Indirect contact with pets can confound the effect of cleaning procedures for reduction of animal allergen levels in house dust

To investigate the capacity of common vacuum cleaners and chemical treatment to reduce cat ( Fel d I) and dog ( Can f I) allergen content in house dust, 52 families with allergic children and no pets at home were recruited. Five groups of 10–11 families used their central vacuum cleaners (n = 10), their own old vacuum cleaners plus either tannic acid (n = 10) or placebo (n = 10) applied to carpets and upholstry after the first sample was collected on Day 0 or new vacuum cleaners equipped with either HEPA (high efficiency particulate air)- (n = 11) or micro-filters (n= 10). Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children on Days 0, 7, 21, and 35. Fel d I and Can f I allergens were determined by sandwich ELISA methods. Central, micro-filter and HEPA-filter vacuum cleaners did not reduce the concentrations nor the total amount/sampling area of Fel d I or Can f I. Tannic acid initially reduced (p < 0.05) both the concentration and the total amount of Fel d I by 30% and Can f I by 10%, but only for one week. The levels increased to base-line after 21–35 days. The concentrations of Fel d I increased 10–30 times in homes visited by cats or cat owners. We conclude, that tannic acid treatment reduced pet allergen concentrations and total amounts in dust for one week only. Central vacuum cleaners or vacuum cleaners equipped with HEPA- or micro-filter did not reduce the pet allergen load in homes of allergics. Indirect contacts with cats caused a pronounced increase in cat allergen levels.     

Placebo-controlled study of the mite allergen-reducing effect of tannic acid plus benzyl benzoate on carpets in homes of children with house dust mite sensitization and asthma

We studied the effect of a spray containing 1% benzyl benzoate, an acaricide, and 1% tannic acid (‘Lowal’; a protein‐denaturing substance), on concentrations of major allergens from house dust mite (HDM) species Dermatophagoides pteronyssinus and D. farinae (Der p 1 and Der f 1, respectively) in carpets. In a double‐blind, placebo‐controlled study with crossover design, 30 homes of children with HDM sensitization and asthma were included. All houses showed ≥ 400 ng/g of Der p 1 + Der f 1 in carpet dust. The first treatment was performed on day 0 (group 1 active treatment, n = 15; group 2 placebo treatment, n = 15). After 2 and 8 weeks, dust samples were collected for quantification of mite allergens. After a 2‐week washout period, the second treatment was performed (group 1 placebo treatment; group 2 active treatment). Again, carpet dust was collected after 2 and 8 weeks. Twenty‐two of 30 families completed the trial: 14/15 in group 1 and eight of 15 in group 2. On day 0, there was no significant difference in mite allergen exposure between group 1 and group 2 (1,498 vs. 2,239 ng/g of Der p 1 + Der f 1, respectively). In group 1, the geometric mean for the difference of mite allergen concentration comparing day 0 and week 6 was 196 ng/g (95% CI: ?7,161 and 8,401) for the first treatment (active) and 15 ng/g (95% CI: ?1,079 and 1,292) for the second treatment (control). In group 2, the difference was 66 ng/g (95% CI: ?398 and 1,515) for the first treatment (control) and 609 ng/g (95% CI: 186 and 9,264) for the second treatment (active). Comparing placebo and active treatment in total, there was a significant decrease following placebo treatment after 14 days (p = 0.026). After 8 weeks, active treatment was superior to placebo treatment (p = 0.049), but the allergen reduction achieved was < 20% (median 1,500 ng/g on day 0 vs. 1,250 ng/g after 8 weeks). We conclude that the slight mite allergen reduction on carpets achieved by the treatment with ‘Lowal’ is unlikely to achieve worthwhile clinical benefit either in the treatment of mite‐sensitive patients or in primary or secondary prophylaxis.     

Concentrations of cat (Fel d 1), dog (Can f 1) and mite (Der f 1 and Der p 1) allergens in the clothing and school environment of Swedish schoolchildren with and without pets at home

To investigate whether our hypothesis that cat and dog owners bring allergens to public areas in their clothes was true or not, we studied the levels of Fel d 1, Can f 1, Der p 1 and Der f 1 in dust from the clothes and classrooms of children in a Swedish school. We also investigated the levels of allergen in different areas in the four classrooms used by the children. Thirty-one children were selected in four classes, forming three groups: cat owners, dog owners and children without a cat or dog at home. Furthermore, a group of children with asthma was included. Cat and dog allergens were detected in all 57 samples from clothes and classrooms. Mite allergen Der f 1 was detected in low concentrations in 6 out of 48 and Der p 1 in 5 out of 46 samples investigated. The concentrations of Can f 1 were higher than those of Fel d 1 in samples from clothes (geometric mean: 2676 ng/g fine dust and 444 ng/g) and classrooms (Can f 1: 1092 ng/g, Fel d 1: 240 ng/g). The dog owners had significantly higher concentrations of Can f 1 (8434 ng/g fine dust) in their clothes than cat owners (1629 ng/g, p <0.01), children without cat or dog (2742 ng/g, p < 0.05) and children with asthma (1518 ng/g, p < 0.001). The cat owners did not have significantly higher levels of Fel d 1 (1105 ng/g) in their clothes compared to the other three groups (D: 247 ng/g, nCnD: 418 ng/g, A: 386 ng/g) but the levels were significantly higher than for all children without a cat at home (345 ng/g, p < 0.05). No concentrations of mite allergen and low concentrations of Fel d 1 and Can f 1 were found in the children's hair. There were significantly higher concentrations of Fel d 1 and Can f 1 in dust from curtains than in samples from floors and bookshelves (p < 0.05). There was no significant difference between the allergen concentrations in samples from curtains and from desks and chairs, including the teachers' chairs, the only upholstered furniture in the rooms. Our results support the hypothesis that cat and dog owners bring allergens to public areas in their clothes and support other studies showing that textiles and upholstered furniture function as reservoirs of cat and dog allergens. Thus, children with asthma and other allergic diseases will be exposed to cat and dog allergens at school and by contact with pet owners, even if they avoid animal allergens at home.     

广州地区1136例过敏患儿常见过敏原分布及尘螨交叉反应分析

目的观察广州市过敏性疾病患儿的过敏原分布及屋尘螨、粉尘螨过敏的交叉反应情况,为临床诊疗提供依据。方法采用MAST过敏原检测系统对1 136名过敏性疾病患儿(婴幼儿组278例、学龄前组455例、学龄组403例)进行35种特异性过敏原IgE检测,统计过敏原阳性率,同时分析尘螨过敏的交叉反应情况,分组间阳性率差异比较采用χ2检验。结果 1 136例过敏儿童前三位的过敏原分别是尘螨(68.13%)、家尘(49.03%)和牛奶(36.18%)。婴幼儿组前三位的过敏原分别为牛奶(70.14%)、芝士(47.84%)和全蛋(36.69%);学龄前期组前三位的过敏原分别为尘螨(80.13%)、家尘(68.35%)和牛奶(38.90%);学龄期组前三位过敏原分别为尘螨(75.93%)、家尘(40.45%)和猫毛狗毛(25.81%)。774例尘螨过敏患儿中,685例(88.50%)对粉尘螨和屋尘螨均呈阳性反应,9.56%仅对粉尘螨过敏,1.94%仅对屋尘螨过敏,各年龄组间差异无统计学意义(P>0.05)。结论广州地区过敏患儿过敏原分布较以往有一定的变化,且与国内其他地区亦存在差别。相当比例的过敏患儿对粉尘螨和屋尘螨同时阳性,仅少...     

The influence of exposure to house dust mite, cat, pollen and fungal allergens in the home on primary sensitisation in asthma

The homes of 68 atopic asthmatic children were studied to estimate the concentrations of perennial and seasonal aeroallergens (Der pl, Fel d1, grass pollen, tree pollen, Cladosporium , Aspergillaceae and Alternaria ) to which children were likely to have been exposed during their first few months of life, by sampling in the child's month of birth. There was a strong association between the presence or absence of the house dust mite allergen Der p1 in the air with the skin test and IgE antibody test results (p < 0.001), with a similar association for cat allergen Pel d 1 (p < 0.01), when using a low volume sampler (equivalent to the minute tidal volume of a small baby). No significant correlation was found between levels of allergen in carpet dust and air in the same room. There was a strong indication that the presence of a cat at birth was linked with a higher risk of development of allergy to cat, but high levels of Fel d 1 were sometimes found in homes even when there was no cat present, indicating that allergen may be introduced from other sources. The levels of tree pollen were significantly higher in the homes of tree pollen-allergic children than in the homes of patients without this sensitivity (p < 0.01); and the degree of sensitivity, determined by RAST, correlated significantly to the level of tree pollen in the home (p < 0.001). However, no relationship was found between specific sensitivity and the levels of Cladosporium , Aspergillaceae, Alternaria or grass pollen measured in the homes. The effect of high allergen exposure was most prominent in children under 7 yr and not beyond that age.     

Prenatal exposure to house dust mite allergen (Der p 1), cord blood T cell phenotype and cytokine production and atopic dermatitis during the first year of life

This study investigated the influence of prenatal exposure to house dust mite (HDM, D. pteronyssinus) on interleukin (IL)-2, interferon-gamma (IFN-gamma) and IL-4 producing CD4(+) and CD8(+) T lymphocytes in cord blood as well as on the development of sensitization and occurrence of atopic dermatitis (AD) as the first symptom of allergy during the first year of life. Dust samples (n = 22) were collected by vacuum cleaning the maternal mattress during early to mid-pregnancy. In these samples, the amount of the major HDM antigen (Der p 1) was assessed by a sensitive enzyme-linked immunosorbent assay technique (detection limit 0.004 microg/g dust). Flow cytometry was used to determine cord blood lymphocyte subtypes and to quantify the intracellular amounts of IL-2, IFN-gamma and IL-4 produced by cord blood CD4(+) helper and CD8(+) cytotoxic T lymphocytes, both spontaneously and after stimulation with phorbol-12-mirystate-13-acetate and ionomycin. Children were followed for 1 yr for the presence of symptoms associated with allergy. In addition, at the age of 1 yr specific IgE to different classical inhalant and food allergens was measured. Higher prenatal exposure to Der p 1 (>0.2 microg/g dust) was associated with a significant lower percentage of IFN-gamma producing stimulated CD4(+) T lymphocytes, compared with lower prenatal Der p 1 exposure (p = 0.03). The presence of AD during the first year of life (n = 9) was associated with an increased number of naive CD4(+) CD45RA(+) lymphocytes (p = 0.03), with an increased spontaneous IL-4 production by CD8(+) lymphocytes (p = 0.04) and with a decreased percentage of IFN-gamma producing stimulated CD4(+) lymphocytes (p = 0.04). Furthermore, exposure to HDM during pregnancy tended to be higher in mothers of children with AD during the first year of life when compared with those without AD (p = 0.08). This study shows that the level of prenatal exposure to Der p 1 influences the immune profile of cord blood T lymphocytes and the clinical outcome in early life. Therefore, the prenatal environment must be regarded as a possible early risk factors for allergic diseases in children.     

Local production of total IgE and specific antibodies to the house dust mite in adenoid tissue

Adenoids are known as immunosecretory organs and those in atopic children present cellular and cytokine profiles different from those of non‐atopic children. We hypothesized that locally produced total IgE and allergen‐specific antibodies could be involved in the inflammatory responses in adenoid tissue. Local productions of total IgE and Dermatophagoides pteronyssinus (DP)‐specific IgE, IgA, IgG1, and IgG4 antibodies were evaluated, as well as their relationships with the markers of allergic inflammation within adenoid tissue. Eighteen atopic subjects, who were sensitized to more than one common aeroallergen, and 22 non‐atopic subjects undergoing adenotonsillectomy, were recruited. Immunoassays using adenoid tissue homogenate were performed to quantify the levels of total IgE, eosinophil cationic protein (ECP), and mast cell tryptase. DP‐specific IgE, IgA, IgG1, and IgG4 antibodies, soluble IL‐2 receptors (sIL‐2R), soluble CD23 (sCD23), and IL‐6 were measured by ELISA. All parameters measured in adenoid tissue homogenate were presented as a ratio to the albumin level found in the adenoid. Median level of total IgE in adenoid tissue homogenate was significantly higher in atopic individuals than in non‐atopic individuals. Median values of DP‐specific IgE and IgA antibodies were significantly higher in atopics than in non‐atopics (p = 0.001, p = 0.006, respectively), while no differences were seen in DP‐specific IgG1 and IgG4 antibodies. ECP and sCD23 levels in adenoid homogenate were significantly higher in atopics than in non‐atopics (p = 0.026, p = 0.048, respectively), while no significant differences were noted in tryptase, sIL‐2R, and IL‐6 levels. The levels of DP‐specific IgE, IgA, IgG1, and IgG4 antibodies in adenoid homogenate correlated significantly with ECP levels, but not with those of sIL‐2R, sCD23, and IL‐6. The presence of total IgE and DP‐specific antibodies in adenoid tissue was confirmed to be more prominent in atopics. In conclusion, locally‐produced total IgE and DP‐specific antibodies may contribute to eosinophilic inflammation in adenoid tissue in atopic children.     

尘螨标准化免疫治疗85例哮喘儿童疗效相关指标分析

Objective The scientific basis and the clinical effectiveness of allergen specific immunotherapy (SIT) administered by subcutaneous injection are well established. This study aimed to observe the changes in amount of inhaled corticosteroids, total IgE, specific IgE, peak expiratory flow rate (PEF), etc. during a standardized SIT against house dust mite in allergic asthmatic children. Method Children (5-13 years old) with mild to moderate allergic asthma seen from February 2005 to June 2008 were enrolled into this study. A non- randomized retrospective study was performed. All children were diagnosed sensitive to dust mites, the treatment group accepted standardized dust mite allergen specific immunotherapy. Each fourth injections were defined as observation points, the study took 3.4 years. The investigators recorded the treatment, the cumulative allergen extract, changes of daffy doses of inhaled corticosteroid, peak expiratory flow (PEF), total IgE (TIgE), specific IgE (SIgE). The control group only received inhaled corticosteroids. The daily doses of inhaled corticosteroid and the number of asthma attacks,and the control rate were compared between the 2 groups. Result Totally 85 children were treated with SIT [(7.6 ± 1.4) years], 45 males and 40 females; 50 children received only drug treatment [(7.7 ± 1.5)years], 28 males and 22 females. The cumulative dose of allergen was up to (69.7 ± 4.8) μg after the 20 times injection, the dose of inhaled corticosteroids was significantly less than that in the control group ( t =2. 359, P ＜ 0.05). PEF was significantly higher than that of pre-treatment level ( F = 7.874, P ＜ 0.05 ).TIgE and SIgE had no significant change (t = 0.313, P ＞ 0.05, tDerp = 0.517, tDerf = 0.717,P ＞ 0.05 ). After the treatment, the control rate of the SIT group was 85.5%, that of the control group was 62.0% (X2 =10.150, P ＜0.01). Conclusion The standardized SIT against house dust mite could reduce steroid use in mild to moderate allergic asthmatic children. After ( 38.7± 2.3 ) weeks, the cumulative dose of allergen was up to (69.7 + 4.8) μg, inhaled corticosteroid was significantly reduced. At the end of SIT, 85% of patients obtained complete control of asthma. Total IgE and mite-specific IgE had no significant changes.     

儿童支气管哮喘过敏原测定及肺功能的变化

目的了解广州地区儿童支气管哮喘的过敏原及哮喘发作和缓解时肺功能的变化。方法应用MAST过敏原测定仪测定73例哮喘儿童的血清总IgE和35种过敏原，然后分别应用F2600型和303型肺功能促进行测定其哮喘发作和缓解时的肺功能变化。结果73例哮喘儿童中血清总IgE升高68例，占93．1％，这68例中可检出过敏原46例，占67．6％，46例中对尘螨过敏43例，占93．5％，对豚草、动物毛、蟑螂过敏3例，占6．5％。0～3a组哮喘发作时75％潮气量与最高呼气流速之比（25－PF）值为0．424±0．089，与正常预定值（0．6±0）比较显著降低．P＜0．01：而哮喘缓解时25－PF值为0．603±0.021，与正常预定值比较差异无显著性，P＞0．05。4～6a组和7a以上组哮喘发作时最大肺活量（FVC）、ls最大呼气量（FEV1）与正常预定值比较差异无显著性，P＞0．05．FEV1／FVC、FEF25％～75％与正常预定值比较差鼻有显著性，P＜0．05；而哮喘缓解时上述参数正常。结论广州地区儿童支气管哮喘与外源性过敏原密切相关．其中尘螨是诱发哮喘最主要的过敏原。肺功能仪测定哮喘儿童的肺功能变化可用来判断哮喘的严重程度，指导治疗和评价预后。     

The determinants of dust mite allergen and its relationship to the prevalence of symptoms of asthma in the Asia-Pacific region

The role that house dust mites play in the primary causation of asthma is controversial. Approximately thirty-six 10-yr-old children in each of 10 centres in the Asia-Pacific region participated. Researchers collected dust from mattresses and living room floors using standardized procedures. Der p1 and Der f1 were analysed using a double monoclonal antibody enzyme-linked immunosorbent assay. Geometric mean allergen levels were calculated for each centre. An ecological analysis was conducted to show the regression of the geometric mean allergen level, using the highest household level, against asthma symptom and severity prevalence data from the International Study of Asthma and Allergies in Childhood, Phase I. Among children aged 13–14 yr, the change in asthma symptom prevalence was associated with per unit change in Der p 1  μ g/g (1.08, 95% CI 0.10–2.06) and Der 1  μ g/g (Der p1 + Der f1) (0.64, 95% CI 0.02–1.26). The change in having four or more attacks of asthma in the last 12 months was associated with per unit change in Der p 1  μ g/g (0.29, 95% CI −0.02 to 0.60) and Der 1  μ g/g (0.20, 95% CI 0.01–0.38). There was no effect for total Der p1 or Der f1 (total or μ g/g). Among children aged 6–7 yr, neither allergen was related to symptoms or severity prevalence. While our findings suggest that Dermatophagoides pteronyssinus may have a role in the primary causation of asthma, the complexity of this association reinforces the need for prospective studies.     

白三烯受体拮抗剂对哮喘大鼠基质金属蛋白酶-9 及其抑制剂表达的影响

目的探讨基质金属蛋白酶-9(MMP-9)及其组织抑制物(TIMP-1)在支气管哮喘发病中的作用,评价白三烯受体拮抗剂对其的调节作用。方法应用ELISA、免疫组织化学、Western-blot及RT-PCR技术对白三烯受体拮抗剂治疗前后大鼠肺组织中MMP-9及TIMP-1表达进行研究。结果①大鼠肺组织MMP-9mRNA表达:哮喘7d组为(2.74±0.41),21d组为(1.69±0.25),白三烯受体拮抗剂治疗组为(0.91±0.20),正常对照组为(0.64±0.13),组间比较差异有统计学意义(F=123.42,P<0.01)。大鼠肺组织TIMP-1mRNA表达:哮喘7d组为(1.53±0.21),21d组为(1.98±0.28),白三烯受体拮抗剂治疗组(1.03±0.17),正常对照组(0.71±0.10),组间比较差异有统计学意义(F=65.59,P<0.01)。②RT-PCR结果与Westernblot结果一致。结论从蛋白质水平及分子水平显示哮喘大鼠模型肺组织MMP-9表达升高,TIMP-1表达亦增强;白三烯受体拮抗剂可能通过下调MMP-9及TIMP-1表达来抑制气道炎症和气道重塑。     

Reduction of catheter-related bloodstream infections in preterm infants by the use of catheters with the AgION antimicrobial system

Objective

The present study aims to assess if use of a silver zeolite-impregnated umbilical catheter (AgION technology) can decrease the occurrence of catheter-related bloodstream infection (CRBSIs) in preterm infants.

Study design

Infants with gestational age < 30 weeks were randomized to receive an AgION impregnated or non-impregnated polyurethane umbilical venous catheter (UVC). The primary endpoint was the incidence of CRBSIs during the time the UVC was in place.

Results

We studied 86 infants, 41 of whom received the AgION catheter and 45 the non-impregnated catheter. During umbilical venous catheterization 2% of infants in the AgION group developed CRBSI in comparison with 22% of infants in the control group (p = 0.005). AgION catheters were well tolerated and none of the patients showed signs attributable to silver toxicity.

Conclusions

The AgION-impregnated UVCs were effective in decreasing the development of CRBSIs in preterm infants compared to non-impregnated polyurethane UVCs.     

Process evaluation of the bassinet restraint loan scheme in Victoria

Abstract The value of the use of safety restraints for all vehicle occupants has been recognized, and corresponding legislation has been implemented in Australia. However, legislation alone has not been sufficient to increase significantly the use of safety restraints for infants. In an attempt to address this issue, a statewide infant safety restraint loan scheme has been in operation in Victoria since May 1985. At the time of this study, 203 of 210 municipalities in Victoria were participating in the scheme.     

The influence of pulmonary function testing on the management of asthma in children

OBJECTIVE: To assess how often in a single encounter that pulmonary function tests (PFTs) influenced management decisions in children with asthma, beyond what was obtained from history and physical examination alone. STUDY DESIGN: Children with asthma (n = 367, age 4 to 18 years) performed spirometry before clinical evaluation. Physicians and nurse practitioners in the outpatient pulmonary office evaluated the children and made initial treatment recommendations before reviewing the spirometry results. Any changes based on the test results were documented. RESULTS: Spirometry was abnormal in 45% of the visits, related to underlying asthma severity but not to clinical findings. PFT results changed management decisions in 15% of visits. This frequency was not affected by the patient's age, disease severity, symptom control, or exam findings. When spirometry did not change treatment decisions, the provider was more likely to maintain therapy (58%) than to increase (17%) or decrease (24%) therapy. In contrast, when spirometry did change treatment decisions, the provider was more likely to increase therapy (75%) than to maintain (20%) or decrease (5%) therapy. CONCLUSION: Without PFTs, providers often overestimated the degree of asthma control. This incorrect assessment could have resulted in suboptimal therapy.