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Biomedical subjects

R G Hamilton

Publications and source records attributed to R G Hamilton.

At least 73 records · Page 4Linked to original sources
PubMed1996

Interlaboratory study evaluating quantitation of antibodies to Haemophilus influenzae type b polysaccharide by enzyme-linked immunosorbent assay.

An interlaboratory study was conducted to determine whether an enzyme-linked immunosorbent assay (ELISA) with an antigen preparation composed of various-sized fragments of Haemophilus influenzae type b polysaccharide conjugated to human serum albumin could be standardized across laboratories and whether the ELISA-derived results from different laboratories are equivalent to those obtained by the standard radioactive antigen binding assay (RABA) for quantitation of anti-H, influenzae type b polysaccharide antibodies. Twenty coded human serum samples were quantitated by ELISA in 11 laboratories and by RABA in 5 laboratories. The mean RABA-derived values served as the basis for all comparisons. While the overall correspondence of antibody values between the two methods was good, significant differences were found among some of the 11 ELISA data sets and among the mean RABA values. Seven laboratories generated higher ELISA antibody values for low-titered sera. Four laboratories generated antibody concentrations that were not statistically different between the two assay methods. The results therefore indicate that the ELISA can tolerate substantial variations in protocol, such as the use of different plates and different antibody reagents, without affecting the quantitation of serum antibodies. However, attention should be focused on low-titered sera, as some assay conditions may yield spurious results. This ELISA is a serologic assay which can serve as an alternative to the RABA for quantitation of antibodies to H. influenzae type h polysaccharide.

Adult↗
PubMed1995

Purification of immunoglobulin E (IgE) antibodies from sera with high IgE titers.

A three stage method for the ultrapurification of polyclonal IgE from human serum is reported using anion exchange chromatography followed by monoclonal antibody based positive and negative affinity chromatography. Following dialysis of 25-100 ml of serum (2.3-14 micrograms IgE/ml, n = 4) against 0.05 M Tris pH 8, each specimen was subjected to diethylaminoethyl (DEAE)-cellulose chromatography (serum/matrix = 1/4). IgE was eluted with 0.05 M Tris, 0.05 M NaCl pH 8, yielding an IgE recovery of 61-93%, with removal of approximately 90% of other serum proteins and an IgE purity ([IgE]/[Igs]) of 0.1-1.1%. After adjusting to 0.1 M NaCl and concentrating approximately 30-fold, the eluted IgE was further purified by affinity chromatography using a panel of IUIS/WHO-documented mouse monoclonal anti-human immunoglobulin antibodies (alpha hIg-MAbs). First, the IgE-enriched DEAE-cellulose chromatography fraction was incubated in a batch mode with two alpha hIgE-Fc MAbs (HP6029, HP6061) coupled to CNBr-Sepharose, CL-4B. IgE was eluted with 0.05 M glycine pH 2.8 and immediately neutralized. The IgE recovery was 32-52% and IgE purity was 72-97%. Silver-stained SDS-PAGE and noncompetitive solid-phase two-site immunoenzymetric assays for total human IgA, IgE, IgG and IgM indicated that IgA, IgG and IgM were the only contaminants. Next, the IgE was concentrated 10-30-fold in the presence of 0.1% HSA. One IgE specimen was ultrapurified in a batch mode by negative selection chromatography using three pairs of alpha hIg-MAbs (alpha hIgA: HP6111 + HP6123; alpha hIgG: HP6017 + HP6046; alpha hIgM: HP6081 + HP6083) coupled to CNBr-Sepharose, CL-4B. IgE purity increased from 91% to > 99.9% with approximately 70% recovery of IgE for this step. The ultrapurified IgE antibody was shown to be functionally reactive for allergen and Fc epsilon RI receptors on human basophils. We conclude that alpha hIg-MAbs are powerful tools to facilitate the affinity purification of functionally active human IgE from serum; however, when the analyte is present in low concentration, a carrier protein needs to be added to minimize non-specific loss of the material during this process.

Antibodies, Anti-Idiotypic↗
PubMed1995

IgA, IgG and IgM quantification in bronchoalveolar lavage fluids from allergic rhinitics, allergic asthmatics, and normal subjects by monoclonal antibody-based immunoenzymetric assays.

Recent reports have suggested that human secretory IgA (sIgA) may have a role in the mediation of atopic disease. We have studied the levels of sIgA, IgA, IgG and IgM in bronchoalveolar lavage (BAL) fluids collected from lungs of healthy non-allergic adults (n = 14), allergic subjects with rhinitis (n = 15), and allergic asthmatics (n = 13), using a panel of monoclonal antibody-based immunoenzymetric assays (IEMAs). In contrast to commercially available immunodiffusion and nephelometric assays, these IEMAs employ highly specific monoclonal antibodies and demonstrate required precision (intra-assay CVs < 17%), parallelism (inter-dilutional CVs < 20%) at minimal detectable immunoglobulin levels in the ng/ml range, and excellent specificity with < 0.1% crossreactivity for heterologous immunoglobulin isotypes. Using these assays, we have observed a significant correlation between sIgA levels and total IgA levels in BAL fluids from all the study patients (r = 0.94; p < 0.01). The percentage of sIgA to total IgA was 84.0 +/- 2.2%. sIgA in BAL fluids from allergic rhinitics (18.0 +/- 2.5 micrograms/ml) and allergic asthmatics (15.5 +/- 2.5 micrograms/ml) were higher than those from nonallergic subjects (10.2 +/- 1.9 micrograms/ml). The only statistically significant difference in sIgA levels was observed in BAL fluids from the rhinitics and nonallergic groups (p = 0.03). Similar differences among the groups were found for levels of total IgA in BAL fluid. There were no significant differences in the levels of IgM and IgG in BAL fluids among the three groups of subjects. We conclude from these results that IgA is the predominant immunoglobulin on the airway surface and that it appears to be produced locally.

Adult↗
PubMed1995

Association of interleukin-4 plasma levels with traumatic injury and clinical course.

OBJECTIVES: To determine if interleukin-4 (IL-4) could be detected in plasma of trauma patients and if IL-4 activity is associated with patterns of clinical events, complications, or outcomes. METHODS: A prospective case series conducted in a tertiary care referral center with a level I trauma center. One hundred patients admitted to the trauma intensive care unit for at least 3 days were included. Plasma concentrations of IL-4 and IgE were determined from admission to intensive care unit discharge. Data on clinical outcome were collected, including death, sepsis, severe sepsis, adult respiratory distress syndrome, pneumonia, and renal dysfunction. RESULTS: Interleukin-4 was detected in the plasma of 87 patients. Patients with an Injury Severity Score of greater than 25 had higher admission IL-4 levels (P = .03) and greater maximal IL-4 levels (P < .001). Admission hypotension (P = .04) and age 30 years or younger (P < .001) were also associated with higher admission IL-4 levels. Increases in IL-4 levels were significantly greater for patients in whom sepsis, severe sepsis, or pneumonia developed (P < .05). A low admission IL-4 level was associated with a greater incidence of nosocomial pneumonia (P < .001). Additional indirect evidence of IL-4 activation included increased plasma IgE levels. CONCLUSIONS: Anti-inflammatory cytokine mechanisms are activated after injury and are associated with the development of infectious complications (sepsis, severe sepsis, and pneumonia). Exogenous administration of interleukin-4 should be evaluated as an experimental therapeutic approach after trauma and associated sepsis.

Adult↗
PubMed1995

Characterization of the allergen(s) in latex protein extracts.

BACKGROUND: Immediate hypersensitivity to latex, induced by natural latex proteins remaining on the finished products, may lead to severe anaphylactic reactions. METHODS: We investigated the distribution of latex proteins by molecular weight and identified the specific allergenic molecules. Proteins extracted from various latex products were compared with those extracted from raw latex sap, both ammoniated and nonammoniated. RESULTS: Variations in the levels of extractable protein, as well as in the number of molecules and the molecular weight distribution, were observed especially among finished latex products. To identify allergenic (i.e., IgE-binding) molecules, we performed immunoblots with the sera from latex-sensitive persons. The results indicated that antigenic molecule profiles differed among the products and also between the finished products and the raw material. In addition, specificities of the anti-latex IgE antibodies varied among the sensitized persons. CONCLUSIONS: It appeared that persons with the same history of sensitization had similar patterns of antigenic specificities. If the history of exposure, as well as genetic predisposition and medical history of the patient, plays a significant role in the specific IgE response, it may be difficult to select a "standard" antigen and a "standard" antiserum for the evaluation of the latex sensitivity and allergenicity.

Adult↗
PubMed1995

Immunoglobulin G subclass response of juvenile periodontitis subjects to principal outer membrane proteins of Actinobacillus actinomycetemcomitans.

The cell envelope of Actinobacillus actinomycetemcomitans includes a number of outer membrane proteins (OMPs) which appear to be important targets for immunoglobulin G (IgG) antibodies in sera from localized juvenile periodontitis (LJP) patients. In this study, we examined the subclass distribution of IgG antibodies reactive to the 16.6- and 29-kDa OMPs of A. actinomycetemcomitans in sera from LJP patients and periodontally healthy individuals. Antibody responses were determined in a quantitative enzyme-linked immunosorbent assay that employed human IgG subclass-restricted monoclonal antibodies. High-titer LJP sera (93% black; geometric mean titer, 32,673) were found to contain significantly elevated levels of IgG1, IgG2, and IgG3 antibodies to the 29-kDa OMP of A. actinomycetemcomitans, compared with those of low-titer LJP sera (mean titer, 1,421) and sera from periodontally healthy, race-matched control subjects. The concentration of IgG2 antibody to this protein was greater than or equal to the corresponding IgG1 concentration in 7 of 14 high-titer sera, although mean IgG1 and IgG2 concentrations were not significantly different. The concentrations of IgG1 and IgG2 antibodies to the 16.6-kDa protein were also significantly elevated in LJP sera, although of considerably lesser magnitude than that observed for the 29-kDa protein. The IgG2 response to the 29-kDa protein could not be attributed to the presence of IgG2 antibodies to lipopolysaccharide contaminants or to Fc-binding activity, nor does this molecule appear to be a glycoprotein. Hence, LJP subjects produce IgG2 antibodies, as well as IgG1 and IgG3 antibodies, directed to at least one of the major OMPs of A. actinomycetemcomitans.

Adolescent↗
PubMed1995

Immunoglobulin G2 antibodies promote neutrophil killing of Actinobacillus actinomycetemcomitans.

Sera from patients with localized juvenile periodontitis (LJP) often contain markedly elevated levels of immunoglobulin G2 (IgG2) antibodies reactive to cell envelope constituents of Actinobacillus actinomycetemcomitans. The objective of this study was to determine if these IgG2 antibodies are capable of supporting phagocytosis and killing of A. actinomycetemcomitans by human neutrophils. Polyclonal IgG2 antibodies were prepared from high-titer LJP serum by affinity chromatography, yielding a preparation which was > 99% subclass restricted and retained immunoreactivity to A. actinomycetemcomitans antigens. Affinity-purified IgG2 antibodies were evaluated by an in vitro opsonophagocytic assay that employed neutrophils obtained from donors who were homozygous for the H131 allotype of Fc gamma receptor type IIa (CD32), which efficiently binds human IgG2 antibodies. Affinity-purified IgG2 antibodies from LJP serum but not from sera of periodontally healthy individuals promoted phagocytosis and killing of A. actinomycetemcomitans. The expression of IgG2-dependent opsonic activity required the presence of complement. Incubation of A. actinomycetemcomitans with neutrophils in the presence of an optimal concentration of LJP IgG2 (50 micrograms/ml) and 5% hypogammaglobulinemic serum (as a complement source) resulted in a > 1 log10 reduction in bacterial viability within 30 min. The opsonic activity of IgG2 antibodies was found to be comparable to that observed with affinity-purified IgG1 antibodies. Moreover, IgG1 antibodies interacted synergistically with IgG2 antibodies in promoting opsonophagocytosis of A. actinomycetemcomitans. The results of this study indicate that LJP serum contains IgG2 antibodies which, when employed in conjunction with neutrophils that express Fc gamma receptors capable of recognizing this subclass, are opsonic for A. actinomycetemcomitans.

Agammaglobulinemia↗
PubMed1994

Occupational latex exposure: characteristics of contact and systemic reactions in 47 workers.

BACKGROUND: Recent reports have noted an apparent increase in the prevalence of natural rubber latex (NRL) allergy among workers with occupational latex exposure (OLE). The risk factors for and the natural history of NRL allergy in this population are not well delineated, and the utility and comparability of immunoassays as confirmatory testing are unclear. METHODS: Serum samples and medical histories were obtained from 47 symptomatic workers with OLE, from nine other individuals with a history consistent with NRL allergy, and from 10 atopic asymptomatic NRL-exposed control subjects. Sera were coded and analyzed in a blinded manner for latex-specific IgE, using a variety of antigen sources, including ammoniated and nonammoniated raw latex preparations and three finished glove preparations. RESULTS: Risk factors for the latex allergy in workers with OLE appear to include a history of atopy or preexisting dermatitis involving the hands. In this population, NRL allergy is commonly preceded by latex glove-associated contact dermatitis. Serologic testing confirmed the suspected diagnosis in 62% of workers (15 of 24) with systemic symptoms but was only positive in 27% of workers (4 of 15) with symptoms limited to contact urticaria. CONCLUSIONS: The appearance of a latex glove-associated contact rash may precede the development of NRL allergy, particularly in atopic persons. Workers at risk should be advised to use alternate types and brands of latex gloves or to switch to nonlatex gloves entirely.

Adult↗
PubMed1994

Cornstarch powder on latex products is an allergen carrier.

Allergic reactions of the upper respiratory tract during use of powdered latex rubber gloves have been recently associated with sensitivity to latex. We have studied the ability of cornstarch powder to bind latex proteins and evaluated allergenic properties of the bound protein. Allergenicity was determined by competitive inhibition of human anti-latex IgE binding to solid-phase latex antigen. Cornstarch extracted from powdered latex products and clean cornstarch exposed to latex protein extracts were evaluated in comparison with clean unexposed cornstarch. Both exposed cornstarch preparations inhibited specific binding of anti-latex IgE antibodies to latex proteins in a dose-response manner. Latex-exposed cornstarch diluted 50% vol/vol produced complete inhibition, whereas greater dilutions exhibited variable levels of inhibition, depending on the source of cornstarch-bound proteins, insolubilized latex proteins, and IgE antibody-containing human serum used. Cornstarch not exposed to latex had no inhibitory activity. The study demonstrates that cornstarch indeed binds allergenic latex proteins and supports the causative relationship between allergic reactions in individuals with latex sensitivity and the exposure to airborne particles from powdered latex products.

Adsorption↗
PubMed1994

Lipopolysaccharide-reactive immunoglobulin E is associated with lower mortality and organ failure in traumatically injured patients.

Antilipopolysaccharide (anti-LPS) immunoglobulin G (IgG) and IgM have been associated with protection from LPS effects in vivo. We investigated the presence of IgE and anti-LPS in 32 patients that had experienced severe traumatic injury and in 35 healthy volunteers; we also investigated whether IgE anti-LPS was associated with important clinical events. Plasma samples were collected daily from patients in the intensive care unit and on one occasion from volunteers; the samples were assayed for IgE anti-LPS. IgE anti-LPS was assayed by enzyme-linked immunosorbent assay with monoclonal anti-human IgE as the capture antibody. Detection was accomplished with biotin-labeled LPS (Escherichia coli J5 mutant) followed by streptavidin-peroxidase with 2,2'-azino(3-ethylbenzthiazoline)sulfonic acid as the substrate. The assay was demonstrated to be specific for IgE and LPS-biotin by nonreactivity of control sera with high-titer anti-LPS IgG and IgM and by inhibition with unlabeled LPS. IgE anti-LPS was detected in 1 of 35 healthy controls (2.9%) and 25 of 32 traumatically injured patients (78%) (P < 0.001). The presence of IgE anti-LPS was associated with a lower incidence of death (P = 0.026) and of renal failure (P = 0.0012). There was no apparent temporal relationship between detection of IgE anti-LPS and clinical events. IgG anti-LPS was detected more frequently in patients that were positive for IgE anti-LPS (P = 0.06) but was not associated with clinical events. The inability to detect IgE anti-LPS may be related to adverse clinical events through depletion of specific IgE due to LPS exposure after trauma or through saturation of the assay by IgE with other specificities. We have reported increased total IgE concentrations in these patients. (J.T. DiPiro, R.G. Hamilton, T. R. Howdieshell, N. F. Adkinson, and A. R. Mansberger, Ann. Surg. 215:460-466, 1992).

Acute Kidney Injury↗
PubMed1994

Multi-centre comparison of ABBOTT MATRIX Aero to Pharmacia Standard RAST, Modified RAST and skin puncture tests.

ABBOTT MATRIX Aero is an enzyme immunoassay which measures specific IgE antibodies to 14 individually calibrated airborne allergens using a single serum specimen. In this study, ABBOTT MATRIX performance was evaluated in comparison to the results of skin puncture test and the Standard and Modified RAST procedures. The ABBOTT MATRIX demonstrated overall sensitivity of 89% vs. Standard RAST and Modified RAST, with specificity greater than 92% vs. both methods. ABBOTT MATRIX sensitivity vs. skin test (71%) exceeded that of the Standard and Modified RAST procedures (62% and 67% respectively). Positive results reported by ABBOTT MATRIX but not RAST were corroborated by skin test results for 3 of 5 allergens evaluated. All in vitro systems demonstrated specificity of approximately 90% vs. skin test. The ABBOTT MATRIX system provided results which compared favorably with the results of skin test and RAST, but required less hands-on time to obtain quantitative specific IgE measurements to multiple allergens.

Adolescent↗
PubMed1994

The clinical immunology laboratory of the future.

The clinical immunology laboratory assumes the responsibility of providing a complete array of analytical measurements for the diagnosis and management of patients with dysfunction of the humoral (antibody, complement) and cellular (T/B cells, phagocyte) immune system. To identify trends in the activities of the clinical immunology laboratory of the future, I first define the current status of the clinical/diagnostic immunology laboratory, examining six aspects: scope of work, analyte groups, assay methods, specimen types, instrumentation, and standardization. The scope of the clinical immunology laboratory's testing is expected to expand, with a trend toward consolidation of work into fewer, more well-equipped laboratories. An increase is expected in the total number of analytes examined as well as in the numbers of analyte groups and specificities. Assay methods will continue to improve in analytical and clinical sensitivity and specificity, with an emphasis toward less-complex procedures. The primary specimens evaluated will still be serum, urine, tissue, and cells, with a minor expansion into the use of other, less-accessible human body fluids. Instrumentation will move toward increased automation, with the concurrent development of "universal" automated immunoanalyzers for use in humoral and cellular immunology. Finally, standardization of immunological measurements with calibrated reference proteins and antibodies will promote interlaboratory agreement. I describe the diagnostic allergy laboratory to illustrate the immunology laboratory environment.

Allergy and Immunology↗
PubMed1994

Serologic methods in the laboratory diagnosis of latex rubber allergy: study of nonammoniated, ammoniated latex, and glove (end-product) extracts as allergen reagent sources.

In the absence of approved natural rubber latex skin testing reagents, serologic methods for the detection of latex-specific immunoglobulin E (IgE) antibody are useful in the definitive diagnosis of latex allergy. In this study we examined extracts from two nonammoniated latex (NAL), two ammoniated latex (AL), and three diverse latex rubber gloves as sources of allergen for their utility in solid phase radioimmunoassays (SPRIAs) for latex-specific IgE. Serum samples were collected from 46 healthcare workers (HCWs), one beautician, two clerks, and seven children with spina bifida who exhibited clinical evidence of latex-associated contact dermatitis (CD, n = 8), contact urticaria (CU) with or without CD (n = 15), or systemic reactions involving respiratory symptoms with or without anaphylaxis (n = 33) and from 10 latex-exposed HCW control subjects with no latex allergy symptoms. Serum samples were coded and analyzed in a blinded manner in two laboratories by three particulate and four nonparticulate SPRIAs with different latex extracts on the allergosorbent. Intraassay coefficient of variation as assessed with 44 split, randomized, blinded serum specimens was < 20%. Agreement within a source of latex (e.g., NAL, AL, or gloves) and between laboratories was > 90% concordant for Glove 1/Glove 2 and NAL1/2. Specific IgE antilatex was detected in one of 10 latex-exposed control serum samples by five of the seven SPRIAs, despite a lack of clinical evidence for latex allergy in this otherwise atopic individual. Latex-specific IgE was detected in the serum of 22% of subjects with CU with or without CD, suggesting that IgE antibody may not be the primary factor involved in the induction of these local reactions. Approximately two thirds of the systemic reactor group had detectable latex-specific IgE in their serum, with levels ranging from 0.7 to 338 ng/ml. The predictive characteristics of these assays will await future provocation testing. We conclude that glove extracts contain as complete a repertoire of allergens as the NAL and AL. Of the three source latex materials, NAL and glove extracts provided the most sensitive and greatest consistency of IgE antibody results between laboratories.

Adult↗
PubMed1993

Epitope mapping of human immunoglobulin-specific murine monoclonal antibodies with domain-switched, deleted and point-mutated chimeric antibodies.

27 engineered chimeric antibodies possessing human gamma, epsilon, mu or alpha constant regions and V region specificity for nitrophenyl or dansyl were used to study the isotype specificity of 29 murine monoclonal antibodies (MAbs) specific for human immunoglobulins (IgG1-4, IgE, IgM, IgA or secretory piece). The isotype-restricted immunoreactivity observed with wild-type chimeric antibodies paralleled the pattern of each MAb's reactivity with purified human myeloma proteins. 16 mutant IgG anti-dansyl chimeric antibodies with genetically engineered domain switches, deletions or point-mutations were used as antigens to further characterize the epitopes recognized by the human IgG subclass-specific MAbs. The binding of three human IgG1-specific MAbs (HP6069, HP6070 and HP6091) was mapped to similar epitopes on the CH2 domain of human IgG1. Of the two anti-human IgG2 MAbs tested, HP6002 reacted with the CH2 of IgG2 while HP6014 bound to the CH1 domain. Both anti-human IgG3 MAbs (HP6047, HP6050) reacted with different regions of the IgG3 hinge. The anti-human IgG4 MAbs (HP6023, HP6025) bound to a similar epitope on the carboxyl terminus of CH2 or the CH3 of human IgG4. The three exclusion antibodies (HP6019, HP6030 and HP6058) bound to different epitopes in the CH2 domain of three of four IgG subclasses. The domain mapping was confirmed by competitive inhibition experiments. These results were used to select a group of IgG-reactive MAbs for construction of a poly-monoclonal anti-IgG capture and detection reagent that uniformly bound all four subclasses of human IgG. This study provides support for the use of engineered chimeric human chimeric antibodies as replacements for increasingly rare, purified human paraproteins in the specificity analysis of immunochemical reagents used in clinical and research laboratories for the detection and quantitation of human antibodies. Moreover, these studies demonstrate how the MAbs can serve as effective probes for examining conformational differences among the four human IgG subclasses.

Animals↗
PubMed1993

Quantitative measurement of human thyroglobulin-specific antibodies by use of a sensitive enzyme-linked immunoassay.

A quantitative enzyme-linked immunoassay that measures in absolute terms the subclass concentration of human thyroglobulin (huTg)-specific IgG autoantibody was developed. Unique to this study was the use of an affinity-purified anti-huTg standard with a known concentration of the four IgG subclasses. The sensitivity of the ELISA assay was 1-5 ng/ml depending on the IgG subclass being measured. We examined 22 sera of patients with autoimmune thyroid disease. The total huTg-specific antibody concentrations in serum ranged from 0 to nearly 3000 micrograms/ml of IgG. The IgG subclass distribution in individuals with low huTg-specific IgG (< 10 micrograms/ml) was primarily IgG1 and IgG3 Ab. Patients with intermediate levels of huTg IgG (10-600 micrograms/ml) expressed all four subclasses; however, no particular subclass was dominant. Individuals with > 1000 micrograms/ml also showed huTg-Ab in all four subclasses, however, IgG1 and IgG2 were dominant. All four IgG subclasses were used in the response to huTg, although the pattern of usage varied between individuals. There was no dominant subclass usage seen in this patient population.

Adult↗
PubMed1993

Selection of Hymenoptera venoms for immunotherapy on the basis of patient's IgE antibody cross-reactivity.

BACKGROUND: Positive skin test results to multiple venoms in patients with Hymenoptera venom allergy may result from IgE antibody cross-reactivity among venom proteins. To avoid treatment with unnecessary and costly venoms, we have developed a venom RAST inhibition test that identifies individuals in whom a positive venom IgE RAST result is due to cross-reactive venom-specific IgE antibody. METHODS: Serum samples (n = 412) were collected over 5 years from patients with clinically characterized Hymenoptera venom allergy who had positive skin test results to more than one venom. Venom allergosorbent was added to serum containing IgE antivenin and buffer or 100 micrograms of homologous or heterologous venom. Bound IgE was detected with radiolabeled anti-human IgE. Intraassay variation less than 10% coefficient of variation and homologous venom inhibition greater than 80% were required for acceptance of data. A "cross-reactivity index" (CRI) was computed as a ratio of percent inhibition produced by heterologous versus homologous venom. RESULTS: Of the 412 sera-venom combinations analyzed, 41 (10%) were excluded because of incomplete homologous venom inhibition. Of the 371 remaining sera, 82% (n = 305) were studied for IgE anti-Polistes wasp venom (PWV) cross-reactivity with yellow jacket venom (YJV) and the other 66 for other venom specificity cross-inhibitions. Of the serum samples tested, 36.4% (111 of 305) contained IgE anti-PWV venom of which the binding to solid-phase PWV was inhibited with soluble YJV to a level that produced CRIs greater than 95%. We believe that this constitutes complete inhibition and demonstrates exclusively YJV cross-reactive antibody in these samples. The remaining 63.6% had CRIs from 0% to 95%, indicating IgE specific for a spectrum of unique and cross-reactive PWV allergens. Only 4.3% (13 of 305) had CRIs less than 5%, which is consistent with IgE restricted to PWV unique allergens. The degree of the IgE anti-PWV inhibition to solid-phase PWV by YJV was independent of the IgE anti-PWV level. CONCLUSIONS: This study shows that one third of patients with Hymenoptera venom allergy evaluated with positive YJV- and PWV-reactive IgE in the skin and/or serum were identified as candidates for exclusion of PWV from their immunotherapy regimen because their IgE anti-PWV was more than 95% cross-inhibitable with YJV. Cost analysis of the venom RAST inhibition test and a conventional 5-year Hymenoptera venom immunotherapy program indicates that this serologic evaluation is cost-effective.

Animals↗
PubMed1993

Intranasal steroids inhibit seasonal increases in ragweed-specific immunoglobulin E antibodies.

We performed two seasonal studies to evaluate the effect of continuous treatment with intranasal steroids, beginning approximately 1 week before the appearance of ragweed pollen, on the level of ragweed-specific IgE antibodies in serum. In both studies the control groups showed the anticipated rise in ragweed-specific IgE antibodies after the ragweed season. In the first study, employing aqueous beclomethasone dipropionate (168 micrograms twice daily), no rise occurred in serum ragweed IgE after seasonal exposure and the level actually decreased in eight of 12 treated subjects. In the second study, with triamcinolone acetonide (220 micrograms twice daily), the expected rise in ragweed IgE antibody was also reduced, although less dramatically, probably as a result of the lower potency of the dose delivered. Our studies not only support the benefits of intranasal steroids in the treatment of seasonal allergic rhinitis but also suggest that specific IgE production may be down-regulated by their continuous use, which may alter the subsequent clinical course of the disease.

Administration, Intranasal↗