Serum immunoglobulin E reactivity to cross-reacting panallergen components in north-eastern Poland patients pollen sensitized.

Background: The presence of immunoglobulin E (IgE), which cross-reacts with allergen components, such as profilins, polcalcins, and cross-reacting carbohydrate determinants (CCD), creates a problem when selecting patients for allergen immunotherapy by using conventional methods. The aim of this study was to evaluate the prevalence of sensitization to profilins, polcalcins, and CCDs in patients with seasonal pollen allergic rhinitis. Methods: The study was performed on a group of 112 patients with seasonal pollen allergic rhinitis, ages 14 to 55 years, with sensitization to at least one seasonal allergen (IgE > 0.7 kUA/L). The presence of IgE sensitization to recombinant (r) Bet v 2, rPhl p 12, rBet v 4, rPhl p 7, and CCDs, in addition to rBet v 1, rPhl p 1, rPhl p 5, was evaluated by using a multiparameter immunoblot. Results: Among the studied patients, 64.3, 80.4, and 41.1% were sensitized to birch, timothy grass, and mugwort pollen, respectively. Sensitization to profilins rBet v 2/Phl p 12 was demonstrated in 28.6%, to polcalcins Bet v 4/Phl p 7 in 8.9%, and to CCDs in 25%. In 29.3%, serum IgE reactivity to any of the cross-reactive components could be demonstrated. Serum IgE reactivity to rBet v 2 was always accompanied by IgE reactivity to rPhl p 12, and IgE reactivity to rBet v 4 was always accompanied by IgE reactivity to rPhl p 7. Among the patients with pollinosis co-sensitized to at least two allergen sources according to extract-based diagnosis, possible false-positive results due to sensitization to cross-reactive components were detected in 17.9%. Conclusion: Evaluation of sensitization to cross-reacting components may be useful in evaluation of patients with pollen allergy who are being assessed for allergen immunotherapy to optimize the constitution of their immunotherapy vaccines.

Synergistic effect of Dermatophagoides pteronyssinus allergens and dexamethasone on the expression of CD163 by peripheral blood mononuclear cells.

BACKGROUND: The CD163 is a marker of monocyte/macrophage anti-inflammatory function. Its soluble form (sCD163) also exert anti-inflammatory activities including inhibition of T cell proliferation. OBJECTIVE: To evaluate the effect of dexamethasone (Dx) and Dermatophagoides pteronyssinus (Dp) on ex vivo production of sCD163 by peripheral blood mononuclear cells (PBMCs). METHODS: PBMCs from 26 allergic asthma patients (AAs) and 12 non-atopic healthy controls (HCs) were cultured with Dp, Dx, Dp + Dx or without any stimulation for up to 144 h (T144). Concentration of sCD163, interleukin (IL) -6 and IL-10 in PMBC culture supernatants was evaluated using ELISA. The mRNA expression of CD163 by PBMCs was estimated using quantitative PCR (qPCR). RESULTS: At T144 the median concentration of CD163 in unstimulated PBMC cultures of AAs was greater than that in HCs (p = 0.008). Concomitant application of Dp and Dx resulted in a synergistic effect reflected by a dramatic increase of sCD163 concentration both in HCs (p = 0.0002) and AAs (p < 0.0001). Also a synergistic effect of Dp and Dx on CD163 mRNA expression was seen at T24 and T48 but not at T6 or T12. Among asthmatic patients the effect of Dx on sCD163 production was attenuated in severe in comparison to mild-to-moderate AAs (p = 0.0007). Moreover, Dp-induced production of IL-6 but not IL-10 was inhibited by Dx (p < 0.0001). Inhibition of IL-10 decreased sCD163 concentration by more than 50%. CONCLUSIONS: Dx-triggered upregulation of anti-inflammatory CD163 expression by monocytes is synergistic with endogenous mechanisms involved in the resolution of Dp-induced inflammation. This effect is impaired in severe asthma patients.

The role of 12/15-lipoxygenase in production of selected eicosanoids in allergic airway inflammation.

PURPOSE: To evaluate the role of 12/15-lipoxygenase (LOX) in regulation of synthesis of selected eicosanoids in mice sensitized and challenged with Dermatophagoides pteronyssinus (Dp) allergen extract. MATERIALS AND METHODS: Both C57Bl and 12/15-LOX knockout mice were sensitized by 2 intraperitoneal injections and subsequently challenged by inhalation with Dp allergen extract. Sham sensitized and challenged mice were used as controls. Samples of bronchoalveolar lavage (BAL) were used for assessment of prostaglandin E2 (PGE2), cysteinyl leukotreienes (cysLT), lipoxin A4 (LXA4) and 15-hydroxyeicosatetraenoic acid (15-HETE) concentration using ELISA method. Whole lung samples were used for isolation of RNA and evaluation of selected genes involved in eicosanoid metabolism, including cyclooxygenase-2 (COX-2), 12/15-LOX, 5-LOX and 5-LOX activated protein (FLAP). RESULTS: Allergen-induced airway inflammation was associated with significant (9-fold, 95% CI 8.068-9.932-fold; p<0.05) up-regulation of 12/15-LOX in wild type but not in the 12/15-LOX knockout mice in which 12/15-LOX mRNA remained undetectable. Lack of 12/15-LOX was associated with significant attenuation of production of 15-HETE in response to allergen challenge. On the contrary, the greatest up-regulation of COX-2 after allergen exposure was demonstrated in the 12/15-LOX knockout mice (4.3-fold vs sham group) and was significantly greater than in the wild type counterparts (5.185-fold, 95% CI 4.723-6.309-fold; p<0.05 vs wild type mice). Also, allergen challenged 12/15-LOX knockout mice were characterized by greater production of PGE2 and cysLT. CONCLUSION: The 12/15-LOX plays an important role in the metabolism of eicosanoids in response to allergen-induced airway inflammation.