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PubMed2001

Current indoor allergen levels of fungi and cats, but not house dust mites, influence allergy and asthma in adults with high dust mite exposure.

We assessed the influence of current indoor levels of fungi, house dust mite allergen (Der p 1), and cat allergen (Fel d 1) on sensitization and asthma in adults. A total of 485 adults answered a questionnaire and had skin prick tests and lung function tests. Dust and air samples were collected from their bedrooms. The dust was analyzed for Der p 1, Fel d 1, and fungal biomass (ergosterol). Fungal propagules were measured in air samples. Current asthma was defined as having wheezed during the past 12 mo plus bronchial hyperreactivity (BHR) to methacholine. High exposure to total airborne fungi was associated with increased BHR, but perhaps paradoxically with a lower risk of being sensitized to fungi. Ergosterol levels in floor dust were a risk factor both for being sensitized to fungi and having wheezed within the last year. High Fel d 1 levels in floor dust were found to increase the risk of being sensitized to cats and in beds to increase the risk of current asthma. Although Der p 1 levels in homes were high, people exposed to high Der p 1 levels in floor dust were less likely to be sensitized to house dust mites or to have wheezed within the past year. Current indoor levels of fungi and Fel d 1, but not Der p 1, influenced sensitization and asthma in adults with high dust mite exposure.

Adult↗

PubMed2002

Cloning and sequence analysis of a cDNA encoding Pso o II, a mite group II allergen of the sheep scab mite (Acari: Psoroptidae).

Psoroptes ovis (Hering), the sheep scab mite, is responsible for psoroptic scabies of cattle and sheep. Reverse translation of 30 N-terminal amino acids of the major P. ovis allergen, previously chosen as a candidate immunogen and identified as a 16 kDa protein yielded a degenerate sequence used to design oligodeoxynucleotide polymerase chain reaction (PCR) primers. Use of the PCR primers with a P. ovis cDNA library succeeded in amplification of a 90 bp cDNA gene fragment that was cloned, sequenced, and used to select unique sequencing/PCR primers. Primer walking generated overlapping subclones which yielded the 588 nucleotide consensus sequence of the cDNA encoding the 143 amino acid P. ovis allergen precursor. Nucleotide and translated sequences of the cDNA were compared with sequences in GenBank and found to be homologous to mite group II allergens Lep d II (formerly Lep d I) of Lepidoglyphus destructor Schrank, DerfII of Dermatophagoides farinae Hughes, Der p II of Derrmatophagoides pteronyssinus (Trouessart), Tyr p II of Tyrophagus putrescentiae (Schrank), Eur m II of Euroglyphus maynei (Cooreman) and Gly d II of Glycophagus domesticus (De Geer). The mature P. ovis allergen is composed of 126 amino acids with a calculated molecular mass of 13,468 Da, three disulfide bonds, and pI of 6.06 with one potential o-glycosylation site at Thr116. We designate the P. ovis 16 kDa protein as Pso o II in conformity with nomenclature for mite group II allergens.

Allergens↗

PubMed1992

Lymphocyte transformation test for house dust mite in atopic dermatitis: relationship between mite antigens for type I and type IV allergy.

Using a crude extract obtained from Dermatophagoides farinae, and its four fractions (I, II, III and IV) partially purified by high-speed gel filtration chromatography, scratch tests and lymphocyte transformation tests (LTTs) were performed on 37 patients with atopic dermatitis. Crude mite antigen provoked positive scratch test reactions in 25 (68%), and positive LTT reactions in 19 (51%) of the 37 patients examined. Mite antigen fractions I, II, III and IV induced a positive LTT reaction in 19, 22, 17 and 7 patients, respectively. Of the 65 positive LTT reactions, 25 accompanied a positive scratch test to the antigen fraction which provoked the positive LTT reaction, but 40 accompanied a negative scratch test. These findings suggest that house dust mite antigen fractions for type IV allergy are different from those for type I allergy in a considerable proportion of patients with atopic dermatitis.

Adolescent↗

PubMed1991

Induction of IgE-Fc receptor (Fc epsilon R2/CD23) expression on lymphocytes from patients with mite-allergic bronchial asthma by mite allergen.

The present study was designed to clarify whether Fc epsilon R2 can be induced on lymphocytes of patients with bronchial asthma by stimulation with specific antigen. Expression of Fc epsilon R2 on freshly isolated lymphocytes (at 0 hour) was significantly higher in both patients with mite-allergic asthma and those with nonmite-atopic asthma than in healthy individuals. In addition, expression of Fc epsilon R2 on lymphocytes was still higher in patients during acute asthma. Marked induction of Fc epsilon R2 on lymphocytes was observed 48 hours or more after addition of mite-allergen in patients with mite-allergic asthma while no Fc epsilon R2 expression was induced in patients with nonmite-atopic asthma or healthy individuals. Induction of Fc epsilon R2 expression was not observed at 30 minutes, two hours, and five hours, which are equivalent in kinetics to immediate asthmatic response and late asthmatic response in allergen inhalational challenges.

Allergens↗

PubMed1990

[Result of "as is patch test" using mite elements in atopic dermatitis (AD) patient. 2nd report, "Mite lipid"].

The antigenicity of mite lipid was studied, taking atopic dermatitis as an allergic disease. Lipid was extracted from Dermatophagoides pteronyssinus (Dp) and D. farinae (Df). It was tentatively designated a mite lipid antigen (Dp-L, Df-L), and then a patch test was performed. An extract from animal food (LC) and acetone were used as the controls. With only Dp-L, a positive reaction of more than one plus (+) of the ICDRG standard was noted in 3 out of 21 cases of AD. Histology of the above-mentioned positive cases revealed spongiosis and infiltration of small round cells in the upper dermis along with scattered eosinophiles. Leu 6 positive cells were noted frequently in the epidermis and dermis. The lipid components of Dp-L were made up mostly of phospholipid and triglycerides+, and lipoprotein was not contained. Judging from the findings above it appears necessary to study not only protein but also lipid in connection with the mite antigenicity++ in AD in the future.

Adolescent↗

PubMed1986

Increased serum IgE antibodies in institutionalized asthmatic children after a transient return home. The role of house dust mite allergens in the home as a trigger of asthmatic attacks in mite-sensitive patients.

Increased serum IgE antibodies to Dermatophagoides pteronyssinus, a house dust mite, were observed in 12 of 13 institutionalized mite-sensitive asthmatic children after returning for four days to their own homes. These results implicate the house dust mite as a trigger of asthmatic attacks in these patients.

Adolescent↗

PubMed1981

Tropical rat mite dermatitis. Report of six cases and review of mite infestations.

Six cases of tropical rat mite (Ornithonyssus bacoti) dermatitis are presented. The patients experienced papular urticaria, and mites were found on and identified in several of the patients. The presence of rodents in or around the home was confirmed in most cases. The role of other parasitic mites found on bats, birds, and snakes is reviewed. The importance of obtaining a history of rodent activity or exposure to other animals is emphasized when considering the cause of arthropod bites.

Adult↗

PubMed1981

Antigens and allergens in Dermatophagoïdes farinae mite. I. Immunochemical and physicochemical study of two allergenic fractions from a partially-purified Dermatophagoïdes farinae mite extract.

The fractionation of a partially-purified extract of Dermatophagoïdes farinae mite culture has been undertaken by gel filtration. Two fractions were isolated. One, P25, is a protein-rich fraction with mol. wt about 25,000. The other, GP8, is a polysaccharide-rich fraction with mol. wt around 8,000. By crossed immunoelectrophoresis, we detected eleven antigens in the partially-purified dialysed D. farinae extract (Df 80d) as well as in P25 fraction. One of them, ag 11, seems the most important allergen since in crossed-radio immunoelectrophoresis experiments it displays the faster radiostaining, implying that it binds the greatest part of the mite-specific IgE present in a pool of sera from mite-sensitive patients. By crossed-line immunoelectrophoresis, we demonstrated the absence of ag 11 in GP8, in which only ag 5 and ag 6 were identifiable. By radioalloergosorbent tests (RAST), it was found that P25- and GP8- coated paper discs can fix specific IgE induced in the majority of D. farinae sensitive patients. Defining a 'major allergen' as an allergen to which the majority of sensitive patients develop specific IgE, both P25 and GP8 do appear to contain at least one major allergen. By RAST inhibition method, using Df 80d as a solid phase, the allergenic activity of P25 appeared as slightly higher than that of Df 80d, whereas GP8 displayed a very weak inhibitor capacity. Thus, the allergic specificity of GP8 differs from that of Df 80d or P25.

Allergens↗

PubMed1995

[Desensitization immunotherapy on patients with mite-positive bronchial asthma using purified mite feces antigen fractions].

At present, we are performing desensitization immunotherapy on patients with mite-positive bronchial asthma using purified mite feces antigen fractions. We obtained the following results in 13 patients 4 to 12 months after the start of treatment. 1) The fraction showing the maximum reaction in the skin test was HM1-2 (molecular weight: 150-155 kD) in two patients, HM2 (30-40 kD) in nine patients and HM3 (10-20 kD) in two patients, and immunotherapy was performed using these fractions. None of the patients showed the maximum skin reactions or was treated with HM4 (less than 10 kD). 2) In nine patients with perennial asthma, the effects of treatment were excellent in four and moderate in three, while two cases remained unchanged. In four patients with seasonal asthma, the treatment was effective in all cases. 3) In patients in whom immunotherapy was effective, specific IgG antibody increased after the treatment, but it did not increase in the unchanged cases. Among the subclasses of specific IgG antibody increased by the treatment, no clear changes were seen in IgG4 antibody and no conclusion has been reached at present. 4) None of the patients had definite adverse reactions such as the occurrence of asthma attacks or anaphylaxis. These results suggested that purified mite feces antigens are safe and effective. We plan to continue this study with more patients in the future.

Adolescent↗

PubMed2003

Quantitation of house dust mites and house dust mite allergens in the microenvironment of dogs.

OBJECTIVE: To quantitate the density of Dermatophagoides farinae and D pteronyssinus and concentrations of house dust mite (HDM) allergens (Der f 1, Der p 1, and Group 2 allergens) in the indoor microenvironment of dogs. SAMPLE POPULATION: 50 homes in Columbus, Ohio. PROCEDURES: In each home, samples of dust were collected from 3 locations in which dogs spent most time. Whenever possible, the species of mites collected was identified. Mite density (mites/g of dust) was assessed, and allergen concentrations were assayed by standardized ELISAs. Relative humidity and temperature in each home were monitored during a 5-day period. Characteristics of homes and sample sources were evaluated. RESULTS: Dust samples from all 50 homes contained > or = 1 HDM allergen; Der f 1 and Der p 1 were detected in 100 and 74% of homes, respectively. Fifteen homes had HDMs; compared with D pteronyssinus, D farinae was found more commonly (14/15 homes) and at a higher density. Basements, homes without central air-conditioning, and dog beds that were > or = 1 year old had high HDM allergen concentrations. Homes with > or = 2 microg of Der f 1 or Group 2 allergens/g of dust or > or = 100 mites/g of dust were significantly more likely to have a maximum relative humidity > or = 75%. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated the presence of HDMs and HDM allergens in the specific microenvironment of dogs in homes. Factors associated with high levels of exposure were identified, which may be associated with increased risk for sensitization and development of atopic diseases.

Allergens↗

PubMed1976

Anti-mite measurements in mite-sensitive adult asthma. A controlled trial.

A cross-over controlled trial has been conducted among 32 adult patients with mite-sensitive asthma. The bedclothes and pillows of each subject were laundered and vacuum-cleaned and a plastic cover applied to the mattress for six weeks in an attempt to reduce exposure to mites. No improvement in daily peak-flow reading or drug usage was found in comparison with a control period.

Adult↗

PubMed1975

[Biology of the house dust mite dermatophagoides pteronyssinus. II. Incidence of mites in the various regions of Switzerland and its dependence on climate].

Seasonal examinations of dust samples from Basel and surroundings have shown that the number of mites increases during the months of August through October. Dust samples were then collected from various climatic regions of Switzerland during August and tseptember. Samples originating from places where the temperature was above 12 degrees C and relative humidity above 68% over a period of 4-5 months yielded a high mite count. Regions with these climatic conditions are therefore unfavourable for patients allergic to house-dust.

Altitude↗

PubMed2005

The involvement of volatile infochemicals from spider mites and from food-plants in prey location of the generalist predatory mite Neoseiulus californicus.

We investigated volatile infochemicals possibly involved in location of the generalist predatory mite Neoseiulus californicus to plants infested with spider mites in a Y-tube olfactometer. The predators significantly preferred volatiles from lima bean leaves infested with Tetranychus urticae to uninfested lima bean leaves. Likewise, they were attracted to volatiles from artificially damaged lima bean leaves and those from T. urticae plus their visible products. Significantly more predators chose infested lima bean leaves from which T. urticae plus their visible products had been removed than artificially damaged leaves, T. urticae, and their visible products. These results suggest that N. californicus is capable of exploiting a variety of volatile infochemicals originating from their prey, from the prey-foodplants themselves, and from the complex of the prey and the host plants (e.g., herbivore-induced volatiles). We also investigated predator response to some of the synthetic samples identified as volatile components emitted from T. urticae-infested lima bean leaves and/or artificially damaged lima bean leaves. The predators were attracted to each of the five synthetic volatile components: linalool, methyl salicylate, (Z)-3-hexen-1-ol, (E)-2-hexenal, and (Z)-3-hexenyl acetate. The role of each volatile compound in prey-searching behavior is discussed.

Acetates↗

PubMed1992

Isolation of Der pI, the Dermatophagoides pteronyssinus major mite allergen, from a crude mite culture extract, purification by ion-chromatography, and comparison between the material obtained and a cDNA-coded Der pI.

A high degree of purity is a prerequisite for an allergen preparation to be suitable for clinical diagnosis and therapy. A pure allergen can easily be obtained from a crude mite culture extract by using an immunosorbent prepared with highly specific monoclonal antibodies or from a cDNA-coded material. However, up to now none of these methods has been performed on a process scale. Here large-scale purification is defined as a process in which a crude Dermatophagoides pteronyssinus mite culture extract is essentially fractionated by acetone and ammonium sulphate precipitations followed by anion-exchange high-performance liquid chromatography. A high yield of a very pure Der pI allergen is obtained during the first isocratic run, as shown by sodium dodecylsulphate-polyacrylamide gel electrophoresis, capillary electrophoresis, chromatofocusing and a two site monoclonal antibody enzyme-linked immunosorbent assay. Microsequencing revealed that the 25-residue sequence obtained is entirely in agreement with the sequence derived from the cDNA of Der pI.

Allergens↗

PubMed1993

A double-blind, placebo controlled trial of solidified benzyl benzoate applied in dwellings of asthmatic patients sensitive to mites: clinical efficacy and effect on mite allergens.

BACKGROUND: The aim of this double-blind, randomized study was to investigate the effectiveness of an acaricidal cleaning product in modifying both clinical symptoms and mite allergen levels over a period of at least 1 year. METHODS: Twenty-six asthmatic patients with proven Dermatophagoides pteronyssinus (Dp) asthma were selected; three were withdrawn from the trial. The patients' homes were divided into two groups; 11 homes were treated with solidified benzyl benzoate and tenside agents (A), and 12 were treated with a placebo (P). Two applications were performed at the beginning of the trial and at least 6 months later. Patients were examined 1 month before the trial, at the beginning of the trial, and every 3 months over a period of 1 year. Indoor mite exposure was evaluated by three methods: semiquantitative guanine determinations, quantitative guanine determinations, and the measurement of Der p I + Der f 1 (antigen P, of Dp + antigen F1 of D. farinae) levels. RESULTS: The symptom scores established at the beginning of the trial and 12 months later showed a statistically significant improvement only in the A group (p < 0.01). The visual analog scale also showed a statistically significant difference both in the A (p < 0.05) and P groups (p < 0.01). No statistical differences were found between medication scores in the A or P groups. A statistically significant increase was also observed for forced expiratory volume in 1 second and maximal expiratory flow rate 25/75 in the two groups (p < 0.05 for P group; p < 0.01 for A group). The mean decreases in Der p I + Der f 1 in patient mattresses between the beginning of the trial and after 12 months were 20% for the acaricide group and 17% for the placebo group, respectively (NS). For house dust samples with origins other than the patients' mattresses we found significant decreases in Der p I+Der f 1 in the A group (p < 0.01 for carpets and p < 0.05 for upholstery elements).

Adolescent↗

PubMed2003

Nitric oxide production by alveolar macrophages in response to house dust mite fecal pellets and the mite allergens, Der p 1 and Der p 2.

BACKGROUND: Allergens are frequently found within or attached to particulate material. For example, house dust mite fecal pellets (HDMFP) contain the major mite allergens, exposure to which have been implicated in the development of asthma. Although several studies have examined the ability of purified allergens to generate inflammatory responses, few studies have investigated whether HDMFP per se, are biologically active. OBJECTIVE: Our objective was to examine the ability of whole HDMFP to stimulate nitric oxide (NO) release from alveolar macrophages. METHODS: The rat alveolar macrophage cell line, NR8383, was exposed to HDMFP, Der p 1, or Der p 2, and nitrite levels in the culture supernatants were measured with the Griess reagent. NO synthase mRNA expression was determined by RT-PCR. RESULTS: HDMFP stimulated the production of NO in a dose-dependent and time-dependent manner, with maximum NO levels measured after 48 hours of exposure. Inclusion of polymyxin B did not influence NO production, suggesting that LPS was not responsible for NO production. HDMFP-mediated NO release was down-modulated after treatment with N(G)-nitro-l-arginine methyl ester (L-NAME), dexamethasone, EDTA, and cysteine, but not heat treatment. Inducible nitric oxide synthase mRNA was observed 3 hours after HDMFP exposure, with maximum levels after 48 hours. Both purified Der p 1 and Der p 2 induced NO production, and inhibition of the cysteine protease activity of Der p 1 had little effect on NO production. CONCLUSIONS: HDMFP, Der p 1 and Der p 2 are potent inducers of NO. Neither LPS nor the enzymatic activity of Der p 1 was responsible for NO production observed.

Allergens↗

PubMed2000

Potential of the mite-pathogenic fungus Neozygites floridana (Entomophthorales: Neozygitaceae) for control of the cassava green mite Mononychellus tanajoa (Acari: Tetranychidae).

The cassava green mite, Mononychellus tanajoa (Bondar), is an exotic pest in Africa and is the target of a classical biological control programme. Field data from the Neotropics, where it is indigenous, are presented for the first time, charting the variation in abundance of M. tanajoa over several seasons. This was highly variable, with a characteristic trough mid-year and a peak at the turn of the year. This pattern corresponded positively with rainfall levels, appearing to fit a phenology also characteristic of African studies, where rainfall at the start of the wet season promotes a leaf flush and so growth in M. tanajoa populations. Analyses implied some impact of leaf-inhabiting predatory mites (predominantly Neoseiulus idaeus Denmark & Muma) and a considerable impact of the fungal pathogen Neozygites floridana Fisher on M. tanajoa populations. This pathogen was not observed in the host population for several (generally dry) periods implying survival outside the host, perhaps as resting spores. This is a particularly desirable characteristic of a biological control agent. It is therefore proposed that N. floridana might be of particular use in drier cassava-growing areas where rainfall at the outset of the wet season is not sufficiently intense to cause heavy M. tanajoa mortality but may be sufficient to stimulate epizootics of the fungal pathogen, protecting the flush of new cassava growth.

Animals↗

PubMed2000

Life cycle and parasitic interaction of the lizard-parasitizing mite Ophionyssus galloticolus (Acari: Gamasida: Macronyssidae), with remarks about the evolutionary consequences of parasitism in mites.

Wild-caught specimens of the lacertid lizard Gallotia galloti eisentrauti from the Canary Island of Tenerife were checked for ectoparasites. The parasitic gamasid mite Ophionyssus galloticolus Fain and Bannert (2000) was very abundant on these lizards. Additionally, parasitism by larvae of two species of Trombiculidae (Prostigmata: Parasitengona) was observed. O. galloticolus was reared in the laboratory on its natural host in order to investigate its life cycle, reproductive biology, and development. The life history of O. galloticolus is documented in detail and compared to literature data of other Ophionyssus species. O. galloticolus was found to be similar to other species of the same genus with respect to the duration of development, the precopulatory association of protonymphs, and the arrhenotokous development of eggs. However, it seems to be more tolerant towards low relative humidity and longer starvation periods than other Ophionyssus species. Evolutionary transformations of the life-history pattern of this genus and other parasitic mites in comparison to its predatory precursors involve a reduction or partial suppression of ontogenetic instars in order to decrease mortality during host-seeking phases, and a compensating increase in growth capacity of the remaining feeding instars facilitated by replacement of sclerites through elastic cuticle or by growth of new cuticle unrelated to a moult (neosomy).

Animals↗