Efficacy of occupant-collected dust samples in the evaluation of residential allergen and fungal levels.

This study evaluated the ability of a resident to evaluate their home for allergens and mold using a settled dust test kit compared with evaluation and collection of settled dust by an industrial hygienist. Forty-three home residents were provided with a kit containing written instructions and a vacuum cleaner attachment for collecting a settled dust sample. Within 2 weeks of receiving the occupant-collected sample, an industrial hygienist evaluated these homes, including a visual inspection, collection of settled dust, and collection of spore trap samples. Settled dust samples were analyzed for major dog, cat, dust mite, and cockroach allergens using immunoassay methods, and for mold spore equivalents using quantitative polymerase chain reaction methods for the 13 mold species or species groups comprising the American Relative Moldiness Index (ARMI). Allergen concentrations and ARMIs were compared between the resident- and industrial hygienist-collected samples. Linear regression between the two sets of samples showed strong correlations for dog allergen (r(2) = 0.92) and cat allergen (r(2) = 0.90). Correlations for dust mite (r(2) = 0.57) and cockroach allergens (r(2) = 0.22) were lower, likely due to most samples being near the limit of detection. ARMIs were highly correlated (r(2) = 0.68) and were in categorical (high, medium, or low) agreement for 76% of residences. These results show that residents can reliably follow directions and collect settled dust samples, providing an efficient method to remotely screen homes for elevated allergen levels and to identify homes with a potential mold or moisture problem that may need further evaluation.

DNA:anti-DNA complexes: their detection in systemic lupus erythematosus sera.

Antibody to DNA was measured before and after treatment of systemic lupus erythematosus (SLE) sera with bovine pancreatic deoxyribonuclease (DNase I). In 11 of 15 cases of SLE with active renal disease there was a significant increase in DNA-binding after DNase digestion, while no such increase was noted in inactive SLE, normal controls or in patients with nonlupus renal disease. The significant rise in DNA-binding after digestion indicated that DNA had bound in vivo to the anti-DNA in these sera. A striking correlation between the occurrence of these complexes and disease activity was shown. In eight cases of SLE nephritis where serial blood samples were obtained, the greatest increase in DNA-binding after DNase digestion occurred at the time of the severest renal disease. In addition, serum from a case of SLE with acute cerebritis but without evidence of renal disease also had a significant rise in binding during the acute phase. This assay provides proof of the existence of circulating DNA:anti-DNA complexes in some cases of SLE and can also be used to measure an apparently critical parameter of disease activity.

Degradation of circulating DNA by extracorporeal circulation over nuclease immobilized on nylon microcapsules.

Studies were undertaken to determine whether deoxyribonuclease I, (DNase I) once immobilized on activated nylon microspheres, would be capable of degrading circulating DNA in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 4.73 mg of Dnase I. In vitro studies showed that DNase I immobilized on microspheres degreded a significant percentage of 125I-native DNA (nDNA) within 15 min. Mongrel dogs were injected with 125I-nDNA and a variation in initial t 1/2 in individual animals was observed. Therefore, for experimental studies, 125I-nDNA was injected and decay was recorded during a control period in which untreated microcapsules were utilized in the extracorporeal system. DNase I microspheres were then introduced into the extracorporeal circuit which resulted in an acceleration of degradation of acid precipitable 125I-nDNA. When 200 mug of unlabeled DNA with 125I-nDNA was injected, a similar augmentation of DNA degradation was noted after extracorporeal circulation over DNase I microcapsules. This effect could not be attributed to release of DNase I from the microspheres since no 131I-DNase was detected in the serum or organs of the dogs at the conclusion of the experiments. 125I-nDNA:anti-DNA complexes were passively injected into dogs and after a similar control period of circulation over untreated microcapsules. DNase I microspheres were introduced. Results showed a rapid acceleration in the degradation rate of 125I-nDNA:anti-DNA complexes precipitable with (NH4)2SO4. Extracorporeal circulation over nylon microspheres resulted in no significant alteration of the host's hematocrit or platelet count, and little residual cellular debris on the microcapsules. These data suggest that DNAase immobilized on nylon microspheres may have a potential role in the specific therapy of systemic lupus erythematosus, when it is desirable to hydrolyze DNA circulating free or in combination with antibody.

Presence of IgE antibodies to staphylococcal exotoxins on the skin of patients with atopic dermatitis. Evidence for a new group of allergens.

In the current study, we investigated whether Staphylococcus aureus grown from affected skin of atopic dermatitis (AD) patients secreted identifiable toxins that could act as allergens to induce IgE-mediated basophil histamine release. The secreted toxins of S. aureus grown from AD patients were identified by ELISA using antibodies specific for staphylococcal enterotoxin (SE) exfoliative toxin (ET), or toxic shock syndrome toxin (TSST-1). S. aureus isolates from 24 of 42 AD patients secreted identifiable toxins with SEA, SEB, and TSST accounting for 92% of the isolates. 32 of 56 AD sera (57%) tested contained significant levels of IgE primarily to SEA, SEB, and/or TSST. In contrast, although SEA, SEB, or TSST secreting S. aureus could be recovered from the skin of psoriasis patients, their sera did not contain IgE antitoxins. Freshly isolated basophils from 10 AD patients released 5-59% of total histamine in response to SEA, SEB, or TSST-1 but only with toxins to which patients had specific IgE. Basophils from eight other AD patients and six normal controls who had no IgE antitoxin failed to demonstrate toxin-induced basophil histamine release. Stripped basophils sensitized with three AD sera containing IgE to toxin released 15-41% of total basophil histamine only when exposed to the relevant toxin, but not to other toxins. Sensitization of basophils with AD sera lacking IgE antitoxin did not result in release of histamine to any of the toxins tested. These data indicate that a subset of patients with AD mount an IgE response to SEs that can be grown from their skin. These toxins may exacerbate AD by activating mast cells, basophils, and/or other Fc epsilon-receptor bearing cells armed with the relevant IgE antitoxin.

Staphylococcal toxins augment specific IgE responses by atopic patients exposed to allergen.

Microbial agents are known to play a significant role in aggravating allergic diseases. Recently described viral and bacterial superantigens represent one important strategy by which infectious agents can stimulate the immune response. In previous work, we reported that the staphylococcal toxin toxic shock toxin-1 (TSST-1), a prototypic superantigen, induces in vitro total IgE synthesis after cross-linking T and B cells. This study was carried out to establish a potential link between superantigens and the enhanced IgE response to specific allergens in allergic patients. Peripheral blood mononuclear cells from atopic patients were isolated during and outside the pollen allergen season and stimulated with TSST-1, a prototypic superantigen. Total IgE and interferon-gamma production were measured in supernatants of these cultures. Outside the pollen season, TSST-1 significantly increased total IgE production only in the presence of exogenous interleukin-4, whereas during the pollen season IgE production was significantly enhanced without the need of exogenous interleukin-4. This increase in the absence of exogenous interleukin-4 was associated with significantly lower interferon-gamma production by peripheral blood mononuclear cells stimulated by TSST-1 during the pollen season. Moreover, TSST-1 stimulation of peripheral blood mononuclear cells from inhalant allergic patients was followed by an increased production of allergen-specific IgE that was restricted to the allergen to which the patient was allergic and recently exposed. In addition, TSST-1 induced on B cells the expression of B7.2, a molecule that has recently been demonstrated to enhance T helper 2 responses and to be involved in IgE regulation. This study, by demonstrating that superantigens can augment allergen-specific IgE synthesis and B7.2 expression, provides a mechanism by which microbial superantigens may modulate allergic responses.

Chronic immune complex disease: behavioral and immunological correlates.

Using a fear avoidance paradigm, behavioral effects were seen in Sprague-Dawley rats in which chronic immune complex disease was induced. These effects were related to changes in urine protein that developed during the course of the experiment. Experimental animals also had glomerular deposits of rat gamma globulin and BSA as determined by immunofluorescence; C3 deposits were observed in half of these animals. BSA and/or rat gamma-globulin, but not C3, was seen in the choroid plexus of half of the experimental animals. This is the first study to report behavioral changes associated with the induction of chronic immune complex disease in experimental animals.

The isolation and characterization of enriched microvascular endothelial cells from mouse adipose tissue. The induction of class II molecules of the major histocompatibility complex (MHC) by interferon-gamma (IFN-gamma).

Collagenase digestion and selective filtration have been used to establish primary cultures from mouse omentum of cells enriched for microvascular endothelium. In culture these cells exhibit a cobblestone morphology characteristic of endothelial cells, metabolize an acetylated low-density lipoprotein, and exhibit trace levels of angiotensin-converting enzyme activity. In primary cultures, the cells are negative for class II molecules (Ia) of the major histocompatibility complex (MHC) but can be induced to express these molecules by exposure to a supernatant from concanavalin A (ConA)-treated rat spleen cells or by recombinant interferon-gamma (rIFN-gamma). This procedure can provide a readily available source of enriched endothelial cells which can be used to understand the interactions between these cells and cells of the immune system.

The prognostic and therapeutic implications of DNA:anti-DNA immune complexes in systemic lupus erythematosus (SLE).

Serum samples serially obtained from 50 patients with systemic lupus erythematosus (SLE) were studied for antibody to deoxyribonucleic acid (DNA) and circulating DNA:anti-DNA complexes during the active and inactive phases of their disease. The patients were divided into four categories: Group I: six patients without clinical evidence of central nervous system (CNS) or renal involvement. Group II: three patients with CNS lupus. Group III: nine patients with normal urinalyses and glomerular filtration rates, but morphologic evidence of glomerular disease. Group IV: 32 patients with overt lupus nephritis. Elevated anti-DNA levels were observed in 16 of 18 patients (88 per cent) in groups I, II and III during active disease. This persisted in 14 (77 per cent) during remission. DNA:anti-DNA complexes were demonstrated in four of 18 (22 per cent) during active disease and disappeared in all but one patient with progressive disease. In 30 of the 32 patients (94 per cent) in group IV, DNA binding was increased during active disease; this persisted in 21 (70 per cent) despite remission. Complexes were observed in 25 of the patients in group IV (78 per cent) with active disease. In six of these patients, complexes have persisted; two have died, one has progressed to renal failure and the remaining three patients continue to manifest active disease. This study suggests that measurement of DNA:anti-DNA complexes provides a valuable additional index of disease activity and prognosis in SLE.

The immune system can affect learning: chronic immune complex disease in a rat model.

Evidence is presented that the immune system can affect central nervous system functioning, leading to changes in learning. Immune complex disease is induced in rats and their behavior tested using a Lashley maze. Significant differences in behavior were found between the animals with high disease activity and those with low disease activity and the non-disease controls. These changes were not due to uremia and are most likely due to the immune response. There is some evidence immune complex deposits in the choroid plexus may play some role, but not the sole or major role in the behavioral changes. This provides a model by which immunologic processes can cause neuropsychiatric manifestations in autoimmune diseases like lupus, as well as showing that immune processes can affect behavioral functioning.

Suppression of water intake by immune complex formation in the hypothalamus. Implications for systemic lupus erythematosus.

Immune complex formation in the perifornical region of the hypothalamus resulted in depressed water consumption in rats, but did not consistently alter body temperature. The antibody with an unrelated antigen did not affect water consumption or body temperature. These results support the notion that immune complex reactions within the central nervous system can alter behavior.

Anti-Ia antibodies inhibit the spontaneous secretion of IL-1 from silicotic rat alveolar macrophages.

Class II antigens of the major histocompatibility complex (Ia) are important components in the investigation of cell-mediated immune responses. Several reports have indicated that anti-Ia monoclonal antibodies suppress disease development in animal models. In this paper, the expression of Ia and the effect of anti-Ia on IL-1 secretion from alveolar macrophages (AM) from silica-treated rats was examined. The results obtained showed that 45% of silicotic AM, but only 5% of AM from normal control rats, express Ia antigen. Anti-Ia treatment of silicotic AM reduced IL-1 secretion by 55%. We conclude that anti-Ia immune suppression may involve the inhibition of IL-1 secretion.

Class II antigens of the major histocompatibility complex are increased in lungs of bleomycin-treated rats.

The expression of class II molecules (Ia) of the major histocompatibility complex by isolated alveolar macrophages (AM) and alveolar type II cells from the lungs of rats with bleomycin-induced pulmonary fibrosis was examined. The percentage of Ia-positive AM and type II cells from rats treated with bleomycin as detected by flow cytometry was increased three times and two times, respectively, over the values obtained from control rats. The relative density of Ia expression, determined with a radioimmunoassay technique, showed a 50% increase in Ia density on AM and a 35% increase on type II cells. Recombinant interferon-gamma increased the expression of Ia on type II cells in vitro by 35% to the level obtained on type II cells in bleomycin-induced lung disease. We conclude that the increase of Ia expression on cells of the immune system and on pulmonary epithelial cells may have an important role in the initiation and/or amplification of inflammatory reactions in the lung and may contribute to the development of pulmonary fibrosis.

Prediction of early-onset asthma in genetically at-risk children.

The W.T. Grant Foundation Asthma Risk Study was designed to prospectively examine children who were considered at a genetically increased risk for the development of asthma. The respective contributions of 11 potential risk factors, both environmental and biological, were assessed in order to determine their relative roles in affecting the early onset of asthma. This is a report of an inception cohort of children born to asthmatic mothers and followed for a 3-year period. All 150 families were recruited from the general community and living within 2 h of the National Jewish Center for Immunology and Respiratory Medicine (Denver, CO). Mothers in the index risk sample had been previously diagnosed with asthma and were recruited during their pregnancy through physician referrals and media solicitation. The index sample of 150 families was 92% Caucasian and predominantly middle class. The mean age of mothers was 29.3 years, and of fathers, 31.1 years. The main outcome was the determination of the early onset of asthma and its association with quantified risk factors. By age 3 years, 14 of the 150 children had developed asthma. Frequent illness, IgE levels at age 6 months, parenting difficulties, and early eczema were significantly associated with the onset of asthma (P = 0.003, P = 0.006, P = 0.01, and P = 0.03, respectively). Only frequent illness, elevated serum IgE levels, and parenting difficulties entered a predictive model where they were independently related to the development of asthma.

Comparison of exhaled nitric oxide, serum eosinophilic cationic protein, and soluble interleukin-2 receptor in exacerbations of pediatric asthma.

The hypotheses tested in this study were that during acute asthma exacerbations (1) exhaled nitric oxide concentrations [eNO] are a more sensitive, noninvasive indicator of asthma disease activity than serum markers of inflammation such as eosinophil cationic protein (ECP) or soluble interleukin 2 receptor (sIL2R), and (2) elevated [eNO] are reduced after treatment with glucocorticoids (GC). Peak eNO levels were measured by chemiluminescence during slow expiration. Seven asthmatic subjects (mean age 11 yrs; mean morning FEV1 65% predicted) receiving inhaled GC, and with no radiographic evidence of acute sinusitis, were studied before and after a course of oral GC. Measurements of [eNO], ECP and sIL2R levels, and FEV1% were obtained before and after a course of GC. Six atopic nonasthmatic subjects (mean age 12 years; mean FEV1 94% predicted) and seven normal subjects (mean age 13 years; mean FEV1 100% predicted) were studied. The mean peak [eNO] level (parts per billion: ppb) for the asthma subjects before treatment (52 +/- 5 ppb SEM) was greater than the value for both nonasthmatic atopic and normal subjects (16 +/- 2 ppb and 14 +/- 2 ppb SEM, respectively; P < 0.0001). There was no significant difference in ECP or sIL2R values between asthmatic subjects and either atopic or normal subjects (P > 0.05). Baseline pre-GC treatment ECP levels in the asthmatic subjects were significantly higher (P < 0.002) than post-GC treatment values. The mean peak [eNO] level in the asthmatic subjects declined after oral GC treatment to 14 +/- 1 ppb (P < 0.0002) and was less than 2 ppb different from either control group (P > 0.75). We conclude that [eNO] is a more sensitive marker of asthma disease activity than ECP and sIL2R levels. In addition, [eNO] appears to be a more useful indicator of the beneficial response to GC therapy than these other measurements in pediatric asthma.

Effect of pH on the stability of methacholine chloride in solution.

Methacholine chloride bronchoprovocation challenges are performed for the diagnosis and investigation of hyperreactive airways. Over the last 20 yrs various formulations and pH values for the preparation of solutions of methacholine have been described. To determine the stability of methacholine chloride solutions prepared in a variety of buffers with differing pH values and under varying storage temperatures, we measured methacholine concentrations at intervals from 1 to 5 weeks. It was found that methacholine chloride solutions rapidly decompose if the pH is greater than 6 and that decomposition is more rapid as the pH is raised; solutions at pH 9, i.e. bicarbonate buffer, and stored at 27 degrees C have degradation up to 36% after only one week. Solutions of the same pH but prepared in different buffers can have both varied rates of deterioration and different absolute amounts of methacholine hydrolysed, e.g. solutions prepared in pH 9 borate buffer and stored at 27 degrees C have up to 60% degradation after 1 week. Solutions prepared in saline are stable probably because methacholine solutions are weakly acidic. The results emphasise the importance of preparing methacholine chloride in the proper buffers for use in the accurate assessment of airway responsiveness.

An apparatus for the measurement of lung volume and compliance in mice.

Pressure-volume (P-V) curves and total lung capacity (TLC) were measured in excised lung of mice using a water manometer and a closed system in which the humidity and temperature were controlled. In pathogen-free mice there are no significant differences in elastic properties of these lungs in relation to their age. The measured TLC in those normal mice was approximately 2.9 ml. This relatively simple apparatus which allows one to make sensitive and accurate measurements of pulmonary function in mice and other small animals.

Staphylococcus aureus isolated from Kawasaki disease patients hyper-releases extracellular protein A.

S. aureus isolates from patients with Kawasaki disease (KD) release high levels of extracellular protein A (SpA), as compared to S. aureus in other diseases. The molecular weight of this released protein A is about 70 kDa. Extracellular KD SpA purified by affinity chromatography possessed the same amino acid sequence at the NH2-terminal IgG binding region and the same antigenic specificity as recombinant and cell-wall-bound SpA preparations. The size of DNA fragments containing the spa gene from S. aureus KD strains was 160-165 kb. All of these DNA fragments contained the igb portion encoding the IgG-binding region of KD SpA. Significantly higher molecular size of the SpA molecules hyper-released in the stationary-phase culture and the lack of production of other exo-proteins allow us to speculate that S. aureus isolated from patients with KD have mutations occurring in the agr locus.