Clinical symptoms and biomarkers of Bermuda grass-induced allergic rhinitis using the nasal allergen challenge model.

BACKGROUND: Bermuda grass is a prevalent allergen that flourishes in tropical climates. Its exposure is traditionally believed to be low in Ontario due to the colder environment. However, high sensitization rates have been observed in Kingston, Ontario. OBJECTIVE: We sought to investigate whether its allergens can provoke allergic rhinitis (AR) symptoms in sensitized participants from south-eastern Ontario and determine if nasal allergen challenge (NAC) model is appropriate to study Bermuda grass-induced AR. METHODS: Twenty-one participants sensitized to Bermuda grass and 12 nonallergic participants completed a titrated NAC with increasing allergen concentrations at a screening visit. Total nasal symptom score (TNSS) and peak nasal inspiratory flow were collected before allergen exposure and 10 minutes after delivery of each concentration. Twelve participants with a Bermuda grass allergy who met the qualifying criteria (TNSS ≥ 8 and peak nasal inspiratory flow fall ≥ 50%) and 11 nonallergic controls returned for single-dose NAC visit. RESULTS: At titrated NAC, 19 of 21 sensitized participants met the criteria of positive allergic response when challenged. During single-dose NAC, participants with allergy had significantly greater TNSS between 15 minutes and 3 hours after NAC than controls. Likewise, allergic participants had a significantly increased number of nasal lavage eosinophils at both 1 and 6 hours after NAC. Bermuda grass-specific immunoglobulin E was significantly increased in Bermuda grass allergic participants at NAC than screening visit. CONCLUSION: Although Bermuda grass is a non-native allergen in Ontario, it can induce AR symptoms in sensitized participants, and the NAC model is appropriate to study Bermuda grass-induced AR.

Bermuda grass pollen allergen implicated in clinically relevant cross-reactivity to multiple grains: A case report.

BACKGROUND: Anaphylaxis is a severe and potentially fatal type of allergic reaction and is characterized by the rapid development of symptoms in the respiratory and circulatory systems, possibly leading to death if not treated properly. Occupational anaphylaxis, which does not exhibit significant differences in pathogenesis from the nonoccupational form, develops in response to work-related triggers. However, the onset of occupational anaphylaxis can also be triggered by other factors. Therefore, an unexpected episode may occur due to exposure to a previously sensitized antigen or cross-reaction in the occupational environment, even if the direct trigger has been removed. Accordingly, it is difficult to diagnosis and treat such cases and ensure avoidance of potential triggers. CASE PRESENTATION: An adult male patient developed anaphylaxis following exposure to grass antigens while replacing and burying sewer pipes at a theme park. He later developed cross-reactivity to other grains. Despite symptomatic treatment, his total serum level of allergen-specific immunoglobulin E (Ig E) antibodies continuously increased, and thus, he was admitted with severe hypersensitivity, at which time his serum levels of Ig E antibodies specific for Bermuda grass, wheat, and rice had also increased. CONCLUSION: In Korea, Bermuda grass is rarely seen and is generally found in athletic fields or theme parks. Following exposure to this relatively rare grass, our patient exhibited new anaphylactic responses to various external antigens. Therefore, we attribute his severe anaphylaxis to sensitization caused by Bermuda grass exposure and cross-reactive hypersensitivity to other grains.

Relevance of allergenic sensitization to cynodon dactylon and Phragmites communis: cross-reactivity with pooideae grasses

Background and Objectives: The homologous group of sweet grasses belongs to the Pooideae subfamily, but grass pollen species from other subfamilies can also cause allergy, such as Cynodon dactylon (Chloridoideae) and Phragmites communi (Arundinoideae). C dactylon and P communis have not been included in the sweet grasses homologous group because of their low cross-reactivity with other grasses. The aims of this study were to investigate the profile of sensitization to C dactylon and P communis in patients sensitized to grasses and to analyze cross-reactivity between these 2 species and temperate grasses. Methods: Patients were skin prick tested with a grass mixture (GM). Specific IgE to GM, C dactylon, P communis, Cyn d 1, and Phl p 1 was measured by ImmunoCAP. A pool of sera was used for the immunoblot assays. Cross-reactivity was studied by ELISA and immunoblot inhibition. Results: Thirty patients had sIgE to GM. Twenty-four (80%) had positive results for C dactylon, 27 (90%) for P communis, 22 (73.3%) or nCyn d 1, and 92.9% for rPhl p 1. Bands were detected in the 3 extracts by immunoblot. Inhibition of GM was not observed with C dactylon or P communis by immunoblot or ELISA inhibition. When C dactylon or P communis were used in the solid phase, GM produced almost complete inhibition. Conclusions: Eighty percent of patients sensitized to grasses were also sensitized to C dactylon and 90% were sensitized to P communis. Sensitization to these species seems to be induced by allergens different to those in sweet grasses (AU)

Antecedentes y Objetivos: Desde un punto de vista taxonómico, el grupo homólogo de las gramíneas pertenece a la sub-familia Pooideae. Sin embargo, existen también otras especies de gramíneas alergénicas que pertenecen a sub-familias diferentes como son Cynodon dactylon (Chloridoideae) o Phragmites communis (Arundinoideae). C. dactylon y P. communis no están incluidas en este grupo homólogo debido a que la reactividad cruzada con otras gramíneas es limitada. Los objetivos del estudio fueron investigar el perfil de sensibilización a C. dactylon y P. communis en pacientes sensibilizados a gramíneas y analizar la reactividad cruzada entre estas dos especies y las gramíneas más comunes. Métodos: A los pacientes se les realizó una prueba cutánea con una mezcla de gramíneas (MG). Mediante ImmunoCAP se midió la IgE específica para MG, C. dactylon P. communis , Cyn d 1 y Phl p 1. Un pool de sueros se utilizó para ensayos de inmunoblot. La reactividad cruzada se estudió mediante ELISA e inmunoblot inhibición Resultados: Treinta pacientes tuvieron IgE específica para MG. Veinticuatro (80%) fueron positivos a C. dactylon, 27 (90%) a P. communis, 22 (73,3%) a nCyn d 1 y 92,9% fueron positivos a rPhl p 1. Se detectaron bandas en los tres extractos mediante inmunoblot. No se observó inhibición de MG con las otras dos especies mediante inmunoblot o ELISA inhibición. Cuando C. dactylon o P. communis se usaron en fase sólida, MG produjo una inhibición casi completa. Conclusiones: El 80% de los pacientes sensibilizados a gramíneas estaban también sensibilizados a C. dactylon y el 90% a P. communis. La sensibilización a estas especies parece estar inducida por diferentes alérgenos que en el caso de gramíneas (AU)

Chronic use of the immunomodulating tripeptide feG-COOH in experimental feline asthma.

We have previously documented that a single dose of feG-COOH prior to allergen challenge significantly decreased eosinophilic airway inflammation in cats with experimental asthma, but did not result in complete resolution of airway inflammation. This study was undertaken to determine if a chronic (2 weeks) course of feG-COOH in experimentally asthmatic cats would induce complete remission of airway inflammation and clinical signs of asthma. Experimental asthma was induced using Bermuda grass allergen (BGA) and cats were randomly selected to receive either feG-COOH (1mg/kg, PO) or saline for 2 weeks, followed by a 2-week washout period. Cats then received the alternate treatment. Aerosol challenge with BGA was performed weekly throughout the study and bronchoalveolar lavage fluid (BALF) and blood were collected prior to and after each of the 2-week treatment periods. Regular use of feG-COOH had no significant effect on airway inflammation, BALF and plasma TNF bioactivity or a clinical sign compared to placebo. Regular use of feG-COOH can thus not be recommended as the sole therapy for feline allergic asthma.

Rye grass is associated with fewer non-contact anterior cruciate ligament injuries than bermuda grass.

OBJECTIVE: To assess the contribution of ground variables including grass type to the rate of anterior cruciate ligament (ACL) injury in the Australian Football League (AFL), specifically which factors are primarily responsible for previously observed warm season and early season biases for ACL injuries. METHODS: Grass types used at the major AFL venues from 1992 to 2004 were established by consultation with ground managers, and ground hardness and other weather variables were measured prospectively. RESULTS: There were 115 ACL injuries occurring in matches during the survey time period, 88 with a non-contact mechanism. In multivariate analysis, use of bermuda (couch) grass as opposed to rye grass, higher grade of match, and earlier stage of the season were independent risk factors for non-contact ACL injury. Ground hardness readings did not show a significant association with ACL injury risk, whereas weather variables of high evaporation and low prior rainfall showed univariate association with injury risk but could not be entered into a logistic regression equation. DISCUSSION: Rye grass appears to offer protection against ACL injury compared with bermuda (couch) grass fields. The likely mechanism is reduced "trapping" of football boots by less thatch. Grass species as a single consideration cannot fully explain the ACL early season bias, but is probably responsible for the warm season bias seen in the AFL. Weather variables previously identified as predictors are probably markers for predominance of bermuda over rye grass in mixed fields.

Dynamic changes in sensitization to specific aeroallergens in children raised in a desert environment.

BACKGROUND: Allergen skin test reactivity and total serum IgE are objective measures used to characterize and help diagnose allergic diseases. Cross-sectional studies have shown that overall aeroallergen skin test reactivity increases throughout childhood. However, little attention has been paid to whether individual aeroallergen remittance occurs, which could distort or mask relationships to disease. OBJECTIVE: To access the incidence and remittance of skin test reactions to individual allergens in children aged 6-11 years. METHODS: Longitudinal sensitization to six aeroallergens and total IgE were assessed in 828 children raised in the semi-arid US southwest at ages 6 and 11 years. RESULTS: New sensitization (to any allergen) between 6 and 11 years occurred in 30.2% of children compared with 39.7% before age 6 years. The rate of complete remittance from positive to negative between ages 6 and 11 years was 8.2%, and total IgE at age 6 years was not predictive. Remittance rates for individual allergens were high and variable (19-49%). The perennial allergens Bermuda and Alternaria were early sensitizers and had low remittance rates. Early sensitization to the four seasonal allergens was less common and more subject to remittance with the bulk of sensitization occurring between 6 and 11 years. CONCLUSION: This study shows that sensitization to individual aeroallergens in childhood is dynamic and indicates the limitation of single point assessment of skin test reactivity.

Factors associated with development of ileal impaction in horses with surgical colic: 78 cases (1986-2000).

Deal impaction is prevalent in the south-eastern USA, where feeding of Coastal Bermuda hay has been implicated as a risk factor. Alternatively, infection with the tapeworm Anoplocephala perfoliata has been identified as a risk factor for ileal impaction in the UK. We hypothesised that feeding Coastal Bermuda hay and failure to administer routinely an anthelmintic with efficacy against tapeworms would place horses at risk of developing ileal impaction in the USA. Seventy-eight horses, with surgically confirmed ileal impaction and 100 horses admitted for colic that did not have an ileal impaction, were selected retrospectively for logistic regression analysis. Using odds ratios (OR) as an index of risk, feeding Coastal Bermuda hay (OR = 2.9) and failure to administer a pyrantel salt within 3 months of admission (OR = 3.1) placed horses at risk of development of ileal impaction. This study confirms the belief that feeding Coastal Bermuda hay places horses at risk of ileal impaction, although the quality of the hay may also play a role. Periodic administration of anthelmintics with efficacy against tapeworms should be considered to reduce risk of ileal impaction.