IN SUBJECTS ALLERGIC TO GRASS POLLEN, BASOPHIL SENSITIVITY DECREASES DURING SUBCUTANEOUS IMMUNOTHERAPY DUE TO BOTH HUMORAL FACTORS AND CELLULAR DESENSITIZATION

Research output: Contribution to conferencePosterResearchpeer-review

Johannes Martin Schmid, Ronald Dahl, and Hans Juergen Hoffmann
Department of Respiratory Medicine, Aarhus, Denmark
Background: The major effect of SCIT is a change in
allergen specific immunoglobulin. We measure the contribution
of competing immunoglobulin to the effect of SCIT in
patients with allergic rhino-conjunctivitis with basophil activation
tests (BAT).
Methods: We have randomized 24 patients to a treatment
(18) and an open control group (6). Repeated BAT
were performed at baseline and througout treatment. Heparinized
blood was centrifuged, plasma was removed, the
cells washed twice, then reconstituted with plasma from
the present and baseline visit, and medium. The cells were
406 ESCCA AND ICyS ABSTRACTS
Cytometry Part B: Clinical Cytometry
incubated with log dilutions of grass pollen extract and
washed again. Basophil activation was measured as the percentage
of CD63 expression on CD193
þ
basophils. The
LC50 was calculated as the log of the allergen concentration
leading to half maximum basophil activation. Specific IgE
and IgG4 was measured using ISAC panel.
Results: We found a 15-fold reduction in basophil sensitivity
in the treated group during updosing, compared to
their baseline sensitivity (n ¼ 18; P < 0.001). The sensitivity
still decreases on maintenance dose, and is now
approaching a 60-fold reduction. There is no change in sensitivity
in the control group.
We show an effect due to changes in IgX, but also that
there appears to be a desensitization of basophils independent
of IgX with an about six-fold decrease in cellular sensitivity.
Conclusion: We found an increasing protective effect
of SCIT after 1 year of treatment measured by basophil activation
test. During the early treatment period, this effect is
primarily based on a shift towards protecting IgX, while
there seems to be a cellular desensitisation after 1 year.
Selected for presentation during the Poster Walk on Friday.
(2011), Abstracts of the 11th Euroconference on Clinical Cell Analysis. Dublin, Ireland, 14–17 September 2011. Cytometry, 80B: 390–429. doi: 10.1002/cyto.b.20619

Original languageEnglish
Publication year20 Sep 2011
Number of pages1
Publication statusPublished - 20 Sep 2011

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