A study of Hemophilus influenzae precipitins in the serum of working men in relation to smoking habits, bronchial infection, and airway obstruction

Immune response to Haemophilus parainfluenzae in patients with chronic obstructive lung disease

Haemophilus parainfluenzae is often isolated from the sputa of patients with chronic obstructive lung disease. We have investigated the immune response to this organism in patients with chronic bronchitis (n = 3) and bronchiectasis (n = 10) and in healthy controls (n = 9). Outer membrane proteins (OMPs) of H. parainfluenzae were purified for use in enzyme-linked immunosorbent and immunoblot assays. Whole-cell H. parainfluenzae preparations were used to adsorb antibodies from serum samples, which were subsequently immunoblot assayed to investigate the antibody response to surface-exposed epitopes. Levels of H. parainfluenzae-specific immunoglobulin G (IgG), but not IgA or IgM, were increased in the sera of patients with chronic obstructive lung disease compared to levels in control subjects. The species specificity of the antibody response was confirmed, although a degree of cross-reactivity with H. influenzae antigens was observed. IgA and IgG specific for OMPs of H. parainfluenzae were demonstrated to be present in the sputa and sera of five patients with chronic obstructive lung disease. Variation in the pattern and intensity of antigen recognition was observed among patients and among immunoglobulin classes. OMPs of approximately 36, 22, and 15 kDa were confirmed to possess epitopes exposed on the surface of intact H. parainfluenzae. We have demonstrated the presence of a species-specific systemic immune response to H. parainfluenzae in colonized patients. A specific antibody response was also observed in sputum, and the antigen specificity of these responses in patients with chronic obstructive lung disease was investigated for the first time. The presence of a specific immune response suggests that H. parainfluenzae may have a pathogenic role in patients with chronic obstructive lung disease.

Antigen of Haemophilus influenzae in bronchial tissue

Haemophilus influenzae antigen was detected in five of seven bronchial biopsies obtained from patients undergoing diagnostic bronchoscopy. Antibody against H influenzae antigens was obtained from a patient with bronchiectasis. Immunofluorescent techniques were used. This provides further evidence to support the pathogenicity of H influenzae in lower respiratory tract disorders.

Effect of tobacco and nicotine on growth of Haemophilus influenzae in vitro

Two nutritionally poor bacteriological media, prepared from phosphate-buffered saline and from bronchial secretions, support the growth of Haemophilus influenzae only poorly. The presence of tobacco or pure nicotine in these media stimulates the growth of the organism, and the component(s) responsible appear(s) to be volatile.

Abnormalities of the tracheobronchial lymph nodes in smokers and subjects with chronic bronchitis: a necropsy study of the distribution of immunoglobulins

Soutar, C. A. (1977).Thorax, 32, 397-405. Abnormalities of the tracheobronchial lymph nodes in smokers and subjects with chronic bronchitis: a necropsy study of the distribution of immunoglobulins. The tracheobronchial lymph nodes obtained at necropsy from small groups of subjects (normal non-smokers, normal smokers, subjects with chronic bronchitis which was incidental to the cause of death, and subjects who had died from long-standing chronic bronchitis) have been examined by immunofluorescent methods to detect immunoglobulin.

Cells containing immunoglobulin were seen scattered in the medullary cords and corticomedullary junctions, and also as conglomerates within active germinal centres. Sampling methods on multiple sections were used to count the numbers of single cells containing immunoglobulin (excluding those in germinal centres) and also the numbers of germinal centres containing immunoglobulin.

This work has shown that there were fewer plasma cells containing IgA and IgM in `fatal' bronchitics than in normal non-smokers, normal smokers, and `incidental' bronchitics (IgA p<0·005; IgM p<0·01). These results indicate that the reported depletion of plasma cells found in the airways in a small group of subjects with fatal chronic bronchitis was accompanied by a similar depletion in the regional lymph nodes.

It was also found that the numbers of active germinal centres containing immunoglobulin (mostly IgM) were increased in normal smokers, `incidental' bronchitics, and `fatal' bronchitics, although in these small numbers of subjects the significance of this difference (p<0·05) depends on grouping these subjects together. This suggests that cigarette smoking alters germinal centre activity even in subjects without chronic cough.

An improved test for Haemophilus influenzae precipitins in the serum of patients with chronic respiratory disease

The detection of antibacterial precipitins in the serum of patients with chronic lower respiratory infections has been shown to be of great value in the assessment of pathogenicity of the corresponding bacterial species in the sputum. The test used hitherto, however, is time-consuming and cumbersome owing to the need to distinguish, by immunoelectrophoresis, between antibodies specific to the organism in question and those which react with antigens common to various Gram-negative species. A method has now been devised for the preparation of an extract of Haemophilus influenzae containing species-specific antigens only. Use of this extract obviates the need for immuno-electrophoresis and improves the sensitivity of the test.