Chemokines during anaphylaxis : the importance of CCL2 and CCL2-dependent chemotactic activity for basophils

Background: The role of chemokines in anaphylaxis is unclear. Methods: We prospectively recruited 49 patients presenting to the emergency department with an acute episode of anaphylaxis and 28 healthy subjects. We measured serum levels of the chemokines CCL2, CCL5, CCL7, CCL8, CCL11, CCL13, CCL17, CCL21, CCL22, CCL24, and CCL26, tryptase, the absolute number of circulating basophils, monocytes, lymphocytes, and PMNs, and whole blood FCER1A, CPA3 and HDC gene expression at two time points: during the anaphylactic episode and in convalescent samples collected approximately 3 months later. We then investigated the in vitro chemotactic activity of chemokines induced during anaphylaxis for the in vitro migration of the corresponding cells. Results: Only CCL2 chemokine levels were signifcantly increased in anaphylaxis samples (median 514 pg/ml) compared to convalescent samples (284 pg/ml, P<0.0001) and healthy subjects (279 pg/ml, P<0.0001)there was no signifcant diference in any of the other chemokines. There was a signifcant positive correlation between the rates of increase of serum CCL2 (median [range]: 106.0% [-44.7% to 557.4%]) and tryptase (133.8% [-6.6% to 893.4%]r=0.68, P<0.0001) and between the acute concentration of serum CCL2 and the acute concentration of serum tryptase (r=0.77, P<0.0001). The number of circulating basophils, but not other blood cells, signifcantly decreased during anaphylaxis (median 5.0 vs. 19.1 cells/[micro]l in convalescent samplesP<0.0001)a decrease in whole-blood gene expression of basophil markers (P</=0.0018) confirmed these changes. Anaphylactic serum enhances the in vitro migration of basophils via CCL2-dependent chemotactic activityin contrast, no CCL2-dependent chemotactic activity was observed for convalescent samples. Conclusions: Our findings imply an important and specifc role for CCL2-mediated chemotactic activity in the pathophysiology of human anaphylaxis

Down-regulation of FcεRI-mediated CD63 basophil response during short-term VIT determined venom-nonspecific desensitization.

BACKGROUND: We recently showed a desensitization of FcεRI-mediated basophil response after short-term VIT. Our aim was to evaluate the allergen specificity of this desensitization. METHODS: In 11 Hymenoptera-venom double positive subjects, basophil threshold sensitivity (CD-sens) to anti-FcεRI, honeybee, and Vespula venom was assessed at the beginning and just before the first maintenance dose (MD) of single ultra-rush VIT. In some patients we also monitored CD-sens to rApi m 1 and/or rVes v 5 or other co-sensitizations (i.e., grass pollen). In additional 7 patients, basophils were stripped and sensitized with house dust mite (HDM) IgEs at the same time points. RESULTS: We demonstrated a marked reduction of CD-sens to anti-FcεRI and VIT-specific venom before the first MD in all 18 subjects included. Furthermore, in 10 out of 11 double positive subjects, a significant and comparable decrease before the first MD was also evident for non-VIT venom; this nonspecific decrease was further supported by the opposite recombinant species-specific major allergen. In one subject with additional grass pollen allergy, a decrease of CD-sens to grass allergen was also demonstrated. Similarly, in 7 cases of patients with passively HDM-sensitized basophils, a significant reduction of CD-sens was also evident to de novo sensitized HDM allergen. CONCLUSIONS: Short-term VIT induced basophil desensitization to VIT-specific as well as to VIT-nonspecific venom. As opposed to long-term VIT, which induces venom-specific changes, the effect of short-term VIT seems to be venom-nonspecific

Patch testing with the European baseline series and 10 added allergens : single centre study of 748 patients

Background. The European baseline series (EBS) of contact allergens is subject to change. An allergen is considered for inclusion when routine patch testing of patients with suspected contact dermatitis results in ≥ 0.5% prevalence rate. Objectives. We aimed to determine the frequency of sensitizations to 30 EBS allergens and 10 locally added allergens. Additionally, we assessed the strength and evolution of reactions to all tested allergens and co-reactivity of additional allergens. Methods. Patch testing with our baseline series of 40 allergens was done in 748 consecutive adults. Tests were applied to the upper back and removed by patients after 48 hours. Readings were done on day 3 (D3) and D6 or D7 (D6/7). Positive reactions fulfilled the criteria of at least one plus (+) reaction. Retrospective analysis was done. Results. Eight allergens not listed in the EBS had ≥ 0.5% prevalence rate (i.e., cocamidopropyl betaine, thiomersal, disperse blue mix 106/124, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, propylene glycol, Compositae mix II, and dexamethasone-21-phosphate), and 16.6% of positive reactions would have been missed without D6/7 readings. Conclusion. We propose further studies to evaluate whether cocamidopropyl betaine, disperse blue mix 106/124, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, and Compositae mix II need to be added to the EBS

A–F. Basophil response to recombinant species-specific major allergens.

<p>CD63 basophil dose-response curves in double positive patients nos. 6 and 10 in <b>A</b> to anti-FcεRI in <b>B</b> to honeybee and in <b>C</b> to rVes v 5 stimulation before treatment and the first maintenance dose of honeybee ultra-rush VIT and in double positive patient no. 7 in <b>D</b> to anti-FcεRI in <b>E</b> to rVes v 5 and in <b>F</b> to rApi m 1 stimulation before treatment and the first maintenance dose of <i>Vespula</i> ultra-rush VIT.</p

A–F. Passive IgE sensitization (dose-response curves).

<p>CD63 basophil dose-response curves in patients nos. 12–18 in <b>A</b> and <b>D</b> to anti-FcεRI in <b>B</b> and <b>E</b> to VIT venom and in <b>C</b> and <b>F</b> after passive IgE sensitization of stripped basophils also to house dust mite stimulation, all before treatment and the first maintenance dose of ultra-rush VIT.</p

A–C. Passive IgE sensitization (CD-sens).

<p>CD-sens in in patients nos. 12–18 in <b>A</b> to anti-FcεRI in <b>B</b> to VIT venom and in <b>C</b> after passive IgE sensitization of stripped basophils also to house dust mite stimulation before treatment and the first maintenance dose of ultra-rush VIT. Data are presented as median values with interquartile range. *<i>P</i><.05.</p

A–C. Basophil threshold sensitivity (CD-sens).

<p>Basophil threshold sensitivity (CD-sens) in 11 double and 7 single positive subjects in <b>A</b> to anti-FcεRI and in <b>B</b> to VIT venom and in 11 double positive subjects in <b>C</b> to non-VIT venom stimulation before treatment and the first maintenance dose of single ultra-rush VIT. Data are presented as median values with interquartile range. **<i>P</i><.01 ***<i>P</i><.001.</p

Clinical data, sIgE and BAT in double positive subjects.

<p>M: male, F: female, HB(V): Honeybee (venom), V(V): <i>Vespula</i> (venom).</p><p>LLR: large local reaction, nk: the degree of reaction after the sting is not known.</p><p>Diagnostic BAT: the threshold value for diagnostically positive results was defined as 15% of CD63-positive basophils <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094762#pone.0094762-itnik1" target="_blank">[20]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094762#pone.0094762-Koroec2" target="_blank">[22]</a>.</p><p>*Patient with additional grass pollen sensitization: skin prick test (mixed grasses; HAL Allergy) pos; sIgE Timothy (g6): 31.1 kUA/L; rPhl p 1,5b (g213): 9.15 kUA/L.</p><p>All sIgE were measured with ImmunoCAP-FEIA (Phadia, Thermo Fisher Scientific, Uppsala, Sweden).</p

Clinical data, sIgE and BAT in subjects for passive IgE sensitization.

<p>M: male, F: female, HB(V): Honeybee (venom), V(V): <i>Vespula</i> (venom).</p><p>Diagnostic BAT: the threshold value for diagnostically positive results was defined as 15% of CD63-positive basophils <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094762#pone.0094762-itnik1" target="_blank">[20]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0094762#pone.0094762-Koroec2" target="_blank">[22]</a>.</p><p>All sIgE were measured with ImmunoCAP-FEIA (Phadia, Thermo Fisher Scientific, Uppsala, Sweden).</p