Multidimensional severity assessment in bronchiectasis: an analysis of seven European cohorts

INTRODUCTION

Bronchiectasis is a multidimensional disease associated with substantial morbidity and mortality. Two disease-specific clinical prediction tools have been developed, the Bronchiectasis Severity Index (BSI) and the FACED score, both of which stratify patients into severity risk categories to predict the probability of mortality.

METHODS

We aimed to compare the predictive utility of BSI and FACED in assessing clinically relevant disease outcomes across seven European cohorts independent of their original validation studies.

RESULTS

The combined cohorts totalled 1612. Pooled analysis showed that both scores had a good discriminatory predictive value for mortality (pooled area under the curve (AUC) 0.76, 95% CI 0.74 to 0.78 for both scores) with the BSI demonstrating a higher sensitivity (65% vs 28%) but lower specificity (70% vs 93%) compared with the FACED score. Calibration analysis suggested that the BSI performed consistently well across all cohorts, while FACED consistently overestimated mortality in 'severe' patients (pooled OR 0.33 (0.23 to 0.48), p<0.0001). The BSI accurately predicted hospitalisations (pooled AUC 0.82, 95% CI 0.78 to 0.84), exacerbations, quality of life (QoL) and respiratory symptoms across all risk categories. FACED had poor discrimination for hospital admissions (pooled AUC 0.65, 95% CI 0.63 to 0.67) with low sensitivity at 16% and did not consistently predict future risk of exacerbations, QoL or respiratory symptoms. No association was observed with FACED and 6 min walk distance (6MWD) or lung function decline.

CONCLUSION

The BSI accurately predicts mortality, hospital admissions, exacerbations, QoL, respiratory symptoms, 6MWD and lung function decline in bronchiectasis, providing a clinically relevant evaluation of disease severity.

Ultra rush bee venom immunotherapy does not reduce cutaneous weal responses to bee venom and codeine phosphate

BACKGROUND

The rapid administration of bee venom in cumulative doses exceeding the quantity contained in one bee sting is well tolerated by most of the patients during 3.5 h of ultra-rush bee venom immunotherapy (VIT). The mechanism of this tolerance is unknown.

OBJECTIVE

The aim of the study was to verify the hypothesis that either slow mediator depletion of mast cells or blockade of their surface receptor mechanisms by increasing doses of allergen might be the major mechanisms of tolerance induced by ultra-rush VIT.

METHODS

Nine bee venom allergic patients with a history of severe systemic reactions after a bee sting, positive skin tests and bee venom specific serum IgE antibodies were treated as follows: on the first day a cumulative dose of 111 micrograms was administered over 3.5 h under intensive care conditions. Further injections were given on day 7, day 21 and thereafter at 4 week intervals. Intradermal tests with codeine phosphate (non-specific mast cell degranulation) and bee venom were performed before the initiation of VIT and 30 min after the last injection on the same day as well as before the subsequent bee venom injections.

RESULTS

No significant changes of skin reactivity to both codeine phosphate and bee venom were observed on day 1 (before initiation of VIT and after the last injection on the same day).

CONCLUSIONS

Ultra-rush VIT does not induce mediator depletion or surface receptor blockade in skin mast cells.

Type I skin reactivity to native and recombinant phospholipase A2 from honeybee venom is similar

Phospholipase A2 is the major allergen in honeybee venom. Recombinant phospholipase A2 was produced in prokaryotes and tested for its biologic activity by intracutaneous skin testing with serial 10-fold dilutions in comparison with native and deglycosylated phospholipase A2 in patients allergic to bee venom. Linear regressions of the log of the wheal area versus the log of the allergen concentration were calculated for all allergens in each patient. The relative allergenic potency of the various preparations was analyzed by comparing the linear regressions. Native phospholipase A2 was about 10 times more potent than whole bee venom. None of 58 patients allergic to bee venom was missed by testing with native phospholipase A2 alone. This allergen and deglycosylated native phospholipase A2 resulted in similar skin reactions, indicating that the sugar residues were of little relevance for IgE-binding in the patients tested. Native phospholipase A2 also had relative potency similar to that of recombinant refolded phospholipase A2, whereas recombinant nonrefolded phospholipase A2 had almost no biologic activity in skin testing. These results demonstrate in vivo activity of the recombinant bee venom allergen phospholipase A2. Although correct refolding is a prerequisite for type I skin reactivity, glycosylation seems to be less important.

Bee venom immunotherapy results in decrease of IL-4 and IL-5 and increase of IFN-gamma secretion in specific allergen-stimulated T cell cultures

The mechanisms of bee venom immunotherapy (VIT) are largely unknown. The aim of this study was to follow the changes of T cell cytokine secretion during the course of VIT. Ten bee venom-allergic patients with a history of severe systemic reactions, positive skin tests, and bee venom (BV)-specific serum IgE Abs were treated as follows: on the first day, a cumulative dose of 111 micrograms, starting with 0.1 microgram, was administered s.c. under intensive care conditions. Further injections of 100 micrograms BV were given on day 7, day 21, and thereafter at intervals of 4 wk. Blood samples were obtained just before the initiation of VIT, after the last injection on the same day, and before the subsequent BV injections on days 7, 21, and 50 of VIT. Peripheral blood mononuclear cells (PBMC) were stimulated with phospholipase A (PLA), the major BV allergen, or with a control Ag tetanus toxoid (TT). Cytokine secretion was measured 24 h after restimulation of the cultures with solid-phase bound OKT3 F(ab')2 mAbs after 7 days of culture. In PLA-stimulated cultures, VIT resulted in decreased IL-4 and IL-5 and increased IFN-gamma secretion. In TT-stimulated cultures, we observed similar levels of cytokines before and during VIT. We conclude that ultra-rush VIT changes allergen-specific T cell reactivity.

Bee venom immunotherapy results in decrease of IL-4 and IL-5 and increase of IFN-gamma secretion in specific allergen-stimulated T cell cultures

The mechanisms of bee venom immunotherapy (VIT) are largely unknown. The aim of this study was to follow the changes of T cell cytokine secretion during the course of VIT. Ten bee venom-allergic patients with a history of severe systemic reactions, positive skin tests, and bee venom (BV)-specific serum IgE Abs were treated as follows: on the first day, a cumulative dose of 111 micrograms, starting with 0.1 microgram, was administered s.c. under intensive care conditions. Further injections of 100 micrograms BV were given on day 7, day 21, and thereafter at intervals of 4 wk. Blood samples were obtained just before the initiation of VIT, after the last injection on the same day, and before the subsequent BV injections on days 7, 21, and 50 of VIT. Peripheral blood mononuclear cells (PBMC) were stimulated with phospholipase A (PLA), the major BV allergen, or with a control Ag tetanus toxoid (TT). Cytokine secretion was measured 24 h after restimulation of the cultures with solid-phase bound OKT3 F(ab')2 mAbs after 7 days of culture. In PLA-stimulated cultures, VIT resulted in decreased IL-4 and IL-5 and increased IFN-gamma secretion. In TT-stimulated cultures, we observed similar levels of cytokines before and during VIT. We conclude that ultra-rush VIT changes allergen-specific T cell reactivity.