Peripheral erythrocytes decrease upon specific respiratory challenge with grass pollen allergen in sensitized mice and in human subjects.
OBJECTIVE
Specific hyper-responsiveness towards an allergen and non-specific airway hyperreactivity both impair quality of life in patients with respiratory allergic diseases. We aimed to investigate cellular responses following specific and non-specific airway challenges locally and systemically in i) sensitized BALB/c mice challenged with grass pollen allergen Phl p 5, and in ii) grass pollen sensitized allergic rhinitis subjects undergoing specific airway challenge in the Vienna Challenge Chamber (VCC).


RESULTS
BALB/c mice (n = 20) were intraperitoneally immunized with grass pollen allergen Phl p 5 and afterwards aerosol challenged with either the specific allergen Phl p 5 (n = 10) or the non-specific antigen ovalbumin (OVA) (n = 10). A protocol for inducing allergic asthma as well as allergic rhinitis, according to the united airway concept, was used. Both groups of exposed mice showed significantly reduced physical activity after airway challenge. Specific airway challenge further resulted in goblet cell hyperplasia, enhanced mucous secretion, intrapulmonary leukocyte infiltration and lymphoid follicle formation, associated with significant expression of IL-4, IL-5 and IL-13 in splenocytes and also partially in lung tissue. Concerning circulating blood cell dynamics, we observed a significant drop of erythrocyte counts, hemoglobin and hematocrit levels in both mouse groups, challenged with allergen or OVA. A significant decrease in circulating erythrocytes and hematocrit levels after airway challenges with grass pollen allergen was also found in grass pollen sensitized human rhinitis subjects (n = 42) at the VCC. The effects on peripheral leukocyte counts in mice and humans however were opposed, possibly due to the different primary inflammation sites.


CONCLUSIONS
Our data revealed that, besides significant leukocyte dynamics, particularly erythrocytes are involved in acute hypersensitivity reactions to respiratory allergens. A rapid recruitment of erythrocytes to the lungs to compensate for hypoxia is a possible explanation for these findings.
Comparative Medicine, Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University of Vienna & University of Vienna, Vienna, Austria ; Institute of Occupational Medicine, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria.
Galateja
G
Jordakieva
Comparative Medicine, Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University of Vienna & University of Vienna, Vienna, Austria.
Julia
J
Wallmann
Vienna Challenge Chamber (VCC), Vienna, Austria.
René
R
Schmutz
Vienna Challenge Chamber (VCC), Vienna, Austria.
Patrick
P
Lemell
Priority Area Asthma & Allergy, Leibniz Center for Medicine and Biosciences, Research Center Borstel, Airway Research Center North, Member of the German Center for Lung Research, Borstel, Germany.
Michael
M
Wegmann
Comparative Medicine, Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University of Vienna & University of Vienna, Vienna, Austria.
Thomas
T
Nittke
Section for Clinical Biometrics, Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
Martina
M
Mittlböck
Priority Area Asthma & Allergy, Leibniz Center for Medicine and Biosciences, Research Center Borstel, Airway Research Center North, Member of the German Center for Lung Research, Borstel, Germany.
Heinz
H
Fehrenbach
Institute of Occupational Medicine, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria.
Jasminka
J
Godnic-Cvar
Vienna Challenge Chamber (VCC), Vienna, Austria.
René
R
Zieglmayer
Comparative Medicine, Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University of Vienna & University of Vienna, Vienna, Austria ; Institute of Pathophysiology and Allergy Research, Center of Pathophysiology Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
Erika
E
Jensen-Jarolim
D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant / Q000276:immunology; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000166:cytology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008297:Male; D051379:Mice; D006109:Poaceae / Q000009:adverse effects*; D011058:Pollen / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000097:blood* / Q000276:immunology* / Q000503:physiopathology; D055815:Young Adult
D000485:Allergens; D052179:Antigens, Plant; D007073:Immunoglobulin E