Expression of activation markers on basophils in a controlled model of anaphylaxis.
BACKGROUND
Anaphylaxis has variable clinical presentations and lacks reliable biomarkers. Expression of activation markers on basophils has been useful in assessing sensitization in IgE-mediated diseases but has not been examined in vivo in anaphylaxis.


OBJECTIVE
The study's goals were to assess the baseline expression of activation markers on basophils in individuals with a sting reaction history, the degree of change in expression of these markers after intentional sting challenge, and the relationship between in vitro and in vivo activation marker expression.


METHODS
Patients allergic to insect venom were enrolled and grouped by clinical category defined by a history of a systemic or large local reaction and use of venom immunotherapy. Blood was collected before and after sting challenge. Enriched basophils were analyzed for activation marker expression. In select subjects, basophils were examined after in vitro stimulation with insect venom for activation marker expression and histamine release.


RESULTS
Of 35 sting-challenge participants, 21 provided adequate samples for analysis. Pre-sting basophil CD63 expression was significantly higher in systemic reactors on immunotherapy. Following sting challenge, the rise in basophil CD69 expression and CD203c was significantly higher in systemic reactors on immunotherapy. Levels of activation markers on basophils were greater after in vitro venom stimulation than after in vivo challenge.


CONCLUSIONS
Broader shifts in expression of basophil activation markers after in vivo challenge occurred among subjects with a history of in vivo systemic anaphylaxis despite venom immunotherapy.


CONCLUSIONS
Basophil activation markers may be potential biomarkers for anaphylaxis.
Gober
Laura M
LM
Department of Medicine, Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
Eckman
John A
JA
Sterba
Patricia M
PM
Vasagar
Kavitha
K
Schroeder
John T
JT
Golden
David B K
DB
Saini
Sarbjit S
SS
D000707:Anaphylaxis / Q000276:immunology*; D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D001180:Arthropod Venoms / Q000009:adverse effects / Q000276:immunology; D001491:Basophils / Q000276:immunology*; D015415:Biomarkers; D003888:Desensitization, Immunologic; D005434:Flow Cytometry; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007299:Insect Bites and Stings / Q000276:immunology; D037181:Lectins, C-Type; D010727:Phosphoric Diester Hydrolases / Q000096:biosynthesis; D011755:Pyrophosphatases / Q000096:biosynthesis; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D001180:Arthropod Venoms; D015415:Biomarkers; D037181:Lectins, C-Type; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases; D000099192:CD69 Antigens; C427944:ENPP3 protein, human