Accumulation of CRTH2-positive leukocytes in human allergic nasal mucosa

BACKGROUND

Prostaglandin D2 (PGD2) has been thought to be a potent mediator involved in allergic rhinitis because PGD2 has been recovered from the nasal lavage fluid of patients with allergic rhinitis after allergen provocation and because PGD2 receptor antagonists relieved nasal allergic symptoms in an animal model of allergic rhinitis. The inflammatory effects of PGD2 are exerted through high-affinity interactions with 2 G protein-coupled receptors: D-prostanoid receptor 1 and chemoattractant-homologous receptor expressed on TH2 cells (CRTH2). CRTH2 may mediate the recruitment of leukocytes during a nasal allergic response.

OBJECTIVE

To evaluate the number of CRTH2-expressing cells in allergic and nonallergic human nasal mucosa by means of immunohistochemical analysis.

METHODS

Human turbinates were obtained after turbinectomy from 14 patients with nasal obstruction refractory to medical therapy. To identify cells expressing the CRTH2 protein, double immunostaining was performed using anti-CRTH2 antibody and monoclonal anti-leukocyte antibodies.

RESULTS

The immunohistochemical study revealed that anti-CRTH2 antibody labeled eosinophils, macrophages, mast cells, T lymphocytes, epithelial cells, and submucosal glands in the nasal mucosa. CRTH2 expressions of these leukocytes in allergic nasal mucosa are significantly up-regulated compared with those in nonallergic nasal mucosa.

CONCLUSION

These results suggest that CRTH2 may play an important role in the recruitment of leukocytes into allergic nasal mucosa.

[evaluation of relationships between foods and pollen antigens in peach oral allergy patients -serous specific IgE levels of peach recombinant Antigen-]

PURPOSE

Evaluation of the relationships between foods and pollen allergens in oral allergy syndrome (OAS).

METHODS

Serous level of specific IgE against recombinant peach allergens (rPru p 1, rPru p 3 and rPru p 4) in 17 peach OAS patients were examined by Pharmacia CAP RASTsystem.

RESULTS

In 17 pollinosis patients, the number of patients positive to peach, rPru p 1, rPru p 4 and rPru p 3 RAST were 13 (76%), 14 (82%), 6 (35%) and 0 (0%), respectively. The RAST value of rPru p 1 was significantly correlated with that of natural birch pollen extract (r=0.745, p=0.0003), but not with that of mugwort pollen extract. The RAST value of rPru p 4 was significantly correlated with that of mugwort pollen extract (r=0.602, p=0.0092), but not with that of natural birch pollen extract.

CONCLUSION

Concerning to peach OAS, the most important cross-reactive antigen is Pru p 1 in birch pollinosis, and is Pru p 4 in mugwort pollinosis.

Cysteinyl leukotriene receptor CysLT1 as a novel therapeutic target for allergic rhinitis treatment

BACKGROUND

Cysteinyl leukotrienes (cys-LTs) play an important role in allergic rhinitis because CysLT(1) receptor antagonists relieve the symptoms of allergic rhinitis.

OBJECTIVE

I overview the clinical pharmacology of CysLT(1) receptor antagonists and their potential role in patients with allergic rhinitis.

METHODS

I review the evidence regarding the release of cys-LTs and localization of CysLT(1) receptor on nasal mucosa, and evaluate the clinical efficacy of CysLT(1) receptor antagonist in allergic rhinitis.

RESULTS/CONCLUSION

Immunohistochemical studies show that in allergic rhinitis, the major target of CysLT(1) receptor antagonists are the vascular bed and infiltrated leukocytes such as mast cells, eosinophils and macrophages. CysLT(1) receptor antagonists provide a new opportunity for simultaneous management of allergic diseases of the upper and lower respiratory tract.

Platelet-activating factor (PAF) increases NO production in human endothelial cells-real-time monitoring by DAR-4M AM

BACKGROUND

Platelet-activating factor (PAF) is a potent inflammatory lipid mediator that increases vascular permeability and vasodilation. Several studies have addressed the effect of PAF on nitric oxide (NO) production from microvessels in vivo.

OBJECTIVE

The aim of present study was to evaluate the effect of PAF on NO production in primary cultured human vascular endothelial cells.

METHODS

Human umbilical vein endothelial cells (HUVECs) were loaded with diaminorhodamine-4M acetoxymethyl ester (DAR-4MAM), and the cells were stimulated with PAF. Intracellular NO production was monitored as increase in fluorescence intensity. Also, NO production was visualized at cellular levels using DAR-4M AM and fluorescence imaging.

RESULTS

Significant increases in NO production in HUVECs were soon after the PAF stimulation, reaching a plateau after 10 min of the stimulation. The increase of NO production at 10 min after the stimulation was statistically significant (p<0.05) for 0.01-10 microM PAF. PAF-induced NO production was abolished by pretreatment of HUVECs with a NOS inhibitor N(G)-monomethyl-L-arginine (L-NMMA) or PAF receptor antagonist BN 52021. LysoPAF, the inactive metabolite of PAF, did not exert a significant effect on intracellular NO levels.

CONCLUSIONS

These results provide direct evidence that PAF cause intracellular NO production via activation of PAF receptors in human vascular endothelial cells.

Detection of specific IgE antibodies in sera of Japanese birch-allergic patients using recombinant allergens Bet v 1, Bet v 2 and Bet v 4

BACKGROUND

Birch pollen is the major allergen in pollinosis in northern Japan. IgE reactivity to individual birch pollen allergens has been shown to differ between populations of birch pollen-allergic patients living in different countries. In this study, we examined the IgE profiles to recombinant birch pollen allergens in birch-sensitive patients living in Sapporo.

METHODS

This study used the sera of 40 patients with specific IgE toward birch pollen extract. Their sera were analyzed for specific IgE reactivity to individual birch pollen allergens (recombinant Bet v 1, Bet v 2 and Bet v 4) and natural birch pollen extract using Pharmacia CAP SystemTM.

RESULTS

Of 40 sera with positive CAP results for natural birch pollen extract, 39 (97.5%) had specific IgE towards Bet v 1; 6 (15%) contained specific IgE against Bet v 2. Bet v 4 reactivity was documented in only one subject (2.5%).

CONCLUSIONS

The present data suggest that the specific IgE reactivity profiles to birch pollen allergen in birch-sensitive patients in Sapporo correspond to those in Scandinavia, possibly due to the heavy birch pollen exposure in this area. This observation provides useful information for future birch allergen-specific immunotherapy in Japan.

Agonist- and T(H)2 cytokine-induced up-regulation of cysteinyl leukotriene receptor messenger RNA in human monocytes

BACKGROUND

The cysteinyl leukotrienes (CysLTs) are lipid mediators that have been implicated in the pathogenesis of allergic diseases, and their actions are mediated via specific receptors named CysLT1 receptor (CysLT1R) and CysLT2 receptor (CysLT2R). Little information is known about the role of T(H)2 cytokines in the regulation of both CysLT1R and CysLT2R expression.

OBJECTIVE

To investigate the possible modulation of both CysLT1R and CysLT2R messenger RNA (mRNA) expression, we have developed a real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay based on the TaqMan fluorescence method to quantify CysLT1R and CysLT2R mRNA in human monocytes.

METHODS

Human monocytes were stimulated with leukotriene D4 or interleukin (IL) 4 or IL-13, and the levels of CysLT1R and CysLT2R mRNA were measured by the quantitative RT-PCR.

RESULTS

CysLT1R and CysLT2R mRNA was increased after stimulation with leukotriene D4. CysLT1R mRNA was augmented 150-fold after treatment with IL-4; however, no significant increase was observed in CysLT2R mRNA level. IL-13 could induce a biphasic augmentation of CysLT1R mRNA level. In contrast to IL-4, IL-13 enhanced CysLT2R mRNA level, with a maximal effect at 2 hours of incubation.

CONCLUSIONS

CysLT1R and CysLT2R expression can be regulated by CysLT itself and T(H)2 cytokines at the transcriptional level.

Expression and localization of the thromboxane A2 receptor in human nasal mucosa

Thromboxane A2 (TXA2) has been thought a potent mediator involved in allergic rhinitis, because TXA2 was recovered from the nasal lavage fluid of allergic rhinitis patients after allergen provocation and TXA2 receptor antagonists relief nasal allergic symptoms. In order to clarify the expression of TXA2 receptor in human nasal mucosa, we investigated TXA2 receptor mRNA expression and its protein localization by polymerase chain reaction (PCR) and immunohistochemistry, respectively. Human turbinates were obtained after turbinectomy from 10 patients with nasal obstruction refractory to medical therapy. RT-PCR analysis of total RNA from nasal mucosa demonstrated the expression of TXA2 receptor alpha mRNA. The immunohistochemical studies revealed that anti-TXA2 receptor alpha antibody labeled vascular smooth muscle cells, vascular endothelial cells, epithelial cells and submucosal glands in the nasal mucosa. The results may have an important clinical implication for understanding the role of TXA2 receptor on upper airway diseases such as allergic rhinitis and non-allergic rhinitis.

Capsaicin induces the production of IL-6 in human upper respiratory epithelial cells

Capsaicin, a type of alkaloid and the pungent component of chili peppers, is used as a therapeutic drug against allergic rhinitis and also as an index of bronchial hypersensitivity. Capsaicin receptor (TRPV1) expression has been identified in non-neuronal cells as well as neuronal cells. In our previous study, both TRPV1 protein and its gene expression on nasal epithelial cells were confirmed by immunohistochemistry and RT-PCR, respectively. In order to clarify whether or not TRPV1 acts as a functional receptor, we examined the effects of capsaicin on the production of IL-6 from primary cultured human airway epithelial cells at both protein and mRNA levels. Human nasal epithelial cells (HNECs) and normal human bronchial/tracheal epithelial cells (NHBE cells) were stimulated with increasing concentrations of capsaicin and/or pretreatment with capsazepine (TRPV1 antagonist) at 37 degrees C. The supernatant and total RNA were collected at 0, 4, 12, 24 and 48 h after treatment. IL-6 concentration and the IL-6 mRNA level were evaluated by ELISA and real-time PCR, respectively. Capsaicin (10 nM-10 muM) induced production of IL-6 from HNECs and NHBE cells and this effect was inhibited by pretreatment with capsazepine. Our findings suggest that topical application of capsaicin to the airway induces IL-6 production from respiratory epithelial cells via activation of TRPV1.

The MM2-cortical form of sporadic Creutzfeldt-Jakob disease presenting with visual disturbance

A subclass of sporadic Creutzfeldt-Jakob disease (sCJD) characterized by onset with visual symptoms (Heidenhain variant) has been reported to belong to the MM1 or MV1 type according to Parchi's classification. The authors report a 65-year-old woman with MM2-cortical sCJD with slowly progressive visual disturbance as the initial symptom. Diffusion-weighted MRIs revealed hyperintensity in both occipital cortices at an early stage.

Distribution of specific binding sites for cysteinyl leukotriene 1 receptor antagonist in human nasal mucosa

CONCLUSION

The high density of [3H]-pranlukast binding sites on the local leukocytes in human nasal mucosa suggests that CysLT1 receptor antagonists may directly modulate cellular function of the local leukocytes through binding to CysLT1 receptor on allergic nasal mucosa.

OBJECTIVES

The cysteinyl leukotrienes (CysLTs) are lipid mediators that have been implicated in the pathogenesis of allergic diseases. Pharmacological studies using CysLTs indicate that two classes of receptors named CysLT1 and CysLT2 receptor exist. The former is sensitive to the CysLT1 receptor antagonist currently used to treat asthma and allergic rhinitis. To confirm the binding sites of CysLT1 receptor antagonist in human nasal mucosa, the autoradiographic distribution of CysLT1 receptor was studied in human nasal inferior turbinates.

MATERIALS AND METHODS

Cryostat sections were incubated with [3H]-pranlukast for autoradiography. Nonspecific binding was determined by adding unlabelled pranlukast.

RESULTS

Autoradiograms indicated [3H]-pranlukast densely labeled on the interstitial cells. Blood vessels were sparsely labeled. There was no specific labeling in the submucosal glands or epithelium. These results support our previous report from in situ hybridization and immunohistochemistry of CysLT1 receptor.

Expression and localization of TRPV1 in human nasal mucosa

Capsaicin is the pungent principle in chili peppers and previous studies reported that topical application of capsaicin to patients with allergic and non-allergic rhinitis produced significant and long-lasting relief of symptoms. The capsaicin receptor (TRPV1, VR1) is a nociceptive transducer and the existence of TRPV1 in non-neuronal cells as well as neuronal cells has been reported. In order to clarify the role of TRPV1 on the upper airway, we examined the localization and the expression of TRPV1 in human nasal mucosa. Surgically obtained human nasal specimens were processed for immunohistochemistry with commercial anti-TRPV1 antibody. We also performed immunofluorescence with anti-TRPV1 antibody and anti-neurofilament antibody or anti-CD31 antibody. Epithelial cells and vascular endothelial cells were cultured from nasal turbinates, respectively. For RT-PCR analysis, total RNA was isolated, and then RT-PCR was performed. Immunohistochemical studies revealed that TRPV1 positive cells were found on epithelial cells, vascular endothelial cells, submucosal glands and nerves in human nasal mucosa. By RT-PCR analysis, the mRNA expression of TRPV1 was confirmed in human nasal mucosa. These results suggest that capsaicin can directly influence the epithelial secretory and various functions via TRPV1 as well as the activation of the sensory neurons.

[Relationship between pollen allergy and oral allergy syndrome]

We recently evaluated the relationship between pollen allergy and oral and pharyngeal hypersensitivity to fruits and vegetables (oral allergy syndrome) over 8 years (1995 approximately 2002) in Sapporo. 1. Of 843 patients with birch pollen (BP) allergy (CAP score 2 or more), 378 patients (37%) had episodes of oral allergy syndrome (OAS), and the rate in BP allergy was higher than in other allergies. 2. In patients with BP allergy, the most frequent foods causing OAS were apple, peach and cherry, followed by kiwi, pear, plum and melon. BP allergy patients demonstrated much more OAS with these foods than the patients without BP allergy. The higher the CAP score of BP, the higher the incidence of OAS to these foods was found to be. In patients with OAS and BP allergy, the higher the CAP score of BP, the higher the number of foods causing OAS was found to be. 3. In patients with BP allergy, a multiple logistic regression analysis was performed to identify factors affecting the rate of OAS. Positive factors were a high BP CAP score and being female. A negative factor was mite CAP positive. Furthermore, mugwort pollen (MP) CAP positive patients had much more OAS to kiwi and tomato than MP CAP negative patients.

Expression and localization of platelet-activating factor receptor in human nasal mucosa

BACKGROUND

Platelet-activating factor (PAF) has been thought to be a potent mediator of allergic rhinitis because PAF was recovered from the nasal lavage fluid of patients with allergic rhinitis after allergen provocation. Furthermore, PAF receptor antagonist attenuates the antigen-induced increase in nasal airway resistance and nasal vascular permeability in sensitized guinea pigs.

OBJECTIVE

To clarify the expression of PAF receptor in human nasal mucosa by investigating PAF receptor messenger RNA (mRNA) expression and its protein localization using polymerase chain reaction (PCR) and immunohistochemical analyses, respectively.

METHODS

Human turbinates were obtained after turbinectomy from 6 patients with nasal obstruction refractory to medical therapy. Total RNA was isolated from human nasal mucosa, and PAF receptor mRNA was detected in these tissues by using reverse transcriptase-PCR analysis. To identify the cells expressing PAF receptor protein, double immunostaining was performed using anti-PAF receptor antibody and monoclonal antileukocyte antibodies.

RESULTS

Reverse transcriptase-PCR analysis of total nasal RNA demonstrated the expression of PAF receptor mRNA. The immunohistochemical studies revealed that anti-PAF receptor antibody-labeled eosinophils, macrophages, neutrophils, mast cells, lymphocytes, vascular endothelial cells, epithelial cells, and submucosal glands in nasal mucosa.

CONCLUSIONS

These results may have important clinical implications for understanding the role of PAF receptor on upper airway diseases such as allergic and nonallergic rhinitis.

Culture of cells harvested with nasal brushing: a method for evaluating ciliary function

OBJECTIVES

Usefulness and reliability of nasal brush samples in a monolayer cell culture was studied for evaluation of ciliary movement.

METHODS

Cells for cultures were harvested under the middle turbinate from patients with chronic sinusitis and from controls. Ciliary function was analysed using a microscope equipped with a high-speed video camera. Ciliary beat frequency (CBF), ciliary amplitude, waveform and coordination were analysed from the cultures 4-6 h after the harvest of brush samples and 3 days after the culture.

RESULTS

The average success rate of cell cultures was 82.5%. There were not statistically significant differences in CBF between patients and controls but there was significant difference between brush biopsy and cultured brush biopsy in controls. The ciliary beat amplitude and the waveform were normal in all samples in both groups.

CONCLUSIONS

Miniculture method for culturing nasal cells from brush biopsies proved reliable and non-invasive for detailed analysing of ciliary function and for excluding possible secondary ciliary dyskinesia. Compared to conventional mucosal cell cultures where thick and invasive specimens are needed for successful cultures, it is easier and quicker to perform and well tolerated by patients. Thin monolayer cultures enable the evaluation of frequency, amplitude and the waveform of the cilia beat under the microscope whereas floating cells and cell clusters do not give this opportunity.

Expression and localization of steroid receptors in human nasal mucosa

OBJECTIVE

To investigate the expression of glucocorticoid receptor (GR), oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) in nasal mucosa.

MATERIAL AND METHODS

Human turbinates were obtained after turbinectomy from seven patients. The expression and localization of steroid receptors were examined using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

Using RT-PCR, GR and ER alpha mRNA were detected in all cases. In contrast, ER beta, PR and AR mRNA were found in five, four and six cases, respectively. Using immunohistochemistry, antibodies to GR showed the presence of GR within all cells of nasal mucosa, with the highest quantities of GR being localized in epithelial cells, submucosal glands and inflammatory leukocytes. Immunohistochemical analysis of sex steroid receptor revealed that anti-ER alpha antibody labelled mainly mast cells and anti-ER beta antibody labelled submucosal glands, and that no PR or AR expression was detected in any of the samples tested.

CONCLUSIONS

The role of ER in mast cells and submucosal glands has not been well clarified. However, precise knowledge of the identity and distribution of sex steroid receptor should be of considerable interest in understanding the role of sex hormones in upper airway diseases such as allergic and non-allergic rhinitis.

Expression of neurokinin a receptor mRNA in human nasal mucosa

In airway tissues, it has been suggested that tachykinins act as the transmitter for afferent sensory nerves which respond to various irritants and may be involved in airway allergic reactions. Three classes of tachykinin receptor have been recognized, denoted NK1, NK2 and NK3, which exhibit preferential affinity for substance P, neurokinin A and neurokinin B, respectively. We used molecular probes to study the gene expression and distribution of NK2 receptor in human nasal mucosa. Total RNA was isolated from human nasal mucosa and NK2 receptor mRNA was detected in these tissues using reverse transcriptase polymerase chain reaction (RT-PCR). For an in situ hybridization study of human nasal mucosa, we utilized the PCR directly to incorporate a T7 RNA polymerase promoter sequence onto the NK2 receptor cDNA, and these PCR products were used as the DNA template for producing digoxigenin-labeled antisense and sense RNA probes. These studies revealed that NK2 receptor mRNA was expressed in blood vessels. The results suggest a primary role for neurokinin A in the form of vascular responses in the upper respiratory tract.

Effects of glucocorticoids on infiltrating cells and epithelial cells of nasal polyps

Glucocorticoids are known to be effective in the treatment of nasal polyps (NPs). To examine the mechanisms of their effect, we evaluated 1) the ability of glucocorticoids to induce the apoptosis of eosinophils and T lymphocytes in NPs, and 2) the ability of dexamethasone to down-regulate epithelial cell functions that relate to eosinophilic inflammation. In vitro and in vivo, glucocorticoids increased the apoptosis of both eosinophils and T lymphocytes in NPs. Dexamethasone inhibited the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) from both NP epithelial cells that were unstimulated and NP epithelial cells that were stimulated with interleukin-4 or tumor necrosis factor alpha. These results suggest that the clinical efficacy of glucocorticoids on NPs may be due to 1) induction of apoptosis in both eosinophils and T lymphocytes that infiltrate NPs, and 2) down-regulation of epithelial GM-CSF production, which prolongs eosinophil survival.

[Study of thromboxane A2 antagonist reduction in the treatment of patients with perennial allergic rhinitis]

We investigated whether or not we could reduce the medication for patients with perennial allergic rhinitis after improvement of the nasal symptoms. We administered the thromboxane A2 receptor antagonist Ramatroban, which also improves non-specific hypersensitivity, for 4 weeks and then reduced the dose to half for 4 weeks and investigated the severity of general symptoms and each nasal symptom (sneeze, rhinorrhea, and congestion). There was a significant improvement in the severity of general symptoms and each nasal symptom for the first 4 weeks (p<0.01), which was maintained for 4 weeks after reduction of the dose (n=14). There was no difference in the severity of symptoms between the reduced dosage (n=14) and the maintained dosage (n=15) groups. We also investigated the level of eosinophilia in nasal smears before and after the treatment (n=14) and showed that the level was significantly (p<0.01) reduced after the start of treatment. In conclusion, it was noted that we could reduce the dose of Ramatroban after the improvement of nasal symptoms on patients with perennial allergic rhinitis.

Melanin pigmented oncocytic metaplasia of the nasopharynx

A case of melanin pigmented oncocytic metaplasia is reported. A 62-year-old man presented with a history of discomfort of the ear of a 2 weeks' duration. Nasoscopic examination revealed a black nodule of about 5mm at the left Eustachian opening, and several black spots were discovered around the bilateral torus tubarius. The nodule was biopsied to determine the histology. Microscopically, there were oncocytic cells with abundant pigmented granules showing glandular pattern. Such a pigmented variant of benign oncocytic lesion is very rare.