P38 mitogen-activated protein kinase signal transduction in the diagnosis and follow up of immunotherapy of wasp venom allergy.
BACKGROUND
P38 mitogen-activated protein kinase (MAPK) is known to govern IgE-mediated basophil activation. Intracellular phosphorylated p38 MAPK (Pp38 MAPK) in IgE-activated basophils can be quantified flow cytometrically.


OBJECTIVE
To study whether Pp38 MAPK constitutes a potential novel read-out for flow-assisted diagnosis of hymenoptera venom allergy and to investigate whether this marker allows follow-up of successful venom immunotherapy (VIT).


METHODS
Fifty-two patients with documented wasp venom allergy and seven wasp-stung asymptomatic control individuals were enrolled. Wasp venom-induced basophil activation was analyzed flow cytometrically with anti-IgE, anti-CD63, and anti-Pp38 MAPK to assess their activation status before starting immunotherapy. To assess whether p38 MAPK constitutes a candidate marker for monitoring VIT, we repeated the basophil activation test (BAT) in 25 patients on the fifth day of a build-up immunotherapy. In addition, we investigated whether the Pp38 MAPK-based BAT could contribute in the decision of discontinuing VIT in a cross-sectional analysis in 13 patients receiving treatment for 3 years and 14 patients receiving treatment for 5 years.


RESULTS
Patients exhibited a dose-dependent basophil activation with phosphorylation of p38 MAPK and upregulation of downstream CD63. In contrast, stung controls demonstrated a dose-dependent but "abrogated" signal transduction in basophils with less and shorter duration of the phosphorylation of p38 MAPK and without subsequent upregulation of CD63. When repeated after 5 days of VIT and when investigated cross-sectionally after 3 years or 5 years of maintenance therapy, no effect of VIT on the phosphorylation of p38 MAPK was demonstrable.


CONCLUSIONS
This study discloses that not only basophils from patients, but also from the stung control individuals, respond to wasp venom stimulation with phosphorylation of p38 MAPK, although to a lesser extend. No clear effect of VIT on the phosphorylation of p38 MAPK was shown. Thus, although p38 MAPK provides an additional tool in the diagnosis of wasp venom allergy, it does not contribute to the decision whether to stop successful VIT. © 2010 International Clinical Cytometry Society.
Department of Immunology-Allergology-Rheumatology, Faculty of Medicine, University of Antwerp, Antwerp, Belgium. immuno@ua.ac.be
Marjoke M
MM
Verweij
Kathleen J
KJ
De Knop
Chris H
CH
Bridts
Luc S
LS
De Clerck
Wim J
WJ
Stevens
Didier G
DG
Ebo
D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology; D001491:Basophils / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002648:Child; D003430:Cross-Sectional Studies; D003888:Desensitization, Immunologic; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis* / Q000628:therapy*; D007073:Immunoglobulin E / Q000032:analysis / Q000276:immunology; D007299:Insect Bites and Stings / Q000175:diagnosis* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010766:Phosphorylation; D010980:Platelet Membrane Glycoproteins / Q000032:analysis / Q000276:immunology; D015398:Signal Transduction; D060149:Tetraspanin 30; D014862:Wasp Venoms / Q000276:immunology*; D055815:Young Adult; D048051:p38 Mitogen-Activated Protein Kinases / Q000032:analysis* / Q000378:metabolism
D015703:Antigens, CD; D015415:Biomarkers; C554586:CD63 protein, human; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30; D014862:Wasp Venoms; D007073:Immunoglobulin E; D048051:p38 Mitogen-Activated Protein Kinases