Prevalence of occupational allergy to Chrysanthemum pollen in greenhouses in the Netherlands

BACKGROUND: An increasing number of allergic complaints appear to have occurred among Chrysanthemum greenhouse employees. The aim of this study was to estimate the prevalence of work-related allergic symptoms and the prevalence of sensitization to pollen of different members of the Chrysanthemum family. METHODS: We studied 104 employees who were invited to answer an extensive questionnaire and to complete a rhinitis quality of life questionnaire. In addition, they were skin prick tested on location with inhalant allergens and home-made pollen extracts of seven different members of the Chrysanthemum family. Radio-allergo-sorbent tests were performed to confirm IgE-mediated reactions. RESULTS: Work-related symptoms were reported in 56.7% of all cases, with the main symptom being rhinitis. Sensitization to Chrysanthemum pollen was found in 20.2% of the employees without one member of the Chrysanthemum family in particular being most prevalent. Sensitization to Chrysanthemum pollen was considered to be an important risk factor for the occurrence of work-related symptoms of the upper airways. Furthermore, inhalant atopy as well as sensitization to common airborne pollen including mugwort were closely associated with sensitization to Chrysanthemum what might be suggestive for cross-sensitization. CONCLUSIONS: There is a high prevalence of work-related symptoms in Chrysanthemum greenhouses. In one-third of the employees these symptoms were caused by an IgE-mediated allergy caused by the pollen of the flowers. Inhalant atopy appeared to have a great impact on the development of such a sensitization. Measurements to reduce the pollen exposure are necessary to prevent a further increase of this occupational allergy.     

mfERG response dynamics of the aging retina

PURPOSE. To determine age-related changes in retinal response dynamics derived from multifocal electroretinograms (mfERGs). METHODS. MfERG data were obtained from 70 subjects with normal phakic eyes, age 9 to 80 years. Whereas the first- and higher-order kernels resulting from the mfERG contain detailed information regarding the nonlinear response dynamics of the retina, they do not lend themselves directly to an easy and intuitive interpretation. To achieve a better appreciation of fast adaptive mechanisms and their changes with aging, regional averages of the kernel series were translated at different retinal eccentricities (0 degrees -5 degrees, 5 degrees -15 degrees, and 15 degrees -25 degrees ) into responses generated in different contexts. Specifically, the effect of aging on responses to stimuli presented in isolation was compared with the effect on responses adapted by preceding stimuli ("forward" effect). The interference of the immediately following stimuli with the response generation ("backward effect") was also considered. RESULTS. Age-related changes were found in the isolated flash response as well as in the backward and forward interactions between consecutive flash responses. Larger fractional changes with age were found in response density than in implicit time, and the rate of change with age was larger for responses to isolated flashes than for responses adapted by preceding flashes. CONCLUSIONS. Senescent changes in the isolated flash response and in consecutive flash interactions derived from the binary kernel series indicate an aging process at an early stage in the visual system. Mechanisms of retinal adaptation may partially compensate for age-related reductions in the isolated flash response.     

Four-Year persistence patterns among patients initiating therapy with the angiotensin II receptor antagonist losartan versus other artihypertensive drug classes

BACKGROUND: It has been reported that a statistically greater percentage of patients initially treated with losartan, an angiotensin II receptor antagonist (AIIA), stayed on therapy at 1 year compared with patients treated with antihypertensive drugs from other classes. OBJECTIVE: The purpose of this study was to determine whether the stay-on-therapy (persistence) patterns observed in the previous analysis were maintained over a 4-year period. METHODS: We investigated a subgroup of 15,175 hypertensive patients from an earlier studied cohort who were continuously eligible for benefits over a 4-year follow-up period. A linear regression model was developed to test the statistical significance of differences in the percentage of patients staying on therapy from 12 months to 48 months for the different antihypertensive classes. RESULTS: From 12 to 48 months, there was a slow continuous decline in persistence that was similar across all classes of antihypertensive medications. A greater percentage of patients treated with an AIIA (losartan) stayed on therapy from 12 to 48 months compared with patients treated with angiotensin-converting enzyme inhibitors (67.4% vs 60.7% at 12 months, P < 0.01; 50.9% vs 46.5% at 48 months, P = 0.095), calcium antagonists (67.4% vs 54.1% at 12 months, P < 0.01; 50.9% vs 40.7% at 48 months, P < 0.03), beta-blockers (67.4% vs 45.6% at 12 months, P < 0.01; 50.9% vs 34.7% at 48 months, P < 0.03), or thiazide diuretics (67.4% vs 20.8% at 12 months, P < 0.01; 50.9% vs 16.4% at 48 months, P < 0.03). The percentage of patients staying on AIIA therapy from 12 months to 48 months was statistically greater (P < 0.001) than the percentage of patients staying on therapy with other antihypertensive drug classes. CONCLUSIONS: This analysis supports the observation that initiation of antihylertensive therapy with an AIIA such as losartan results in a greater persistence rate over a 4-year period than does therapy with any other antihypertensive class. These findings may have important implications for blood pressure control, reduction of cardiovascular risks, and health care resource utilization.     

Losartan reduces the costs associated with diabetic end-stage renal disease: the RENAAL study economic evaluation

OBJECTIVE: To evaluate the within-trial effect of losartan and conventional antihypertensive therapy (CT) compared with placebo and CT on the economic cost associated with end-stage renal disease (ESRD). RESEARCH DESIGN AND METHODS: The Reduction of End Points in Type 2 Diabetes With the Angiotensin II Antagonist Losartan (RENAAL) study was a multinational double-blind randomized placebo-controlled clinical trial designed to evaluate the renal protective effects of losartan on a background of CT (excluding ACE inhibitors and angiotensin II receptor agonists [AIIAs]) in patients with type 2 diabetes and nephropathy. The primary composite end point was doubling of serum creatinine, ESRD, or death. Data on the duration of ESRD were used to estimate the economic benefits of slowing the progression of nephropathy. The cost associated with ESRD was estimated by combining the days each patient experienced ESRD with the cost of ESRD over time. The cost of ESRD for individuals with diabetes was estimated using data from the U.S. Renal Data System. Total cost was estimated as the sum of the cost associated with ESRD and the cost of study therapy. RESULTS-We estimated that losartan and CT compared with placebo and CT reduced the number of days with ESRD by 33.6 per patient over 3.5 years (P = 0.004, 95% CI 10.9-56.3). This reduction in ESRD days resulted in a decrease in cost associated with ESRD of 5144 US dollars per patient (P = 0.003, 95% CI 1701 to 8587 US dollars). After accounting for the cost of losartan, the reduction in ESRD days resulted in a net savings of 3522 US dollars per patient over 3.5 years (P = 0.041, 143 to 6900 US dollars). CONCLUSIONS: Treatment with losartan in patients with type 2 diabetes and nephropathy not only reduced the incidence of ESRD, but also resulted in substantial cost savings.     

Forced expiration through the nose is a stimulus for NANIPER but not for controls

OBJECTIVE: Is forced expiration through the nose a mechanical stimulus to which patients with nasal hyperreactivity react? Do parameters, such as peak nasal expiratory flow rate (PNEF), influence nasal airway resistance (NAR) in these patients? METHOD: NAR, mucus production and sneezing were measured on 2 occasions two weeks apart. Measurements were conducted before and during a period of 10 minutes after 3 repeated PNEFs in 15 non-allergic non-infectious perennial rhinitis (NANIPER) patients suffering from nasal hyperreactivity, and in 15 controls. RESULTS: In NANIPER versus controls PNEF measurements attributed to a statistically significant increase in NAR. The main effect was within the first minute after stimulus, suggesting a neuronal mechanism. Mucus secretions and sneezing were hardly present. PNEF (highest of 3) and bronchial peak expiratory flow rate (BpEFR) are lower in NANIPER than controls but are correlated. Impaired bronchial capacity is likely to influence PNEF, resulting in a lower decrease of nasal patency. CONCLUSION: PNEF depends on BpEFR and is an adequate mechanical stimulus for NANIPER patients, but not for non-rhinitic controls, resulting in a brief increase in NAR.     

Parental and child factors associated with inhalant and food allergy in a population-based prospective cohort study: the Generation R Study

The prevalence of allergic diseases in children is markedly increasing to epidemic proportions. The aim of this study is to describe the presence and examine associated parental and child characteristics of allergic sensitization and physician-diagnosed allergy in Dutch children at age 10 years. This study among 5471 children was performed in a population-based prospective cohort from fetal life onwards. Allergic sensitization was measured by skin prick tests. Physician-diagnosed allergy and parental and child characteristics were collected by questionnaires. In children aged 10 years, inhalant and food allergic sensitization was present in 32.2% and 7.1%, and physician-diagnosed inhalant and food allergy in 12.4% and 2.3%. Maternal and paternal history of allergy, eczema or asthma was associated with increased risks of physician-diagnosed inhalant allergy (aOR (95% CI) 1.44 (1.23–1.70) and 1.59 (1.30–1.94), respectively), but not with food allergy. Asthma and eczema ever at age 10 years were associated with increased risks of physician-diagnosed inhalant allergy (4.60 (3.55–5.96) and 2.42 (1.94–3.03), respectively). Eczema ever at age 10 years was associated with an increased risk of physician-diagnosed food allergy (5.78, 3.04–9.52), with the highest risk of cashew (7.36, 3.20–16.94) and peanut (5.58, 3.08–10.10) food allergy.

Conclusions: We found strong effects of parental history of allergy, eczema or asthma on the presence of physician-diagnosed inhalant allergy in children at age 10 years. Eczema ever at age 10 years was a strong risk factor for the development of physician-diagnosed inhalant and food allergy.

Occupational pollinosis in gardeners

The symptoms of occupational pollinosis are described on the basis of case histories, skin tests and serological tests of six commercial gardeners. Exposure to gerberas, freesias, chrysanthemums and to genera of the nightshade family (Solanaceae) such as paprikas, tomatoes, egg plants and potatoes may lead to allergy with raised IgE levels.     

Nasal hyperreactivity.

Nasal hyperreactivity is an important feature of allergic and non-allergic rhinitis. This paper reviews the possible mechanisms behind hyperreactivity. Distinct mechanisms may play a role in allergic rhinitis--an inflammatory disease--and non-allergic rhinitis, mainly a non-inflammatory disease. In allergic rhinitis, particularly in perennial allergic rhinitis, there is a close connection between allergic response and non-specific hyperreactivity. In non-allergic rhinitis, a pathological entity comprising a heterogeneous series of diseases, understanding and measuring nasal hyperreactivity is much more difficult. A variety of methods to assess nasal hyperreactivity are available. Given the heterogeneity of mechanisms, the various patients groups and the lack of standardization in tests, it is not surprising that measurement of nasal hyperreactivity is not included in the diagnostic arsenal of the clinician.     

Immunotherapy in children and adolescents with allergic rhinoconjunctivitis: a systematic review

Allergen‐specific immunotherapy is one of the cornerstones of allergic rhinoconjunctivitis treatment. Since the development of non‐invasive administration forms with better safety profiles, there is an increasing tendency to prescribe immunotherapy in youngsters. However, no overview is available on the efficacy of immunotherapy in all its different administration forms in youngsters. Therefore, we systematically reviewed randomized controlled trials (RCTs) to evaluate the effect of immunotherapy with inhalant allergens on symptoms and medication use in children and adolescents with allergic rhinoconjunctivitis. Medline, EMBASE, the Cochrane Controlled Clinical Trials Register and reference lists of recent reviews and published trials were searched. RCTs including youngsters aged 0–18 yr with allergic rhinoconjunctivitis and comparing immunotherapy with placebo, symptomatic treatment or a different administration form of immunotherapy were included. Primary outcome measures were rhinoconjunctivitis symptom and/or medication scores. Methodological quality was assessed using the validated Delphi list. A method of best evidence synthesis, a rating system with levels of evidence based on the overall quality and the outcome of the trials, was used to assess efficacy. Six subcutaneous (SCIT), four nasal (LNIT), seven oral (OIT) and 11 sublingual (SLIT) immunotherapy trials, comprising 1619 youngsters, were included. Only 39% of the trials were of high methodological quality. For the SCIT and OIT subgroups the level of evidence for efficacy was conflicting. Moderate evidence of effect was found for LNIT. Analysis of the SLIT subgroup showed no evidence of effect. The evidence for the perennial and seasonal allergen trials within the subgroups varied from moderate evidence of effect to no evidence of effect. In conclusion, there is at present insufficient evidence that immunotherapy in any administration form has a positive effect on symptoms and/or medication use in children and adolescents with allergic rhinoconjunctivitis.