Serum concentration of baseline mast cell tryptase: evidence for a decline during long-term immunotherapy for Hymenoptera venom allergy.
BACKGROUND
Baseline serum mast cell tryptase concentration (BTC) is thought to reflect the constitutive mast cell load or activity of an individual patient. Little is known about the individual stability of BTC during long-term venom immunotherapy (VIT).


OBJECTIVE
To investigate the intra-individual stability of BTC over time in patients with Hymenoptera venom allergy.


METHODS
Three hundred and two patients were studied. BTC was measured before and at least twice during VIT. At least 4 weeks lay between BTC measurements and the most recent field sting, in-hospital sting, or preceding venom injection. Multifactorial mixed linear models were used to analyse BTC changes over time.


RESULTS
Median observation time was 4.2 years (range 2-12 years). Before VIT, the median BTC was 6.8 microg/L (range 1.14-177 microg/L). The median coefficient of variation (CV) over time was 15.3% (range 1.9-63.8%). The median CV was significantly smaller in patients presenting with an elevated BTC (>11.4 microg/L) than in patients with a normal BTC (11.4%, range 2.6-39.5%; vs. 17.6%, range 1.9- 63.8%; P<0.001). During VIT and after adjusting for age and gender, we found a slight but significant decrease of BTC over time (2.5% per year, 95% confidence interval 2.0-3.0%, P<0.001).


CONCLUSIONS
Individual variation of BTC during VIT does not rise when BTC is increased before therapy. VIT is associated with a small, but continuous decrease of BTC over time possibly indicating a dampened mast cell function or a decline in mast cell burden.
Dugas-Breit
S
S
AllergieZentrum, Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität, München, Germany.
Przybilla
B
B
Dugas
M
M
Arnold
A
A
Pfundstein
G
G
Küchenhoff
H
H
Ruëff
F
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology / Q000627:therapeutic use; D000818:Animals; D001514:Bee Venoms / Q000276:immunology / Q000627:therapeutic use*; D001516:Bees / Q000276:immunology; D002648:Child; D003888:Desensitization, Immunologic / Q000379:methods*; D005260:Female; D006801:Humans; D006927:Hymenoptera / Q000276:immunology*; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000628:therapy*; D007299:Insect Bites and Stings / Q000188:drug therapy / Q000276:immunology; D008297:Male; D008407:Mast Cells / Q000276:immunology; D008415:Mastocytosis / Q000276:immunology; D008875:Middle Aged; D013997:Time Factors; D053802:Tryptases / Q000097:blood*; D014862:Wasp Venoms / Q000276:immunology / Q000627:therapeutic use*; D014863:Wasps / Q000276:immunology; D055815:Young Adult
D000485:Allergens; D001514:Bee Venoms; D014862:Wasp Venoms; D053802:Tryptases