) in the blood and the LBA of 13 patients suffering from pulmonary sarcoidosis. In the control subjects the OKT4/OKT8 ratio was 1.9 +/- 0.3 in the blood (38 subjects) and of 2 +/- 0.2 in the LBA (6 subjects). Six patients suffering from inactive sarcoidosis (stabilised) had an OKT4/OKT8 ratio on average of 1.2 +/- 0.39 in the blood and of 1.86 +/- 0.46 in the LBA. By contrast in 7 patients suffering from "active" sarcoidosis, on average the ratio was 1.88 +/- 1.20 in the blood but 5.13 +/- 3.51 in the LBA; this ratio was notably raised in the LBA in 5 cases and was due as much to an increase in the T-"Helper" (OKT4) percentage as to a fall in the T-"Suppressor" (OKT8). It is probable that the T-"Helper" lymphocytes found in great numbers in the lung in active sarcoidosis cases participate in the formation of sarcoid granulomas and attract phagocytic mononuclear cells. This phenomenon seems to correspond to a local immune disturbance without producing a similar result in the peripheral blood of the patients.

Trends in basic research in thoracic medicine are increasingly orientated to biochemical and cellular studies. The need for "biochemical markers" as evidence of a particular type of cell is soon appreciated, both from a qualitative as well as quantitative viewpoint. The ideal criteria which these "markers" should possess (specificity for the organ and cell population and reflecting a well defined metabolic activity) are unfortunately rarely satisfied; the "marker" may be analysed in plasma or broncho-alveolar lavage liquid. Two examples are presented and the difficulties of their interpretation are discussed. First in relation to the determination of serum angiotensin converting enzyme activity and then elastolytic activity in the broncho-alveolar liquid. A good knowledge of basic biological phenomena is necessary to take full advantage of the information which can be obtained by measuring "markers" of activity or function of pulmonary cells.

The activation, aggregation and adhesion of polymorphonuclear leukocytes on the endothelial wall of the pulmonary capillaries are responsible for lesions of variable severity on the alveolar-capillary membrane. The mechanism and the contribution of this leukocyte aggregation was studied to explain the respiratory abnormalities observed during the course of haemodialysis, leukapharesis and the end of extra-corporeal circulation. The activation of complement, by the formation of C5a is probably the initiator of this phenomenon. Based on these experimental models, the varied steps in the intra-capillary aggregation of leukocytes is envisaged as an explanation for the lesions in the acute respiratory distress syndrome, alveolitis caused by immune complexes and pulmonary toxicity caused by oxygen. Corticosteroids may inhibit leukocyte aggregation under certain conditions. These studies allow for a more precise pathophysiological approach for the use of steroids in their disorders.

A campaign of tuberculin testing in standard fashion, followed by BCG vaccination in those giving an inadequate reaction, was carried out on all children in the Bas-Rhin department in France in their first primary school year for the year 1976-1977. Of 15,560 pupils enrolled 64.5 percent had already had at least one BCG vaccination. 12,820 had the standard test, the remaining 2,740 were either absent or parents refused permission. 27.8 percent of those vaccinated had an indurated area of more than 4 mm diameter, compared to 7.4 percent among those not vaccinated. 9,517 children were vaccinated or revaccinated during the campaign, by means of scarification of intradermal injection. 4,472 had a standard post-vaccine test during the following school-year: a diameter of induration of 4 mm or less was found in 28.9 percent. The proportion varied according to the doctors who had vaccinated them but was lower among the children vaccinated by intradermal injection.