Long-term intense exposure to grass pollen can mask positive effects of allergenic immunotherapy on non-specific bronchial hyperresponsiveness

INTRODUCTION

There are many potential factors that can modulate bronchial reactivity, including exposure to allergens, viral infections, and medications. The aim of this study was to analyze the effect of grass pollination intensity on the bronchial reactivity in seasonal allergic rhinitis (SAR) patients subjected to subcutaneous allergenic immunotherapy (SCIT).

MATERIAL AND METHODS

This study, performed between 2005 and 2008, included 41 patients with confirmed sensitivity to grass pollens and predominating symptoms of SAR, randomly assigned to desensitization by pre-seasonal or maintenance SCIT. Bronchial provocation challenge with histamine was performed before the onset of immunotherapy, and repeated three times after each pollen season covered by this study. Bronchial reactivity was analyzed with regard to grass pollination intensity in 2005-2008 (air concentration of grass pollen grains, seasonal number of days when air concentration of grass pollen reached at least 20 or 50 grains per 1 m(3)).

RESULTS

After 3 years of SCIT, a significant decrease in bronchial responsiveness was observed in the analyzed group as confirmed by an increase in PC20 FEV1 histamine values (p = 0.001). An inverse tendency was observed after 2 years of SCIT, however. This second year of SCIT corresponded to the 2007 season, when a significantly higher number of days with at least 50 grains of pollen per 1 m(3) of air was recorded.

CONCLUSIONS

FLUCTUATIONS IN POLLINATION INTENSITY OBSERVED DURING CONSECUTIVE YEARS OF IMMUNOTHERAPY CAN INFLUENCE BRONCHIAL REACTIVITY IN PATIENTS SUBJECTED TO SCIT (ISRCTN REGISTER: ISRCTN 86562422).

Allergenic immunotherapy and seasonal changes in nitric oxide concentration in exhaled air in seasonal rhinitis patients

BACKGROUND

Concentration of nitric oxide in exhaled air (FeNO) was revealed to decrease as a result of immunotherapy. However, individuals who are exposed to environmental allergens are characterized by elevated values of FeNO. The aim of this study was to analyze the effects of subcutaneous immunotherapy (SCIT) on the dynamics of FeNO determined during consecutive pollination seasons.

METHODS

This study, performed between 2005 and 2008, included 41 patients with confirmed sensitivity to grass pollens and predominating symptoms of seasonal allergic rhinitis, randomly assigned to desensitization by preseasonal or maintenance SCIT. FeNO was measured prior to and during each pollen season (November-January and May-July, respectively). The results were conferred to data on grass pollination intensity in 2006-2008 (air concentration of grass pollen grains, seasonal number of days when air concentration of grass pollen reached at least 50 grains per 1 m(3)).

RESULTS

Median content of FeNO in exhaled air was significantly higher in 2007 compared to 2006 and 2008 pollen seasons. During 2007 and 2008 pollen seasons, significant increase in FeNO was observed compared to the respective preseasonal values. Median number of days with air concentration of grass pollen ≥ 50 grains per 1 m(3) of air during 4 weeks preceding seasonal FeNO measurement was significantly higher in 2007, corresponding to higher FeNO value recorded during this pollen season. However, no significant correlation was observed between seasonal number of days with ≥ 50 grass pollen grains per 1 m(3) of air and FeNO in exhaled air (r=0.09, p=0.362).

CONCLUSIONS

Most seasonal allergic rhinitis patients show physiological levels of FeNO prior to the pollen seasons and a marked increase in this parameter, probably proportional to pollination intensity, is observed within the seasons. ISRCTN Registry: ISRCTN86562422.

Antiasthmatic versus surgical treatment-how important is the precise analysis of spirometry?

OBJECTIVE

Carcinoids are low-grade, slow growing malignant tumors in the bronchi usually producing symptoms secondary to bronchial obstruction. We describe a case of 25-year-old woman who was initially diagnosed with asthma.

METHOD

Case report.

RESULTS

Because of exacerbation and unresponsiveness to proper asthma treatment she was referred to spirometry, which showed low values of forced expiratory volume in 1 second. The shape of inspiratory limb of flow volume curve suggested an obstruction in the main bronchus or in the trachea. Further bronchoscopy revealed a tumor of the right main bronchus with characteristic histological features for carcinoid.

CONCLUSIONS

Both the inspiratory curve and the expiratory part of the flow-volume loop should be evaluated in patients being evaluated for asthma. If there are changes in the shape of the inspiratory limb suggesting an obstruction, CT and/or bronchoscopy should be considered.