Influence of specific immunotherapy on the activity of human T lymphocyte Kv1.3 voltage-gated potassium channels in insect venom allergic patients.

Kv1.3 channels play an important role in T lymphocytes function. CD4(+) and CD4(+)CD25(+) T cells are two broad categories of T cells that are critically involved in the immunoresponse to allergens and that are also a major target for allergen immunotherapy. The aim of the study was to evaluate the effects of venom immunotherapy (VIT) on the activity of Kv1.3. channels on noncultured subsets: CD4(+) and CD4(+)CD25(+) T cells of insect venom allergic patients. Eleven patients with allergic reactions to bee or wasp venoms participated in the study. The patients were provided VIT according to the ultrarush protocol. CD4(+) and CD4(+)CD25(+) T cells were isolated from peripheral blood mononuclear cells of VIT-treated patients by an immunomagnetic method. We used the whole-cell patch clamp technique to investigate the whole potassium chord conductance (gK) of Kv1.3. channels in CD4(+) and CD4(+)CD25(+) T cells of venom-sensitive patients before and during the course of VIT. The conductance of Kv1.3. channels on CD4(+)CD25(+) T cells decreased during the course of VIT. On day 0 it was 0.054 ± 0.07 [nS], and on day 70 it was 0.008 ± 0.09 [nS] (P = 0.03). The observed decrease of the gK of the Kv1.3 channels in the subpopulation of activated T cells may contribute to T cell tolerance and functional unresponsiveness of these cells to allergen in the early stages of VIT.

9α,11ß-PGF2, a Prostaglandin D2 Metabolite, as a Marker of Mast Cell Activation in Bee Venom-Allergic Patients.

Mast cell (MC) mediators, among them prostaglandin D2 (PGD2) and 9α,11ß-PGF2, PGD2's metabolite, play a key role in allergic reactions, including bee venom anaphylaxis (BVA). Assessment of these mediators has never been performed in BVA. The aim of the study was to assess the activation of MC during in vivo provocation with bee venom (BV) and to measure PGD2 and 9α,11ß-PGF2 in the course of an allergen challenge. The second aim was to determine if assessment of these mediators could be useful for predicting adverse events during venom immunotherapy (VIT). In 16 BV-VIT patients and 12 healthy subjects, levels of PGD2 and 9α,11ß-PGF2 were assessed during BV provocation by means of the skin chamber method. Chamber fluids, collected at 5 and 15 min, were analyzed for both mediators by gas chromatography mass spectrometry negative ion chemical ionization. BVA in comparison to non-allergic patients had a significantly higher ratio of 9α,11ß-PGF2 in allergen-challenged chambers to 9α,11ß-PGF2 in allergen-free chambers after 15 min of provocation (p = 0.039). Allergen challenge resulted in a significant increase of 9α,11ß-PGF2 levels between 5 and 15 min after provocation only in BVA patients (p < 0.05). Analysis of log-transformed PGD2 levels showed significant difference between changes in PGD2 concentration between BVA and healthy subjects. No study patient developed adverse reactions during. 9α,11ß-PGF2 is actively generated during the early allergic response to BV. Skin chamber seems to be a promising, non-invasive and safe model of in vivo allergen provocation in BV-allergic patients. High or low levels of both mediators do not predict occurrence of adverse events during VIT.