Conjunctival Challenge Research Articles

Biopreparation of titanium dioxide nanoparticles mediated by Calendula officinalis flower extract for catalytic reduction of 4-nitrophenol and treatment of allergic conjunctivitis

This study investigates the an eco-friendly synthesis for the production of titanium dioxide nanoparticles (TiO2 NPs) by employing the water-soluble flower extract of Calendula officinalis as a natural reducing and stabilizing agent. The green produced TiO2 NPs/C. officinalis were characterized using different advanced analytical techniques, including FT-IR, FE-SEM, EDS-elemental mapping, XRD, ICP-OES and TEM. It represents the TiO2 NPs were found to be spherical in shape and well distributed without agglomeration. It also revealed the particle sizes were in the range of 30–50 nm. EDX represented the Ti atomic species along with C and O are seen to be well-dispersed in a homogeneous manner. The broad absorption band appeared at 3200–3450 cm−1 assigned to OH bond stretching belong to the adsorbed water over the titanium dioxide nanoparticles. Further, newly synthesized TiO2 NPs/C. officinalis are used as a nanocatalyst for the reduction of 4-nitrophenol (4-NP). A UV–Vis spectrophotometer is employed to track the effectiveness of the reduction process. Recyclability in 8 further degradation cycles is used to assess the sustainability of this catalyst, and the results show a steady and notable degradation activity. After a week of daily treatment, the allergic conjunctivitis clinical scores in Dunkin-Hartley guinea pigs were evaluated. The guinea pigs were sensitized with intraperitoneal ovalbumin and then subjected to topical conjunctival challenge. Different doses of TiO2 NPs/C. officinalis (20 and 100 µg/kg), prednisolone (30 mg/kg), chlorpheniramine (10 mg/kg), or PBS (10 mL/kg) were administered. The levels of serum Immunoglobulins were measured by ELISA. It was observed that the levels of ovalbumin-specific IgE notably decreased. Notably, the treatment with TiO2 NPs/C. officinalis at both doses led to a notably lower clinical score for allergic conjunctivitis. Furthermore, the TiO2 NPs/C. officinalis-treated guinea pigs conjunctival tissue showed mild mononuclear infiltration compared with the intense conjunctival tissue inflammatory infiltration observed in the PBS-treated group. These data suggest that TiO2 NPs/C. officinalis may have clinical efficacy in alleviating allergic conjunctivitis.

Protective properties of AgNPs green-synthesized by Camellia sinensis on ovalbumin-induced allergic conjunctivitis

Allergic conjunctivitis is the main usual red eye cause influencing many people. Allergic conjunctivitis is like an umbrella that includes different types of clinical manifestations, from a mild but annoying form of IgE-dependent allergy to inhaled allergens to very severe forms such as keratoconjunctivitis. Cornea involvement in allergic conjunctivitis needs the steroids use, which can cause severe eye complications. Research on allergic conjunctivitis should focus more on more severe forms of eye allergies to gain a better the pathophysiology understanding of the disease, diagnosis methods should be standardized and new treatment methods should be suggested. In the recent study, due to high therapeutic effects of Camellia sinensis, we used its aqueous extract for green-synthesizing of the silver nanoparticles and allergic conjunctivitis treatment in the in vivo condition. UV–Vis spectroscopy, FE-SEM and TEM were used for characterization of nanoparticles. This research therefore evaluated the AgNPs@Camellia sinensis antiallergic potential in ovalbumin-induced allergic conjunctivitis and attempted to predict its mode of action. ELISA determined serum ovalbumin-specific total IgE, IgE and IgG. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in Dunkin-Hartley guinea pigs were estimated after treatment with 10, 20, 40 and 80 µg kg−1 AgNPs@Camellia sinensis, 10 mg kg−1 chlorpheniramine, 30 mg kg−1 prednisolone, or 10 mL kg−1 PBS. Serum ovalbumin-specific total IgE, IgE and IgG decreased significantly (p < 0.01). The conjunctival tissue in AgNPs@Camellia sinensis treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration. The 40 and 80 mg kg−1 AgNPs@Camellia sinensis treatment resulted in allergic conjunctivitis low clinical score.

Formulation of a drug for the treatment of allergic conjunctivitis: Copper nanoparticles containing Olea europaea leaf aqueous extract

Olea europaea or Olive is the main ingredient of the Mediterranean diet. They are associated with many health benefits, especially for heart health and cancer prevention. Olive is rich in antioxidants and its health benefits range from fighting inflammation to reducing the growth of microorganisms. Recently, metallic nanoparticles green-formulated by ethnomedicinal plants have been used due to the antioxidant and anti-inflammatory potentials. Present research discloses the CuNPs biosynthesizing capability of the leaves of pharmacologically important Olea europaea. In addition, we investigated the Olea europaea green-formulated copper nanoparticles for the treatment of ovalbumin-induced allergic conjunctivitis. For determining the physicochemical properties of the recent nanoparticles, FT-IR, FE-SEM, UV-Vis and TEM were used. ELISA test was applied to measure the serum ovalbumin-specific IgG and IgE and total IgE. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in guinea pigs were determined after a week’s daily treatment with 30 mg kg−1 prednisolone, 10 mg kg−1 chlorpheniramine, 2, 4, 8 and 16 µg kg−1 copper nanoparticles, or 10 mL kg−1 PBS. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p<0.01). All doses of copper nanoparticles treatment resulted in a significantly (p<0.01) low clinical score of allergic conjunctivitis. The conjunctival tissue in copper nanoparticles treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration.

Green formulation and characterization of Camellia azalea synthesized copper nanoparticles and its application in the treatment of ovalbumin-induced allergic conjunctivitis

Camellia azalea can treat many stubborn and malignant diseases, according to traditional Chinese medicine. In addition, it has been indicated that copper nanoparticles containing the plant have many therapeutic effects. Recently, metallic nanoparticles have been used due to the antioxidant and anti-inflammatory potentials. Present research discloses the CuNPs biosynthesizing capability of the leaves of pharmacologically important Camellia azalea. For determining the physicochemical properties of the recent nanoparticles, FE-SEM, FT-IR, TEM and UV-Vis were used. This study therefore assessed the antiallergic potential of copper nanoparticles in ovalbumin-induced allergic conjunctivitis and attempted to predict its action mode. ELISA test was applied to measure the serum ovalbumin-specific IgG and IgE and total IgE. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization and topical conjunctival challenge in Dunkin-Hartley guinea pigs were determined after a week’s daily treatment with 10 mg kg−1 chlorpheniramine, 30 mg kg−1 prednisolone, 15 and 80 µg kg−1 copper nanoparticles, or 10 mL kg−1 PBS. The 15 and 60 mg kg−1 copper nanoparticles treatment resulted in a significantly (p < 0.01) low clinical score of allergic conjunctivitis. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p < 0.01). The conjunctival tissue in copper nanoparticles treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration.

Characterization of Ebola Virus Mucosal Challenge Routes in Cynomolgus Macaques.

Zaïre ebolavirus (EBOV) causes Ebola virus disease (EVD), a devastating viral hemorrhagic fever in humans. Nonhuman primate (NHP) models of EVD traditionally use intramuscular infection with higher case fatality rates and reduced mean time-to-death compared to contact transmission typical of human cases of EVD. A cynomolgus macaque model of oral and conjunctival EBOV was used to further characterize the more clinically relevant contact transmission of EVD. NHPs challenged via the oral route had an overall 50% survival rate. NHPs challenged with a target dose of 1 × 102 PFU or 1 × 104 PFU of EBOV via the conjunctival route had 40% and 100% mortality, respectively. Classic signs of lethal EVD-like disease were observed in all NHPs that succumbed to EBOV infection including viremia, hematological abnormalities, clinical chemistries indicative of hepatic and renal disease, and histopathological findings. Evidence of EBOV viral persistence in the eye was observed in NHPs challenged via the conjunctival route. IMPORTANCE This study is the first to examine the Kikwit strain of EBOV, the most commonly used strain, in the gold-standard macaque model of infection. Additionally, this is the first description of the detection of virus in the vitreous fluid, an immune privileged site that has been proposed as a viral reservoir, following conjunctival challenge. The oral and conjunctival macaque challenge model of EVD described here more faithfully recapitulates the prodrome that has been reported for human EVD. This work paves the way for more advanced studies to model contact transmission of EVD, including early events in mucosal infection and immunity, as well as the establishment of persistent viral infection and the emergence from these reservoirs.

Clinical Characteristics and Sensitization Profile of Patients Allergic to Cow Epithelium

Introduction: Cow epithelium allergy (CEA) has been described in workers highly exposed to cattle, such as farmers and veterinarians, being a health problem in this population since it is their main livelihood. This study aimed to characterize the main clinical manifestations and define the sensitization profile of the cow epithelium-allergic population treated in our health area. Methods: This is a retrospective study including a total of 34 patients with a clinical diagnosis of CEA, confirmed by skin tests, bovine epithelium-specific IgE levels and allergen-specific conjunctival challenge test in some cases. They were distributed by age, sex, profession, clinical symptoms, specific IgE levels to other mammalian epithelia, pollens, mites, and foods. Immunoblotting was performed with extracts from cow dander, cow body fluids (urine and saliva), bull urine, and 17 sera from immunotherapy-untreated CEA patients. Results: The mean age of the patients was 44 years, with a higher incidence in cattle farmers. Rhinoconjunctivitis occurred in 100% of cases, with 35% having monosensitization to cow epithelium. Sera from most patients detected a 20-kDa IgE-binding band in cow dander, cow saliva, cow urine, and bull urine, corresponding to the major allergen Bos d 2 (bovine lipocalin). In 70% of the patients, a 25-kDa band was detected in cow and bull urine extracts, whose identification by mass spectrometry and investigation with protein databases led to the identification of a Bos taurus lipocalin (UniProt protein ID: A0A3Q1LGU7_BOVIN). Conclusion: CEA should be considered in patients exposed to cattle and as a cause of occupational disease. The IgE immunodetection revealed sensitization to a protein present in cow and bull urine (odorant-binding protein) not previously described.

Natural history of nonhuman primates after conjunctival exposure to Ebola virus

Transmission of Ebola virus (EBOV) primarily occurs via contact exposure of mucosal surfaces with infected body fluids. Historically, nonhuman primate (NHP) challenge studies have employed intramuscular (i.m.) or small particle aerosol exposure, which are largely lethal routes of infection, but mimic worst-case scenarios such as a needlestick or intentional release, respectively. When exposed by more likely routes of natural infection, limited NHP studies have shown delayed onset of disease and reduced mortality. Here, we performed a series of systematic natural history studies in cynomolgus macaques with a range of conjunctival exposure doses. Challenge with 10,000 plaque forming units (PFU) of EBOV was uniformly lethal, whereas 5/6 subjects survived lower dose challenges (100 or 500 PFU). Conjunctival challenge resulted in a protracted time-to death compared to i.m. Asymptomatic infection was observed in survivors with limited detection of EBOV replication. Inconsistent seropositivity in survivors may suggest physical or natural immunological barriers are sufficient to prevent widespread viral dissemination.

Экспериментальное изучение аллергизирующего действия препарата на основе гиалуронидазы, пегилированной по технологии электронно-лучевого синтеза

Introduction. Hyaluronidase is an enzyme preparation widely used in medicine, including ophthalmology. Hyaluronidase, having a protein structure, carries a potential danger in the form of undesirable allergic reactions. To avoid allergenic effects, protein structures are modified by combining with a polymer carrier, for example, by polyethylene glycol (PEG). Aim. To study the possible allergenic potential of hyaluronidase, PEGylated using the technology of electron beam synthesis, with various routes of administration. Materials and methods. The object of the study is PEGylated hyaluronidase (PEG-Hyal). Experimental animals are hybrid mice and guinea pigs. Seven types of experiments were carried out: anaphylactogenic activity; conjunctival challenge test; cutaneous applications; delayed-type hypersensitivity (DTH); active cutaneous anaphylaxis; indirect mast cell degranulation; inflammatory response to concanavalin A (ConA). Results. When studying anaphylactogenic activity, an anaphylactic reaction was not observed in guinea pigs. The conjunctival challenge test also revealed no signs of hypersensitivity to the drug. In the study of sensitization, no development of local allergic reactions was observed. In experiments to the study DTH in mice, there were no significant differences for the DTH index in the experimental and control groups. The assessment of active skin anaphylaxis has been showed that the diameter of the stained spot did not significantly differ in both experimental groups from the control one. In indirect mast cell degranulation experiments, it was found that there was no statistically significant change in the mast cell degranulation index. Evaluation of the allergenic potential of PEG-Hyal in the inflammatory response to ConA showed that there is no statistically significant difference between the experimental and control groups. Conclusion. Based on the results of the experiments, it can be concluded that PEG-Hyal does not have an allergenic potential in various routes of administration, which significantly expands the possibilities of its clinical use.

Intralymphatic immunotherapy with one or two allergens renders similar clinical response in patients with allergic rhinitis due to birch and grass pollen.

IntroductionThere is a need for a fast, efficient and safe way to induce tolerance in patients with severe allergic rhinitis. Intralymphatic immune therapy has been shown to be effective.MethodsPatients with severe birch and timothy allergy were randomized and received three doses of 0.1 ml of birch and 5‐grass allergen extracts (10,000 SQ units/ml, ALK‐Abelló), or birch and placebo or 5‐grass and placebo by ultrasound‐guided injections into inguinal lymph nodes at monthly intervals. Rhinoconjunctivitis total symptom score, medication score and rhinoconjunctivitis quality of life questionnaire were evaluated before treatment and after each birch and grass pollen season during three subsequent years. Circulating proportions of T helper subsets and allergen‐induced cytokine and chemokine production were analysed by flow cytometry and Luminex.ResultsThe three groups reported fewer symptoms, lower use of medication and improved quality of life during the birch and grass pollen seasons each year after treatment at an almost similar rate independently of treatment with one or two allergens. Mild local pain was the most common adverse event. IgE levels to birch decreased, whereas birch‐induced IL‐10 secretion increased in all three groups. IgG4 levels to birch and timothy and skin prick test reactivity remained mainly unchanged. Conjunctival challenge tests with timothy extract showed a higher threshold for allergen. In all three groups, regulatory T cell frequencies were increased 3 years after treatment.ConclusionsIntralymphatic immunotherapy with one or two allergens in patients with grass and birch pollen allergy was safe, effective and may be associated with bystander immune modulatory responses. Clinical Trial Registration: EudraCT (2013‐004726‐28).

Profilin is a marker of severity in allergic respiratory diseases.

The capacity of profilin to induce allergic symptoms in patients with respiratory allergy has been questioned. In this sense, the aim of this study was to investigate the correlation between profilin exposure and induction of symptoms in a prospective case-control study. The concentration of profilin as well as pollen levels in the air was measured. A diary score of symptoms was collected from allergic patients. Seventy-nine individuals were included in the study; fifty cases and 28 controls were positive or negative to profilin, respectively. Conjunctival and bronchial provocation tests were performed with purified profilin (Pho d 2) in a subgroup of cases and controls. Profilin was detected in the environment on 133days (maximum peak of 0.56ng/m3 ). A positive correlation between profilin and pollen count of Olea and Poaceae was observed (ρ=0.24; P<.001). Intensity of total, nasal and ocular symptoms was statistically higher in cases than in controls (P<.001). The risk of suffering symptoms, measured by the percentage of patients who presented any of the symptoms each day, was also higher in cases than in controls. The provocation test was positive in 95% of bronchial and 90% of conjunctival challenges in cases, and negative in all controls. Profilin was detected in the environment and had the ability to induce a specific allergen response. Patients sensitized to this panallergen showed more symptoms and were more likely to have symptoms. Therefore, sensitization to profilin seems to be a marker of severity in patients with rhinoconjunctivitis and asthma mediated by pollen.

Real-Time PCR Reveals Rapid Dissemination of Leptospira interrogans after Intraperitoneal and Conjunctival Inoculation of Hamsters.

The pathogen Leptospira interrogans is a highly motile spirochete that causes acute and fulminant infections in humans and other accidental hosts. Hematogenous dissemination is important for infection by the pathogen but remains poorly understood because few animal model studies have used sensitive tools to quantify the bacteria. We evaluated the kinetics of leptospiral infection in Golden Syrian hamsters by a sensitive quantitative real-time PCR (TaqMan) with lipl32 as the target gene. The dissemination and bacterial burden were measured after intraperitoneal infection with a high dose (10(8)) or low dose (2.5 × 10(2)) of leptospires. We also examined the conjunctival challenge route to mimic the natural history of infection. Quantification of leptospires in perfused animals revealed that pathogens were detected in all organs of intraperitoneally infected hamsters, including the eye and brain, within 1 h after inoculation of 10(8) virulent L. interrogans bacteria. Peaks of 10(5) to 10(8) leptospires per gram or per milliliter were achieved in blood and all tissues between day 4 and day 8 after intraperitoneal inoculation of high- and low-dose challenges, respectively, coinciding with macroscopic and histological changes. The conjunctival route resulted in a delay in the time to peak organ burden in comparison to intraperitoneal infection, indicating that although infection could be established, penetration efficiency was low across this epithelial barrier. Surprisingly, infection with a large inoculum of high-passage-number attenuated L. interrogans strains resulted in dissemination to all organs in the first 4 days postinfection, albeit with a lower burden, followed by clearance from the blood and organs 7 days postinfection and survival of all animals. These results demonstrate that leptospiral dissemination and tissue invasion occur. In contrast, development of a critical level of tissue burden and pathology are dependent on the virulence of the infecting strain.

Possible Mechanism of Action of the Antiallergic Effect of an Aqueous Extract of Heliotropium indicum L. in Ovalbumin-Induced Allergic Conjunctivitis.

Heliotropium indicum is used traditionally as a remedy for conjunctivitis in Ghana. This study therefore evaluated the antiallergic potential of an aqueous whole plant extract of Heliotropium indicum (HIE) in ovalbumin-induced allergic conjunctivitis and attempted to predict its mode of action. Clinical scores for allergic conjunctivitis induced by intraperitoneal ovalbumin sensitization (100 : 10 μg OVA/Al(OH)3 in phosphate-buffered saline [PBS]) and topical conjunctival challenge (1.5 mg OVA in 10 μL PBS) in Dunkin-Hartley guinea pigs were estimated after a week's daily treatment with 30–300 mg kg−1 HIE, 30 mg kg−1 prednisolone, 10 mg kg−1 chlorpheniramine, or 10 mL kg−1 PBS. Ovalbumin-specific IgG and IgE and total IgE in serum were estimated using Enzyme-Linked Immunosorbent Assay. Histopathological assessment of the exenterated conjunctivae was also performed. The 30 and 300 mg kg−1 HIE treatment resulted in a significantly (p ≤ 0.001) low clinical score of allergic conjunctivitis. Ovalbumin-specific IgG and IgE as well as total serum IgE also decreased significantly (p ≤ 0.01–0.001). The conjunctival tissue in HIE treated guinea pigs had mild mononuclear infiltration compared to the PBS-treated ones, which had intense conjunctival tissue inflammatory infiltration. HIE exhibited antiallergic effect possibly by immunomodulation or immunosuppression.

Occupational Rhinoconjunctivitis due to Maize in a Snack Processor: A Cross-Reactivity Study Between Lipid Transfer Proteins From Different Cereals and Peach.

We report the case of a snack processor who developed occupational rhinoconjunctivitis due to maize brand exposure during the extrusion process, and who experienced abdominal pain upon drinking beer. The allergens implicated and the cross-reactivity between non-specific lipid transfer proteins (LTPs) from different cereals and peach were investigated. Skin prick tests and specific IgE to cereal flours, pulmonary functions tests and specific conjunctival and inhalation challenges to maize extract were performed. In vitro studies included IgE immunoblotting and ELISA inhibition assays. Skin prick tests with maize flour, maize brand and wheat flour extracts were positive, whereas serum specific IgE was positive only to maize flour. Specific inhalation challenge (SIC) to maize flour did not elicit an asthmatic reaction; however, conjunctival challenge test with the same extract was positive. Patient's serum recognized IgE-binding bands in the maize and beer extracts corresponding to LTPs. In the ELISA inhibition assays, a significant degree of allergenic cross-reactivity was found between maize and beer LTPs, whereas no cross-reactivity was observed between maize LTP and wheat and peach LTPs.

Profilin as an Aeroallergen by Means of Conjunctival Allergen Challenge with Purified Date Palm Profilin

Background: The role of profilin as a food allergen is well established, but little research has been done about its ability to elicit respiratory disease. Profilin is considered more of a confounding allergen on skin testing with whole pollen extracts than other airborne allergens. Our aim was to find out whether or not profilin can cause symptoms in sensitized individuals, which would be compatible with its role as an airborne allergen. Methods: We performed conjunctival allergen challenges with date palm profilin in a series of consecutive pollen-allergic patients with rhino-conjunctivitis, divided in two groups: profilin sensitized (n = 17) and not sensitized (n = 14), who served as controls. We investigated the possible association between profilin sensitization and profilin allergy in these groups of patients. Results: None of the patients from the not profilin-sensitized group had a positive result in conjunctival allergen challenges. In contrast, 65% of profilin sensitized patients had a positive conjunctival allergen challenge and were considered allergic to profilin. We found a significant statistical association between being profilin allergic and being profilin sensitized (χ² = 10.39, p < 0.005). Conclusions: Profilin seems to work as an aeroallergen in a significant proportion of profilin-sensitized patients. This might explain the uselessness of conjunctival challenges with whole pollen extracts to disclose genuine sensitization. In the future, the possibility of quantifying this allergen in pollen immunotherapy vaccines should be considered.

Specific immunotherapy, one century later

Specific immunotherapy, one century later

Randomized, double-blind, placebo-controlled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients.

BackgroundNatural rubber latex allergy is a common and unsolved health problem. Since the avoidance of exposure is very difficult, immunotherapy is strongly recommended, but before its use in patients, it is essential to prove the efficacy and safety of extracts.The aim of the present randomised, double-blind, placebo-controlled clinical trial was to assess the efficacy and tolerability of latex sublingual immunotherapy in adult patients undergoing permanent latex avoidance.MethodsTwenty-eight adult latex-allergic patients (5 males and 23 females), with mean age of 39 years (range 24-57) were randomized to receive a commercial latex-sublingual immunotherapy or placebo during one year, followed by another year of open, active therapy. The following outcomes were measured at baseline and at the end of first and second year of follow-up: skin prick test, gloves-use score, conjunctival challenge test, total and specific IgE, basophil activation test, and adverse reactions monitoring.ResultsNo significant difference in any of the efficacy in vivo variables was observed between active and placebo groups at the end of the placebo-controlled phase, nor when each group was compared with their baseline values at the end of the two year-study. An improvement in the average percentage of basophils activated was observed. During the induction phase, 4 reactions in the active group and 5 in the placebo group were recorded. During the maintenance phase, two patients dropped out due to pruritus and to acute dermatitis respectively.ConclusionFurther studies are needed to evaluate latex-sublingual immunotherapy, since efficacy could not be demonstrated in adult patients with avoidance of the allergen.Trial registration numberACTRN12611000543987

The Editor takes a closer look at some of this month's articles

Clinical & Experimental AllergyVolume 41, Issue 8 p. 1047-1047 Free Access The Editor takes a closer look at some of this month's articles First published: 13 July 2011 https://doi.org/10.1111/j.1365-2222.2011.03826.xAboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Pre-school wheeze: biomarkers of corticosteroid responsiveness Pre-school wheeze is common and includes non-asthma viral-induced wheeze, which is not corticosteroid responsive and classical atopic asthma which generally is [1]. The question is how to distinguish between the different phenotypes so that the right treatment is matched to the right patient. Exhaled nitric oxide is linked to eosinophilic airway inflammation, which is probably the best marker of corticosteroid responsiveness, at least in adults [2]. Exhaled breath condensate is also widely used as a non-invasive marker of airway inflammation [3]. Van der Kant and colleagues (pp. 1076–1083) have investigated whether either of these measurements are helpful in guiding corticosteroid therapy in 93 pre-school wheezers. They were not helpful, dealing another blow to the idea that currently available non-invasive measurements can be used to guide treatment. Back to the drawing board. [ Kim van der Kant (author) ] [ see figure 4 in Spycher BD, et al. [1] ] Basophil sensitivity: a biomarker of allergen responsiveness in asthma? Atopy is undoubtedly an important contributor to asthma. However, while in some patients there is a clear-cut relationship between exposure and symptoms, this is far from being universal. In addition, allergen avoidance studies have not provided compelling evidence that allergy is the key driver of asthma. An objective test that reliably predicted the airway response to allergen would be very helpful to guide allergen avoidance both in clinical trials and clinical practice. Allergen challenge is too invasive to use routinely and so Dahlén and colleagues (pp. 1091–1097) have asked whether basophil threshold sensitivity (CD-sens) to in vitro challenge correlates with allergen PD20. They found that it does, with a particularly strong correlation in those patients who were relatively insensitive to allergen challenge. Studies are now needed to validate the clinical relevance of this observation by showing that patients with a high basophil sensitivity get more symptoms and do better with allergen avoidance than those whose basophil responsiveness is more sluggish. [ Barbro Dahlén (author) ] [ See fig 1A (pp. 1091–1097) ] Specific IgE: concentrations are not closely related to clinical response Huss-Marp and colleagues (pp. 1116–1124) have addressed the same question as Dahlén et al. using specific IgE as the biomarker and nasal, conjunctival and skin challenge as the clinical outcome. They point out that for a given level of exposure to grass pollen symptoms of rhinitis are very variable. They asked whether this observation could be explained by the amount of circulating specific IgE. They measured specific IgE levels to timothy grass in 104 patients with seasonal allergic rhinitis and related this to the dose threshold for challenge. There was no relationship with uncorrected levels of specific IgE and only a weak correlation between the skin test and conjunctival challenge and the specific IgE/total IgE ratio. Therefore specific IgE, although essential for diagnosis is not very good at assessing severity, at least to aeroallergens. The full implications of this study are discussed in an excellent editorial by Robert Hamilton. [ Johannes Huss-Marp (author) ] [ Nasal provocation (courtesy Johannes Huss-Marp) ] References 1 Spycher BD, Silverman M, Kuehni CE. Phenotypes of childhood asthma: are they real? Clin Exp Allergy 2010; 40: 1130– 41. CASWeb of Science®Google Scholar 2 Gibson PG. Using fractional exhaled nitric oxide to guide asthma therapy: design and methodological issues for ASthma TReatment ALgorithm studies. Clin Exp Allergy 2009; 39: 478– 90. CASPubMedWeb of Science®Google Scholar 3 Kostikas K, Koutsokera A, Papiris S, Gourgoulianis KI, Loukides S. Exhaled breath condensate in patients with asthma: implications for application in clinical practice. Clin Exp Allergy 2008; 38: 557– 65. CASPubMedWeb of Science®Google Scholar Volume41, Issue8August 2011Pages 1047-1047 ReferencesRelatedInformation

A Prospective, Clinical Study on Asymptomatic Sensitisation and Development of Allergic Rhinitis: High Negative Predictive Value of Allergological Testing

Background: Asymptomatic aeroallergen sensitisation affects approximately 10% of Western adolescents and is an established risk factor for the development of respiratory allergy. The reported incidence is 2–20% annually. Previous studies are based on out-seasonal symptom recollection or selected populations, conferring bias towards higher incidence rates. Objective: The aim was to determine the incidence of onset of symptoms among clinically well-characterised asymptomatic, sensitised subjects compared with controls, and to evaluate the predictive values of common allergological tests. Methods: We performed a prospective, clinical, non-interventional, 2-year follow-up study on subjects (identified by population screening) with seasonal allergic birch or grass pollen rhinitis (n = 52), asymptomatic sensitisation to grass or birch (AS, n = 52) or non-atopic, healthy control subjects (n = 39). Experimental allergen susceptibility was assessed at inclusion and at follow-up by skin prick test, conjunctival challenge, intradermal late-phase reaction and measurement of specific IgE. Participants completed in-seasonal symptom and medication diaries during 2 subsequent seasons. Results: We observed an annual incidence rate of 5% for the onset of symptoms in the AS group (healthy control group 0%). At baseline, the AS group displayed intermediate experimental allergen susceptibility. Subjects developing symptoms had higher levels of specific IgE and larger late-phase reaction than those persistently asymptomatic. However, the positive predictive values were low (14–27%) in contrast to the negative predictive values (95–100%). Conclusion: In a well-characterised young population, asymptomatic aeroallergen sensitisation conferred a low risk for onset of symptoms during the 2-year follow-up. Persistent asymptomatic phenotype could be accurately predicted by negative results from simple allergological testing.

Immune Responses and Protection against ExperimentalBrucella suisBiovar 1 Challenge in Nonvaccinated orB. abortusStrain RB51-Vaccinated Cattle

Twenty Hereford heifers approximately 9 months of age were vaccinated with saline (control) or 2 × 10(10) CFU of the Brucella abortus strain RB51 (RB51) vaccine. Immunologic responses after inoculation demonstrated significantly greater (P < 0.05) antibody and proliferative responses to RB51 antigens in cattle vaccinated with RB51 than in the controls. Pregnant cattle received a conjunctival challenge at approximately 6 months of gestation with 10(7) CFU of B. suis bv. 1 strains isolated from naturally infected cattle. The fluorescence polarization assay and the buffered acid plate agglutination test had the highest sensitivities in detecting B. suis-infected cattle between 2 and 12 weeks after experimental infection. Serologic responses and lymphocyte proliferative responses to B. suis antigens did not differ between control and RB51 vaccinees after experimental infection. No abortions occurred in cattle in either treatment group after challenge, although there appeared to be an increased incidence of retained placenta after parturition in both the control and the RB51 vaccination treatment groups. Our data suggest that the mammary gland is a preferred site for B. suis localization in cattle. Vaccination with RB51 did not reduce B. suis infection rates in maternal or fetal tissues. In conclusion, although B. suis is unlikely to cause abortions and fetal losses in cattle, our data suggest that RB51 vaccination will not protect cattle against B. suis infection after exposure.

CCR5 is not required for mucosal protection against Trypanosoma cruzi (39.28)

Abstract Trypanosoma cruzi is an intracellular obligate parasite and the causative agent of Chagas disease. Previous work has shown that the chemokine receptor CCR5 plays a role in systemic responses against T. cruzi. We evaluated whether CCR5 plays a critical role in mucosal protection against natural oral and conjunctival challenges. Memory-immune CCR5-/- and wild-type C57BL/6 mice were generated by repeated infectious challenges with sublethal doses of insect-derived metacyclic trypomastigotes. Similar IgA, IgG and IFN-γ responses were detected in the spleen in both memory-immune and primary infected wild-type and CCR5-/- mice. More importantly, protection was evaluated in memory-immune mice via real-time PCR and limiting dilution assay for parasite outgrowth. CCR5-/- memory-immune mice developed equivalent levels of protection against both oral and conjunctival mucosal challenges. Preliminary studies from the stomachs of CCR5-/- memory-immune mice showed an increase in the transcript levels of CCL5 as compared to memory-immune wild-type mice. Overall, it appears that CCR5 does not play a critical role in the control of parasite replication and immune responses at sites of initial mucosal infection with T. cruzi. However, CCL5 signaling through CCR1 and/or CCR3 may compensate for the absence of CCR5.