Levocetirizine modulates lymphocyte activation in patients with allergic rhinitis

Long-term effects of ciclosporin and oclacitinib on mediators of tolerance, regulatory T-cells, IL-10 and TGF-β, in dogs with atopic dermatitis

BACKGROUND

Atopic dogs often are managed with allergen-specific immunotherapy (AIT) and concurrent dosages of ciclosporin (CSA) or oclacitinib to alleviate their clinical signs. Both drugs might affect proper tolerance induction by inhibiting regulatory T-cell (Treg) induction.

HYPOTHESIS/OBJECTIVES

We evaluated Treg cell numbers and serum interleukin (IL)-10 and transforming growth factor-beta (TGF-β)1 levels in dogs diagnosed with atopic dermatitis (AD) and successfully treated with either CSA or oclacitinib for nine or more months.

ANIMALS

We included 15 dogs receiving oclacitinib, 14 dogs treated with CSA, 15 healthy dogs, 13 dogs with untreated moderate-to-severe AD and 15 atopic dogs controlled with AIT.

MATERIALS AND METHODS

Peripheral blood CD4+CD25+FOXP3+ T-cell percentages were determined using flow cytometry. Serum concentrations of IL-10 and TGF-β1 were measured by enzyme-linked immunosorbent assay.

RESULTS

The percentage of Treg cells in the CSA group was significantly lower in comparison with the healthy group (p = 0.0003), the nontreated AD group (p = 0.0056) or the AIT group (p = 0.0186). There was no significant difference in Treg cell percentages between the CSA and oclacitinib groups, nor between the oclacitinib and the healthy, nontreated AD or AIT-treated dogs. No significant differences were detected in IL-10 and TGF-β1 serum concentrations between the five groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Lower Treg cell percentages in the CSA-treated dogs suggest an impact of this drug on this cell population; however, it does not necessarily mean that it diminishes tolerance. Functionality and cytokine production may be more important than the number of Treg cells. Further studies evaluating the treatment outcome of dogs receiving AIT and concurrent drugs are needed to show clinical relevance.

Baicalin modulates immuno-inflammatory response in patients with ulcerative colitis

AIM: To evaluate the mechanisms underlying the therapeutic effect of baicalin on ulcerative colitis (UC) in terms of its effect on CD4⁺CD29⁺ T helper cells, surface markers and serum inflammatory cytokines.

METHODS: Flow cytometry was used to detect the percentage of CD4⁺CD29⁺ cells in patients with UC. Real-time polymerase chain reaction (PCR) was used to detect the expression of GATA-3, forkhead box P3 (FOXP3), T-box expressed in T cells (T-bet), and retinoic acid-related orphan nuclear hormone receptor C (RORC). Western blot was used to analyze the expression of nuclear factor-kappa B (NF-κB) p65, p-NF-κB p65, STAT4, p-STAT4, STAT6, and p-STAT6. The concentrations of interferon γ (IFN-γ), interleukin (IL)-4, IL-5, IL-6, IL-10, and tumor growth factor-β (TGF-β) in serum were determined by ELISA assay.

RESULTS: The percentages of CD4⁺CD29⁺ T cells were significantly lower in cells treated with 40 and 20 μmol/L baicalin than in untreated cells. Treatment with 40 or 20 μmol/L baicalin significantly upregulated the expression of IL-4, TGF-β1 and IL-10, increased the p-STAT6/STAT6 ratio, but downregulated the expression of IFN-γ, IL-5, IL-6, RORC, FOXP3, and T-bet, and decreased the ratios of T-bet/GATA-3, p-STAT4/STAT4, and p-NF-κB/NF-κB compared to those in untreated cells.

CONCLUSION: Baicalin regulates immune balance and relieves UC induced inflammation response possibly by promoting the proliferation of CD4⁺CD29⁺ cells and modulating immunosuppressive pathways.

Levocetirizine inhibits migration of immune cells to lymph nodes and induces treg cells in a murine type I allergic conjunctivitis model

Background & Purpose:

Levocetirizine is a histamine H(1) receptor antagonist. Here, we utilised DO11.10TCR transgenic mice to establish an antigen-specific T cell-dependent allergic conjunctivitis (AC) model to determine the effect of the topical application of an ophthalmic formulation of Levoceritizine as a treatment for AC.

Experimental Approach:

DO11.10 mice (n=6/each) were exposed to ovalbumin (OVA, 50 µg) and treated with a Levocetirizine ophthalmic formulation (0.001–0.02% v/w) or placebo (vehicle) for 24–72 h. Serum, aqueous/vitreous humour and conjunctiva were obtained. Immunoglobulin (Ig)-E, interleukin (IL)-10 and lipoxin (LX)A₄ were determined by ELISA. Levels of tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interferon (IFN)-γ and 18rS expression were measured by RT-PCR. Proportions of total and activated antigen-presenting cells (APC), recruited T lymphocytes (CD4+), activated T lymphocytes (CD25+) and T regulatory cells (Treg) were measured by flow cytometry.

Key Results:

OVA exposure induced AC in the animal model indicated by increased expression of LXA₄, TNF-α and TGF-β. Levocetirizine treatment (0.01–0.02% v/w) reduced LXA₄ in the eye humours. This treatment approach increased systemic IL-10 secretion and reduced TNF-α and TGF-β expression in conjunctiva without changing IFN-γ expression. Levocetirizine reduced APC levels in draining lymph nodes but increased the proportion of total lymphocytes recruited and their differentiation to Treg cells.

Conclusions & Implications:

Levocetirizine effectively reduces the activation and migration of APC to local draining lymph nodes and induces differentiation of Treg cells as one possible mechanism of its anti-inflammatory action.

Therapeutic hotline. Effectiveness of the association of cetirizine and topical steroids in lichen planus pilaris--an open-label clinical trial

Lichen planus is considered a T cell-mediated immunological disease. Even mast cells may contribute to the pathogenesis of the disease. Keratinocytes of the basal layer of the skin and/or the hair follicle may represent the "target/victim" of an immune aggression, determining the destruction of the hair follicle and thus scarring alopecia. Therefore, there is a compelling urgency for effective treatment of this potentially disfiguring dermatosis. Our data provide a further therapeutic opportunity: the use of an antihistaminic drug--cetirizine (CTZ)--in an "anti-inflammatory" regimen. We propose the use of CTZ at the dosage of 30 mg/daily. Twenty-one patients affected by lichen planus pilaris (LPP) of the scalp have been treated. Topical application of steroids has been coadministered in all cases during the therapy. Clinical effects, in the sense of stabilization with cessation of the inflammation (erythema, follicular hyperkeratosis, loss of anagen hair), were achieved in all patients but three. One patient developed cardiac arrhythmia after 3 months of successful treatment and dropped out. Our cases indicate that a combined therapy of topical steroid with CTZ can be a safe and effective choice even in severe cases of lichen planus pilaris, so often refractory to the therapy.

Levocetrizine has anti-inflammatory effects against Toll-like receptor (TLR)3 through the inhibition of Toll-IL-1 receptor (TIR)-domain-containing adapter inducing IFN-beta (TRIF) and receptor-interacting protein (RIP)

OBJECTIVE

To investigate the anti-inflammatory effect of levocetrizine (LCEZ) on the intracellular adhesion molecule-1 (ICAM-1) in human nasal epithelial cells stimulated by TLR3 and further analyze the anti-inflammatory mechanism of LCEZ in the MyD88-independent pathway before NF-κB is activated.

METHODS

A primary culture of human nasal epithelial cells (HNECs) was generated from nasal polyps. After stimulation of epithelial cells with LTA, double-stranded RNA (dsRNA), and LPS, reverse transcription-polymerase chain reaction (RT-PCR) was performed at 1, 6, and 24 h to clarify the optimal stimulation of ICAM-1 in HNECs. To investigate the anti-inflammatory effects of LCEZ, HNECs were pretreated with three different concentrations of LCEZ (500, 50, and 5 nM) for 2 h. HNECs were washed and then stimulated with dsRNA. At 1, 6, and 24 h after stimulation, the level of ICAM-1 was measured by RT-PCR and ELISA. Western blots for TRIF and RIP were performed.

RESULTS

The level of ICAM-1 was significantly elevated by dsRNA. Pretreatment with LCEZ decreased the secretion of ICAM-1, which was observed in RT-PCR and Western blots but not in ELISA analyses. The expression of TRIF and RIP, measured by Western blot, was decreased by pretreatment with LCEZ.

CONCLUSION

The activation of HNECs by TLRs (especially TLR3) could trigger an inflammatory process, which might be inhibited by LCEZ through the suppression of TRIF and RIP proteins.

Histamine in allergic rhinitis

Histamine plays a major role in allergic rhinitis. In susceptible individuals, allergen induces nasal mast cell degranulation and the release of histamine into the nasal mucosa. Histamine has been detected after controlled challenges with allergen and, when administered into the nasal cavity, elicits signs and symptoms similar to those elicited by allergen. All four histamine receptors have been demonstrated in the nasal mucosa. The role of the four histamine receptors in the pathophysiology of allergic rhinitis are discussed.

The anti-inflammatory effects of levocetirizine--are they clinically relevant or just an interesting additional effect?

Levocetirizine, the R-enantiomer of cetirizine dihydrochloride has pharmacodynamically and pharmacokinetically favourable characteristics, including rapid onset of action, high bioavailability, high affinity for and occupancy of the H1-receptor, limited distribution, minimal hepatic metabolism together with minimal untoward effects. Several well conducted randomised clinical trials have demonstrated the effectiveness of levocetirizine for the treatment of allergic rhinitis and chronic idiopathic urticaria in adults and children. In addition to the treatment for the immediate short-term manifestations of allergic disease, there appears to be a growing trend for the use of levocetirizine as long-term therapy. In addition to its being a potent antihistamine, levocetirizine has several documented anti-inflammatory effects that are observed at clinically relevant concentrations that may enhance its therapeutic benefit. This review will consider the potential or otherwise of the reported anti-inflammatory effects of levocetirizine to enhance its effectiveness in the treatment of allergic disease.

Levocetirizine in the treatment of allergic diseases

BACKGROUND

Levocetirizine, the R-enantiomer of cetirizine dihydrochloride, is a new molecule with a potent and selective antihistamine activity.

OBJECTIVE

To investigate the evidence that levocetirizine is an effective therapy for allergic disease.

METHODS

Evaluation of published articles in English, or having an English abstract.

RESULTS

Clinical trials indicate that levocetirizine is safe and effective for the treatment of allergic rhinitis and chronic idiopathic urticaria. The compound shows a rapid onset of action, high bioavailability and affinity for the H1 receptor. Moreover, this molecule demonstrates many anti-inflammatory effects that enhance the clinical therapeutic benefit not only in short-term but also in long-term treatments, as reported in recent trials utilizing levocetirizine for several months.

CONCLUSION

Levocetirizine confirms its safe effective activity for treatment of allergic disease in both adults and children.

A review of the efficacy of desloratadine, fexofenadine, and levocetirizine in the treatment of nasal congestion in patients with allergic rhinitis

BACKGROUND

Nasal congestion is the most troublesome symptom of allergic rhinitis (AR). First-generation and older second-generation antihistamines, while effective against nasal itching, sneezing, and rhinorrhea, have limited efficacy in relieving nasal congestion.

OBJECTIVE

This review included nasal challenge studies and clinical trials that reported the effects on nasal congestion of the newer second-generation antihistamines desloratadine, fexofenadine, and levocetirizine.

METHODS

MEDLINE and EMBASE were searched for nasal challenge studies and clinical trials published in English between January 1, 1991, and January 31, 2009, using the following terms, alone or in combination: antihistamines, second-generation antihistamines, allergic rhinitis, intermittent allergic rhinitis, perennial allergic rhinitis, persistent allergic rhinitis, seasonal allergic rhinitis, nasal challenge, nasal blockage, and nasal congestion. Studies that were not active or placebo controlled, that did not evaluate change in nasal congestion scores, or that focused on treatments other than desloratadine, fexofenadine, and levocetirizine for nasal congestion associated with AR were excluded.

RESULTS

Twenty-six clinical trials met the criteria for inclusion in the review. In 11 placebo-controlled trials that included objective assessment of nasal congestion, desloratadine, fexofenadine, and levocetirizine were associated with reductions in the severity of nasal congestion through maintenance of nasal airflow. The mean AUC for nasal airflow over 6 hours was significantly greater with desloratadine compared with placebo in 3 studies (P < 0.05); placebo-controlled trials of fexofenadine and levocetirizine had similar results. In 25 placebo- and active-controlled trials that reported subject-rated symptom scores, the 3 newer antihistamines were efficacious in the treatment of nasal congestion associated with AR. In 10 trials that reported objective and/or subjective measures, desloratadine was associated with significant improvements in nasal congestion compared with placebo (P < or = 0.05), beginning as early as the first 2 hours after allergen challenge. Fexofenadine was associated with significantly lower nasal congestion scores compared with placebo in 4 studies (P <- 0.05); nasal congestion scores were significantly reduced with levocetirizine in 3 placebo-controlled trials (P < or = 0.005).

CONCLUSIONS

In the studies reviewed, desloratadine, fexofenadine, and levocetirizine were effective in relieving the nasal congestion associated with AR compared with placebo. This effect began as early as day 2 and was consistent and progressive throughout treatment. Desloratadine, fexofenadine, and levocetirizine are appropriate options for the treatment of nasal congestion in patients with AR.

Histamine H1-receptor antagonists with immunomodulating activities: potential use for modulating T helper type 1 (Th1)/Th2 cytokine imbalance and inflammatory responses in allergic diseases

Being a first-line treatment for hypersensitivity allergic disease, histamine H1-receptor antagonists possess anti-inflammatory activity in addition to being H1-receptor antagonists. While it is not purely a histamine-related condition, hypersensitivity allergic disease is associated with an increase in the number of T helper type 2 (Th2) cells and Th2 cytokines, and a decrease in the number of Th1 cells and Th1 cytokines. Suppression of Th2-type cytokine production in addition to H1-receptor blockade may therefore represent a successful therapeutic strategy for the treatment of hypersensitivity allergic diseases. H1-receptor antagonists have been reported to modulate immune cascade at various points by acting on T cell-related inflammatory molecules, including adhesion molecules, chemokines and inflammatory cytokines. These effects of H1-receptor antagonists may be optimized for the treatment of allergic diseases. Besides their ability to regulate inflammatory molecules, some H1-receptor antagonists have been reported to down-regulate Th2 cytokine production. In particular, it has been shown that several H1-receptor antagonists specifically inhibit the production of Th2, but not Th1, cytokines. Accumulating evidence indicates a crucial role for Th1/Th2 cytokine imbalance on the development of allergic diseases. Accordingly, the use of H1-receptor antagonist with Th2 cytokine inhibitory activity to modulate Th1/Th2 cytokine imbalance might be a favourable strategy for the treatment of hypersensitivity allergic diseases. Furthermore, the identification of H1-receptor antagonists which possess immunoregulatory activities in addition to their anti-histamine activity will provide an important insight into the development of novel immunoregulatory drugs.