169

BTTA

lung disease indicate that terbutaline may improve tracheobronchial clearance in patients with chronic bronchitis. In asthmatics with severe bronchial obstruction clearance seems to be low and not to be significantly influenced by terbutaline. Inhaled corticosteroids

compared with oral prednisone in asthmatic corticosteroids

patients commencing

regular

I. A. CAMPBELL (Edinburgh) In a multi-centre, double blind trial inhaled beclomethasone dipropionate (BDP) and inhaled betamethasone valerate (BV) were compared with prednisone (P) in the treatment of asthmatic patients starting long term corticosteroids for the first time. A short tetracosactrin (Synacthen) test was performed on entry and peak flow was measured twice daily for 3 days before starting either 800 pg of BDP or 800 pg of BV or 20 mg of P daily. Patients who showed a 20% or more increase in peak flow then began a period of dose reduction, the dose being titrated against the peak flow and the clinical state, until they were stabilised on an appropriate dose. They then entered the second phase of the trial which lasted 24 weeks. Each patient completed a daily diary card and the physician reviewed the dose every 4 weeks. The Synacthen test was repeated at the end of the trial. Of the 75 patients (19 BDP, 23 BV, 33 P) entering the second phase 8 were later withdrawn because of unwanted effects of the drugs (1 BV, 6 P) or because of poor control (1 BV). Sixty-seven patients completed the trial. The mean daily dose in the BDP group was 400 pg, in the BV group 400 pg and in the P group 7.5 mg. Control of asthma was good, no significant difference emerging between treatments. The mean response to Synacthen was halved in group P whilst in the BDP and BV groups the means did not change significantly. The 30% incidence of other unwanted effects of prednisone contrasted sharply with the 5% incidence of symptomatic oropharyngeal candidiasis in the patients receiving inhaled corticosteroids. Empyemas and rheumatoid arthritis P. DIEPPE (London) Pleural effusions are common in rheumatoid arthritis (RA) and pleural histology consistent with rheumatoid involvement is not infrequent. Patients with RA also suffer from an increased susceptibility to infections, including chronic bronchitis, bronchiectasis and pneumonia. In addition there are sporadic case reports of empyemas in association with RA. Five cases of empyema occurring in patients with RA were briefly presented. Important features of these cases were: Patirnt Age 1 68 2 52 3 64 4 53 5 50 (na = not available)

Sex M M M M M

Duration RA (yrs) 20 9 20 10 8

Empyema +m -~ -~ _!_ _.

Pneumorhoras

Pleural histology RA na RA na Nodules

Steroids + -

Organisms

:

From study of these and other cases in the literature, it is concluded that empyemas can arise in 3 ways in patients with RA: 1 Via necrosis of pleural rheumatoid nodules leading to a pyopneumothorax 2 Due to the general susceptibility to infection plus the presence of a serous effusion 3 Rheumatoid disease alone, resulting in a massive exudation of white cells and fibrinoid debris into the pleural space G

Joint effusions in RA frequently look purulent. and darily infected. The pleural fluid changes in rheumatoid that

occur

in the synovium

of affected

can

occasionally disease

rupture

are therefore

or become seconanalogous

10 those

joints.

IgE in atopy; past, present and future S. G. 0. JOHANSSON (Uppsalu, Sweden) IgE was independently discovered in 1966-67 by lshizaka and lshizaka in the U.S. and Johansson and Bennich in Sweden. Access to IgE and antiserum to IgE permitted new approaches in the study of immediate type hypersensitivity disorders. The IgE concentration in serum can be determined by sensitive radio-immunoassays. Mean values in healthy adults have been reported to be in the order of 100 ng/ml (50 units/ml). Raised levels occur in atopic diseases such as extrinsic asthma. hay fever and atopic eczema. IgE-antibody to a great variety of allergens can be measured by the radioallergosorbent test. RAST. An excellent correlation exists between RAST and biological tests for reaginic activity. immunological analyses of IgE and IgE-antibody will be valuable tests in investigations of atopic diseases. In addition, RaST has the potential of being a realistic solution to the problem of standardization of allergen extracts. It is hoped that knowledge of the basic structure of IgE will increase the understanding of the immunological mechanisms of the immediate hypersensitivity reactions.

Studies of the cellular immune response to BCG in mice and guinea pigs B. S. NILSSON (Stockholm,

Sweden)

The aim of this investigation has been to establish in some detail the cellular events occurring after BCG immunization in the two animal species studied. Mice were injected intraperitoneally, guinea pigs intracutaneously with varying doses of BCG. At various times after the immunization spleen cells (mice) or spleen cells, lymph node cells and blood cells (guinea pigs) were examined for their capacity to become activated by various concentrations of PPD tuberculin in vitro. The immune response in the two animal species followed distinctly different patterns. In mice. CBA or A/Sri strains, there was in some cases a very rapid response occurring within one week after immunization, but then strong fluctuations occurred and after 6-8 weeks generally only a very faint immune response was left. When purified populations of thymus-derived lymphocytes were used, essentially the same pattern was found, indicating that the immune response to BCG is essentially a T lymphocyte response. Taken as a whole the immune response in mice was rather faint and inconstant. In guinea pigs the initial response was delayed for several weeks. After this time an increasing response was found which then stabilized on a high and rather constant level. This remained roughly unchanged during several months. The strongest response was found in lymph node cells. Compared to responses in human blood lymphocytes, the mouse response is a very weak one. whereas the response in guinea pigs is probably somewhat stronger. The dose response curves, i.e. the response pattern to various concentrations of PPD tuberculin, in the guinea pigs looked much the same as in humans, possibly with a somewhat higher tuberculin sensitivity than in humans. Apart from a number of other conclusions which were discussed, it may be concluded from the present investigation that the mouse is not a very suitable experimental animal for studies of immune responses to BCG, whereas the guinea pig system shows a number of similarities to the human system and therefore should be quite suitable. The guinea pig also offers great possibilities to study in detail the migration of immunized cells between different compartments of the immune system. a matter which we are at present investigating.

Proceedings: Empyemas and rheumatoid arthritis.

169 BTTA lung disease indicate that terbutaline may improve tracheobronchial clearance in patients with chronic bronchitis. In asthmatics with sever...
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